Do marine fish juveniles use intertidal tide pools as feeding grounds

Abstract Several authors have put forward the hypothesis that juveniles of transient marine fish concentrate in intertidal tide pools, not only to benefit from refuge and higher temperatures, but also to use them as feeding grounds. However, there have been no attempts to test this. The feeding ecology of fish was studied in intertidal tide pools to evaluate the importance of these habitats as feeding grounds for non-resident juvenile fish. Fish were collected in 5 beaches in Southeastern Brazil. Juveniles of four species of non-resident fish were identified in the pools: Abudefduf saxatilis (Linnaeus, 1758), Diplodus argenteus (Valenciennes, 1830), Eucinostomus melanopterus (Bleeker, 1863) and Odontesthes argentinensis (Valenciennes, 1835). The most abundant species was A. saxatilis , followed by E. melanopterus and D. argenteus . The diet of those three species was characterized and correlated to the supply of potential food items in the pool where they were collected, in the surrounding intertidal and the nearest subtidal habitat. There was extensive diet overlap among species, largely explained by a generalized predation on copepods. The diet of all species was best correlated to the frequency of resources in tide pools, except for the diet of E. melanopterus which was equally correlated to the intertidal nearby habitat. The consistent similarity between stomach contents and prey availability inside the pool, observed for all species, indicates that intertidal tide pools are likely used as feeding grounds by juvenile stages of these transient fish.