The aims of this study include (1) Examine the total mercury and organic mercury concentrations in the muscle and liver tissues of dolphinfish, Coryphaena hippurus that collected in Tungkang and Taitung, Taiwan, in order to understand their safety consumption by human beings due to their high trophic level in a marine ecosystem; (2) Investigate the species difference in comparison to other marine high trophic organisms, e.g. shark, tuna; (3) Look for the pattern of Hg bioaccumulation to see whether it matches the three models defined by Holsbeek et al. A total of 209 samples of Coryphaena hippurus were collected from Tungkang and Taitung. In the 34 samples from Tungkang, males and females were 11 and 23, respectively, whereas 197 samples from Taitung included 92 males and 83 females. Samples from Tungkang were investigated individually, but those from Taitung were pooled by size into 58 samples, 27 males and 24 females. The Hg levels in the samples were wet digested and determined by cold vapor atomic absorption spectrophotometer. The results showed that there was no gender and site difference in the relationship between fork length and body weight in both Tungkang and Taitung samples. The relationship was BW = 0.00005 FL2.7443. The mean and range of total and organic Hg concentrations in muscles and livers of dolphinfish were 0.138 (0.045~0.506) and 0.103 (0.009~0.388), and 0.103 (0.037~0.260) and 0.077 (0.003~0.249), respectively. These concentrations were lower than the WHO food safety level for human consumption and Hg concentrations of shark and tuna. The total Hg concentrations in the muscles were significantly higher than those in livers in both sites. However, only samples of Taitung revealed the organic Hg concentrations of muscles were higher than those of livers. Concerning the site difference, the muscle concentrations of organic Hg, and the liver concentrations of total and organic Hg in Taitung were higher than those of Tungkang. There was positive linear relationship between total and organic Hg as well as in muscle and liver. However, no significant relationship was found between the Hg concentrations and fork length/body weight. The Hg bioaccumulative model of dolphinfish was similiar with Holsbeek et al.¡¦s models. In muscle, the largest sizes of the fish contained the highest organic Hg levels. In companying with no variation of total and inorganic Hg, it looks like Type I model of Holsbeek et al.¡¦s results.

Submitted by (ana.araujo@ufrpe.br) on 2016-08-10T12:06:43Z No. of bitstreams: 1 Paulo Jose Duarte Neto.pdf: 927067 bytes, checksum: 6f9466ce92dc195b6b58522421427737 (MD5) / Made available in DSpace on 2016-08-10T12:06:43Z (GMT). No. of bitstreams: 1 Paulo Jose Duarte Neto.pdf: 927067 bytes, checksum: 6f9466ce92dc195b6b58522421427737 (MD5) Previous issue date: 2005-02-28 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The otolith shape of dolphinfish, C. Hippurus, was studied to verify the hypotheses of two stocks in the northeastern Brazilian coast. Eighty two sagittal otoliths were collected from specimens caught by the artisanal fleet in two regions of northestern Brazil (Maranhão – MA and Rio Grande do Norte – RN coasts), in December of 2003 and April to May of 2004, respectively. Several types of shape descriptors were taken (area, perimeter, rectangularity, circularity, eccentricity, fractal dimension and Fourier coeficients) to evaluate the similarity level between regions. Differences between left and rigth otoliths and by sex were not found in the sample. Cluster and principal components (PC) analyses, based in the Fourier coeficients of 30th harmonics, revealed a three morfotypes pattern, concerning general differences of otolith shape. This pattern is supposed to be influenced by genetic factors, according to ANOVA results among the six signicant PC, regardless clinal variation between samples. When the two geographical regions were compared, significants differences were found in the otolith structure using both MANOVA and ANOVA, for all shape descriptors. Canonical discriminant analysis suggested the separation of the two regions samples, with a sucess classification of 57,1% for MA and 69,6% for RN, despite the high variability among otoliths shapes. The fractal dimension was a powerful descriptor to discriminate the two samples in this work, since the significance in all cases and high DSC value. Differencesin sagittal otoliths shape, possibly are due to different growth rates, added evidences to confirm the two stocks hypotheses of C. hippurus along the Brazilian coast. / A forma do otólito sagita do dourado, C. hippurus, foi estudada para verificar a hipótese de dois estoques na costa nordeste do Brasil. Oitenta e dois otólitos foram coletados de espécimes desembarcados pela frota artesanal na costa do estado do Maranhão (MA), em dezembro 2003, e na costa do Rio Grande do Norte (RN), de abril a maio de 2004. A partir da imagem do otólito, foram obtidos vários descritores da forma (área, perímetro, retangularidade, circularidade, excentricidade, dimensão fractal e coeficientes de Fourier) para avaliar, sobre vários aspectos, qual o nível de similaridade entre os otólitos das duas amostras. Nenhuma diferença significativa, na amostra, foi observada entre os otólitos direitos e esquerdos e entre sexos. As análises de agrupamento e de componentes principais, baseadas nos coeficientes de Fourier das 30 primeiras harmônicas, estabeleceram um padrão de 3 morfotipos do otóltio de dourado, os quais estão correlacionados a diferenças gerais da forma. A ANOVA entre os CPs sugeriu que este padrão esteja relacionado a características genéticas, pois nenhuma evidência de seleção clinal foi encontrada. Na comparação das amostras do MA e do RN, foram encontradas diferenças significativas na estrutura do otólito entre as duas regiões estudadas, tanto nas análises de variância uni e multivariada, como também na análise discriminante canônica. O sucesso de classificação foi de 57,1% para a amostra do MA e 69,6% para a do RN. A dimensão fractal demonstrou ser um eficiente descritor, pois foi significativamente diferente em todas as análises e apresentou um dos maiores valores de DSC. Os resultados sobre diferenças das características da forma do otólito sagita, que aparentam estar relacionadas a taxas de crescimento, adicionou evidências indicativas para a confirmação da hipótese de 2 circuitos migratórios do C. hippurus ao longo da costa brasileira mesmo havendo uma grande variabilidade individual.

Submitted by (edna.saturno@ufrpe.br) on 2017-02-07T16:15:43Z No. of bitstreams: 1 Andrea Carla Lira dos Santos.pdf: 1934014 bytes, checksum: e310b95a7aeab6a66aacfa421b42a846 (MD5) / Made available in DSpace on 2017-02-07T16:15:43Z (GMT). No. of bitstreams: 1 Andrea Carla Lira dos Santos.pdf: 1934014 bytes, checksum: e310b95a7aeab6a66aacfa421b42a846 (MD5) Previous issue date: 2012-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The dolphinfish, Coryphaena hippurus, an oceanic pelagic species with circumtropical distribution, is an important fishery resource around the world. The Archipelago of St Peter and St Paul plays an important role in the migratory route of several species of high commercial value, including the dolphinfish. In this context, studies of reproductive biology may help conservation and management of these stocks by providing essential information, such as the size at first sexual maturity and spawning season. In this study, a total of 861 individuals were examined, 811 of which were sexed (279 female and 532 male). Of these, the stage of sexual maturity was identified in 565 specimens. The fork length (FL) of specimens ranged between 27 and 150 cm, with a sex ratio of 1 male to 1.9 females. The distribution of average monthly Gonadal Index of adults ranged between 0.58 and 3.73 for males and between 3.22 and 34.90 for females. Size at first sexual maturity (L50) was estimated at 68.8 cm FL, for males, and 67.7 cm FL, for females. The results suggest that the period of greatest reproductive activity occurs between April and June. / O dourado, Coryphaena hippurus, é uma espécie pelágica e oceânica com distribuição circumtropical, que representa um importante recurso pesqueiro em todo o mundo. O Arquipélago de São Pedro e São Paulo se encontra na rota migratória de várias espécies de elevado valor comercial, entre elas o dourado. Diante desse contexto os estudos de biologia reprodutiva representam uma ferramenta útil para o auxílio da conservação e gestão desses estoques através do aporte de informações, como, por exemplo, tamanho de primeira maturação sexual e época de desova. Nesse trabalho, 861 indivíduos de dourado foram examinados, dos quais 811 foram sexados (279 machos e 532 fêmeas), tendo sido identificados os estágios de maturação gonadal de 565. O comprimento zoológico dos exemplares variou entre 27 e 150 cm, com proporção sexual de 1 macho para 1,9 fêmeas. A distribuição da média mensal do Índice Gonadal dos indivíduos adultos variou entre 0,58 e 3,73 para os machos e entre 3,22 e 34,90 para as fêmeas. O comprimento de primeira maturação sexual (L50) foi estimado em 68,8 cm de Comprimento Zoológico (CZ), para os machos, e 67,7cm de CZ, para as fêmeas. Os resultados sugerem que o período de maior atividade reprodutiva ocorre entre abril e junho.

Mercury accumulation of upper trophic level marine fishes is a growing concern for human consumers. Diet is the primary source of mercury bioaccumulation in both fish and humans and yet remains unexamined in many intensely fished regions such as southern New England (SNE). The feeding ecology and mercury concentrations of recreationally caught albacore (Thunnus alalunga) and yellowfin (T. albacares) tunas, shortfin mako (Isurus oxyrinchus) and common thresher (Alopias vulpinus) sharks and dolphinfish (Coryphaena hippurus) were evaluated. Important prey were identified and also measured for total mercury content. Seventy percent of the predator fishes sampled in this study had mercury concentrations greater than the EPA recommended 0.3ppm, and included shortfin makos (2.65 ± 1.16ppm), threshers (0.87 ± 0.71ppm) and albacore (0.45 ± 0.14ppm). Mercury concentrations were lowest in dolphinfish (0.20 ± 0.17ppm) and yellowfin (0.32 ± 0.09ppm). Length was positively correlated with mercury content and bioaccumulation rates were linear for tunas and dolphinfish, while exponential for both shark species. Small schooling fishes (Pomatomus saltatrix, 0.110 ± 0.102ppm) were the primary prey of shortfin makos. Shortfin squid (Illex illecebrosus, 0.028 ± 0.005ppm) was a principal and consistent dietary component of both tunas and dolphinfish diets. The diets of SNE dolphinfish and yellowfin tuna were more invertebrate dominated than other regions previously examined. Though the method of sample collection for this study biases toward larger individuals, these are the sizes of fish targeted by anglers, generally for human consumption.