Activity, habitat use, feeding behavior, and diet of four sympatric species of Serranidae (Actinopterygii: Perciformes) in southeastern Brazil

Abstract

Diplectrum formosum (the sand perch), Diplectrum radiale (the aquavina), Epinephelus marginatus (the dusky grouper) and Mycteroperca acutirostris (the comb grouper) are four sympatric serranid of remarkable ecological and commercial importance. This study investigated the feeding of these four species in the São Sebastião Channel, São Paulo State (southeastern Brazil), comparing their diet, habitat utilization and morphological features related to foraging. These four serranids are opportunistic visual predators that use a total of nine different tactics to capture their preys, feed mostly on crustaceans during the day and twilight, and keep stationary and quiescent at night. The ecomorphological study was conducted to test its predictive value to infer lifestyles. It was verified that such analysis should be used carefully and must be complemented by field observations. Although morphologically and behaviorally very similar, D. formosum and D. radiale showed different preferences to the substratum type used by large individuals, which are exclusively sit-and-wait predators. On the other hand, E. marginatus displayed more sedentary habits than M. acutirostris, the most versatile predator from the studied species. The studied species of Diplectrum and E. marginatus can be regarded as benthic serranids, while M. acutirostris could be viewed as a nektobenthic species.