Larimus breviceps, Isopisthus parvipinnis, and Paralonchurus brasiliensis are the 3 most abundant species of Sciaenidae in the Marine Extractive Reserve of Corumbau in Bahia (northeastern Brazil). Ontogenetic and seasonal changes in the diet of these species were analyzed. These changes may reflect adaptations and coexistence mechanisms used by those species. Sampling took place between December 2007 and September 2008 with otter trawlers. Fishes and shrimps were the main resources consumed by these 3 species. For L. breviceps and P. brasiliensis, Sergestidae was the dominant food item (together with polychaetes for the latter) and fishes were the most important item for I. parvipinnis. Low values of niche breadth were observed for all species. The Morisita Similarity Index indicated a general pattern of low overlap between the diets of the three species analyzed in most of the seasons, with the exception of L. breviceps and I. parvipinnis, which showed values higher than 80% in all seasons, with the exception of summer. Although these species showed differences in the position and orientation of their mouth, they essentially use the same resources. The carnivorous feeding habit prevailed among the studied Sciaenidae, with predominance of the carcinophagous habit.

Larimus breviceps, Isopisthus parvipinnis y Paralonchurus brasiliensis son las 3 especies de Sciaenidae más abundantes en la Reserva Extractiva Marina de Corumbau, en Bahia, nordeste de Brasil. Se analizaron los cambios ontogenéticos y estacionales en las dietas de estas especies. Estos cambios pueden reflejar las adaptaciones y mecanismos de coexistencia utilizados por estas especies. El muestreo se llevó a cabo entre diciembre 2007 y septiembre 2008 con arrastreros. Los peces y las gambas fueron los principales recursos consumidos por estas 3 especies. Para L. breviceps y P. brasiliensis, Sergestidae fue el alimento dominante (junto con poliquetos para el segundo), mientras que los peces fueron el elemento más importante para I. parvipinnis. Se observaron valores bajos de amplitud de nicho para todas las especies. El Índice de Similitud de Morisita indicó baja superposición entre las dietas de las 3 especies en la mayoría de las estaciones del año, a excepción de L. breviceps y I. parvipinnis, que mostraron valores superiores al 80% en todas las estaciones, excepto en verano. Aunque estas especies mostraron diferencias en la posición y orientación de su boca, esencialmente utilizan los mismos recursos. El hábito de alimentación carnívoro, principalmente carcinófago, prevaleció entre los Sciaenidae estudiados.

A pesca de arrasto é o método mais comum de captura de camarão. Esta técnica causa impactos negativos na fauna demersal devido ao grande número de animais que são capturados acidentalmente e que geralmente são devolvidos mortos ao mar. As conseqüências desta metodologia de pesca e os aspectos biológicos das espécies envolvidas são pouco estudados, especialmente no Nordeste do Brasil. Este estudo tem como objetivo mostrar aspectos biológicos de Isopisthus parvipinnis (tortinha) capturada como fauna acompanhante da pesca do camarão sete barbas (Xiphopenaeus kroyeri) na região de Ilhéus, no estado da Bahia, Brasil. Um total de 1290 indivíduos foram capturados em coletas mensais, em três pontos de coleta distintos, de março de 2003 a fevereiro de 2005. O índice de dispersão de Morisita padronizado sugere que a espécie, na área analisada, apresenta uma distribuição agregada. O número de indivíduos variou significativamente entre as estações do ano (p < 0,0001), sendo maior durante o inverno. O comprimento estimado de primeira maturação (L50) foi de 159 mm, sendo que 95% dos indivíduos capturados estavam abaixo deste valor. A razão sexual encontrada foi de 1,5 machos para cada fêmea. Quanto à dieta, foram identificadas 10 categorias alimentares, sendo que Decapoda Dendobranchiata foi a mais importante em freqüência numérica e de ocorrência. Este fato sugere que Isopisthus parvipinnis é uma espécie carnívora, com tendência a carcinofagia, ao menos nos indivíduos jovens.

Trawling is the most common method of shrimp harvesting. This technique causes a negative impact on the fauna due to the high bycatch rates and to the animals that are accidentally caught and generally returned to the sea dead. The consequences of this technique and the biological aspects of the involved species are poorly studied, specially in the Brazilian northeast. The objective of this study was to show some aspects of the population biology of Isopisthus parvipinnis (Bigtooth corvina) captured as bycatch during sea-bob (Xiphopenaeus kroyeri) shrimp fishing in the region of Ilhéus, in the state of Bahia in Brazil. A total of 1290 individuals were caught in a monthly sampling at three different stations, from March, 2003 to February, 2005. The standardized Morisita index of dispersion suggests that this species has a clumped distribution in the studied area. The number of individuals showed a significant variation (p < 0.0001) between the seasons, being higher during the winter. The estimated first maturation length (L50) was about 159 mm, and 95% of the captured individuals were below this value. The sexual ratio found was 1.5 males for each female. Concerning to diet, 10 feeding categories were identified, and Decapoda Dendobranchiata was the most important in numeric frequency and occurrence. This fact suggests that Isopisthus parvipinnis is a carnivorous species, with a tendency toward crustacean-eating at least in the younger individuals.

A distribuição e a abundância de peixes demersais na plataforma continental de Ubatuba, até 50 m de profundidade, foram examinadas durante dois anos. Foram coletadas 111 espécies. As flutuações sazonais de abund-ncia estiveram relacionadas com a din-mica das massas d'água. Três comunidades ocupam a área:. Sciaenidae Tropical, Sciaenidae Subtropical e Gerreidae-Haemulidae, sendo a primeira a mais importante, dominada por Ctenosciaena gracilicirrhus, Paralonchurus brasiliensis e Cynoscion jamaicensis.

Fluctuations in the distribution and abundance of demersal fishes collected by otter trawl on the continental shelf of Ubatuba were examined over a two-year sampling period, in an area up to 50 m depth. A total of 111 species were collected. Seasonal and annual fluctuations in species abundance were related to differences in the distribution of Coastal Water and South Atlantic Central Water masses. The demersal fish fauna in the area was divided into three ecologically distinct communities: Tropical Sciaenid, Subtropical Sciaenid, and Gerreid-Haemulid. The most important one is the Tropical Sciaenid Community, characterized by Ctenosciaena gracilicirrhus, Paralonchurus brasiliensis, and Cynoscion jamaicensis.