Efeito da pesca de arrasto do camarão-rosa sobre a dinâmica populacional de Callinectes danae e Callinectes ornatus (Crustacea, Portunidae), na Baía de Guanabara, Rio de Janeiro, Brasil.

The present work analyzed the population dynamics of Callinectes danae Smith, 1869 and Callinectes ornatus Ordway, 1863 (Crustacea, Portunidae) captured as by-catch from pink-shrimp trawlings at Guanabara Bay. Three aspects were approached: reproduction, growth and mortality. The reproductive analysis pointed out four stages of gonadal maturation for both species, corroborated by histological procedures and classified as: stage I - immature, stage II - developing, stage III - ripe and stage IV - spent. The presence of oocytes I and oocytes II in the stages ripe and spent confirmed the multiple spawning hypotheses for the species. The size at first gonadal maturity was 85.2 mm and 67.2 mm respectively for C. danae and C. ornatus. The continuous reproduction pattern was observed, however with seasonal and alternated reproductive picks in the bay. While C. danae presented reproductive picks in the autumn and in the winter, C. ornatus presented an apparent reproductive pick in the summer and probably another one in the spring. The sexual proportions diverged in C. danae significantly in females favor (3.0:1). However, to C. ornatus the proportions diverged with prevalence of males (1.2:1). This pattern indicated that possibly the females of C. danae return to the estuary after the spawning, while the ovigerous females of C. ornatus migrate to adjacent coastal areas around the bay. The growth analysis was based on indirect methods of size-frequency distributions. The growth parameters were estimated according von Bertalanffy s (1938) growth function and longevity according D Incao & Fonseca (1999). The L∞ value corresponded to the largest individual captured for each species and for each sex. For C. danae the growth x parameters were the following ones: females - L∞ = 113 mm, k = 0.005088387 and longevity = 2.48 years; males - L∞ = 120 mm, k = 0.005550913 and longevity = 2.27 years. For C. ornatus the growth parameters were: males - L∞ = 94 mm, k = 0.005372092 and longevity = 2.34 years; females - L∞ = 110 mm, k = 0.00594237 and longevity = 2.25 years. The instantaneous rate of total losses (Z ) from Ricker's (1975) catch curve associated to the natural mortality from Taylor's (1959) method showed high values of (F) mainly on the females of both species. However, for the females of C. ornatus the migration actuated in an intense way increasing the instantaneous rate of total losses. The stocks explotation rates were also high. Except for the males of C. danae, all the others were above the acceptable exploration. Besides that, 50.7% and 87.2% of females respectively from C. danae and C. ornatus were captured below the mean size at gonadal maturation. The diagnostic above suggests more effective management actions on these natural resources, not only by the responsible governmental organs, but also, by all the actors involved in the process.O presente trabalho analisou a dinâmica populacional de Callinectes danae Smith, 1869 e Callinectes ornatus Ordway, 1863 (Crustacea, Portunidae) capturados como fauna-acompanhante da pesca de arrasto do camarão-rosa na Baía de Guanabara. Três enfoques foram abordados: a reprodução, o crescimento e a mortalidade. A análise reprodutiva evidenciou quatro estágios de maturação gonadal para ambas as espécies, corroborados pela análise histológica e classificados como: estágio I - imaturo, estágio II - em maturação, estágio III - maduro e estágio IV - desovado. A presença de oócitos I e de oócitos II nos estágios maduro e desovado confirmou a hipótese de desova parcelada para as espécies. O tamanho de primeira maturação gonadal foi de 85,2 mm e 67,2 mm respectivamente para C. danae e C. ornatus. Foi observado um padrão contínuo de reprodução, entretanto com picos reprodutivos sazonais alternados na Baía de Guanabara. Enquanto C. danae predominantemente apresentou picos reprodutivos no outono e no inverno, C. ornatus apresentou um pico reprodutivo claro no verão e provavelmente outro na primavera. As proporções sexuais foram desviadas em C. danae e C. ornatus. Em C. danae foram significativamente a favor das fêmeas (3,0:1) e em C. ornatus significativamente a favor dos machos (1,2:1). Esse padrão indicou que possivelmente as fêmeas de C. danae retornam para o estuário após a desova, enquanto que as fêmeas ovadas de C. ornatus migrariam para locais adjacentes à baía. A análise do crescimento foi baseada no método indireto de distribuição de freqüências por classes de tamanho. Os parâmetros das curvas de crescimento foram estimados segundo o modelo de Bertalanffy (1938) e a longevidade máxima segundo D Incao & Fonseca (1999). O valor de L∞ foi viii fixado correspondendo ao maior indivíduo capturado para cada espécie e para cada sexo. Para C. danae os parâmetros populacionais foram os seguintes: fêmeas - L∞ = 113 mm, k = 0,005088387 e longevidade máxima = 2,48 anos; machos - L∞ = 120 mm, k = 0,005550913 e longevidade máxima = 2,27 anos. Já, para C. ornatus os parâmetros de ajuste das curvas de crescimento foram: machos - L∞ = 94 mm, k = 0,005372092 e longevidade máxima = 2,34 anos; fêmeas - L∞ = 110 mm, k = 0,00594237 e longevidade máxima = 2,25 anos. Os coeficientes de perdas totais (Z ) que foram estimados pela curva de captura de Ricker (1975) associados ao método de Taylor (1959) de mortalidade natural evidenciaram valores elevados de (F), principalmente sobre as fêmeas de ambas as espécies. No entanto, para as fêmeas de C. ornatus o fator migração atuou de forma intensa aumentando consideravelmente os valores do coeficiente de perdas totais. As taxas de explotação dos estoques também foram elevadas. Com exceção dos machos de C. danae, todas as demais estavam acima dos níveis aceitáveis de exploração ótima. Não obstante, 50,7% e 87,2% das fêmeas respectivamente de C. danae e de C. ornatus foram capturadas abaixo do tamanho médio de primeira maturação. Esse diagnóstico sugere ações de manejo mais efetivas sobre o recurso não apenas por parte dos órgãos responsáveis, mas também por todos os atores envolvidos no processo

O primeiro estádio juvenil de Aegla platensis Schimitt, 1942 (crustacea, decapoda, aeglidae)

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O primeiro estádio juvenil de Aegla platensis (crustacea, decapoda, anomura, aeglidae)

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The pink-shrimp trawling bycatch in the northen coast of São Paulo, Brazil, with emphasis on crustaceans

The pink shrimp trawling fishery (Farfantepenaeus brasiliensis and F. paulensis) in the Ubatuba region acts intensely on the populations of some benthic species. The impact of fisheries on herbenthic community is unknown. Samples of herbenthic community were obtained monthly from July/1995 to August/1996. The last haul from a commercial trawler operating on the northern coast of São Paulo State and the southern coast of Rio de Janeiro State was preserved (from being discarded) and identified at the species level. 29 species of crustaceans were found, but only Hepatus pudibundus, Callinectes ornatus, Dardanus insignis, Libinia spinosa, Sicyonia tipica, Portunus spinimanus, Portunus spinicarpus, and Persephona mediterranea had high occurrence and frequency values. Such species were the main crustacean itens in the bycatch of the pink shrimp fisheries in Ubatuba for the period of study. The total bycatch was about 1502 tons, composed by 119 tons of incidental catch and 1383 tons of discarded catch. Considering the study area, these values were quite high demonstrating that some species may have beenove rfished

The pink-shrimp trawling bycatch in the northern coast of São Paulo, Brazil, with emphasis on crustaceans

The pink shrimp trawling fishery (Farfantepenaeus brasiliensis and F. paulensis) in the Ubatuba region acts intensely on the populations of some benthic species. The impact of fisheries on herbenthic community is unknown. Samples of herbenthic community were obtained monthly from July/1995 to August/1996. The last haul from a commercial trawler operating on the northern coast of São Paulo State and the southern coast of Rio de Janeiro State was preserved (from being discarded) and identified at the species level. 29 species of crustaceans were found, but only Hepatus pudibundus, Callinectes ornatus, Dardanus insignis, Libinia spinosa, Sicyonia tipica, Portunus spinimanus, Portunus spinicarpus, and Persephona mediterranea had high occurrence and frequency values. Such species were the main crustacean itens in the bycatch of the pink shrimp fisheries in Ubatuba for the period of study. The total bycatch was about 1502 tons, composed by 119 tons of incidental catch and 1383 tons of discarded catch. Considering the study area, these values were quite high demonstrating that some species may have been overfishe

Age and growth of Callinectes danae and C. ornatus (Crustacea, Decapoda) in Guanabara Bay, Rio de Janeiro, Brazil.

Submitted by Thainã Moraes ([email protected]) on 2012-11-13T20:22:39Z No. of bitstreams: 1 Idade e crescimento de Callinectes danae e C. ornatus (Crustacea, Decapoda) na Baía de Guanabara, Rio de Janeiro, Brasil..pdf: 412973 bytes, checksum: b64f84eb61c6861fd84a393a90e27597 (MD5)Approved for entry into archive by Michele Fernanda([email protected]) on 2012-11-21T20:58:45Z (GMT) No. of bitstreams: 1 Idade e crescimento de Callinectes danae e C. ornatus (Crustacea, Decapoda) na Baía de Guanabara, Rio de Janeiro, Brasil..pdf: 412973 bytes, checksum: b64f84eb61c6861fd84a393a90e27597 (MD5)Made available in DSpace on 2012-11-21T20:58:45Z (GMT). No. of bitstreams: 1 Idade e crescimento de Callinectes danae e C. ornatus (Crustacea, Decapoda) na Baía de Guanabara, Rio de Janeiro, Brasil..pdf: 412973 bytes, checksum: b64f84eb61c6861fd84a393a90e27597 (MD5) Previous issue date: 2008Callinectes danae Smith, 1869 e C. ornatus Ordway, 1863 constituem uma parcela importante da produção pesqueira na Baía de Guanabara. Ambas espécies compõem uma fração significativa da fauna-acompanhante sendo exaustivamente descartadas pelas pescarias de arrasto de camarões na costa brasileira. As curvas de crescimento de C. danae e C. ornatus foram calculadas por meio da análise de progressão modal. Para estimar os parâmetros biológicos, foi aplicado o modelo de crescimento de Bertalanffy e para estimar a longevidade foi usada a sua fórmula inversa. As curvas de crescimento foram: ♂ LC = 120 (1 - e -0,005t ), ♀ LC = 113 (1 - e -0,005t); ♂ LC = 94 (1 - e -0,005t ) e ♀ LC = 110 (1 - e -0,005t ), respectivamente para C. danae e C. ornatus. A longevidade alcançada para as duas espécies foi em torno de 2,5 anos, além de validar as curvas de crescimento. O estudo do crescimento em crustáceos é de extrema importância, pois além de fornecer a informação biológica básica para o grupo, os parâmetros estimados subsidiam o ordenamento e manejo pesqueiro das espécies exploradas.Callinectes danae Smith, 1869 and C. ornatus Ordway, 1863 constitute an important portion from the fishing products at Guanabara Bay. Both species compose a significant by-catch fraction being a lot discarded during shrimp trawlings along Brazilian coast. Growth curves were estimated by modal progression analysis. For the biological parameters it was applied the Bertalanffy growth function and for the age it was used its inverse formula. Growth curves of C. danae and C. ornatus were respectively: LC = 120 (1 – e -0,005t), LC = 113 (1 – e -0,005t); LC = 94 (1 – e -0,005t) and LC = 110 (1 – e -0,005t). The age for both species reached around 2.5 years, besides to confirm growth curves. Growth study in crustaceans is very important, because besides supplying biological information it subsidizes fishery management for exploted species