Ecotype differences in aggression, neural activity and behaviorally relevant gene expression in cichlid fish

In Lake Malawi, two ecologically distinct lineages of cichlid fishes (rock‐ vs sand‐dwelling ecotypes, each comprised of over 200 species) evolved within the last million years. The rock‐dwelling species ( Mbuna ) are aggressively territorial year‐round and males court and spawn with females over rocky substrate. In contrast, males of sand‐dwelling species are not territorial and instead aggregate on seasonal breeding leks in which males...