Feeding Biology Of A Guild Of Benthivorous Fishes In A Sandy Shore On South-eastern Brazilian Coast.

The feeding biology of eight species of benthivorous fishes was studied in a sandy shore at Anchieta Island, south-eastern Brazilian coast. The fishes fed mainly on Amphipoda and Mysidacea crustaceans. The diet of the most abundant species, the drum Umbrina coroides, was analyzed in three standard length classes (20-55, 56-90 and 91-135 mm). This sciaenid showed an ontogenetic diet shift from Mysidacea to Amphipoda. The feeding behaviour of the sciaenid U. coroides and the gerreid Eucinostomus gula was recorded while snorkeling. During their foraging both species uncovered small organisms buried in the sand. Notwithstanding general similarities in diet, U. coroides and E. gula presented differences in feeding behaviour and morphology. Two carangid species of the genus Trachinotus differed in diet composition and consumed a larger array of food items than the remaining fish species. Differences in diet and feeding activity between the remaining benthivorous species were noted. These differences possibly reduce overlap in resource use and favour the coexistence of guilds of benthivorous fishes on sandy shores.60351151

Hábitos alimentares de uma guilda de peixes bentívoros em uma praia arenosa na costa Sudeste do Brasil

The feeding biology of eight species of benthivorous fishes was studied in a sandy shore at Anchieta Island, south-eastern Brazilian coast. The fishes fed mainly on Amphipoda and Mysidacea crustaceans. The diet of the most abundant species, the drum Umbrina coroides, was analyzed in three standard length classes (20-55, 56-90 and 91-135 mm). This sciaenid showed an ontogenetic diet shift from Mysidacea to Amphipoda. The feeding behaviour of the sciaenid U. coroides and the gerreid Eucinostomus gula was recorded while snorkeling. During their foraging both species uncovered small organisms buried in the sand. Notwithstanding general similarities in diet, U. coroides and E. gula presented differences in feeding behaviour and morphology. Two carangid species of the genus Trachinotus differed in diet composition and consumed a larger array of food items than the remaining fish species. Differences in diet and feeding activity between the remaining benthivorous species were noted. These differences possibly reduce overlap in resource use and favour the coexistence of guilds of benthivorous fishes on sandy shores.Os hábitos alimentares de oito espécies de peixes bentívoros foram estudados em uma praia arenosa na Ilha Anchieta, costa Sudeste do Brasil. Os peixes consumiram principalmente crustáceos das ordens Amphipoda e Mysidacea. A dieta da espécie mais abundante, o sciaenídeo Umbrina coroides, foi analisada em três classes de comprimento-padrão (20-55, 56-90 e 91-135 mm). Este sciaenídeo apresentou uma variação ontogenética na dieta, a qual variou de Mysidacea para Amphipoda. O comportamento alimentar do sciaenídeo U. coroides e do gerrídeo Eucinostomus gula foi estudado com uso de mergulho livre. Ao forragear, ambas as espécies desenterraram pequenos organismos enterrados na areia. Apesar das semelhanças gerais na dieta, U. coroides e E. gula apresentaram diferenças quanto ao comportamento alimentar e morfologia. Duas espécies de carangídeos do gênero Trachinotus diferiram quanto à composição da dieta e consumiram variedade maior de itens alimentares que as outras espécies de peixes estudadas. Diferenças de dieta e atividade alimentar entre as outras espécies bentívoras foram registradas. Estas diferenças possivelmente reduzem a sobreposição na utilização dos recursos alimentares, favorecendo a coexistência de guildas de peixes bentívoros em praias arenosas.511518Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Ecologia alimentar da corvina, Pachyurus bonariensis (Perciformes, Sciaenidae) em duas baías do Pantanal, Mato Grosso, Brasil Feeding ecology of Pachyurus bonariensis (Perciformes, Sciaenidae) in two bays of the Pantanal, Mato Grosso State, Brazil

Foi investigada a dieta de Pachyurus bonariensis Steindachner, 1879 associando-a à variações espaciais, temporais e ontogenéticas. Os peixes foram coletados mensalmente de março/2000 a fevereiro/2001 e de agosto/2002 a fevereiro/2003 em duas baías do Pantanal, Chacororé e Sinhá Mariana. Conteúdos estomacais de 359 exemplares foram analisados através dos métodos de freqüência de ocorrência e volumétrico. A dieta foi composta essencialmente por larvas bentônicas de Chironomidae e Ephemeroptera, independente do local e período (seca e cheia) analisados. Entretanto, nota-se marcante diferença na composição alimentar de acordo com o tamanho do peixe. Os menores exemplares (comprimento padrão = 1,6 a 7,2 cm) consumiram preferencialmente Chironomidae e os maiores (comprimento padrão = 13,0 a 18,6 cm) Ephemeroptera. Conclui-se que P. bonariensis tem hábito alimentar bentívoro e especializado, devido principalmente ao restrito espectro alimentar aliado à posição e forma da boca adaptada a explorar o substrato.<br>Spatial, temporal and ontogenetic variations in the diet of Pachyurus bonariensis Steindachner, 1879 were analyzed. Fishes were taken monthly from March 2000 to February 2001 and from August 2002 to February 2003 in the Chacororé and Sinhá Mariana bays. Diet was determined analyzing 359 stomach contents. To express diet results, were used occurrence and volumetric methods. The individuals consumed expressive amount of Chironomidae and Ephemeroptera larvae, in both bays and periods (dry and wet). Ontogenetic analysis showed that small individuals (Standard length = 1.6 to 7.2 cm) ate mainly Chironomidae, whereas larger ones (Standard length = 13.0 to 18.6 cm) consumed mainly Ephemeroptera. Then it is possible to infer that P. bonariensis is benthic-feeding fish with specialized diet. This characteristic was attributed because its narrow niche breadth allied with position and form of its mouth adapted to feed on the bottom