Rhinobatos percellens é uma das três espécies de Rhinobatidae encontrada na costa brasileira e uma das espécies de elasmobrânquio mais abundante na plataforma continental dos estados do Paraná e Santa Catarina. Indivíduos capturados pela pesca artesanal entre Julho/2001 e Março/2003 nas comunidades pesqueiras localizadas entre o Paraná e Santa Catarina tiveram seus conteúdos estomacais analisados. O Índice de Importância Alimentar (IAi) mostrou que as principais presas consumidas foram Decapoda (69%) e Teleostei (22%). Polychaeta, principal presa ingerida por várias espécies de peixes bentônicos foi pouco expressiva na alimentação de R. percellens. Essa diferença pode estar relacionada com a disponibilidade de presas no ambiente ou com o tamanho das raias analisadas (ontogenia). De acordo com análises sazonais, observou-se que os camarões Dendrobranchiata e Pleocyemata foram as principais presas consumidas durante a primavera e outono, Teleostei durante o inverno e Brachyura durante o verão.

Rhinobatos percellens is one of three species of Rhinobatidae found on Brazilian shores and is one of the most abundant species on the shallow continental shelf of Paraná and Santa Catarina States. Specimens caught by artisanal fishery between July/2001 and March/2003 by fishing communities located on the frontier between two southern Brazilian States (Paraná and Santa Catarina) had their stomach contents analyzed. According to the Alimentary Index (IAi), Decapoda (69%) and Teleostei (22%) were the main items consumed. Polychaeta, a common prey consumed by several benthonic fishes, was poorly represented in the feeding of R. percellens. This fact may be related to the availability of prey in the environment, or to the size of the guitarfish analyzed (ontogeny). Seasonal variance of main preys (with higher IAi) was observed: Dendrobranchiata and Pleocyemata displayed higher percentages in spring and autumn, Teleostei in the winter and Brachyura during the summer.

O presente estudo foi conduzido em duas comunidades da pesca artesanal nas cidades Guaratuba (Paraná) e Itapoá (Santa Catarina), no sul da costa brasileira. Os conteúdos estomacais de indivíduos Sphyrna zygaena foram identificados, sendo os itens alimentares agrupados em três categorias. As categorias mais importantes foram teleósteos (78,6%) e cefalópodes (60,7%), representados pela sardinha Harengula clupeola e a lula Loligo sp., ambos considerados como principais itens alimentares de S. zygaena na região estudada.

The present study was conducted in two artisan fishing communities in the cities Guaratuba (Paraná) and Itapoá (Santa Catarina), in the South Brazilian coast. Stomach contents of Sphyrna zygaena specimens were identified, showing three categories of food items. The most important feeding categories were teleosts (78.6%) and cephalopods (60.7%), represented by the sardine Harengula clupeola the squid Loligo sp., both considered the main food items of S. zygaena in the studied region.

A survey performed in the Guaratuba Bay (25º52'S; 48º39'W) and the adjacent marine area has provided additional data about the habits of the croaker in the southern coast of Brazil. A dynamic pattern of movements along the marine and estuarine waters was observed, but it does not indicate spawning activity in the study area. During autumn/winter, pre-adults and adults use the marine waters. In spring/summer, following gonadal maturation,the individuals leave this area and probably move to deeper waters, where they spawn. Until the end of summer, the estuary is then occupied by juveniles coming from the marine spawning area. In autumn/winter, these juveniles and the new pre-adults move to the marine zone adjacent to the bay and begin gonadal maturation. It is suggested that the Guaratuba Bay and the adjacent marine area constitute an important site for growth and recruitment of the early lifestages of M. furnieri and initial stages of reproductive activity.

A survey performed in the Guaratuba Bay supports the hypothesis that the G. melanopterus individuals migrate to reproduce at the sea during summer. In autumn and winter, the adults return to the Bay, a pattern not yet described in the literature for this species. G. melanopterus explores the most internal areas of the Bay when the continental influence is lower. Differences in feeding habits were registered between individuals occupying the investigated area and those from a nearby mangrove previously studied.