Nonapeptide neuronal phenotypes in eight species of lamprologine cichlid fishes from Isotocin neuronal phenotypes differ among social systems in cichlid fishes

Body size, cell number and average cell size for isotocin and vasotocin producing neurons in the parvocellular, magnocellular and gigantocellular regions of the preoptic area in 4 species of cooperatively breeding cichlids and 4 independently breeding species.