Ecologia alimentar de três espécies de vermelhos (Teleostei:Lutjanidae) desembarcadas na praia do Mucuripe,Fortaleza-CE.

Abstract

The species Lutjanus analis, L. synagris and Ocyurus chrysurus popularly known as mutton snapper, lane snapper and yellowtail snapper, respectively, are recognized for their high commercial value and local ecological importance, mainly in northeastern Brazil. The present study aims to determine the feeding ecology of these species to evaluate their diets and understand their trophic relationships. Sampling was conducted from January to December 2019 at Mucuripe beach, where 10 specimens of each species were acquired monthly. In the laboratory the stomachs were removed and the food items stored for analysis. Solid wastes found in the samples were separated for measurement and sorted by color. The following analyses were performed: frequency of occurrence, volume frequency, feeding index,

repletion index, prey-specific abundance parameter, niche range, and niche overlap. Ninety- eight stomachs of mutton snapper, and 59 stomachs of lane snapper and 59 of yellowtail

snapper were analyzed. The lengths ranged from 20 to 70 cm in the mutton snapper specimens and from 20 to 50 cm in the lane snapper and yellowtail snapper specimens. In all three species, the most frequent items were of animal origin, reaffirming the generalist character of these species. It was also possible to observe that the rainfall did not influence the richness of food items. The results of niche range and niche overlap analysis reaffirmed that the species feed on animal organic matter that varies from invertebrates to vertebrates, and for this reason they compete for the same food. Feeding preference did not vary between the sexes. The solid waste found was classified into five colors, where it was observed a wide occurrence of blue filaments, abundant in the marine environment and of possible anthropogenic origin. We conclude that the differences in the diet of the three species are directly linked to food availability, and that the intake by microplastics is not significant when compared to food items, but some filaments are considerably more frequent than others.