Consulta: subjectFacets:"Sex ratio"
Registros recuperados: 84
Data/hora: 01/06/2024 00:38:42

Caracterización de la estructura de la población y uso de hábitat del zorzal cola rufa (Catharus guttatus) y el Chipe gorra rufa (Basileuterus rufifrons) en el parque estatal sierra de Tepotzotlán, Estado de México.
Provedor de dados: 32
Autores: Saavedra Alpizar, Oscar.
La calidad del hábitat de muchas especies animales podría ser mejor evaluada mediante  características poblacionales diferentes a la abundancia, dado que ésta puede ser engañosa.  En este estudio se contrastó la proporción de sexos, la estructura de edades y algunos índices  de condición corporal, como indicadores de la calidad del hábitat de dos aves de sotobosque  comunes durante el invierno en las zonas montañosas del Valle de México: el zorzal cola rufa  (Catharus guttatus), una ave migratoria y estenotópica, y el chipe gorra rufa (Basileuterus  rufifrons), residente y generalista de hábitat. Se capturaron y anillaron aves mediante una  estrategia de esfuerzo constante con redes de niebla, de octubre de 2007 a abril de 2008, en  una parcela de 20 ha de...
Palavras-chave: Calidad del hábitat; Estructura de edades; Proporción de sexos; Condición corporal; Abundancia habitat quality; Age structure; Sex ratio; Corporal condition; Abundance.
Ano: 2012
URL: http://hdl.handle.net/10521/794

Caracterización de la estructura de la población y uso de hábitat del zorzal cola rufa (Catharus guttatus) y el Chipe gorra rufa (Basileuterus rufifrons) en el parque estatal sierra de Tepotzotlán, Estado de México.
Provedor de dados: 32
Autores: Saavedra Alpizar, Oscar.
La calidad del hábitat de muchas especies animales podría ser mejor evaluada mediante  características poblacionales diferentes a la abundancia, dado que ésta puede ser engañosa.  En este estudio se contrastó la proporción de sexos, la estructura de edades y algunos índices  de condición corporal, como indicadores de la calidad del hábitat de dos aves de sotobosque  comunes durante el invierno en las zonas montañosas del Valle de México: el zorzal cola rufa  (Catharus guttatus), una ave migratoria y estenotópica, y el chipe gorra rufa (Basileuterus  rufifrons), residente y generalista de hábitat. Se capturaron y anillaron aves mediante una  estrategia de esfuerzo constante con redes de niebla, de octubre de 2007 a abril de 2008, en  una parcela de 20 ha de...
Palavras-chave: Calidad del hábitat; Estructura de edades; Proporción de sexos; Condición corporal; Abundancia habitat quality; Age structure; Sex ratio; Corporal condition; Abundance.
Ano: 2012
URL: http://hdl.handle.net/10521/914

Caracterización de la estructura de la población y uso de hábitat del zorzal cola rufa (Catharus guttatus) y el Chipe gorra rufa (Basileuterus rufifrons) en el parque estatal sierra de Tepotzotlán, Estado de México.
Provedor de dados: 32
Autores: Saavedra Alpizar, Oscar.
La calidad del hábitat de muchas especies animales podría ser mejor evaluada mediante características poblacionales diferentes a la abundancia, dado que ésta puede ser engañosa. En este estudio se contrastó la proporción de sexos, la estructura de edades y algunos índices de condición corporal, como indicadores de la calidad del hábitat de dos aves de sotobosque comunes durante el invierno en las zonas montañosas del Valle de México: el zorzal cola rufa (Catharus guttatus), una ave migratoria y estenotópica, y el chipe gorra rufa (Basileuterus rufifrons), residente y generalista de hábitat. Se capturaron y anillaron aves mediante una estrategia de esfuerzo constante con redes de niebla, de octubre de 2007 a abril de 2008, en  una parcela de 20 ha de bosque...
Tipo: Tesis
Palavras-chave: Calidad del hábitat; Estructura de edades; Proporción de sexos; Condición corporal; Abundancia; Habitat quality; Age structure; Sex ratio; Corporal condition; Abundance.
Ano: 2009
URL: http://hdl.handle.net/10521/1177

Efectos de la calidad del huésped y edad del parasitoide en la proporción sexual de Tamarixia triozae (Hymenoptera: Eulophidae).
Provedor de dados: 32
Autores: Escudero Giffard, Gabriela Guadalupe.
. Tamarixia triozae (Burks) es un ectoparasitoide solitario sinovigénico, el cual es considerado como un agente de control biológico potencial de Bactericera cockerelli (Sulc). En liberaciones masivas de parasitoides, la proporción sexual que favorece a hembras es un factor que incrementa los niveles de éxito, por lo que este estudio tuvo como finalidad determinar los efectos de la calidad del huésped, y la edad del parasitoide, en la proporción sexual de T. triozae. Se considero calidad del huésped, a la talla de las ninfas de B. cockerelli. Los resultados mostraron que las hembras asignaron mayor descendencia hembra en huéspedes con más recursos, con un máximo de 10 hembras por cada macho entre las tallas de los huéspedes de 1370 and 1570 µm. La talla...
Palavras-chave: Bactericera cockerelli; Control biológico; Parasitoides; Proporción sexual; Biological control; Parasitoids; Sex ratio; Entomología y Acarología; Maestría.
Ano: 2011
URL: http://hdl.handle.net/10521/592

Differences and Congruencies between PVA Packages: the Importance of Sex Ratio for Predictions of Extinction Risk
Provedor de dados: 7
Autores: Brook, Barry W; Northern Territory University; barry.brook@ntu.edu.au; Burgman, Mark A; University of Melbourne; m.burgman@botany.unimelb.edu.au; Frankham, Richard; Macquarie University; rfrankha@rna.bio.mq.edu.au.
Population viability analysis (PVA) is used in conservation biology to predict extinction probabilities for threatened species. Previous studies have revealed large differences between the predictions of PVA modeling packages, but these comparisons included a range of nonstandard factors. A standardized comparison of five PVA packages (GAPPS, INMAT, RAMAS Metapop, RAMAS Stage, and VORTEX) was conducted on six examples (two mammals, two birds, one reptile, and a hypothetical bird/mammal-like life history). The individual-based packages (GAPPS and VORTEX) predicted a consistently higher risk of extinction than their matrix-based counterparts (INMAT and the RAMAS programs). This arose as only the former considered the effect of demographic stochasticity in...
Tipo: Peer-Reviewed Reports
Palavras-chave: Demographic stochasticity; Extinction risk; Individual-based models; Matrix-based models; Model comparison; Parameter estimation; Population viability analysis; Sex ratio.
Ano: 2000

Selection of Trichogramma species for controlling the Diamondback moth
Provedor de dados: 75
Autores: Pratissoli,Dirceu; Polanczyk,Ricardo A; Holtz,Anderson M; Dalvi,Leandro P; Silva,Alexandre F; Silva,Luciano N.
Biological characteristics of the egg parasitoids Trichogramma acacioi, T. atopovirilia, and T. bennetti were studied to select the one with better performance on the control of the Diamondback moth, Plutella xylostella. Parasitism rate, viability, and sex ratio were studied. Parasitism rate ranged from 1.67 to 41.33%. T. atopovirilia and T. acacioi were respectively the most and less aggressive species. The viability ranged from 6.20% for T. acacioi to 53.34% for T. atopovirilia. There were no differences on sex ratio (p&lt;0.05) that remained above 0,88. T. atopovirilia was the species with best performance in the laboratory when rearing on the Diamondback moth eggs.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Plutella xylostella; Biological control; Egg parasitoids; Parasitism; Sex ratio; Viability.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-05362008000200026

Selection of Trichogramma species for controlling the Diamondback moth
Provedor de dados: 75
Autores: Pratissoli,Dirceu; Polanczyk,Ricardo A; Holtz,Anderson M; Dalvi,Leandro P; Silva,Alexandre F; Silva,Luciano N.
Biological characteristics of the egg parasitoids Trichogramma acacioi, T. atopovirilia, and T. bennetti were studied to select the one with better performance on the control of the Diamondback moth, Plutella xylostella. Parasitism rate, viability, and sex ratio were studied. Parasitism rate ranged from 1.67 to 41.33%. T. atopovirilia and T. acacioi were respectively the most and less aggressive species. The viability ranged from 6.20% for T. acacioi to 53.34% for T. atopovirilia. There were no differences on sex ratio (P &lt; 0.05) that remained above 0,88. T. atopovirilia was the species with best performance in the laboratory when rearing on the Diamondback moth eggs.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Plutella xylostella; Biological control; Egg parasitoids; Parasitism; Sex ratio; Viability.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-05362008000200013

Cтруктура популяций массовых видов планктонных остракод Южной Атлантики (1976-1979 гг.)
Provedor de dados: 13
Autores: Драпун, И. Е.
Анализировали соотношение полов ( ♀/♂) и возрастную структуру в популяциях 16 видов планктонных остра­код (сем. Halocyprididae) из разных районов Южной Атлантики на основе зоопланктонных материалов, соб­ранных в 1976 - 1979 гг. в трех рейсах научных судов. В популяциях планктонных остракод, как правило, преобладали самки, превышая количество самцов в среднем в два - три раза. Величины соотношения полов, заметно отклоняющиеся от 1. а также неравномерное в большинстве случаев распределение в популяциях одновозрастных групп, вероятно, свидетельствуют о периодичности размножения, характерной для боль­шинства видов остракод. Наблюдаемое разнообразие форм возрастных пирамид у массовых видов остракод указывает на возможные различия в их биологии, в частности, на...
Tipo: Journal Contribution
Palavras-chave: Планктонные остракоды; Возрастная структура; Соотношение полов; Юж­ная Атлантика; Planktonic ostracods; Halocyprididae; Age structure; Sex ratio; South Atlantic Sex ratio Sex ratio http://aims.fao.org/aos/agrovoc/c_7014.
Ano: 2005
URL: http://repository.ibss.org.ua/dspace/handle/99011/218

Capacidade reprodutiva de fêmeas de Apanteles galleriae (Hymenoptera, Braconidae) em lagartas de Galleria mellonella e Achroia grisella (Lepidoptera, Pyralidae) criadas com dietas diferentes
Provedor de dados: 76
Autores: Zacarin,Giuliano Grici; Gobbi,Nivar; Chaud-Netto,José.
The reproductive capacity of females of Apanteles galleriae (Wilkinson, 1932) was evaluated in fifth instar caterpillars of Galleria mellonella (Linnaeus, 1758) and Achroia grisella (Fabricius, 1754) fed on standard diet and diets enriched with protein. The reproductive capacity of parasitoid females on fifth instar caterpillars of G. mellonella and A. grisella with variable weight was also evaluated. The host weight interfered in the sex ratio of the obtained parasitoids. In heavier caterpillars, the investment in female descendants was greater than in males, and in lighter caterpillars the inverse occurred.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Biological control; Wax moths; Sex ratio.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212004000200005

Sex ratio and morphological characteristics of rufous gnateaters, Conopophaga lineata (Aves, Passeriformes) in Atlantic forest fragments
Provedor de dados: 76
Autores: Dantas,Gisele P. M.; Santos,Fabrício R.; Marini,Miguel Ângelo.
Unequal sex ratios lead to the loss of genetic variability, decreasing the viability of populations in the long term. Anthropogenic activities often disturb the natural habitats and can cause alterations in sex ratio and morphological characteristics of several species. Forest fragmentation is a major conservation concern, so that understanding its effects in natural populations is essential. In this study, we evaluated the sex ratio and the morphological characteristics of Rufous Gnateaters (Conopophaga lineata (Wied, 1831)) in small and large forest fragments in Minas Gerais, Brazil. Birds (n = 89) were sexed by plumage characteristics and molecular markers. The molecular analysis showed that plumage is not a totally reliable method for sexing Rufous...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Forest fragmentation; Sex ratio; Atlantic forest; Conopophagidae.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212009000100017

Natural history of G ynaikothrips uzeli (Thysanoptera, Phlaeothripidae) in galls of Ficus benjamina (Rosales, Moraceae)
Provedor de dados: 76
Autores: Mascarenhas,André Luiz S.; Silva Junior,Juvenal C.
ABSTRACT Galls induced by thrips are simple structures when compared to those of other groups of arthropods, and little is known regarding many of their aspects. This study aimed to investigate aspects of the natural history of Gynaikothrips uzeli Zimmermann, 1900 in galls of Ficus benjamina L., 1753 using seasonal sampling (summer and winter). Twenty trees were sampled and divided into quadrants. From each of them, five galls were collected, forming a total of 400 galls per collection. Thrips showed greater abundance at higher temperatures (25.7°C) and no precipitation. Sex ratio was biased towards females (0.022 males per female), pointing to an inbred mating structure. Arthropod fauna associated with galls was more abundant (N=798) in winter, and it...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Leaf galls; Natural enemies; Sex ratio; Thrips.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212016000100216

Accessing camera trap survey feasibility for estimating Blastocerus dichotomus (Cetartiodactyla, Cervidae) demographic parameters
Provedor de dados: 76
Autores: Peres,Pedro Henrique F.; Polverini,Maxihilian S.; Oliveira,Márcio L.; Duarte,José Maurício B.
ABSTRACT Demographic information is the basis for evaluating and planning conservation strategies for an endangered species. However, in numerous situations there are methodological or financial limitations to obtain such information for some species. The marsh deer, an endangered Neotropical cervid, is a challenging species to obtain biological information. To help achieve such aims, the study evaluated the applicability of camera traps to obtain demographic information on the marsh deer compared to the traditional aerial census method. Fourteen camera traps were installed for three months on the Capão da Cruz floodplain, in state of São Paulo, and ten helicopter flyovers were made along a 13-kilometer trajectory to detect resident marsh deer. In addition...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Aerial survey; Capture-recapture; Distance sampling; Population estimate; Sex ratio.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212017000100241

The culture of Hoplosternum littorale : State of the art and perspectives
Provedor de dados: 5
Autores: Luquet, P; Boujard, Thierry; Planquette, P; Moreau, Y; Hostache, G.
Hoplosternum littorale is a siluriform fish of very high commercial value in some countries of South America. Some biological characteristics as easy spawning in confinement and good tolerance of low oxygen level make it easy to cultivate.
Tipo: Text
Palavras-chave: Fish ponds; Incubation; Brood stocks; Circadian rhythms; Sexual maturity; Sex ratio; Rearing; Respiration; Survival; Diets; Larvae; Fecundity; Hatching; Oxygen; Feeding behaviour; Fish culture.
Ano: 1989
URL: http://archimer.ifremer.fr/doc/1989/acte-1491.pdf

Elasmobranch bycatch distributions and mortality: insights from the European tropical tuna purse-seine fishery
Provedor de dados: 5
Autores: Clavareau, Lyndsay; Sabarros, Philippe; Escalle, Lauriane; Bach, Pascal; Abascal, Francisco J.; Lopez, Jon; Murua, Hilario; Pascual Alayon, Pedro J.; Ramos, Maria Lourdes; Ruiz, Jon; Mérigot, Bastien.
Despite bycatch of elasmobranch (sharks and rays) being a major concern in most fisheries worldwide, there is a lack of knowledge on their spatio-temporal species distribution, biology (life stage and sex-ratios), as well as their at-haulback mortality rate. Observer data from the French and Spanish tropical purse-seine tuna fisheries operating in the Eastern Atlantic and Western Indian Oceans between 2005 and 2017 were analysed to investigate elasmobranch bycatch. Data included 24 elasmobranchs species and distribution patterns of catch per unit of effort (CPUE) by species and sex-ratio were found to vary with life stages, areas, seasons and fishing modes. In general, higher catches were found in FAD-associated sets (&gt;40%) than free tuna school sets...
Tipo: Text
Palavras-chave: Biodiversity; Spatio-temporal distribution; Life stage; Sex ratio; At-haulback mortality.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00642/75386/76177.pdf

Reproductive biology of Alvinocarls muricola (Decapoda : Caridea : Alvinocarididae) from cold seeps in the Congo Basin
Provedor de dados: 5
Autores: Ramirez Llodra, Eva; Segonzac, Michel.
The caridean shrimp Alvinocaris niuricola has been observed forming high density populations over mussel beds on the giant pockmark cold seep site Regab in the Gulf of Guinea at 3150 m depth. Samples were collected using the ROV Victor 6000, a beam trawl and a TV grab from two sites. The specimens Were sexed and measured for population structure analysis. In one sample the sex ratio was 1:1, but the other sample had a sex ratio significantly biased towards females. The maximum size of females is larger than males. A sub-sample was used for gametogenesis and fecundity analysis. The oogenesis and spermatogenesis of A. muricola is characteristic of caridean shrimps. The oogonia proliferate from the germinal epithelium and develop into previtellogenic oocytes...
Tipo: Text
Palavras-chave: Reproduction biology; Oogenesis; Sex ratio; Population structure; Caridean shrimp.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-2317.pdf

Oyster sex determination is influenced by temperature - First clues in spat during first gonadic differentiation and gametogenesis
Provedor de dados: 5
Autores: Santerre, Christelle; Sourdaine, Pascal; Marc, Nicolas; Mingant, Christian; Robert, Rene; Martinez, Anne-sophie.
The sex-determining system of Crassostrea gigas is still poorly known, especially regarding the potential influence of temperature. In order to address this question, mRNA expressions of actors of the molecular cascade (Cg-DMI, Cg-SoxE, Cg-beta-catenin, Cg-Foxl2/Cg-FoxI2os) and of Oyvlg, a germ cell marker, were investigated by real-time PCR in spat grown at different temperatures (18, 22, 25 and 28 degrees C). In parallel, gonadic differentiation, gametogenesis and sex ratios were assessed by histology at each of these temperatures. Whatever the temperature, Cg-DMI, Cg-SoxE, Cg-beta-catenin and Oyvlg expressions peaked at the same developmental stage, always after Cg-Foxl2/Cg-Foxl2os (around 40-44 dpf for spat grown at 18 degrees C). Temperatures...
Tipo: Text
Palavras-chave: Oyster spat; Temperature; Sex ratio; TSD; Sex determination pathway.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00136/24767/22874.pdf

Spatio-temporal patterns in demersal elasmobranchs from trawl surveys in the eastern English Channel (1988-2008)
Provedor de dados: 5
Autores: Martin, Corinne; Vaz, Sandrine; Ellis, J. R.; Coppin, Franck; Le Roy, Didier; Carpentier, Andre.
Elasmobranchs have life-history characteristics that make them more vulnerable to fishing than many teleost fish. As commercial landings data are usually not sufficient for the monitoring and assessment of elasmobranchs, fisheries-independent data, geostatistics and Geographic Information Systems were used to investigate the spatio-temporal patterns of sharks (6 species), skates (9 species) and stingray in the eastern English Channel. Temporal trends in relative abundance and distributions of total-length frequencies were investigated using data collected over 21 yr from an annual survey using a Grande Ouverture Verticale (GOV) trawl. Temporal trends in relative abundance were examined qualitatively in relation to the reported conservation status for the...
Tipo: Text
Palavras-chave: Elasmobranchii; Chondrichthyes; Kriging; GIS; Conservation; Sex ratio; Catchability; Channel Ground Fish Survey; CGFS.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00019/13029/10160.pdf

Étude biométrique de la croissance d'Eledone cirrhosa [LAM. 1978 (Cephalopoda, Octopoda)] du golfe du Lion
Provedor de dados: 5
Autores: Moriyasu, M.
Tipo: Text
Palavras-chave: Sex ratio; Croissance; Modèle de Von Bertalanlfy; Céphalopodes; Méditerranée; Sex ratio; Growth; Von Benalanlfy's model; Cephalopoda; Mediterranean.
Ano: 1983
URL: http://archimer.ifremer.fr/doc/00120/23145/20990.pdf

Are sex ratios in wild European sea bass (Dicentrarchus labrax) populations biased?
Provedor de dados: 5
Autores: Vandeputte, Marc; Quillet, Edwige; Chatain, Beatrice.
Sex ratios in farmed European sea bass are highly biased towards males (75 to 95%), which is problematic for aquaculture. In this mini-review, we re-analyse fisheries literature data about sex ratios in wild sea bass from 13 population samples, representing altogether 4889 individuals covering the major part of the distribution range of the species. We find that as a whole, the sex ratio of wild populations is biased towards females (59.4% females, p &lt; 0.001), but that the sex ratio of the younger fish (&lt; 30 cm total length) is balanced (52.0% females, p = 0.15), while the sex ratio of the older fish is heavily biased towards females (69.5% females, p &lt; 0.01). Possible causes of these differences (differential longevity, biased sampling) are...
Tipo: Text
Palavras-chave: Sex ratio; Genetics; Sex determination; Fish aquaculture; Dicentrarchus labrax.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00078/18882/16450.pdf

When survival matters: is decreasing survival underlying the decline of common pochard in western Europe?
Provedor de dados: 5
Autores: Folliot, Benjamin; Souchay, Guillaume; Champagnon, Jocelyn; Guillemain, Matthieu; Durham, Maurice; Hearn, Richard; Hofer, Josef; Laesser, Jacques; Sorin, Christophe; Caizergues, Alain.
In western Europe, common pochard populations have experienced a sharp decline over the last two decades, together with an increasing proportion of males. Both of these changes were suggested to result from decreasing survival of nesting females (i.e. survival of adult females) owing to increasing predation pressure. To test this hypothesis, we used capture–mark–recapture/recovery data of common pochard ringed during autumn–winter (October–February) in three countries of western Europe (Switzerland, United Kingdom and France). We found no evidence for decreasing survival of individuals ringed in the United Kingdom or in Switzerland over the long term (1977–2011). In France, adult males and juvenile females experienced significant decreasing survival over a...
Tipo: Text
Palavras-chave: CMR; Multistate models; Recoveries; Sex ratio; Survival; Waterfowl.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00651/76323/77301.pdf

Characteristics of one sea winter Atlantic salmon stock caught on Elorn river from 1974 to 1984
Provedor de dados: 5
Autores: Prouzet, Patrick; Gaignon, Jean-louis.
From observations gathered on grilse populations sampled during the fishing period (March -mid-June) or after the fishing season, the authors noted: a strong heterogeneity and length, the mean value of which increase from May to December, a sex-ratio not different from 1 male for 1 female, a high relative fecundity superior to those of spring salmon population sampled. The comparison between fish of local and foreign origins did not allow to observe significant differences between the biological characteristics studied (weight, length, sex-ratio and fecundity).
Tipo: Text
Palavras-chave: Salmo salar; Salmonidae; Pisces; Weight; Fecundity; Sex ratio; Length weight relationships; Migratory species.
Ano: 1983
URL: http://archimer.ifremer.fr/doc/1983/publication-1818.pdf

Constitution of aquacultural stocks: Genetic aspects.
Provedor de dados: 5
Autores: Chevassus, B.
Before reaching of production level justifying an elaborated genetic improvement program, the new aquaculture species deserve a minimal strategy to avoid the consequences of uncontrolled genetic phenomena. Three main aspects will be discussed: initial constitution of the broodstock; maintenance of the broodstock; selection of the broodstock.
Tipo: Text
Palavras-chave: Oncorhynchus keta; Salmo salar; Salmo trutta; Salmonidae; Pisces; Marine molluscs; Marine fish; Sex ratio; Females; Males; Eggs; Larvae; Spawning populations; Aquaculture; Population genetics.
Ano: 1989
URL: http://archimer.ifremer.fr/doc/1989/acte-1442.pdf

Contribution à l'étude de la crevette rose Palaemon serratus (Pennant) : Exploitation, Biologie, Elevage, Epidémiologie
Provedor de dados: 5
Autores: Campillo, Albert.
This these is the result of several years of investigations conducted on the common prawn Palaemon serratus in the Roscoff (northern Brittany) and Yeu (bay of Biscay) sectors of the French Atlantic coast.    Following a description of the fishery and fishing strategies, it deals with the species biological aspects, focusing on growth, lifespan, sex-ratio and breeding. Hypotheses on the reasons for apparent variations in interannual abundance are drawn up and compared with field observations.   The second part is devoted to production experiments in a controlled environment (hatchery), explaining how larvae are obtained and their development and survival with respect to food, density and physical parameters like salinity and temperature. The link between...
Tipo: Text
Palavras-chave: Shrimp farm; Larval development; Sex ratio; Breeding; Growth; Fishery; Palaemon serratus; Common prawn; Elevage; Développement larvaire; Sex ratio; Reproduction; Croissance; Pêche; Palaemon serratus; Crevette rose.
Ano: 1979
URL: http://archimer.ifremer.fr/doc/1979/these-1196.pdf

Searching for humpback whales in a historical whaling hotspot of the Coral Sea, South Pacific
Provedor de dados: 5
Autores: Garrigue, C; Derville, S; Bonneville, C; Baker, Cs; Cheeseman, T; Millet, Laurent; Paton, D; Steel, D.
Humpback whales Megaptera novaeangliae were severely depleted by commercial whaling. Understanding key factors in their recovery is a crucial step for their conservation worldwide. In Oceania, the Chesterfield-Bellona archipelago was a primary whaling site in the 19th century, yet has been left almost unaffected by anthropogenic activities since. We present the results of the first multidisciplinary dedicated surveys in the archipelago assessing humpback whale populations 2 centuries post-whaling. We encountered 57 groups during 24 survey days (2016-2017), among which 35 whales were identified using photographs of natural markings (photo-ID), 38 using genotyping and 22 using both. Humpback whales were sparsely distributed (0.041 whales km-1): most...
Tipo: Text
Palavras-chave: Chesterfield-Bellona archipelago; Connectivity; Coral Sea; Habitat use; Humpback whale; Satellite tracking; Sex ratio; Whaling.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00632/74454/74267.pdf

Sex, size and timing: Sampling design for reliable population genetics analyses using microsatellite data
Provedor de dados: 5
Autores: Dubois, Quentin; Lebigre, Christophe; Schtickzelle, Nicolas; Turlure, Camille.
Population genetics is used in a wide variety of fields such as ecology and biodiversity conservation. How estimated genetic characteristics of natural populations can be influenced by the sampling design has been a long-standing concern. Multiple simulation and empirical studies illustrated the influence of both sample size and polymorphism of markers. However, our review of studies on butterfly population genetics indicates no consensus on sample size for the estimation of genetic diversity or differentiation. Furthermore, other aspects of sampling design (sex ratio and timing of sampling) were not addressed and their potential impact on genetic parameter estimates rarely explored. Using a large empirical dataset (with spatial and temporal replicates)...
Tipo: Text
Palavras-chave: Butterfly; Conservation; Genetic diversity; Metapopulation; Number of samples; Period of sampling; Population structure; Sampling scheme optimization; Sex ratio.
Ano: 2018
URL: http://archimer.ifremer.fr/doc/00416/52783/53664.pdf

The sexuality of cultured hermaphroditic fish species: Analysis of morphological and endocrinological features in a protogynous hermaphrodite, Epinephelus microdon , as a basis for further research to control reproduction in the grouper
Provedor de dados: 5
Autores: Debas, L; Fostier, A; Fuchs, Jacques; Weppe, M; Nedelec, Georges; Benett, A; Cauty, C; Jalabert, B.
The Polynesian grouper, Epinephelus microdon , was chosen as an experimental model in order to investigate about factors controlling sexuality in groupers.
Tipo: Text
Palavras-chave: French Polynesia; Epinephelus microdon; Sex ratio; Sexual maturity; Sex hormones; Sex determination; Sex; Fish culture; Endocrinology; Reproduction; Sex reversal; Animal morphology.
Ano: 1989
URL: http://archimer.ifremer.fr/doc/1989/acte-1439.pdf

Low temperature has opposite effects on sex determination in a marine fish at the larval/postlarval and juvenile stages
Provedor de dados: 5
Autores: Vandeputte, Marc; Clota, Frederic; Sadoul, Bastien; Blanc, Marie-odile; Blondeau-bidet, Eva; Bégout, Marie-laure; Cousin, Xavier; Geffroy, Benjamin.
Temperature‐dependent sex determination (TSD) can be observed in multiple reptile and fish species. It is adaptive when varying environmental conditions advantage either males or females. A good knowledge of the thermosensitive period is key to understand how environmental changes may lead to changes in population sex ratio. Here, by manipulating temperature during development, we confirm that cold temperature (16°C) increases the proportion of fish that develop as females in European sea bass (Dicentrarchus labrax) until 56 days posthatching, but show that it has an opposite effect at later stages, with the proportion of males reaching ~90% after 230 days at 16°C. This is the first observation of opposite effects of temperature at different time periods...
Tipo: Text
Palavras-chave: Dicentrarchus labrax; Fish; Sex ratio; Temperature-dependent sex determination; Thermosensitive period; TSD.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00658/76965/78184.pdf

Reproductive dynamics of swordfish (Xiphias gladius) in the southwestern Indian Ocean (Reunion Island). Part 1: oocyte development, sexual maturity and spawning
Provedor de dados: 5
Autores: Poisson, Francois; Fauvel, Christian.
The reproductive dynamics of swordfish (Xiphias gladius) was investigated from catches of the Reunion Island-based longline swordfish fishery between 19-25 degrees S and 48-54 degrees E. Thus, 1727 swordfish (size range 75-289 cm, lower jaw-to-fork length, LJFL) were sampled on board commercial fishing vessels during the period of May 1998 to January 2001. Reproductive activity was assessed using macroscopic gonad characteristics, trends of gonadal indexes for both sexes, oocyte size-frequency distributions and microscopic investigation of oocyte development stages. Size at first maturity (L-50) for female and male swordfish was estimated in Indian Ocean for the first time. L50 was estimated at 170 cm and 120 cm (LJFL) for females and males, respectively....
Tipo: Text
Palavras-chave: Indian Ocean; Xiphias gladius; Swordfish; Seasonal distribution; Size at first maturity; Histology; Spawning season; Sex ratio; Reproduction.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6353.pdf

A polygenic hypothesis for sex determination in the European sea bass - Dicentrarchus labrax
Provedor de dados: 5
Autores: Vandeputte, Marc; Dupont Nivet, M; Chavanne, H; Chatain, Beatrice.
Polygenic sex determination, although suspected in several species, is thought to be evolutionarily unstable and has been proven in very few cases. In the European sea bass, temperature is known to influence the sex ratio. We set up a factorial mating, producing 5.893 individuals from 253 full-sib families, all reared in a single batch to avoid any between-families environmental effects. The proportion of females in the offspring was 18.3%, with a large variation between families. Interpreting sex as a threshold trait, the heritability estimate was 0.62 +/- 0.12. The observed distribution of family sex ratios was in accordance with a polygenic model or with a four-sex-factors system with environmental variance and could not be explained by any genetic...
Tipo: Text
Palavras-chave: Dicentrarchus labrax; Fish; Growth; Heritability; Sex ratio.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-3526.pdf

Development of Melittobia australica Girault and M. digitata Dahms (Parker) (Hymenoptera: Eulophidae) parasitizing Neobellieria bullata (Parker) (Diptera: Sarcophagidae) puparia
Provedor de dados: 82
Autores: Silva-Torres,Christian S.A.; Matthews,Robert W.
The development of Melittobia australica Girault and M. digitata Dahms were studied parasitizing blow fly puparia Neobellieria (=Sarcophaga) bullata (Parker) using from one to five foundress females per host. Aspects of parasitoids biology such as number of descendents produced, longevity, and progeny body size can be affected as the number of foundress increases per host. The percentage of puparia parasitized was higher overall for M. digitata than for M. australica. Regardless of foundress numbers, the average total number of descendents produced was significantly higher for M. digitata (66.5 158.0) than for M. australica (10.9 55.5). The number of descendents produced per female was inversely proportional to the number of foundresses on a host for both...
Tipo: Info:eu-repo/semantics/report
Palavras-chave: Insecta; Parasitoid; Facultative host; Sex ratio; Developmental plasticity.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-566X2003000400015

Size composition, monthly condition factor and morphometrics for fishery-dependent samples of Rioraja agassizi (Chondrichthyes: Rajidae), off Santos, Southeast Brazil
Provedor de dados: 83
Autores: Oddone,M. Cristina; Amorim,Alberto F. de; Mancini,Patrícia L.; Norbis,Walter.
Specimens of Rioraja agassizi were collected monthly off Santos, Southeast Brazil, between latitudes 23º37'S and 27º40'S, from March, 2005 to March, 2006. A total number of 278 males and 1023 females were captured. Observed depth range was 10-120 m, being the species absent above 120 m. Sex ratio significantly favored females. The entire length range of R. agassizi was observed. Females ranged in length from 16.0 to 59.4 cm and males from 13.0 to 47.2 cm. Mean female length was significantly higher than that of males. For grouped length distributions, asymmetry patterns were observed in both sexes. Length-width functions were sexually dimorphic. Males with lengths &lt; 24.5 cm were relatively wider than females. Length-total weight curves were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Skates; Depth; Total length; Elasmobranch; Sex ratio.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252007000300021

Reproductive biology of Triportheus trifurcatus (Castelnau, 1855) (Characiformes: Characidae) in the middle rio Araguaia, MT, Brazil
Provedor de dados: 83
Autores: Martins-Queiroz,Mirian F.; Mateus,Lúcia A. de F.; Garutti,Valdener; Venere,Paulo C.
The study of the reproductive biology of Triportheus trifurcatus of the middle rio Araguaia was carried out using 275 specimens obtained in seven collections conducted in the period between November 2003 and January 2005. Females prevailed among the classes of intermediate length, as well as in the total number of samples. On the other hand, males prevailed in the smaller classes. The average length of females was larger than that of males. Four stages of gonadal maturation were macro- and microscopically identified: B - maturation, C - mature, D - spent and E - resting. Stage A (immature) was not found in the habitats sampled. The smallest-length male was 110 mm in standard length, and the smallest female, 119 mm. The spawning period occurred from...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Fecundity; Sex ratio; Reproductive cycle; Gonadal maturation.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252008000200010

Reproductive biology of Rhaphiodon vulpinus (Ostariophysi: Cynodontidae) in the Tocantins River Basin, Brazil
Provedor de dados: 83
Autores: Neuberger,Andréa L.; Marques,Elineide E.; Agostinho,Carlos S.; Oliveira,Rafael J. de.
In order to evaluate aspects of the reproductive biology of Rhaphiodon vulpinus in the Upper and Middle Tocantins River, samples were taken monthly from October, 1999 through September, 2001, by means of gill nets. Males, which were more abundant than females (chi2 146.87: df=1: p&lt;0.05), matured at a smaller size. The reproductive period of the species extended essentially from November through January, with a peak of activity in November. Fecundity, with an estimated mean value of 98,185 oocytes, varied from 38,177 to 215,841 oocytes, and it did not correlate with the length of the individual female analyzed (r=0.4663: p=0.206). Relative fecundity was 130.6 oocytes/g total weight. Mature oocytes had a mean diameter of 0.98 mm, corresponding to a volume...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Sex ratio; First maturation; Reproduction; Fecundity.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252007000400007

Distribution, abundance and morphometry of Atlantoraja cyclophora (Regan, 1903) (Elasmobranchii: Rajidae) in southern Brazil, Southwestern Atlantic
Provedor de dados: 83
Autores: Oddone,María Cristina; Vooren,Carolus Maria.
A total of 459 individuals of Atlantoraja cyclophora were captured along the Rio Grande do Sul coast between latitudes 30º40'S and 34º30'S. Two surveys were performed, in the winter 2001 and in the summer/autumn 2002, using bottom-trawl between the depths of 100 and 600 m. This species occurred between 100 and 300 m deep, without significant differences in the frequency of occurrence and abundance (CPUE; kg/hour) between latitudes, depth and seasons. The sex ratio was not significantly different from 1:1 in all depths. In the study area, temperature ranged between 10.0 ºC and 17.6 ºC and salinity between 35.2 e 36.0 ppm. There was no correlation between CPUE and depth, temperature and salinity. Mean total length of females (53.2 cm) was significantly...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Abundance; Distribution; Occurrence; Sex ratio; Morphometry.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252004000300005

Reproductive tactics used by the Lambari Astyanax aff. fasciatus in three water supply reservoirs in the same geographic region of the upper Iguaçu River
Provedor de dados: 83
Autores: Silva,Juliano Pilotto Abelardino da; Muelbert,Adriane Esquivel; Oliveira,Elton Celton de; Fávaro,Luís Fernando.
The species Astyanax aff. fasciatus was investigated as regards differences in reproductive tactics in three reservoirs with different ages (Iraí, Piraquara and Passaúna) located in the same geographic region. The biological material was obtained through monthly collections carried out from july/2006 to june/2007. The average value of the gonadosomatic index (GSI) in Passaúna reservoir was significantly higher in relation to the values obtained in the other reservoirs. Spawning was total in Iraí reservoir and partial in the others. Allometric growth of the species was negative in Iraí reservoir and positive in the others. The highest condition factor value was estimated in Iraí reservoir, followed by Piraquara and Passaúna reservoirs, respectively. Females...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Characidae; Succession; Spawning; Condition factors; Sex ratio.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252010000400019

Reproductive biology of Poecilia sphenops Valenciennes, 1846 (Cyprinidontiformes: Poeciliidae) at the Emiliano Zapata Reservoir in Morelos, Mexico
Provedor de dados: 83
Autores: Gómez-Márquez,José L.; Peña-Mendoza,Bertha; Guzmán-Santiago,José L.
ABSTRACT Poecilia sphenops is a native species recently recorded in the Balsas basin and the Amacuzac River in Morelos (Mexico), in which it is abundant and widely distributed. This study analyzed some aspects of the reproductive biology of Poecilia sphenops from the Emiliano Zapata Reservoir, in Central Mexico. Specimens were collected using a 20 m-long seine with a 5 mm mesh size, from January to December 2006. A total of 581 specimens were collected: 407 females (70.0%), 83 males (14.3%) and 91 individuals with no differentiated sex (15.7%). Fish ranged from 20 to 96 mm in total length and 0.01 to 13.07 g in body weight. The female to male sex ratio (4.9:1) deviated significantly from the unity (χ2= 214.2, p&lt;0.05). Monthly variations in gonadosomatic...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Fecundity; Poeciliids; Sex ratio; Sexual maturity; Spawning.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252016000200201

Effects of Sugar Supply on Longevity and Progeny Production of an Aphid Parasitoid, Aphidius ervi (Hymeno-ptera: Aphidiidae)
Provedor de dados: 19
Autores: 林, 佐季; 仲島, 義貴.
We investigated effects of sugar solution on adult longevity, progeny production and progeny sex ratio of Aphidius ervi in the presence and absence of host aphids. When female parasitoids were provided with 50% glucose–fructose solution in 1 : 1 ratio, they lived approximately twice longer than those provided with distilled water, irrespective of host aphid provision. The same effect of sugar solution was also observed on progeny production. When the parasitoid was fed sugar solution, its lifetime progeny production approximately doubled in comparison to that provided with water, whereas daily progeny production did not differ. Total number of female progeny did not differ between adult female provided with water and sugar solution, but significantly...
Palavras-chave: Biological control; Sex ratio; Sugar; Longevity; Fecundity.
Ano: 2014
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4035

Période de ponte, sex-ratio et maturité sexuelle du brochet de mer Sphyraena sphyraena (Teleostei, Sphyraenidae)  au nord et a l’est de la côte Tunisienne (mediterranée occidentale et centrale)
Provedor de dados: 20
Autores: Ezzeddine-Najaï, S.; Chemmam-Abdelkader, Bachra; Kraiem, M.M.
Neuf cent vingt et un (921) spécimens du Brochet de mer (Sphyraena sphyraena) dont 366 mâles et 519 femelles ont été récoltés au Nord et à l’Est de la côte tunisienne.  La période de frai se déroule d’avril à août avec un maximum au mois de mai. L’analyse des rapports gonado–somatique (RGS) et hépato-somatique (RHS) montre que les réserves vitellines sont stockées au niveau du foie, ce qui permet de classer cette espèce parmi les poissons maigres. L’étude de la sex-ratio exprimée par mois et par classe de taille, montre que les femelles sont significativement dominantes tout au long de l’année, sauf pour les mois de mai et juin au cours desquels les proportions s’inversent significativement en faveur des mâles de taille comprise entre 25 et 29cm. Le...
Tipo: Journal Contribution
Palavras-chave: Sphyraena sphyraena; Age at recruitment; Breeding; Length; Sexual maturity; Seasonal variations; Sex ratio; Sexual reproduction; Size; Spawning; Length; Spawning; Breeding; Sexual maturity; Sex ratio; Sexual reproduction; Size; Http://aims.fao.org/aos/agrovoc/c_4260; Http://aims.fao.org/aos/agrovoc/c_14490; Http://aims.fao.org/aos/agrovoc/c_49902; Http://aims.fao.org/aos/agrovoc/c_7016; Http://aims.fao.org/aos/agrovoc/c_7014; Http://aims.fao.org/aos/agrovoc/c_26876; Http://aims.fao.org/aos/agrovoc/c_7093.
Ano: 2007
URL: http://hdl.handle.net/1834/4261

Etude comparative du cycle sexuel  et de la relation taille-poids de deaux espèces d'athérine en Tunisie
Provedor de dados: 20
Autores: Bouriga, N.; Cherif, M.; Hajjej, Gh.; Guignard, J-P.; Faure, E.; Trabelsi, M.
Le présent travail porte sur l’étude des caractères biométriques des athérines de Tunisie pour compléter les études métriques et méristiques établies auparavant. L’objectif principal de cette étude, est de comparer les paramètres biologiques via l’analyse de la croissance et de la reproduction de Atherina boyeri (côtes nord tunisiennes) et Atherina lagunae (île Kerkennah). L’étude de la sex-ratio en fonction des mois a montré que les femelles sont toujours plus nombreuses que les mâles pour les espèces d’athérines. En effet, la valeur globale de la sex-ratio, toute taille confondue, est en faveur des femelles. L’étude du cycle sexuel des athérines insulaires des îles Kerkennah a montré que la période de reproduction s’établie entre le mois de mars et le...
Tipo: Journal Contribution
Palavras-chave: Coastal lagoons; Sex ratio; Growth rate; Length-weight relationships; Spawning seasons.
Ano: 2010
URL: http://hdl.handle.net/1834/4693

Relation taille–masse, condition relative et cycle sexuel des anchois et des sardines des côtesTunisiennes
Provedor de dados: 20
Autores: Khemiri, S.; Gaamour, A.
La biologie reproductive, la relation taille-masse ainsi que la condition relative de l’anchois Engraulis encrasicolus et de la sardine Sardina pilchardus ont été étudiées le long des régions Nord, Golfe de Tunis, la région Est et la région Sud des côtes tunisiennes durant la période 2000-2002.  Pour l’anchois et la sardine, la sex-ratio globale pour toutes les côtes tunisiennes est voisine de 1,0. L’acquisition de la taille de première maturité sexuelle semble être influencée par la température de l’eau dans les quatre régions. Les périodes de reproduction ont lieu dans les quatre régions d’avril à octobre pour l’anchois et d’octobre à mars pour la sardine. Dans les eaux tunisiennes, l’anchois et la sardine ont une allométrie majorante et une condition...
Tipo: Journal Contribution
Palavras-chave: Allometry; Condition factor; Length-weight relationships; Marine fish; Sex ratio; Sexual maturity; Sexual reproduction; Spawning seasons; Marine fishes.
Ano: 2009
URL: http://hdl.handle.net/1834/4487

Reproducción y fecundidad de la cherna americana (Epinephelus morio) en el Banco de Campeche, Mexico
Provedor de dados: 20
Autores: Giménez, E.; Moreno, V.J.; Burgos, R.; Alfonso, S.
La cherna americana o mero (Epinephelus mono), de la familia Serranidae, es la especie en explotación mas importante del Banco de Carnpeche, Mexico, por lo que el conocimiento de los aspectos relacionados con su reproducción, es importante para un manejo adecuado de la especie. Se determinó que la proporcion sexual (WH) vario con la talla de los ejemplares, presentando las mayores proporciones de hembras en la clase de talla de 30 cm (1:31.5). A partir de 10s 75 cm, la proporcion no fue significativamente diferente de 1:1. La talla a partir de la cual comenzó el cambio de sexo se observo entre 30 y 35 cm Lt. El contenido de la grasa mesenterial aumentó durante el otoño (septiembre, octubre, noviembre) y descendió durante el invierno (diciembre, enero,...
Tipo: Journal Contribution
Palavras-chave: Reproduction; Fecundity; Sex ratio; Spawning; Spawning; Reproduction; Fecundity; Sex ratio; Http://aims.fao.org/aos/agrovoc/c_14490; Http://aims.fao.org/aos/agrovoc/c_6507; Http://aims.fao.org/aos/agrovoc/c_15725; Http://aims.fao.org/aos/agrovoc/c_7014.
Ano: 2003
URL: http://hdl.handle.net/1834/1804

Estructura por edad y sexo de la captura de merluza desembarcada. Período 1986-1998
Provedor de dados: 20
Autores: Renzi, M.A.
During the 1986-1998 period the hake (Merluccius hubbsi) fishery in the Argentine Sea (SW Atlantic) turned from moderate to intense exploitation. Age and sex structure analysis showed a change in the exploitation pattern. During the three periods defined  1986-1989, 1990-1992 and 1993-1998 a trend towards catching young individuals and a predominance of females age 3 and older was observed. An increase of total mortality was also detected. As a consequence of the establishment of a closed area in mid 1997 ice-chilling and freezer fleets changed operation areas which brought about differences in the catch structure. Freezers showed higher percentages of older ages. An average decrease of 30 in yield number of individuals per unit effort for all ages was...
Tipo: Journal Contribution
Palavras-chave: Age composition; Sex ratio; Landing statistics; Gadoid fisheries; Age composition; Sex ratio; Http://aims.fao.org/aos/agrovoc/c_29093; Http://aims.fao.org/aos/agrovoc/c_7014.
Ano: 2003
URL: http://hdl.handle.net/1834/2423

Resultados de una campaña de investigación sobre la anchoíta (Engraulis anchoita)del sector bonaerense en el otoño de 1983. Distribución, abundancia y algunos aspectos biológico-pesqueros
Provedor de dados: 20
Autores: Hansen, J.E.; Gru, D.L.; Perrotta, R.G.
An extensive area of the continental shelf -between 37°20' and 34°40'S - was reviewed through hidroacoustical methods in order to evaluate the anchovy biomass. Within the area of highest concentration, further data on anchovy abundance were recorded, and fish samples were taken. Large anchovy shoals were located at about 170 nm from Mar del Plata, mainly in zones with sharp changes in oceanographic conditions. The distribution of the species was not uniform, but "contagious", and the log-normal distribution provided the best fit for the echo-integrator recorded data. The biomass was estimated at 1,061,727 tons (Confidence limits in between 921,010 and 1,223,930 tons). Some parameters of the population were estimated, such as: lenght-weight relationship,...
Tipo: Journal Contribution
Palavras-chave: Length-weight relationships; Sex ratio; Age composition; Growth curves; Echo surveys; Mortality; Age composition; Sex ratio; Mortality; Http://aims.fao.org/aos/agrovoc/c_29093; Http://aims.fao.org/aos/agrovoc/c_7014; Http://aims.fao.org/aos/agrovoc/c_4945.
Ano: 1986
URL: http://hdl.handle.net/1834/2038

Evaluación del stock desovante de anchoveta en la I y II Regiones, año 2004, (Fase 1)
Provedor de dados: 20
Autores: Braun, M.; Reyes, H.; Pizarro, M.; Saavedra, J.; Catasti, V.; Claramunt, G.; Díaz, E.
El informe contiene los resultados correspondientes  al desarrollo del crucero Módulo Huevos y Módulo Adultos del proyecto FIP 200-04-1. De conformidad con la metodología planteada en la propuesta técnica y con el fin de estimar en esta primera fase algunos de los parámetros biológicos aplicables para el Método de Producción de Huevos, a saber: proporción sexual y peso promedio estimado de hembras maduras, además de la determinación de las zonas de distribución y abundancia de huevos y su asociación con las condiciones oceanográficas, se realizaron los respectivos muestreos para el recurso anchoveta, durante el período de máxima actividad reproductiva del año 2004.
Tipo: Report
Palavras-chave: Fish eggs; Abundance; Geographical distribution; Sex ratio; Environmental conditions; Geographical distribution; Sex ratio; Environmental conditions; Http://aims.fao.org/aos/agrovoc/c_5083; Http://aims.fao.org/aos/agrovoc/c_7014; Http://aims.fao.org/aos/agrovoc/c_32980.
Ano: 2005
URL: http://hdl.handle.net/1834/1813

L'anchois ( engraulis encrasicolus) des cotes nord de la Tunisie : reproduction et exploitation
Provedor de dados: 20
Autores: Gaamour, A.; Khemiri, S.; Mili, S.; Ben Abdallah, L.
The reproduction parameters necessary for stock management and catch analysis of anchovy in the North region of Tunisia were studied. The global sex-ratio is close to 1, special caution should be taken using this parameter as it is size dependant. Mean reproduction period extends from April to October. However within this period individuals of population have different spawning and maturation. The size at first sexual maturity Lm50 is about 7.3cm. In the North region of Tunisia, the anchovy landings are lower than the exploitable biomass, therefore the anchovy is an under-exploitable species in this region
Tipo: Journal Contribution
Palavras-chave: Engraulis encrasicolus; Clupeoid fisheries; Catching methods; Fishery management; Reproduction; Sex ratio; Sexual maturity; Spawning; Stock assessment; Fishery management; Spawning; Stock assessment; Reproduction; Sex ratio; Sexual maturity; Http://aims.fao.org/aos/agrovoc/c_24026; Http://aims.fao.org/aos/agrovoc/c_14490; Http://aims.fao.org/aos/agrovoc/c_24251; Http://aims.fao.org/aos/agrovoc/c_6507; Http://aims.fao.org/aos/agrovoc/c_7014; Http://aims.fao.org/aos/agrovoc/c_7016.
Ano: 2004
URL: http://hdl.handle.net/1834/4236

Estructura poblacional del gatuzo (Mustelus shmitti) en la costa bonaerense y uruguaya asociada a condiciones oceanográficas.
Provedor de dados: 20
Autores: Massa, A.M.
The gatuzo, Mustelus schmitti, lives in the Southamerican Atlantic coastal waters from up to 23°S (Brazil)down to 47°S (Argentine), and is the greatest species of the Bonaerense and North Patagonian shores. This species is the most exploited elasmobranch of this region, within the last six years catch has exceeded 10,000 t per year and it is vulnerable to overexploitation due to reproductive aspects, with a low rate of changes, as well as distribution patterns. In order to relate size distribution and nursery areas, and environmental temperature and salinity variability, were obtained within six INIDEP 'Coastal Project' research cruises from 34° to 42°S from boundaries to 50 mts isobaths, during the spring seasons between 1994 to 1997. Cluster analysis...
Tipo: Theses and Dissertations
Palavras-chave: Size distribution; Age composition; Sex ratio; Growth curves; Environmental effects; Brackishwater environment; Age composition; Sex ratio; Brackishwater environment; Http://aims.fao.org/aos/agrovoc/c_29093; Http://aims.fao.org/aos/agrovoc/c_7014; Http://aims.fao.org/aos/agrovoc/c_1050.
Ano: 1998
URL: http://hdl.handle.net/1834/3584

Sex-ratio, relation taille-masse et coefficient de condition de la thonine commune "Euthynnus alletteratus (rafinesque, 1810)" des côtes Tunisiennes
Provedor de dados: 20
Autores: Hajjej, G.; Hattour, A.; Allaya, H.; Jarboui, O.; Bouain, A.
Cette étude, présente des informations sur le sex-ratio, la relation taille-masse et le coefficient de condition de la thonine commune Euthynnus alletteratus (Rafinesque, 1810) collectée à divers endroits des côtes tunisiennes entre janvier 2008 et septembre 2009. Le nombre total des individus collectés était de 536. La longueur à la fourche était comprise entre 19,2 et 97,8cm. Les résultats obtenus montrent que le sex-ratio est significativement en faveur des femelles et varie également avec la taille. Une allométrie négative a été établie pour les mâles ainsi que pour les femelles. Les valeurs calculées du coefficient de condition chez Euthynnus alletteratus  sont 1,606 pour les femelles et  1,587 pour les mâles.
Tipo: Journal Contribution
Palavras-chave: Sex ratio; Length-weight relationships; Tuna fisheries.
Ano: 2009
URL: http://hdl.handle.net/1834/4696

Reproductive biology of red squid (Ommastrephes bartramii) in the Southwest Atlantic
Provedor de dados: 20
Autores: Brunetti, N.E.; Ivanovic, M.L.; Aubone, A.; Pascual, L.N.
Red squid (Ommastrephes bartramii) samples were collected during six exploratory cruises carried out in the Southwest Atlantic region off Argentina and Uruguay (33° S-42° S; 43° W-55° W) during summer-autumn of the period 1997-2002 on board the japanese jigger “Shinko Maru N° 3” under a joint research programme approved by Japan and Argentina. Size ranges of the squids analyzed were 10-40 cm mantle length (ML) for males and 12-49 cm ML for females. Two groups of squids were identified: smaller and larger than 20 cm ML. The group under 20 cm ML was characterized by the presence of immature squids and a sex ratio of around 1:1 in the whole study area. The squids of more than 20 cm ML included from immature to mature individuals. The mean sizes, proportion of...
Tipo: Journal Contribution
Palavras-chave: Cephalopod fisheries; Size distribution; Sexual maturity; Sex ratio; Fishery surveys; Sexual maturity; Sex ratio; Http://aims.fao.org/aos/agrovoc/c_7016; Http://aims.fao.org/aos/agrovoc/c_7014.
Ano: 2006
URL: http://hdl.handle.net/1834/2510

Etude de la reproduction chez "Diplodus sagus cadenati " (sparidae) de la cote de nouadhibou (mauritanie)
Provedor de dados: 20
Autores: Dia, M.; Wague, A.; Ghorbel, M.
L’étude de la reproduction de Diplodus sargus cadenati, de la côte de Nouadhibou a porté sur 513 individus de longueurs à la fourche comprises entre 13,2 cm et 32,2 cm. Cette étude a montré que la période de ponte de cette espèce s’étend de janvier à avril, période où la température de l’eau est en moyenne de 18,4°c. La taille (L50) à la laquelle 50% des individus sont matures est de 21,47 ± 0,45 cm de longueur à la fourche (Lf) pour les mâles et de 20,79 ± 0,55 cm pour les femelles. L’étude de la sex-ratio n’a pas montré la dominance de l’un ou de l’autre sexe.
Tipo: Journal Contribution
Palavras-chave: Animal physiology; Marine fish; Methodology; Reproduction; Sex ratio; Size-at-first-maturity; Spawning seasons; Statistical tables; Fishery biology; Marine fishes.
Ano: 2009
URL: http://hdl.handle.net/1834/4490

Evaluación hidroacústica del stock parental de merluza de tres aletas en su unidad de pesquería, año 2004. FASE I y FASE II
Provedor de dados: 20
Autores: Lillo, S.; Céspedes, R.; Ojeda, V.; Saavedra, A.; Díaz, E.; Adasme, L.
El presente estudio tiene como objetivo evaluar el stock de merluza de tres aletas (Micromesistius australis) a través del método hidroacústico, entre las latitudes 47° 00' S y 51° 00' S. Como parte del proyecto, se realizó entre el 2 y el 14 de septiembre de 2004 un crucero de prospección a bordo del B/C Abate Molina, orientado a evaluar mediante un método de evaluación directa (evaluación acústica) su biomasa, abundancia y distribución, junto con estimar la composición de tallas, edad y proporción sexual del stock desovante en el área de estudio.
Tipo: Report
Palavras-chave: Stock assessment; Spawning populations; Echo surveys; Biomass; Geographical distribution; Sex ratio; Age groups; Body size; Stock assessment; Biomass; Geographical distribution; Body size; Sex ratio; Age groups; Http://aims.fao.org/aos/agrovoc/c_24251; Http://aims.fao.org/aos/agrovoc/c_926; Http://aims.fao.org/aos/agrovoc/c_5083; Http://aims.fao.org/aos/agrovoc/c_35330; Http://aims.fao.org/aos/agrovoc/c_7014; Http://aims.fao.org/aos/agrovoc/c_28628.
Ano: 2005
URL: http://hdl.handle.net/1834/1740

Le Rouget de roche (Mullus surmuletus l. 1758) des côtes nord tunisiennes : reproduction, sexualité et croissance
Provedor de dados: 20
Autores: M’rabet, R; Gharbi, H; Missaoui, H; Cherif, M.; Jarboui, O.
L’objectif principal de ce travail, est la réactualisation des paramètres biologiques du rouget de roches des côtes Nord tunisiennes qui sont indispensables pour toute étude ultérieure d’évaluation de stock. Le suivi mensuel du rapport gonado-somatique a montré que la période de ponte de rouget de roche s’étale sur 3 mois d’avril à juillet. La taille pour laquelle 50% des individus sont matures a été estimée à une longueur totale de 16,43cm pour les femelles et de 16,02cm pour les mâles. L’étude de la sex-ratio en fonction des mois a montré que les femelles sont toujours plus nombreuses que les mâles. La répartition des sexes en fonction de la longueur totale montre que les femelles dominent dans la plupart des classes de taille. Les équations...
Tipo: Journal Contribution
Palavras-chave: Mullus surmuletus; Biological surveys; Growth; Length-weight relationships; Sex ratio; Sexual maturity; Size distribution; Spawning; Growth; Spawning; Sexual maturity; Sex ratio; Http://aims.fao.org/aos/agrovoc/c_3394; Http://aims.fao.org/aos/agrovoc/c_14490; Http://aims.fao.org/aos/agrovoc/c_7016; Http://aims.fao.org/aos/agrovoc/c_7014.
Ano: 2007
URL: http://hdl.handle.net/1834/4151

El dorado, Salminus maxillosus (Pisces, Characiformes)en el Río de la Plata y Río Uruguay inferior
Provedor de dados: 20
Autores: Sverlij, S.B.; Espinach Ros, A.
Catch per unit effort (CPUE), lenght distribution, age, growth, reproduction, migrations and feeding were studies through samples collected with longlines and a gang of gill-nets of several mesh size. CPUE data showed a progressive decrease of the relative abundance in the Río de la Plata, during the study period. Age was studied from scales. Back-calculations of growth revealed the pressence of Lee's phenomenon. Means lenghts at age were greater in females. No significant difference was found in lenght-weight regressions from both sexes and sampling areas. Only young individuals from 1 to 6 years were caught. None of the fish studied had ripening gonads. Extensive migrations were recorded both in the Paraná and Uruguay rivers. Stomach contents analysis...
Tipo: Journal Contribution
Palavras-chave: Migrations; Catch/effort; Sex ratio; Size distribution; Scale reading; Growth curves; Reproduction; Stomach content; Sex ratio; Reproduction; Http://aims.fao.org/aos/agrovoc/c_7014; Http://aims.fao.org/aos/agrovoc/c_6507.
Ano: 1986
URL: http://hdl.handle.net/1834/2032

L'anchois &lt;Engraulis encrasicolus&gt; des côtes nord de la Tunisie: reproduction et exploitation.
Provedor de dados: 20
Autores: Khemiri, S.; Gaamour, A.; Mili, S.; Ben Abdallah, L.
التكاثر والاستغلال - يهتم هذا العمل بدراسة معطيات التكاثر، الضرورية لحسن التصرف في المخزون، وبتحليل إنتاج الصيد البحري لسمك الأنشوة بالسواحل الشمالية لتونس. بالنسبة لجملة العينات يتساوى عدد الإناث والذكور مع العلم أن نسبة كل جنس تتغير حسب طول السمكة. يتكاثر سمك الأنشوة خلال الفترة الممتدة من أفريل إلى أكتوبر مع وجود اختلال بين الأفراد. يبلغ سمك الأنشوة نضجه الجنسي الأول لطول يناهز 7.3 صم. يفوق المخزون المتاح استغلاله من سمك الأنشوة الكميات المنزلة بمواني الصيد البحري، تبعا لذلك فإن سمك الأنشوة بالشمال التونسي دون الاستغلال الأمثل.
Tipo: Journal Contribution
Palavras-chave: Catch statistics; Reproduction; Sex ratio; Sexual maturity; Reproduction; Sex ratio; Sexual maturity; Http://aims.fao.org/aos/agrovoc/c_6507; Http://aims.fao.org/aos/agrovoc/c_7014; Http://aims.fao.org/aos/agrovoc/c_7016.
Ano: 2004
URL: http://hdl.handle.net/1834/1154

Aspectos biológicos del calamar Illex argentinus
Provedor de dados: 20
Autores: Leta, H.R.
La creciente importancia que los recursos de calamar han adquirido en 105 últimos 30 años, los sitúa actualmente entre los más importantes recursos pesqueros del mundo. En consecuencia, paises tradicionalmente no explotadores o consumidores de productos de calamar, han orientado sus esfuerzos hacia el logro de un mejor conocimiento de las especies de cefalópodos que habitan su ambiente marino. En este sentido el aporte de disciplinas tales como la biología ha sido decisivo para desarrollar en forma exitosa pesquerías de calamar, entre otras.El programa de investigaciones del Instituto Nacional de Pesca para 1980 incluyó el estudio integral de la explotación de los calamares como un primer paso hacia el desarrollo de una pesquería del recurso.  Este trabajo...
Tipo: Report
Palavras-chave: Biology; Environmental conditions; Population structure; Spawning; Spawning grounds; Sex ratio; Sexual maturity; Reproduction; Length; Behaviour; Migrations; Growth; Population structure; Spawning; Length; Growth; Biology; Environmental conditions; Spawning grounds; Sex ratio; Sexual maturity; Reproduction; Behaviour; Http://aims.fao.org/aos/agrovoc/c_6115; Http://aims.fao.org/aos/agrovoc/c_14490; Http://aims.fao.org/aos/agrovoc/c_4260; Http://aims.fao.org/aos/agrovoc/c_3394; Http://aims.fao.org/aos/agrovoc/c_925; Http://aims.fao.org/aos/agrovoc/c_32980; Http://aims.fao.org/aos/agrovoc/c_7277; Http://aims.fao.org/aos/agrovoc/c_7014; Http://aims.fao.org/aos/agrovoc/c_7016; Http://aims.fao.org/aos/agrovoc/c_6507; Http://aims.fao.org/aos/agrovoc/c_868.
Ano: 1981
URL: http://hdl.handle.net/1834/2563

Evaluación preliminar de los recursos pelágicos en el Área Común de Pesca Argentino-Uruguaya: año 1978-1979
Provedor de dados: 20
Autores: Nión, H.C.; Castaldo, H.A.; Barea, L.C.
En este trabajo se presenta una evaluación preliminar de los recursos pelágicos del frente oceánico del Río de la Plata y del área común de pesca argentino-uruguaya en el Atlántico Sudoccidental. Dicha evaluación fue llevada a cabo por el Gobierno de la República Oriental del Uruguay, durante la segunda fase del Preyecto Pesquero URU.71.517.
Tipo: Report
Palavras-chave: Pelagic fisheries; Geographical distribution; Size distribution; Zonal distribution; Sex ratio; Length-weight relationships; Stock assessment; Geographical distribution; Stock assessment; Pelagic fisheries; Sex ratio; Http://aims.fao.org/aos/agrovoc/c_5083; Http://aims.fao.org/aos/agrovoc/c_24251; Http://aims.fao.org/aos/agrovoc/c_5659; Http://aims.fao.org/aos/agrovoc/c_7014.
Ano: 1980
URL: http://hdl.handle.net/1834/2556

Estudios de distribución de la anchoíta (Engraulis anchoita)en un área de extensión reducida. I. Densidades mínimas de muestreo para la estimación de algunos parámetros poblacionales
Provedor de dados: 20
Autores: Gru, D.L.; Hansen, J.E.
Results of a research cruise carried out to estimate some biological parameters of anchovy (Engraulis anchoita), during the major spawning season, were analyzed in order to determine the minimum number of samples required to obtain unbiased values. Twelve samples of fishes were taken within an area of 607 nm². Size (total length)distributions, slope of the length-weight relationship, sex ratio and age population structure were considered. Results suggest that those parameters should be estimated by eight or more samples (corresponding to 76 nm² each).
Tipo: Journal Contribution
Palavras-chave: Length-weight relationships; Size distribution; Sex ratio; Age composition; Biological sampling; Age composition; Sex ratio; Http://aims.fao.org/aos/agrovoc/c_29093; Http://aims.fao.org/aos/agrovoc/c_7014.
Ano: 1986
URL: http://hdl.handle.net/1834/2029

Estructura por edad y sexo de la población de merluza
Provedor de dados: 20
Autores: Renzi, M.A.; Santos, B.A.; Simonazzi, M.
Hake Merluccius hubbsi population structure in 1993, 1994, 1996, 1997 and 1998 and age and sex distribution during 1997 are analyzed. Data were obtained in research surveys. At the end of winter 1997 concentrations of juveniles were found in the San Jorge Gulf Argentine Sea, SW Atlantic, with maximum yields of 10,000 individuals per trawl hour for age 1 and 2,500 individuals per trawl hour for age 2. The highest concentrations of adults were found in the Gulf and South of 47°S, between the 100 and 200 m isobath, maximum yields of up to 1,700 individuals per trawl hour for age 3 and up to 90 individuals per trawl hour for age 7 and older. In spite of the decrease in population abundance, the basic age structure juveniles, young adults and old adults  was...
Tipo: Journal Contribution
Palavras-chave: Sex ratio; Age composition; Mortality; Fishery surveys; Gadoid fisheries; Age composition; Sex ratio; Mortality; Http://aims.fao.org/aos/agrovoc/c_29093; Http://aims.fao.org/aos/agrovoc/c_7014; Http://aims.fao.org/aos/agrovoc/c_4945.
Ano: 2003
URL: http://hdl.handle.net/1834/2471

Sex allocation and sex-dependent selection for body size in Trypoxylon rogenhoferi Kohl (Hymenoptera, Sphecidae)
Provedor de dados: 92
Autores: Peruquetti,Rui Carlos; Del Lama,Marco Antônio.
Two populations of the wasp Trypoxylon rogenhoferi Kohl, 1884 from São Carlos and Luís Antônio, State of São Paulo, Brazil, were observed and sampled from May 1999 to February 2001 using trap-nests. This mass-provisioning wasp was used to test some aspects of optimal sex allocation theory. Both populations fit all the predictions of the models of Green and Brockmann and Grafen. Maternal provisions determined the size of each offspring, and females allocated well-stocked brood cells to daughters, the sex that benefits most being large. This strategy resulted in a difference in size between the sexes. In São Carlos, female weight at emergence was 1.18 times that of males, in Luís Antônio this value was 1.13. The brood cell volume was correlated with both...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Body size; Cerrado; Mass provisioning; Sex ratio; Trap-nesting wasp.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0085-56262003000400008

Nesting biology of the trap-nesting Neotropical wasp Trypoxylo n(Trypargilum) aurifrons Shuckard (Hymenoptera, Crabronidae)
Provedor de dados: 92
Autores: Santoni,Mariana Marchi; Del Lama,Marco Antonio.
The present study was carried out in three localities of the state of São Paulo, Brazil: Araras (Dec/03-Dec/06), São Carlos (Nov/04-Nov/06) and Rifaina (Jul/04-Dec/06). Trap-nests were distributed among sites in the sampling areas and were collected every 35 days. Data from 295 nests indicate that T. aurifrons is a multivoltine species, with higher rates of nest building and cell production in the warm, rainy season. The trap-nests used by the females ranged from 117 to 467 mm in length and 3.1 to 16.6 mm in diameter. All nests showed deep plugs and a vestibular cell was found in 37% of the complete nests. The number of cells per nest ranged from one to 12. Females were larger than males, emerged from longer cells and their cocoons were significantly...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Nest architecture; Parasitoid; Prey; Sex ratio; Seasonality.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0085-56262007000300015

Sex ratios in juveniles and adults of Dichroplus maculipennis (Blanchard) and Borellia bruneri (Rehn) (Orthoptera: Acrididae)
Provedor de dados: 92
Autores: Mariottini,Yanina; Pocco,Martina E.; Wysiecki,María L. de; Lange,Carlos E.
Dichroplus maculipennis and Borellia bruneri are two of the 18 grasshopper species of actual or potential economic relevance as pests in Argentina. The objective of this study was to estimate the sex ratios for adults and older nymphs of D. maculipennis and B. bruneri in the field, and analyze possible temporal variations. The study was conducted during seven seasons (2005-06 to 2011-12) in representative plant communities of the southern Pampas region. A total of 4536 individuals of D. maculipennis, and 6038 individuals of B. bruneri were collected. The sex ratio registered in older nymphs for D. maculipennis and B. bruneri did not deviate from a 1:1 ratio (p &gt; 0.05), suggesting that these species have such a primary sex ratio. However, a significant...
Tipo: Info:eu-repo/semantics/report
Palavras-chave: Acrididae; Adults; Nymphs; Pampas region; Sex ratio.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0085-56262015000200096

Sex-dependent foraging effort and vigilance in coal-crested finches, Charitospiza eucosma (Aves: Emberizidae) during the breeding season: evidence of female-biased predation?
Provedor de dados: 103
Autores: Diniz,Pedro.
Sexual dimorphism in birds is often attributed to sexual selection, but another interpretation suggests the evolution of this phenomenon by natural selection. Predation may be an important selective pressure, acting mainly on females. In this study, I tested the latter hypothesis on the coal-crested finch (Charitospiza eucosma Oberholser, 1905) in a neotropical savanna of the Central Brazil (Cerrado). I used capture methods for ascertaining the sex ratio in the population, and focal observations to gather behavioral data. My results show that the sex ratio is skewed toward males (1:1.39). Males were more vigilant, vocalized for longer periods of time, and used higher perches than females. Females foraged more, spent more time on parental care and remained...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Birds; Foraging behavior; Predation risk; Sex ratio; Sexual dimorphism.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702011000200003

Estrutura populacional de Aegla schmitti (Crustacea: Anomura: Aeglidae) nos reservatórios dos Mananciais da Serra, Piraquara, Paraná, Brasil
Provedor de dados: 103
Autores: Teodósio,Érico A. O.; Masunari,Setuko.
A study on population structure of Aegla schmitti Hobbs III, 1979 was carried out at Mananciais da Serra, in the municipality of Piraquara, state of Paraná, Brazil (25º29'S, 48º58'W). The following aspects were treated: temporal fluctuation in abundance, sex ratio, reproductive period and size composition based on carapace length. The animals were colleted with traps, nets, measured and returned to the reservoirs. This population was sampled monthly, in two reservoirs (Carvalho and Carvalhinho) constructed in the headwater streams with swift current and steep gradient, located on west side of Serra do Mar mountains, from November, 2004 to January, 2006. The water temperature varied from 11.0 (July, 2005) to 18.2ºC (March, 2007), dissolved oxygen from 7.0...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Aeglid crab; Sex ratio; Temporal distribution.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702009000100004

Sexual and reproductive traits of the pearl oyster shrimp Pontonia margarita (Decapoda: Palemonidae), symbiotically inhabiting the mantle cavity of the rugose pen shell Pinna rugosa (Bivalvia: Pinnidae)
Provedor de dados: 103
Autores: García-Ulloa,Diego; Landa-Jaime,Víctor; Góngora-Gómez,Andrés Martín; García-Ulloa,Manuel; Hernández-Sepúlveda,Juan Antonio.
ABSTRACT Symbiosis between decapods and mollusks provides a unique opportunity to examine some of the evolutionary strategies employed by marine invertebrates. We describe the sexual and reproductive traits of the pearl oyster shrimp, Pontonia margarita Verril, 1869, found symbiotically inhabiting the mantle cavity of the rugose pen shell, Pinna rugosa Sowerby, 1835. Solitary males and females (ovigerous and non-ovigerous) and heterosexual pairs (with ovigerous and non-ovigerous females) were found in a total of 47 rugose pen shells collected from a sandy area with seagrass meadows on the southeastern coast of the Gulf of California, Mexico. The body length (BL) of female P. margarita was correlated with the shell volume of their rugose pen shell host. The...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Monogamy; Promiscuity; Reproduction; Sex ratio; Shrimp-pen shell association.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702019000100312

Pivotal temperature and sexual dimorphism of Podocnemis expansa hatchlings (Testudines: Podocnemididae) from Bananal Island, Brazil
Provedor de dados: 103
Autores: Lubiana,Adélio; Ferreira Júnior,Paulo Dias.
A common problem when trying to identify the sex of hatchling turtles is that juveniles are not obviously externally dimorphic and current techniques to identify sex are often invasive. In this paper, 300 eggs of Podocnemis expansa from Bananal Island, state of Tocantins (Brazil), were incubated at constant temperatures. The carapaces of the hatchlings were photographed and subjected to geometric morphometric analysis. The hatchlings were subsequently euthanized and had their gonads removed for sex determination. The pivotal temperature of P. expansa was 33.5ºC, confirming that this species has the highest pivotal temperature among reptiles. Geometric morphometric analysis of the shape of the carapace proved efficient in differentiating the sex of the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Carapace; Incubation; Morphometry; Sex ratio; Giant Amazon River turtle.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702009000300016

Reproduction of the flatfish Achirus lineatus (Pleuronectiformes: Achiridae) in Paranaguá Bay, state of Paraná, a subtropical region of Brazil
Provedor de dados: 103
Autores: Oliveira,Elton C. de; Fávaro,Luís Fernando.
The present study characterizes the oogenesis and the ovarian maturation scale, and determines the reproductive period, type of spawning, recruitment period, and population variations in the reproductive process of the flatfish Achirus lineatus (Linnaeus, 1758). Specimens were sampled on a monthly basis in the shallow near shore area of the Paranaguá Bay, state of Paraná, Brazil, from March 2006 to February 2007. The specimens collected were measured for morphometric data (total length and total weight) and their gonads were exposed for macroscopic evaluation. The gonads were subsequently removed, weighed and processed for microscopic analyses. Six phases of the ovarian follicle development were defined, as well as five ovarian development stages. Growth...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Oogenesis; Maturity scale; Reproductive period; Type of spawning; Sex ratio.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702010000400004

Population structure and reproductive biology of Uca rapax (Decapoda: Ocypodidae) in a tropical coastal lagoon, southeast Brazil
Provedor de dados: 103
Autores: Costa,Tarso; Soares-Gomes,Abilio.
A population of the fiddler crab Uca rapax (Smith, 1870) found in Itaipu Lagoon, southeast Brazil, was sampled monthly from July 2006 to June 2007 in order to study population and reproductive features. The sex ratio of the population was statistically different from the expected (1:1) in almost every month, with a predominance of males. The reproductive cycle and the recruitment of juveniles were continuous, with two peaks. The fecundity ranged from 1.110 to 13.189 eggs (4.984 ± 2.493.8), not differing statistically among seasons. In contrast, the relative fecundity (F') and the reproductive intensity index (RII) were highest in the summer. Female size at the onset of sexual maturity was estimated as 6.1 mm and egg diameter ranged from 0.20 to 0.28 mm....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Fiddler crab; Fecundity; Reproduction; Sex ratio.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702009000400009

The chiggerflea Hectopsylla pulex (Siphonaptera: Tungidae): infestation on Molossus molossus (Chiroptera: Molossidae) in the Central Andes of Colombia
Provedor de dados: 103
Autores: Ramírez-Chaves,Héctor E.; Tamayo-Zuluaga,Andrés Fernando; Henao-Osorio,Jose J.; Cardona-Giraldo,Alexandra; Ossa-López,Paula A.; Rivera-Páez,Fredy A.
ABSTRACT Some species of mastiff bats, Molossus Geoffroy, 1805, inhabit human shelters such as houses and barns. Among them, the Pallas’s mastiff bat, Molossus molossus Pallas, 1766, is the most common species in South America. There are a few studies on this bat in Colombia, mostly on colony size, diet, ectoparasite records, and activity patterns in the Andean and Caribbean regions. Here, we provide information on the prevalence of chiggerfleas, Hectopsylla pulex (Haller, 1880), on M. molossus, along with molecular data on the flea, and its distribution in Colombia. In addition, we describe the size and sex ratio of the infested bat colony, located in the central Andes of Colombia. The bat colony was represented by ca. 45 individuals, of which 33 were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Colony; Distribution; Ectoparasites; Sex ratio; Urban ecosystems.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702020000100320

Population biology of Aegla platensis (Decapoda: Anomura: Aeglidae) in a tributary of the Uruguay River, state of Rio Grande do Sul, Brazil
Provedor de dados: 103
Autores: Dalosto,Marcelo M.; Palaoro,Alexandre V.; Oliveira,Davi de; Samuelsson,Évelin; Santos,Sandro.
Aeglids are freshwater anomurans that are endemic from southern South America. While their population biology at the species-level is relatively well understood, intraspecific variation within populations has been poorly investigated. Our goal was to investigate the population biology of Aegla platensis Schmitt, 1942 from the Uruguay River Basin, and compare our data with data from other populations. We estimated biometric data, sex ratio, population density and size-class frequencies, and frequencies of ovigerous females and juveniles, from the austral spring of 2007 until autumn 2008. Sexual dimorphism was present in adults, with males being larger than females. Furthermore, males and females were significantly larger than previously recorded for the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Aeglids; Ecological plasticity; Intraspecific variation; Population density; Sampling methods; Sex ratio.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702014000300002

Activity and population characteristics of Andean Condors in southern Chile
Provedor de dados: 97
Autores: SARNO,RONALD J.; FRANKLIN,WILLIAM L.; PREXL,WALTER S.
Data were collected on general activity patterns and population characteristics of free-ranging Andean Condors Vultur gryphus in Torres del Paine National Park, Chile from July 1992 to June 1994 during 3,680 h of observation. Seasonal differences were evident in relative abundance and activity patterns. The mean number of condors sighted/ observation significantly higher in fall-winter than in spring-summer. There was a significant decrease from spring-summer to fall-winter in the percentage of observations during which we sighted solitary condors and a significant increase in the number of groups of condors. In addition, mean monthly maximum group size was significantly larger in fall-winter than spring-summer. The sex ratio (males:females ) of juveniles...
Tipo: Journal article
Palavras-chave: Andean Condor; Activity; Patagonia; Sex ratio.
Ano: 2000
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2000000100001

Population biology of the hermit crab Petrochirus diogenes (Linnaeus) (Crustacea, Decapoda) in Southern Brazil
Provedor de dados: 104
Autores: Turra,Alexander; Branco,Joaquim Olinto; Souto,Flávio Xavier.
The aim of this study was to provide information on the biology of a subtropical population ofthe hermit crab Petrochirus diogenes focusing size structure, sex ratio, reproductive period and morphometric relationships. Monthly samples were done between January and December 1995 at Armação of Itapocoroy, Penha, southern Brazil, using two over-trawls in depths from 6.0 to 10.0 m. A total of 126 individuais were collected. Overall sex ratio did not differ from 1:1. When the sex ratio was analyzed for each size class, it was skewed for females in the smallest size classes while males outnumbered females in the largest ones. The mean size (cephalothoracic length) of P. diogenes was 30.61 ± 12.52 mm and the size structure of this population was skewed to the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Size distribution; Population structure; Sex ratio; Morphometric relationships; Reproductive activity.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752002000400008

Estrutura populacional de Callinectes ornatus Ordway (Crustacea, Portunidae) no Balneário Shangri-Lá, Pontal do Paraná, Paraná, Brasil
Provedor de dados: 104
Autores: Baptista,Cassiana; Pinheiro,Marcelo A. Amaro; Blankensteyn,Arno; Borzone,Carlos A.
Swimming crabs are commonly found in the otter-trawl shrimp fishery by-catch, which operate intensively in the Coastal Plain of Leste Beach, where is located Shangri-lá Beach (25°37'30"S and 48°25'08"W), Paraná State. This work aimed to study the population structure of Callinectes ornatus Ordway, 1863, the most abundant swimming crab in this beach. Between March 2000 and April 2001, fortnightly visits were accomplished in Shangri-lá at the fish market, where all swimming crabs of one otter-trawl were collected. The following data from each individual of C. ornatus were obtained: sex, carapace width (excluding lateral spines), weight, and the gonadal maturation stage, based on its color and size. Juveniles and mature males were dominant, mean sexual...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: By-catch; Maturity; Population biology; Sex ratio; Swimming crab.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752003000400018

Florivory and sex ratio in Annona dioica St. Hil. (Annonaceae) in the Pantanal at Nhecolândia, southwestern Brazil
Provedor de dados: 39
Autores: Paulino Neto,Hipólito Ferreira; Teixeira,Reinaldo Chaves.
Annona dioica St. Hil. is a species that grows to approximately 2 m tall and is very widespread in the cerrados. Individual plants of this androdioecious species produce numerous hermaphroditic or male flowers, but few fruits. The aim of this study was to determine the sex ratio among the plants and to compare the frequency of herbivory between male and hermaphroditic flowers. The fieldwork was done by studying flowering plants in grasslands used as pasture for cattle at Fazenda Nhumirim. One hundred and forty-seven male plants and 71 hermaphroditic plants were examined and produced a total of 194 and 94 flowers, respectively, during the study period. The male:hermaphrodite sex ratio was 2.07:1, and was similar to the male:hermaphrodite flower ratio of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Annona dioica; Annonaceae; Curculionidae; Florivory; Sex ratio.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062006000200015

Population structure of fishes from an urban stream
Provedor de dados: 3
Autores: Zanatta, Naiara; Pazianoto, Laryssa Helena Ribeiro; Cionek, Vivian de Mello; Sacramento, Patrícia Almeida; Benedito, Evanilde.
 The aim of this study was to identify the population structure of the ichthyofauna in an urban stream within an environmental protection area in southern Brazil. Quarterly samplings were conducted between October 2009 and August 2010. Poecilia reticulata was the most abundant species, followed by Hypostomus ancistroides and Rhamdia quelen. It was found a higher proportion of adults instead of juveniles from P. reticulata and R. quelen populations, while the opposite was recorded for H. ancistroides. Sex ratio of 1:1 was found for H. ancistroides, but differed significantly for P. reticulata and R. quelen. Females of P. reticulata and R. quelen reached higher length than males in the smaller and higher length-classes, while H. ancistroides females were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Sex ratio; Reproduction; Population attributes.
Ano: 2017
URL: http://periodicos.uem.br/ojs/index.php/ActaSciBiolSci/article/view/31899

Reproductive strategies of fish populations from three Neotropical streams - doi: 10.4025/actascibiolsci.v35i2.10932
Provedor de dados: 3
Autores: Zanatta, Naiara; Universidade Estadual de Maringá; Cionek, Vivian de Mello; Universidade Estadual de Maringá; Benedito, Evanilde; Universidade Estadual de Maringá.
This study aimed to characterize the reproductive strategies of fish from first order streams. Samplings were performed every three months from June 2008 to March 2009, using electric fishing at three streams: Conceição, Scherer and Jurema, located in the municipalities of Diamante do Norte and Amaporã, Paraná State, Brazil. We obtained the total weight (g), standard or total length (cm), sex and maturation stage for each specimen. Limnological data were obtained with portable equipments. The minimum length at first maturation was established for each population, and reproduction period was determined by analyzing the distribution of maturation stages. The sex ratio was obtained and tested (X2) for significant differences. Eight species were analyzed and...
Tipo: Reprodução
Palavras-chave: 2.00.00.00-6 upper Paraná river basin; Sex ratio; Conservation unit; Reproductive stages 2.05.02.00-1.
Ano: 2013
URL: http://periodicos.uem.br/ojs/index.php/ActaSciBiolSci/article/view/10932

Population structure and allometry of Podocnemis unifilis (Testudines, Podocnemididae) in a protected area upstream Belo Monte dam in Xingu River, Brazil
Provedor de dados: 42
Autores: MIORANDO,PRISCILA S.; GIARRIZZO,TOMMASO; PEZZUTI,JUAREZ C.B.
ABSTRACT Amazon river turtles are increasingly threatened by habitat loss and alteration due to the Brazilian energy policy based on construction of hydroelectric dams, meanwhile, populational studies remain scarce. We described the population structure, and established body allometric relationships of Podocnemis unifilis in the Terra do Meio Ecological Station in the Iriri River, tributary of the Xingu River upstream the Belo Monte dam under construction Turtles were captured by hand net and diving in 2012 and 2013 dry seasons, and 2013 rainy season. A total of 728 males, 296 females and four juveniles were captured. Adult sex ratio was male-biased by 9.15♂:1&amp;#9792;. Females were significantly larger than males. Mean straight carapace length was 268.9...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Amazon; Clear water river; Length-weight relationship; Sex ratio; Tracajá.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652015000502067

Ecological aspects of natural populations of Hyalella pampeana (Crustacea, Amphipoda, Hyalellidae) from the Natural Reserve Island of Martín García (Río de La Plata, Argentina)
Provedor de dados: 42
Autores: COLLA,MARÍA FLORENCIA; CÉSAR,INÉS I.
Abstract: Freshwater amphipods of the genus Hyalella have a great importance in aquatic ecosystems due to their role in matter and energy cycling and its utilization as bioindicators of environmental health. The aim of this work was to analyze relevant population parameters of Hyalellapampeana, such as population density and structure, individual body size, sex ratio, fecundity and recruitment, and to study the possible relation of these parameters to variations in environmental variables. Samples were taken monthly during a one-year period (2006) at three small ponds in the Natural Reserve Island of Martín García, Argentina. The inland aquatic environments showed distinctive physicochemical characteristics, mainly related to pH and conductivity values....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Freshwater amphipoda; Body size; Fecundity; Sex ratio.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652019000100620

Sexual orientation, handedness, sex ratio and fetomaternal tolerance-rejection
Provedor de dados: 48
Autores: Valenzuela,Carlos Y.
Fraternal birth order (FBO) appears as a prenatal cause of 15% of homosexual males (gays) through mnemonic maternal anti-male factors. Non-right-handed men seem to be protected from homosexuality. Four hypotheses are proposed: (1) androgenic factors of non-right-handedness neutralize anti-male factors; (2) non-right-handedness and homosexuality are lethal or produce mental impairment; (3) non-right-handed male embryos are insensitive to anti-male factors; (4) mothers of non-right-handed fetuses do not produce anti-male factors. Studies of the sex ratio (SR) of older and younger siblings show: (1) a significant heterogeneity in the SR of siblings of right or non-right handed heterosexual men and women; (2) lesbians are born among siblings with high SR; (3)...
Tipo: Journal article
Palavras-chave: Homosexuality; Handedness; Sex ratio; Birth order; Fetomoternal tolerance; Genetic distortions.
Ano: 2010
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602010000300012

Population Structure of Mesoclemmys vanderhaegei (Bour, 1973) (Testudines:Chelidae) in the Cerrado of Chapada dos Guimarães, Mato Grosso, Brazil
Provedor de dados: 49
Autores: Brito,Elizângela Silva de; Strussmann,Christine; Penha,Jerry Magno Ferreira.
Studies on population structure of freshwater turtles belonging to the family Chelidae are scarce in Brazil. Herein we describe the structure of a population of the chelid Mesoclemmys vanderhaegei in a Cerrado area in the municipality of Chapada dos Guimarães, Mato Grosso, Brazil. A total of 80 individuals were captured in five collecting sites, from January to March 2007: 42 adult females, 27 adult males, and 11 juveniles with undetermined sex. Among 80 individuals, 24% were recaptured, at least once. This is the first attempt to estimate the size of a population of Mesoclemmys vanderhaegei. Our results suggest that additional sampling efforts are needed for more accurate estimates of population structure. Nevertheless, they surely provide minimum values...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Chelidae; Neotropics; Sex ratio; Population size; Freshwater turtles.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032009000400024

Population structure, condition and diet of Oligosarcus paranensis (Menezes &amp;amp; Gery, 1983) (Osteichthyes: Characidae) at two reservoirs in South Brazil
Provedor de dados: 49
Autores: Abelha,Milza Celi Fedatto; Kashiwaqui,Elaine Antoniassi Luiz; Goulart,Erivelto.
This study investigated the population parameters, condition and diet of Oligosarcus paranensis at Fiú and Mourão Reservoirs, located in Paraná State, Brazil. The fishes were collected quarterly between 1996/1997 and 1998/1999 using gillnets. Food items were quantified by volumetric method. The specimens at Fiú showed comparatively smaller length and worse condition. Sex ratio was statistically equal to 1:1 at Mourão, whereas there was a significant predominance of males at Fiú. Sex ratio also varied among size classes. Allometric growth prevailed among the studied groups. The diet consisted mainly of fishes and was complemented with invertebrates and plant matter in both reservoirs. There was a change in the feeding pattern as the standard length...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Fish; Sex ratio; Feeding; Dog-tooth characid; Impoundments.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032012000100015

Population and reproductive traits of a freshwater amphipod (Crustacea, Peracarida, Hyalellidae) from northwest of the state of Rio Grande do Sul, Brazil
Provedor de dados: 49
Autores: Castiglioni,Daniela da Silva; Limberger,Marcio; Castro,Vanessa da Silva; Ubessi,Francieli.
Abstract The study of population and reproductive traits provides information about the ecological structure of natural populations. This study aimed to characterize dynamics and reproductive traits of Hyalella palmeirensis from a natural pond from southern Brazil. The amphipods were sampled monthly (August 2012 to July 2013) by a person with the aid of a hand net for 20 minutes. Ovigerous females and pre-copulatory pairs were individualized in the field. A total of 12,325 individuals were sampled, being 1,421 males, 6,983 females (including 215 ovigerous females) and 3,921 juveniles. Paired and unpaired males were significantly greater in size than females. There was a positive correlation between body size (CL) of paired males and females. Males and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Fecundity; Body size; Hyalella palmeirensis; Sex ratio; Reproduction; Recruitment.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032020000200204

Reproductive aspects of Harttia carvalhoi Miranda Ribeiro, 1939, a small loricariid from streams of serra da Mantiqueira eastern, SP, Brazil
Provedor de dados: 49
Autores: Biagiotto,Renan Hohendorff; Rondineli,Giulianna; Carmassi,Alberto Luciano; Braga,Francisco Manoel de Souza.
The aim of this work was to present the reproductive aspects of Harttia carvalhoi Miranda Ribeiro, 1939, a small loricariid whose distribution is restricted to the area of drainage basin of the Paraíba do Sul river. A total of 110 specimens of H. carvalhoi were captured. The reproductive period happens from September to February. A total spawning type was identified and fecundity rate ranged from 16 to 106 oocytes. This type of study is important, since fecundity is a specific feature and is adapted to the conditions of the life cycle, varying with growth, population density, food availability and mortality rate. We also emphasize the importance of this study, since there are no previous studies about the reproduction of this species.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Loricariinae; Sex ratio; Reproductive period; Fecundity; Brazil.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032012000400026

Population aspects of Bryconamericus stramineus in streams of the upper Paraná River basin, Brazil
Provedor de dados: 49
Autores: Vasconcelos,Lilian Paula; Súarez,Yzel Rondon; Lima-Junior,Sidnei Eduardo.
In order to describe some aspects of the population ecology of Bryconamericus stramineus in the Guiraí River basin, upper Paraná River basin, samples were taken bimonthly from October 2006 to August 2007 at seven sites in the basin. A total of 960 individuals, including 532 females, 316 males, and 112 of undetermined sex, were collected. A significant variation in the sex ratio was observed (Χ2 = 32.82; p &lt; 0.001). Females were larger (59.7 mm) than males (58.9 mm); however, males showed a larger angular growth coefficient (b) than females. It was estimated that 50% of females were sexually mature at 36.4 mm. The highest rate of ovary development was observed in October, while in June 2007 no mature females were found. Mean fecundity was estimated at...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Length-weight relationship; Mortality; Reproductive strategy; Sex ratio.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032011000200006

Reproduction of the silver John dory Zenopsis conchifer (Actinopterygii: Zeiformes) based on virgin stock condition
Provedor de dados: 49
Autores: Vaz-dos-Santos,André Martins; Rossi-Wongtschowski,Carmen Lúcia Del Bianco; Honji,Renato Massaaki; Bannwart,Denis.
This study describes the reproduction of the silver John dory, Zenopsis conchifer, based on data collected before its fishery exploitation in the southwestern Atlantic, Brazil, in the early 2000s. Biological material was collected through bottom-trawl surveys in 2001 and 2002 from depths of 100 to 600 m. A total of 1,056 individuals ranging from 57 to 504 mm Ls were analyzed. A sex ratio analysis showed that males were predominant among the shorter fishes (&lt; 240 mm Ls) and females among the longer ones (&gt; 320 mm Ls). Between 240 mm and 319 mm Ls sex-ratio was 1:1. The silver John dory is a multiple spawner. Spawning is protracted and more intensive during August and November, when both females and males in spawning capable actively spawning and in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Spawning period and area; Length at first maturation; Sex ratio; Gonadosomatic index.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032014000300120

Effects on microhymenopteran progeny of different host exposure periods (Chrysomya megacephala, Calliphoridae) to the parasitoid wasp Nasonia vitripennis (Hymenoptera: Pteromalidae)
Provedor de dados: 52
Autores: Mello,Renata da Silva; Borja,Gonzalo Efrain Moya; Coelho,Valéria Magalhães Aguiar.
To test the assumption that exposure of the host to parasitoid for long periods could provoke superparasitism, the aim of this work was to test the consequences on the immature development time, productivity of parasitoids per pupa, sex ratio and rate of parasitism of Nasonia vitripennis bred in Chrysomya megacephala pupae. Each individual pupa was placed in a glass tube with one parasitoid female for 24, 48, 72 and 96 h period of exposure, under controlled laboratory conditions. Twenty replicates of each period were performed. ANOVA with a 5% significance level was applied. The 72 h exposure caused the immature development time to increase. The mean parasitoids emergence per pupa did not vary significantly with the time of exposure. There were a...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Biological control; Calliphorids; Immature development; Sex ratio; Superparasitism.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132010000100010