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| Registros recuperados: 84 | |
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| 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 |
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| 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<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 |
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| 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 < 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 (>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 |
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| 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 |
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| 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 |
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| 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 < 0.001), but that the sex ratio of the younger fish (< 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 < 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 |
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| 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 |
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| Registros recuperados: 84 | |
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