ABSTRACT Pomacentridae is a common family in the aquarium fish trade. Most species are harvested from nature. Here we evaluate the following water parameters in the pomacentrid sergeant major, Abudefduf saxatilis (Linnaeus, 1758), to assess their stress level during a 24, 48, and 72 hours transport: dissolved oxygen (DO), total ammonia, and pH. In addition, we evaluated the following physiological parameters: plasma osmolality, muscle water content, blood glucose, and the enzyme activities of the branchial carbonic anhydrase (CA), the hepatic glutathione S-transferase (GST), catalase (CAT), and superoxide dismutase (SOD). The mortality of fish measuring >6 cm total length was 22%, while no mortality was observed for fish measuring <6 cm. The pH of the water was significantly correlated with fish mortality, especially for the initial 24 hours of transport. Hypoxia after 24-48 hours also led to fish mortality, but build up ammonia was not a problem even after 72 hours. We suggest that a minimum water volume of 125 ml/g fish is necessary for safe and cost-effective transport of the sergeant major, preferably with <6 cm in total length.

A raia viola, Rhinobatos percellens, é um dos batoídeos mais capturados na costa brasileira, e é um importante predador da comunidade bêntica. Estômagos de R. percellens foram amostrados no complexo estuarino de Paranaguá (Março/2006 a Março/2007 e Outubro/2008 a Setembro/2009). Os estômagos obtidos foram utilizados para descrever a dieta de R. percellens, e verificar se há diferenças sazonais e ontogenéticas em sua alimentação nesta área estuarina. A análise geral mostrou uma dieta especializada com a predominância de três espécies em seu conteúdo alimentar: Leptochela serratorbita, restos de Caridea e Ogyrides alphaerostris. Análises ontogenéticas e sazonais não revelaram diferenças significantes no consumo de alimento. Estes dados revelam que R. percellens é um predador especialista em L. serratorbita, e este alimento é consumido por todas as classes de tamanho.

The chola guitarfish, Rhinobatos percellens, is one of the most-captured batoids on the Brazilian coast, and an important predator of benthic community. Stomachs from R. percellens were sampled in the Paranaguá estuarine complex (March/2006 to March/2007 and October/2008 to September/2009). The stomachs obtained were used for describing the diet of R. percellens, and verifying if there are seasonal and ontogenetic differences in their feeding into the estuarine area. The general analysis showed a specialized diet with a predominance of three species in food contents: Leptochela serratorbita, Caridea remains and Ogyrides alphaerostris. Ontogenetic and seasonal analysis did not reveal significant differences in the food consumption. These data reveal that R. percellens is a specialist predator of L. serratorbita, and this food component is consumed by all size classes.