Dimensões do aparato bucal e do trato gastro-intestinal associados à dieta de fases iniciais de espécies de Centropomus (Centropomidae : Actinopterygii)

Abstract

The present study aims at comparing the buccal apparatus and gastrointestinal tract of early life stages of Centropomus spp., and relate them to the diet. A total of 229 individuals collected with a channel net in the Catuama estuary (070 40’ 9,9’’S e 0340 50’ 36,7’’W), northern coast of Pernambuco, were used. Morphometrical and meristic data were analyzed for the two initial developmental phases (larval and juvenile). The differentiation between C. undecimalis e C. paralellus individuals was not possible, owing to overlap of gill raker, vertebrae and fin ray numbers between larvae and juveniles. The digestive tube was taken and characterized morphologically. Its content was identified and the longest transversal axis of food items were measured, and compared to the standard length (SL) and mouth gape size (D) of the individuals. Body measurements´ regressions differed significantly (P<0,001) between larvae and juveniles. The stomachs with food content analyzed (143 individuals) presented a proportion of 62% full and 20% empty (8% damaged), differed in relation to fullness degree and presented a coiled shape when empty. The number of food items in relation to SL and D did not present an evident correlation. Larvae (SL<10mm) feed on small copepods, while juveniles ingest different decapod larvae, showing a distinct diet between the initial developmental phases.