Competition for Breeding Sites between the Cichlid Fishes of Lake Jiloa, Nicaragua

The temporal pattern of breeding, the bathymetric distribution of breading pairs, the microhabitat selection of breeding sites and the sizes of breeding individuals of nine species of cichlid and one eleotrid predator, Gobiomorus dormitor, were examined in Lake Jiloa, Nicaragua. For two relatively short periods of the year, during the middle of both wet and dry seasons, competition for breeding sites between these fishes was intense. Over 90% of all territories were lost prior to completing a breeding cycle. Cichlid pairs in shallow water tended to be more successful and breeding sites in these areas were more vigorously contested. The seasonal pattern of breeding was bimodal with a different species complex breeding in the wet season as contrasted to the dry. In the wet season Cichlasoma citrinellum aggressively excluded all but the two smallest species from breeding in rocky areas. In the dry season, when C. citrinellum was not breeding, all other species were able to breed, but they, in turn, were separated within that season by both depth and timing of breeding.