Spatiotemporal variations of the ichthyofaunal structure accompanying the seabob shrimp, Xiphopenaeus kroyeri (Crustacea: Penaeidae), fishery in important fishery areas of the Santa Catarina shore, Brazil

The present study analyzed qualitatively and quantitatively the temporal and spatial changes in the fish assemblages present in seabob shrimp distribution sites in two important fishing areas of the Santa Catarina coast. Monthly bottom trawls, conducted between March 2007 and February 2008 in Balneário Barra do Sul and Penha, yielded a total of 38,608 specimens belonging to 54 species, of which 35 occurred in both regions. The Sciaenidae was the most represented family in both number of species and abundance of individuals. The dominant species were Stellifer rastrifer (Jordan, 1889), S. brasiliensis (Schultz, 1945), Paralonchurus brasiliensis (Steindachner, 1875), Isopisthus parvipinnis (Cuvier, 1830), Trichiurus lepturus (Linnaeus, 1758), and Pellona harroweri (Fowler, 1917). The ichthyofaunal structure showed a spatiotemporal dependence with significant differences in March 2007 and January and February 2008 between Balneário Barra do Sul and Penha. The main differences were attributed to dominant species, which were responsible for significantly altering the abundance of the assemblages. The species richness was similar in both sites, whereas the diversity and equitability indices showed monthly fluctuation patterns that differed between Balneário Barra do Sul and Penha. The Shannon index differed in August, September and November 2007 and January and February 2008, with an H' ranging from 0.74 to 1.98 influenced by dominant species, whereas significant variations were observed for the Pielou index in November 2007 and February 2008. The Berger-Parker index demonstrated a clear dominance pattern where the monthly numeric contribution of a single species ranged from approximately 30 to 80%. Although the results showed differences between fishing grounds 25% of the time, we conclude that fish assemblies captured as accompanying fauna in artisanal seabob shrimp fisheries showed statistically similar characteristics for most of the year, although Balneário Barra do Sul and Penha are 35 km away from each other.

Spatiotemporal variations of the ichthyofaunal structure accompanying the seabob shrimp, Xiphopenaeus kroyeri (Crustacea: Penaeidae), fishery in important fishery areas of the Santa Catarina shore, Brazil

The present study analyzed qualitatively and quantitatively the temporal and spatial changes in the fish assemblages present in seabob shrimp distribution sites in two important fishing areas of the Santa Catarina coast. Monthly bottom trawls, conducted between March 2007 and February 2008 in Balneário Barra do Sul and Penha, yielded a total of 38,608 specimens belonging to 54 species, of which 35 occurred in both regions. The Sciaenidae was the most represented family in both number of species and abundance of individuals. The dominant species were Stellifer rastrifer (Jordan, 1889), S. brasiliensis (Schultz, 1945), Paralonchurus brasiliensis (Steindachner, 1875), Isopisthus parvipinnis (Cuvier, 1830), Trichiurus lepturus (Linnaeus, 1758), and Pellona harroweri (Fowler, 1917). The ichthyofaunal structure showed a spatiotemporal dependence with significant differences in March 2007 and January and February 2008 between Balneário Barra do Sul and Penha. The main differences were attributed to dominant species, which were responsible for significantly altering the abundance of the assemblages. The species richness was similar in both sites, whereas the diversity and equitability indices showed monthly fluctuation patterns that differed between Balneário Barra do Sul and Penha. The Shannon index differed in August, September and November 2007 and January and February 2008, with an H' ranging from 0.74 to 1.98 influenced by dominant species, whereas significant variations were observed for the Pielou index in November 2007 and February 2008. The Berger-Parker index demonstrated a clear dominance pattern where the monthly numeric contribution of a single species ranged from approximately 30 to 80%. Although the results showed differences between fishing grounds 25% of the time, we conclude that fish assemblies captured as accompanying fauna in artisanal seabob shrimp fisheries showed statistically similar characteristics for most of the year, although Balneário Barra do Sul and Penha are 35 km away from each other.

Spatiotemporal variations of the ichthyofaunal structure accompanying the seabob shrimp, Xiphopenaeus kroyeri (Crustacea: Penaeidae), fishery in important fishery areas of the Santa Catarina shore, Brazil

The present study analyzed qualitatively and quantitatively the temporal and spatial changes in the fish assemblages present in seabob shrimp distribution sites in two important fishing areas of the Santa Catarina coast. Monthly bottom trawls, conducted between March 2007 and February 2008 in Balneário Barra do Sul and Penha, yielded a total of 38,608 specimens belonging to 54 species, of which 35 occurred in both regions. The Sciaenidae was the most represented family in both number of species and abundance of individuals. The dominant species were Stellifer rastrifer (Jordan, 1889), S. brasiliensis (Schultz, 1945), Paralonchurus brasiliensis (Steindachner, 1875), Isopisthus parvipinnis (Cuvier, 1830), Trichiurus lepturus (Linnaeus, 1758), and Pellona harroweri (Fowler, 1917). The ichthyofaunal structure showed a spatiotemporal dependence with significant differences in March 2007 and January and February 2008 between Balneário Barra do Sul and Penha. The main differences were attributed to dominant species, which were responsible for significantly altering the abundance of the assemblages. The species richness was similar in both sites, whereas the diversity and equitability indices showed monthly fluctuation patterns that differed between Balneário Barra do Sul and Penha. The Shannon index differed in August, September and November 2007 and January and February 2008, with an H' ranging from 0.74 to 1.98 influenced by dominant species, whereas significant variations were observed for the Pielou index in November 2007 and February 2008. The Berger-Parker index demonstrated a clear dominance pattern where the monthly numeric contribution of a single species ranged from approximately 30 to 80%. Although the results showed differences between fishing grounds 25% of the time, we conclude that fish assemblies captured as accompanying fauna in artisanal seabob shrimp fisheries showed statistically similar characteristics for most of the year, although Balneário Barra do Sul and Penha are 35 km away from each other.

Idade e crescimento de Callinectes danae e C. ornatus (Crustacea, Decapoda) na Baía de Guanabara, Rio de Janeiro, Brasil

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.

Callinectes 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.

Idade e crescimento de Callinectes danae e C. ornatus (Crustacea, Decapoda) na Baía de Guanabara, Rio de Janeiro, Brasil

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.

Callinectes 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.

(Comparative studies on the growth of Oreochromis, (Osteichthyes, Cichlidae) in monosex culture. II Length and weigth growths and Biomass yield) / ESTUDO COMPARATIVO DO CRESCIMENTO DE Oreochromis (OSTEICHTHYES, CICHLIDAE) EM CULTIVO MONOSSEXO. II CRESCIMENTO EM COMPRIMENTO E PESO, RENDIMENTO E BIOMASSA

The purpose of this study is to verify the economical viability of the monosex cultivations, through the comparative analysis of the length and weight growths, and biomass yield in cultivation of male hybrids ( O. hornorum x O. niloticus) and of males and females of O. niloticus. Fries were stocked in ponds of 100 m2 where the stocking rate was two individuals/m². Biometric data were obtained through monthly samples of 25% of the population of each pond. It was observed that the gain in length and weight were similar both in hybrid males and O. niloticus males, and superior of the females. The mean length and weight "increment" was, respectively, 0.074 cm/day and 2.14 g/day for males cultivations, and 0.050 cm/day and 1.05 g/day for females. Economical analyses of the cultures considering only the ration expenses, showed for the male cultivations a profit about twice that reached by the females. The final production was approximately 140 kg/100 m² year for males, both hybrid and O. niloticus, and 70 kg/100 m2 year for females.

Este estudo tem por objetivo verificar a viabilidade econômica de cultivos monossexo, através da análise comparativa do crescimento em comprimento e em peso e do rendimento em biomassa do cultivo de machos híbridos ( O.hornorum x O. niloticus) e de machos e fêmeas de O. niloticus. Os peixes foram estocados em tanques de alvenaria de 100 m², na densidade de 2 exemplares/m². Mensalmente foram coletadas amostras de 25% dos exemplares de cada tanque para obtenção de comprimento total e peso total. As taxas de crescimento em comprimento e em peso foram semelhantes entre machos híbridos e de O. niloticus, e superiores às das fêmeas, apresentando valores de incremento médio em comprimento e em peso de, respectivamente, 0,074 cm/dia e 2,14 g/dia para machos e de 0,050 cm/dia e 1,05 g/dia para fêmeas. A análise econômica, considerando-se apenas os gastos com ração, mostrou que os cultivos com machos, tanto híbridos como de O. niloticus, apresentaram lucro de aproximadamente o dobro do alcançado com as fêmeas, com produção final ao redor de 140,00 kg/100 m².ano para machos e de 70,00 kg/100 m².ano para fêmeas .

(Comparative studies on the growth of Oreochromis, (Osteichthyes, Cichlidae) in monosex culture. II Length and weigth growths and Biomass yield) / ESTUDO COMPARATIVO DO CRESCIMENTO DE Oreochromis (OSTEICHTHYES, CICHLIDAE) EM CULTIVO MONOSSEXO. II CRESCIMENTO EM COMPRIMENTO E PESO, RENDIMENTO E BIOMASSA

The purpose of this study is to verify the economical viability of the monosex cultivations, through the comparative analysis of the length and weight growths, and biomass yield in cultivation of male hybrids ( O. hornorum x O. niloticus) and of males and females of O. niloticus. Fries were stocked in ponds of 100 m2 where the stocking rate was two individuals/m². Biometric data were obtained through monthly samples of 25% of the population of each pond. It was observed that the gain in length and weight were similar both in hybrid males and O. niloticus males, and superior of the females. The mean length and weight "increment" was, respectively, 0.074 cm/day and 2.14 g/day for males cultivations, and 0.050 cm/day and 1.05 g/day for females. Economical analyses of the cultures considering only the ration expenses, showed for the male cultivations a profit about twice that reached by the females. The final production was approximately 140 kg/100 m² year for males, both hybrid and O. niloticus, and 70 kg/100 m2 year for females.

Este estudo tem por objetivo verificar a viabilidade econômica de cultivos monossexo, através da análise comparativa do crescimento em comprimento e em peso e do rendimento em biomassa do cultivo de machos híbridos ( O.hornorum x O. niloticus) e de machos e fêmeas de O. niloticus. Os peixes foram estocados em tanques de alvenaria de 100 m², na densidade de 2 exemplares/m². Mensalmente foram coletadas amostras de 25% dos exemplares de cada tanque para obtenção de comprimento total e peso total. As taxas de crescimento em comprimento e em peso foram semelhantes entre machos híbridos e de O. niloticus, e superiores às das fêmeas, apresentando valores de incremento médio em comprimento e em peso de, respectivamente, 0,074 cm/dia e 2,14 g/dia para machos e de 0,050 cm/dia e 1,05 g/dia para fêmeas. A análise econômica, considerando-se apenas os gastos com ração, mostrou que os cultivos com machos, tanto híbridos como de O. niloticus, apresentaram lucro de aproximadamente o dobro do alcançado com as fêmeas, com produção final ao redor de 140,00 kg/100 m².ano para machos e de 70,00 kg/100 m².ano para fêmeas .