Jonas de Andrade Santos, Rafael Lima Oliveira, Ana Paula Penha Guedes, Alexandre Clistenes de Alcântara Santos, Leonardo Evangelista Moraes

Tropical sandy beaches have low primary productivity, thus depend on external food sources. Generally, allochthonous macrophytes, form the basis of these food webs, and also may influence factors such as fish’s abundance, richness, species composition, and biomass. However, the role of macrophytes to the feeding ecology of fishes in tropical sandy beaches is uncertain. We aim to explain if this microhabitat acts as restaurants for fishes by performing stomach content and prey availability analyses using Ophioscion punctatissimus as a model because it has an association with detached macrophytes mainly on sandy beaches along the northeastern Brazilian coast. The most consumed prey was crustaceans, mainly amphipods, which were eaten in a specialist way, especially by the smaller fishes. The prey availability along with electivity index suggested that this species choose amphipods. Seasonal variations may indicate that the fishes did not locate their preferential prey as an effect of the availability, this can be also explained by factors such as palatability, and optimal foraging theory. Here, we redefined the O. punctatissimus trophic guild as zooplanktivorous, highlighting macrophytes as restaurants for fishes in tropical sandy beaches as they are the main source of food, adding another function to this microhabitat in this environment.