A trophic analysis of target species of macrobenthos in a subtropical coast community: a taxa relationship essay

Studies on the feeding habits of aquatic organisms are a requirement for the management and sustainable use of marine ecosystems. The aim of the present research was to analyze the habits and trophic similarities of decapods, starfish and fish in order to propose trophic relationships between taxa, using Hennigian methods of phylogenetic systematics. This new grouping hypothesis, based on shared and exclusive food items and food types, corresponds to the broad taxonomic groups used in the analysis. Our results indicate that algae, Mollusca, Polychaeta, Crustacea, Echinodermata and Actinopterygii are the most exploited common resources among the species studied. Starfish were differentiated from other organisms for being stenophagic, and were grouped for feeding on bivalve mollusks. A larger group of fish and crustaceans shares algae and mainly crustaceans as food items. A third group united all eight species of Actinopterygii. This largest subgroup of fish is typically carnivorous, feeding on Anthozoa and a great quantity of Crustacea. Synodus foetens has a special position among fishes, due to its unique feeding on nematodes. A Euclidean distance dendrogram obtained in a previous publication grouped S. foetens with starfish. That result was based on a few non-exclusive shared similarities in feeding modes, as well as on shared absences of items, which are not an adequate grouping factor. Starfish are stenophagic, eating bivalves almost exclusively. Synodus foetens and Isopisthus parvipinnis have restricted food items, and are thus intermediary in relation to starfish, decapods, and other fish, which are euryphagous. The trophic cladogram displays details of food items, whether or not shared by all species. The resulting trophic analysis is consistent with known historical relationships

Aspectos biológicos e pesqueiros de Paralonchurus brasiliensis Steindachner, (Pisces, Sciaenidae), na Armação do Itapocoroy, Penha, Santa Catarina, Brasil Biological and fishing aspects of Paralonchurus brasiliensis Steindachner, (Pisces, Sciaenidae), in the Armação do Itapocoroy, Penha, Santa Catarina, Brazil

Apesar da abundância de Paralonchurus brasiliensis (Steindachner, 1875) na ictiofauna acompanhante do camarão sete-barbas, apresenta baixo valor comercial sendo freqüentemente descartada. Esse trabalho tem como objetivo apresentar informações básicas sobre a biologia e pesca de P. brasiliensis na Armação do Itapocoroy, Penha, Santa Catarina. As coletas foram realizadas mensalmente durante o período de agosto 1996 a julho 2003, em três áreas tradicionais de atuação da pesca artesanal. A espécie apresentou crescimento alométrico positivo, com uma razão sexual de 1:2,1 entre machos e fêmeas, e tamanho de primeira maturação em 14,8 cm e 15,0 cm. P. brasiliensis apresentou amplo espectro trófico composto por 27 itens, sendo que, a partir da primavera ocorreu um incremento gradual na ingestão de alimento até o verão, seguido de queda abrupta no outono e de pequena recuperação no inverno. Apesar das flutuações sazonais ao longo dos sete anos, essa espécie ocupou a segunda posição em número e biomassa entre as integrantes da ictiofauna acompanhante.<br>Due to abundance of P. brasiliensis (Steindachner, 1875) in ictiofauna of the sea-bob-shrimp's bycatch, it presents low commercial value and frequently being discarded. This work aims to present basic information on biology and fisheries of P. brasiliensis in the Armação do Itapocoroy, Penha, Santa Catarina. The collections were carried out monthly during the period of August 1996 to July 2003, in three traditional areas of performance of artisan fisheries. The species presented positive alometric growth, with a sexual ratio of 1:2,1 between males and females, and the size of first maturation in 14,8 cm and 15,0 cm. P. brasiliensis presented a great trophy specter composed by 27 items, being that, from the spring a gradual increment in the food ingestion occurred until the summer, followed of abrupt fall in the autumn and small recovery in the winter. Despite of the seasonal fluctuations during the seven years, this species occupied the second position in number and biomass among the integrant of ictiofauna bycatch

Natural Diet of Callinectes ornatus Ordway, 1863 (Decapoda, Portunidae) in the Itapocoroy Inlet, Penha, SC, Brazil

From January to December 1995, 332 individuals of the Callinectes ornatus species were collected from the Itapocoroy inlet in Penha, Sta. Catarina, Brazil to study its natural diet and the seasonal variations of diet. Results showed a diversified trophic spectrum with a generalized dietary strategy comprising the algae, macrophyta, foraminiferida, mollusca, polychaeta, crustacea, echinodermata, Osteichthyes and NIOM (Nonidentified Organic Matter) groups.<br>Alimentação natural de Callinectes ornatus Ordway, 1863 (Decapoda, Portunidae) na Armação do Itapocoroy, Penha, SC - Brasil. No período de janeiro a dezembro de 1995, foram coletados 332 indivíduos de Callinectes ornatus, procedentes da Armação do Itapocoroy (Penha, SC). Foi estudada a alimentação natural da espécie e as variações sazonais da dieta. Os resultados mostram um espectro trófico diversificado, com estratégia alimentar generalista, sendo Algas, Macrófitas, Foraminiferida, Mollusca, Polychaeta, Crustacea, Echinodermata, Osteichthyes e matéria orgânica não identificada, os grupos que compõem sua dieta

Estrutura populacional do Camarão Sete-Barbas Xiphopenaeus kroyeri (Heller, 1862), na Foz do Rio Itajaí-Açú, Itajaí, SC, Brasil

<abstract language="eng">Xiphopenaeus kroyeri is the most exploited shrimp specie along Center-South coast of Santa Catarina State, Brazil, by artisanal fishery. In the period from March/1996 to February/1997, 3965 shrimps were collected (1843 males and 2122 females) sampled by over-trawl, with the depth oscillating between 5 and 15 meters. Xiphopenaeus kroyeri shows seasonal fluctuations in its abundance with higher rates in autumn. The population's average total-length varied between 7.5cm and 9.1cm, and the presence of juveniles was common along the year. The males and females get to the first gonadal maturation with 7.4 cm and 9.0 cm length, respectively; these lengths were reached within 6 and 8 months of age