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Registros recuperados: 90 | |
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Conti, Stéphane; Roux, Philippe; Fauvel, Christian; Maurer, Benjamin; Demer, David. |
A challenge for the aquaculture community has long been the development of harmless techniques for monitoring fish in a tank. Acoustic telemetry has been used to monitor fish swimming behavior, and passive acoustics have been used to monitor fish feeding, but new techniques are needed to monitor non-invasively their numbers and growth rates. Recently, it has been demonstrated that the acoustical total scattering cross section of fish swimming in a tank can be measured from multiple reverberation time series. These measurements have been used successfully to estimate the number of fish in a tank in laboratory conditions, and to characterize their acoustical signatures. Here, we introduce a novel method for acoustically monitoring fish numerical density and... |
Tipo: Text |
Palavras-chave: Total scattering cross section; Fish counting; Growth rate; Remote monitoring; Fish behavior. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1121.pdf |
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De Donato,Marcos; Ramirez,Raúl; Howell,Chris; Verginelli,Roberto; Orta,Tomás; Cabrera,Saúl; Mata,Enrique; Manrique,Ramón. |
We investigated the effects of family selection on the growth rates of four genetic lines of Litopenaeus vannamei, the Pacific white shrimp, from Venezuela. The mean family weight at selection was 16.79 g and the mean growth rate was 0.169 g d-1 at a mean age of 138 days. The mean growth rates per generation were 0.141 g d-1 for the parental generation (P0), 0.173 g d-1 for the F1 and 0.191 g d-1 for the F2. Survival varied from 83.3% to 94.4%. There were statistically significant differences between lines, with lines B and C, growing at higher temperatures and lower salinities, showing the fastest growth. Regression analysis between growth rate and age for each genetic line showed high r² values, but smaller than those shown between growth rate and... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Family selection; Genetic improvement; Growth rate; Litopenaeus vannamei. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000500009 |
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Revelo, W.. |
Durante el 2009 (excepto mayo, agosto y septiembre), se analizaron un total de 3 772 especímenes de peces conformados por 16 especies, predominando la dica con 1561 individuos (42,3%), las menos capturadas fueron róbalo y chame con un individuo cada una (0,03%). La proporción de sexo macho hembra, talla promedio de captura y media de madurez sexual de las principales especies de peces fue: dama (1: 1,16; 23,7 y 20 cm LT), dica (1: 1,15; 17,3 y 16 cm LT), guanchiche (1: 1,2; 29 y 20 cm LT), ratón (1: 1,25; 23,5 y 19 cm LT) y bocachico (1:1,06; 21,6 y 20 cm LT). En los estadios de madurez sexual, la mayoría de las especies se encontraron en estadio I y II correspondientes a individuos hembras inmaduras; sin embargo, para el guanchiche predominaron las... |
Tipo: Journal Contribution |
Palavras-chave: Rivers; Species diversity; Sexual maturity; Growth rate; Catch composition; Freshwater fish. |
Ano: 2010 |
URL: http://hdl.handle.net/1834/4790 |
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Sartoretto, Stephane; Francour, Patrice. |
Gorgonians are important organisms in the Mediterranean Sea, where they form rocky benthic communities. Four main species (3 Holaxonia and 1 Scleraxonia) are predominant in infra- and circalittoral communities of the northwestern Mediterranean basin. Other species, such as Eunicella verrucosa (Pallas, 1766), are more rarely encountered. The expansion to unusually shallow bathymetric levels has been noted in the region of Marseilles (France) (between 20 and 40 m depth). A ten-year monitoring of colonies was used to assess the growth rate according to age (size): from 3.33 cm year(-1) (height <15 cm) to 0.62 cm year(-1) (height >40 cm). |
Tipo: Text |
Palavras-chave: Eunicella verrucosa; Mediterranean Sea; Growth rate; Population structure. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00087/19859/17508.pdf |
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Blivi, A.B.. |
En Afrique de l'Ouest, particulièrement dans le golfe du Bénin, les grandes villes, Accra, Lomé, Cotonou, Lagos se localisent dans la zone côtière de cordons assez étroits associés à des milieux lagunaires et de vasières relativement importants. Les progrès de modernisation y sont marqués par les installations d'industries de tout genre autour des ports, par le développement des zones d'habitats de caractère formel et informel dû à la croissance de la population et par les nombreuses activités économiques. Cette dynamique se poursuit dans la zone côtière qui continue d'être utilisée presque sans programme de planification et de développement. Les nombreuses ressources socio-économiques évoluent rapidement et attestent le dépassement des possibilités... |
Tipo: Journal Contribution |
Palavras-chave: Growth rate; Harbours Coastal zone Population number Population dynamics Population dynamics http://aims.fao.org/aos/agrovoc/c_6111. |
Ano: 1999 |
URL: http://hdl.handle.net/1834/1238 |
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Cisneros, R.. |
Se estudió el crecimiento poblacional de la cepa Brachionus sp. “Cayman”, cepa Chilca, Perú, en respuesta a diferentes tratamientos con microalgas: Isochrysis galbana (T1), Chaetoceros gracilis (T2), Nannochloropsis oculata (T3), Isochrysis galbana + Chaetoceros gracilis + Nannochloris maculata (T4), Isochrysis galbana + Nannochloris maculata + Nannochloropsis oculata (T5) y Nannochloris maculata (T6). Se evaluó la densidad final de la población (DF), tasa de crecimiento (TC) y productividad (R). Los resultados mostraron diferencias estadísticas entre los tratamientos, encontrándose que T5 presentó mejores resultados en cuanto a DF (190 ± 5,51 indiv.mL-1), TC (0,40 ± 0,01 día-1) y R (38 080 ± 1,53 rot.L-1.día-1). |
Tipo: Journal Contribution |
Palavras-chave: Growth rate; Productivity; Algae resources; Rotifers; Productivity. |
Ano: 2012 |
URL: http://hdl.handle.net/1834/5718 |
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Khoufi, Widien; Elleboode, Romain; Jaziri, Héla; El Fehri, Safouène; Bellamy, Elise; Ben Meriem, Sadok; Romdhane, Mohamed; Mahe, Kelig. |
Hake (Merluccius merluccius) is widely distributed in the Atlantic Ocean and the Mediterranean Sea. It is one of the most exploited demersal fish. In Tunisia, hake is captured from the north to the south (KHOUFI et al., 2010). Hake is an important species of economic interest and thus the subject of a large literature, but its biology remains insufficiently known, particularly on terms of age and growth estimations, which are essential for stock assessment and management. Otolith microstructure provides a useful tool for age determination of juvenile hake, based on daily increment deposition (ARNERI & MORALES-NIN, 2000; MORALES-NIN et al., 2005; KACHER & AMARA, 2005; BELCARI et al., 2006). Consequently, we studied growth and estimated age, using... |
Tipo: Text |
Palavras-chave: Merluccius merluccius; Microstructure journalière; Phase pélagique; Taux de croissance; Merluccius merluccius; Daily microstructure; Pelagic phase; Growth rate. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00116/22681/20416.pdf |
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Ksouri, J.; Challougui, I.; Mensi, F.. |
La culture de Gracilaria a été réalisée selon le mode de bouturage dans la partie Nord-Est du lac de Bizerte du 15 Avril au 31 Mai 2006 afin de déterminer l'effet des conditions initiales optimisées sur le rendement final. Ces conditions initiales, sont caractérisées par une culture sur le fond (sur cordes tendues), un poids initial des touffes de 200 g, une distance entre les rangées de culture de 50 cm et un écartement entre les touffes de 30 cm; de ce fait, la densité initiale est de 1,4 kg/m². Au terme de 46 jours de culture, nous avons enregistré un accroissement du poids de 200 g à 1280 g engendrant un taux de croissance spécifique de 4,03 %/j et une densité finale de 9,1kg/m² (soit 91t poids frais/ha). |
Tipo: Journal Contribution |
Palavras-chave: Algal culture; Aquaculture systems; Aquaculture techniques; Density; Growth rate; Off-bottom culture; Seaweed culture; Aquaculture techniques; Seaweed culture; Algal culture; Density; Growth rate; Http://aims.fao.org/aos/agrovoc/c_28992; Http://aims.fao.org/aos/agrovoc/c_6914; Http://aims.fao.org/aos/agrovoc/c_31892; Http://aims.fao.org/aos/agrovoc/c_2186; Http://aims.fao.org/aos/agrovoc/c_16130. |
Ano: 2008 |
URL: http://hdl.handle.net/1834/3795 |
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Richardi,Vinicius S.; Rebechi,Débora; Aranha,José M. R.; Navarro-Silva,Mário A.. |
Determining the age composition of a population is important when conducting ecological, taxonomic and environmental assessments. Morphometric measurements of the head capsule, especially the length and width, are widely used in the identification of insect instars, but alternative ways for determining the age of insects can expand the options for the analysis of field and laboratory populations. This study evaluated the morphometry of the antennae, mandibles, mentum and ventromental plates to discriminate among the four larval instars of Chironomus sancticaroli Strixino & Strixino, 1981. The larvae were reared in the laboratory under constant temperature (25°C) and photoperiod of 12/12 hours for 19 days, with a supply of food. Fifteen larvae were... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Growth rate; Head capsule; Instars; Morphometry. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702013000200011 |
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Registros recuperados: 90 | |
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