Contrasting feeding and agonistic behaviour of two blenny species on a small and remote island in the equatorial Atlantic Ocean.

We investigated the feeding rates, agonistic behaviour and diet of two blenny species, Entomacrodus vomerinus and Ophioblennius trinitatis, by direct observation and gut content analysis. Both species coexist in small and shallow tide pools in the St Peter and St Paul's Archipelago, equatorial North Atlantic Ocean. The feeding rate of O. trinitatis was c. 55% higher than E. vomerinus. On the other hand, agonistic rate of O. trinitatis was negatively related to body size, whereas in E. vomerinus was positively related. Both species showed a high diet overlap, in which detritus was the most important food item (86% in O. trinitatis and 80% in E. vomerinus). Feeding activity was more intense during the morning for O. trinitatis but afternoon for E. vomerinus. These behavioural observations support the importance of temporal feeding partitioning as the main strategy allowing species co-existence in tide pools.