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.Diplectrum formosum, Diplectrum radiale (micholes-da-areia), Epinephelus marginatus (garoupa-verdadeira) e Mycteroperca acutirostris (badejo-mira) são quatro espécies simpátricas que pertencem à família Serranidae, de reconhecida importância ecológica e comercial. Este estudo analisou a alimentação destas quatro espécies de peixes no Canal de São Sebastião, Estado de São Paulo (sudeste do Brasil), comparando suas dietas, o uso do habitat e algumas características morfológicas relacionadas ao comportamento alimentar e a distribuição vertical na coluna d'água. Estes quatro serranídeos são predadores oportunistas que utilizam um total de nove táticas diferentes para capturar suas presas, alimentando-se principalmente de crustáceos durante o dia e crepúsculo, e permanecendo estacionários e inativos durante a noite. Um estudo ecomorfológico foi empregado para testar seu valor preditivo. Foi verificado que tal abordagem deve ser utilizada com cautela e sempre complementada com observações diretas no ambiente. Apesar de morfologicamente e comportamentalmente muito semelhantes, D. formosum e D. radiale mostraram divergências com relação ao tipo de substrato preferido pelos maiores indivíduos, que são exclusivamente predadores de espreita. Por outro lado, E. marginatus mostrou possuir hábitos de vida mais sedentários do que M. acutirostris, o mais versátil predador dentre as espécies estudadas. As espécies de Diplectrum estudadas, assim como E. marginatus, podem ser classificadas como serranídeos bentônicos, enquanto que M. acutirostris pode ser classificada como uma espécie nectobentônica.

Defensive Responses of Cuttlefish to Different Teleost Predators

“…This behavior was effective in stopping the pursuit of S. cabrilla, and was similar to the responses observed toward black seabass in the present study. Both serranid species closely associate and hunt for prey in demersal and benthic habitats (Labropoulou and Eleftheriou, 1997;Steimle et al, 1999;Gibran, 2007). In a laboratory experiment conducted by Langridge et al (2007), S. officinalis also responded to S. cabrilla with deimatic displays followed by flight.…”

“…Flounder have a compressed body form, spend the majority of their lives on or near the bottom, and are primarily solitary, lie-and-wait predators (Staudinger and Juanes, 2010b). Seabass are a deep-bodied fish that use a variety of sit-and-pursue tactics, including ambush, following, and stalking behaviors, to capture prey in demersal habitats (Schmitz, 2005;Gibran, 2007). Seabass were considered to represent an intermediate hunting mode compared to bluefish (active) and flounder (ambush), and may be solitary or occur in shoals (Steimle et al, 1999).…”

Correlations Between Pre- and Post-Fasting Growth in Nile Tilapia

“…For instance, dominant Nile tilapia makes the food patch unavailable for the subordinate ones (Delicio et al, 2006). In field observations for serranid species, agoaistic interactions take place between individuals of different life stage, leading t o spatial segregation among individuals of different body sizes, avoiding food overlap (Gibran, 2007). The linkage between pre-and post-food-restriction growth would facilitate a rapid recovery of their normal growth rate and pre-food-restriction weight, what might represent a selective advantage for these biological processes affected by body size.…”

Habitat partitioning, habits and convergence among coastal nektonic fish species from the São Sebastião Channel, southeastern Brazil

“…Body shape and fins configuration/positions clearly influence the ecological performance (e.g., hydrodynamics, swimming speed, maneuverability etc.) and habitat use in fishes (see Motta, 1988;Gibran, 2007). Previous studies show that external morphology is not a good predictor of diet (a result in opposition to the ecomorphological hypothesis), but it enables to infer how a fish can eat and where it can feed; morphological similarities observed among species generally reflects similar patterns in habitat use and/or feeding mode (e.g., Motta, 1988;Gibran, 2007).…”

“…In Brazil, the ecomorphological hypothesis has been tested mainly for freshwater fishes (e.g., Casatti & Castro, 2006;Ferreira, 2007, but see Gibran, 2007), and the concept of convergent evolution provides and important interface between ecology, morphology, and phylogenetics (Winemiller, 1991).…”