Length-weight relationship of marine fish species off Sao Sebastiao system, Sao Paulo, Southeastern Brazil

The parameters a and b of the length-weight relationship of the form W = a . L super(b) were estimated for 57 fish species sampled in Sao Sebastiao Channel and shelf system in 1997, Sao Paulo, Brazil. The b values ranged from 2.746 to 3.617. The Student's t-test revealed that mot (44) species had b values significantly different from 3. A normal distribution of the calculated LWR exponents (b) was obtained

Larval condition and growth of Sardinella brasiliensis (Steindachner, 1879): preliminary results from laboratory studies

Brazilian sardine, the most important resource along the southeastern Brazilian coast, presented great variations and declines in its stocks. The main factors contributing to this are: oceanographic structure changes; recruitment failures; excessive catches of juveniles and increase in fishery effort. In spite of this, no alterations in the density-dependent parameters were detected. Consequently, methods analysing the condition of the larvae coupled with methods determining growth using sagittae otolith increment width were applied to evaluate growth under experimental conditions. The results of the readings on the sagittae were compared with the age of the laboratory-reared sardine larvae and confirmed that increments are formed on a daily basis. Under poor feeding conditions, sardine larvae showed a low growth expressed by dry weight, RNA/DNA ratio and tryptic enzyme activity and by the narrow and low contrast increments in the otoliths. The results of the biochemical indices showed an unexpected decline in the feeding group coupled with a decrease in width of increment numbers 8 and 10. Other factors than food availability were affecting the condition of the larvae and might be indicative of physiological processes and ontogenetic changes occurring in sardine larvae

Fish, Sternoptychidae, Maurolicus stehmanni Parin & Kobyliansky, 1993: occurrence and distribution in south and southeastern Brazilian waters

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Maurolicus stehmanni Parin & Kobyliansky, 1993 (Sternoptychidae): length of first maturation, and spawning seasons in the south-southeast Brazilian region

Maurolicus stehmanni (Sternoptychidae) é um pequeno peixe mesopelágico que habita a plataforma continental e o talude da região entre Cabo de São Tomé (22 S) e Chuí (34 S). No Atlântico Oeste, apresenta biomassa de cerca de 1 ton e é um importante componente da dieta de peixes pelágicos e demersais com valor comercial. A partir de capturas realizadas com rede de meia água, em 1996 e 1997, dentro do programa (REVIZEE), exemplares provenientes de 38 lances de pesca foram analisados em relação à estrutura da população em comprimento e aos estágios de maturação macroscópica das gônadas, dados que, associados a dados biométricos, permitiram estimar o tamanho médio da 1ª maturação e épocas de desova da espécie. Foram realizados, ainda, cortes histológicos de ovários e testículos com vistas a aferir a avaliação macroscópica e analisar o desenvolvimento ovocitário da espécie. Os resultados indicam que o tamanho médio da 1ª maturação é de 32 mm de comprimento padrão, as fêmeas desovam o ano todo e que a desova ocorre ao longo de toda a borda da plataforma continental sudeste-sul do Brasil. O desenvolvimento ovocitário é assincrônico, mostrando que M. stehmanni apresenta desova parcelada.Maurolicus stehmanni (Sternoptychidae) is a mesopelagic species of fish inhabiting the outer continental shelf and slope of the south-southeastern Brazilian (ZEE), where it presents a considerable biomass and is an important component of the trophic chain, as a forage species. On the basis of catches made with a mid-water-trawl net in 1996 and 1997, as part of the REVIZEE program, samples from 38 hauls were analyzed as regards the length structure of the population, the average length of the first maturation and the spawning seasons of the species. The analysis of histological cross-sections of the ovaries made it possible to describe the oocytic development and assess the macroscopic criteria used to classify the ovary maturation. Results showed that the average length of the first maturation occurs at 32 mm (standard length), females spawn all year round throughout the area studied and the oocytic development is asynchronous

TOWARDS A FARMER-GOVERNED APPROACH TO AGRICULTURAL RESEARCH FOR DEVELOPMENT: LESSONS FROM INTERNATIONAL EXPERIENCES WITH LOCAL INNOVATION SUPPORT FUNDS

International audienceNovel mechanisms for funding agricultural research for development (ARD) are emerging which strive to give smallholders a central role in deciding what types of innovation they want to explore and develop and how to do this. This paper reports on international experiences with one such mechanism, the Local Innovation Support Fund (LISF), which is being piloted in eight countries across Asia and Africa under the umbrella of the PROLINNOVA international partnership programme. The ways of setting up the LISFs vary greatly between countries, in response to country-specific conditions, experiences and opportunities, but all share certain structural elements: ensuring farmers' effective control over fund governance; making calls for proposals that farmers can easily understand and respond to; developing and applying effective screening criteria; and monitoring and evaluating systematically how the funds are used, the outcomes of the work and the impacts on farmers' lives, including their ability to influence ARD decision-making. After presenting the general rationale for the LISF pilot, the paper examines the diverse results obtained across countries in terms of structure and process of grant administration; number, size and types of grants; thematic foci; monitoring and impact assessment. Some critical issues are discussed: the importance of understanding concepts and its implications for LISF implementation, the purposes for which farmers use the funds, the pros and cons of supporting farmers' own experimentation versus farmer-led joint experimentation, and the perspectives for sustainability and scaling-up of the LISF approach within and beyond the eight countries in which it has been piloted

Relações comprimento-peso da ictiofauna associada à sardinha-verdadeira, Sardinella brasiliensis, na Bacia do Sudeste do Brasil (22ºS‑29ºS) entre 2008 e 2010

In this study, estimates of length-weight relationships are presented for twenty-four species caught in association with the Brazilian sardine, Sardinella brasiliensis, during four acoustics surveys carried out under the Program ECOSAR (Prospecting and evaluation of biomass of the stock of Brazilian sardine on the southeast coast by acoustic methods), which was to evaluate the biomass of species that were caught. The model parameters were estimated with the nonlinear iterative method of least squares. The value of the coefficient of determination (r2) and residual analysis were employed to verify the appropriateness of fit. The coefficient b values were tested with respect to isometry (β=3) using a tα1,0.05 test. The values of coefficient b ranged from 2.377 to 3.538. There is a tendency for positive allometry (b) in the sampled ichythyocenose.No presente estudo são apresentadas as estimativas das relações comprimento-peso para vinte e quatro espécies capturadas em associação com a sardinha-verdadeira (Sardinella brasiliensis) durante quatro cruzeiros de prospecção hidroacústica realizados no âmbito do Programa ECOSAR (Prospecção e avaliação de biomassa do estoque de sardinha-verdadeira, na costa sudeste, por métodos hidroacústicos), cujo objetivo foi permitir a avaliação das biomassas das espécies capturadas. Para estimação dos parâmetros dos modelos foi empregado o método iterativo não linear de mínimos quadrados; o valor do coeficiente de determinação (r2) e a análise de resíduos foram empregados para verificar a adequação dos ajustes. Os valores dos coeficientes b foram testados em relação à isometria (β=3) através de teste tα1,0,05. O valor do coeficiente b variou entre 2,377 e 3,538, tendo sido constatada tendência de alometria positiva para o b na ictiocenose amostrada

Growth parameters estimates of Maurolicus stehmanni Parin & Kobyliansky 1996 (Teleostei, Sternoptichydae) from south and southeastern Brazilian waters

Este estudo, baseado na análise da microestrutura dos otólitos de Maurolicus stehmanni, apresenta estimativas dos parâmetros de crescimento e longevidade para esta espécie que habita a plataforma externa e o talude da ZEE sul-sudeste do Brasil. Estes parâmetros são importantes para o conhecimento da estratégia de vida da espécie e para o manejo deste recurso, que constitui um importante elo entre os componentes iniciais e finais da teia alimentar no ecossistema de mar aberto, sendo um dos principais itens na dieta das lulas e grandes peixes pelágicos. Dentre os vários métodos aplicados, os valores dos parâmetros de crescimento mais coerentes com a estratégia da espécie e que melhor se ajustaram à equação de von Bertallanfy foram: Li= 55mm K= 0.0088/dia e to= 5.5 dias. A espécie vive cerca de 220 dias e as marcas diárias nos otólitos sagita são apropriadas para a determinação da idade.This paper on the otolith microstructure analysis of Maurolicus stehmanni presents estimates of the species growth parameters and longevity. The species inhabits the outer shelf and slope of the southern and southeastern Brazilian Exclusive Economic Zone (EEZ). Growth parameters are important for the knowledge of the species' life history and rational management. M. stehmanni constitutes an important link between the initial and final components of the alimentary chain of the open sea ecosystem, being one of the main food items for squids and large pelagic fish. Among the various applied methods those which presented the most coherent values for growth parameters and were best adapted to the von Bertallanfy's equation were: Li= 55mm K= 0.0088/day and to= 5.5 days Maurolicus stehmanni's longevity is of less than one year (around 220 days) and the sagita daily otolith rings are useful for the determination of its age