Convict cichlids benefit from close proximity to another species of cichlid fish.

The coexistence of species with overlapping resource use is often thought to involve only negative fitness effects as a consequence of interspecific competition. Furthermore, the scarce empirical research on positive species interactions has predominantly focused on sessile organisms. Here, I experimentally assessed the effect of close proximity of a potential brood predator and competitor on reproductive success of a neotropical cichlid fish. I demonstrate that convict cichlid (Archocentrus nigrofasciatus) broods have a higher survival rate near territories of the Nicaragua cichlid (Hypsophrys nicaraguensis), and that escape from predation and nest takeovers is the most likely explanation for the decreased offspring mortality.