ABSTRACT The aim of this study was to determine the composition of gastrointestinal content and protease and lipase activities in summer and winter as well as to evaluate the relationship between digestive enzyme activity and centesimal composition of gastrointestinal content and feeding habits of two omnivorous species, Rhamdia quelen (Quoy & Gaimard, 1824) and Pimelodus maculatus (LaCèpede, 1803), and of two ...
The aim of this study was to compare the influence of different haul distances of a codend beach seine on the catchability of fish in a surf zone. Two different surf zone sites (A and B) at the Cassino Beach (Rio Grande do Sul, Brazil) were sampled at three different distances, parallel to the beach (30, 60, and 90 m). Starting 40 m from the beach line, diagonal distances of approximately 50, 70, and 100 m were...
The present study compares fish species composition, dominance, and size-structure patterns at an open sand beach area (32°15'S, 52°46'W) in Mirim Lake, RS, Brazil, estimated from samples collected with two distinct beach seine nets. The BS-9m net is 9 m long and 1.5 m high, and is made with a 5 mm multifilament mesh on its central portion and 12 mm on the side wings. The BS-30m net is 30 m long and 1.8 m high,...
The purpose of this study was to investigate Na+, Cl-, K+, Ca2+, and Mg2+ levels in the plasma of freshwater and marine/estuarine teleosts collected at different salinities (0 to 34) from the estuarine and freshwater portions of the São Gonçalo channel in Southern Brazil. Any relationship between plasma ion levels and salinity and the capacity of ionic regulation of teleosts found at three or more different sal...
This study analyzes the spatiotemporal variation of the ichthyofauna of the surf zone of Praia do Cassino, municipality of Rio Grande (state of Rio Grande do Sul, Brazil) from October 2005 to September 2006. Fishes were collected monthly and during daytime using a large beach seine net (30 m x 1.8 m, with 12 mm uniform mesh manufactured with monofilament nylon wire). Five hauls were conducted on each of three s...
Based on biological and meteorological long-term database (1979-1983 and 1996-2000), we analyzed the variation in the juvenile recruitment and artisanal fishery landings of the mullet (Mugil platanus) in the Patos Lagoon estuary and its relationships with the regional rainfall and estuarine salinity anomalies during two strong El Niño events (1982-83 and 1997-98). Juvenile and adult mullets declined in abundanc...
Este trabalho avaliou do impacto da pesca do camarão-rosa Farfantepenaeus paulensis (Perez-Farfante, 1967) sobre a assembléia de peixes e crustáceos do Parque Nacional da Lagoa do Peixe. Constatou-se que, em média, a composição nas capturas da pesca do camarão-rosa, com a arte de pesca aviãozinho, é semelhantes àquelas descrita em para outros estuários do Rio Grande do Sul, quando considerada apenas a proporção...