Seasonality, Dietary Overlap and the Role of Taxonomic Resolution in the Study of the Diet of Three Congeneric Fishes from a Tropical Bay

Abstract

Not only seasonality but also taxonomic resolution of prey categories has been shown to affect diet studies. We analyzed the stomach contents of three sympatric species, Stellifer rastrifer, S. brasiliensis and S. stellifer, sampled monthly from August 2003 to October 2004 in Caraguatatuba Bay, southeastern Brazil. General characteristics and similarities among their diets were evaluated by considering high taxonomic ranks of all prey groups, and also the lower taxonomic ranks of the main prey groups. Dietary similarity was relatively high among species and low between seasons, and both evaluation criteria gave the equivalent results. The rare items, however, provided information about resource partition, and the species compositions of the most important groups were apparently good indicators of food availability.

The barred grunt Conodon nobilis (Perciformes: Haemulidae) in shallow areas of a tropical bight: spatial and temporal distribution, body growth and diet

“…The high and constant importance of mysids in the diet, observed here, is interesting since other studies did not find mysids among the food items. Although the local plankton community has not been studied, in other fish species the diet composition shifted considerably from season to season Pombo et al 2013), which indicates that C. nobilis may indeed have a strong preference for mysids and supports its characterization as a specialist feeder, at least as late juveniles (5-11 cm). Mysids are common in the swash zone off sandy beaches, where they may burrow in the sand during the day or enter the water column at night (Calil and Borzone 2008), somewhat matching the occurrence of C. nobilis in sandy-beach environments.…”

Use of food resources by small fish species in Neotropical rivers: responses to spatial and temporal variations

“…The influence of spatial and seasonal changes in trophic relationships has been recognized for a long time (ARGERMEIER 1982, SCHOENER 1989, POLIS et al 1996, HAHN et al 1997, WINEMILLER & JEPSEN 1998, HOLT 2002 and has gained importance recently in the ecological context (GIMENES et al 2010, CORRÊA et al 2011, PETTIT et al 2011, POMBO et al 2013, WOLFF et al 2013. However, some aspects that influence the availability of resources along spatial gradients and aspects related to seasonality need to be further clarified.…”

Young humpback whale Megaptera novaeangliae feeding in Santa Catarina coastal waters, Southern Brazil, and a ship strike report

“…Because A. americanus and P. petrunkevitchi inhabit the pelagic realm, they probably present equivalent potential to be preyed on by whales in the coastal waters of southern Brazil. Besides the inclusion of P. petrunkevitchi in the list of recorded species preyed on by humpback whales, the current report suggests a new contribution of the shrimp as prey in Brazilian waters, being already described as an important food source for sciaenid fishes (Pombo et al 2013) and wasp jellyfish (Nogueira Jr and Haddad 2008) in the area. The total length of the stranded animal (8.63 m) suggests that it was a juvenile, since this size corresponds to a one year old humpback whale (Clapham et al 1999).…”