- Department of Zoology, University of Western Ontario, N6A 5B7, London, Ontario, Canada
Synopsis: Cichlids are unusual among fishes because they have prolonged care of their young. Convict cichlids,Cichlasoma nigrofasciatum, are monogamous and have biparental care of their young. This species has been studied extensively in the laboratory, however, little is known of their reproductive habits in nature. Four populations of convict cichlids were studied in Costa Rican streams during the long dry season in 1990 and 1991. Basic physical and chemical parameters of the study sites are described. In the study area breeding fish paired size assortatively; large males with large females and small males with small females. A comparison of the size distribution of breeding fish to that of non-breeding fish showed that small males and in some cases, small females were excluded from breeding. This suggests competition among males for nest sites and mates or female-female competition. Further evidence of intrasexual competition in females is provided by the black colour phase adopted by some females. Some of these females were active in courtship and had mature ova. Cave guarding behaviour and reuse of caves show that a ready-made spawning site is an important resource shaping the mating system of this species. This description of basic natural history can serve as a source of testable hypotheses for future research and allow the results from laboratory studies on this and related species to be interpreted within the ecological context of the natural habitat.
- 1 - sciences appliquees, technologies et medecines
- 2 - sciences biologiques et medicales
- 3 - sciences biologiques fondamentales et appliquees. psychologie
- 4 - ethologie animale
- 1 - Life Sciences ; 2 - Agricultural and Biological Sciences ; 3 - Aquatic Science
- 1 - Life Sciences ; 2 - Agricultural and Biological Sciences ; 3 - Ecology, Evolution, Behavior and Systematics