Visual processes in African cichlid fishes

点击翻译按钮获取中文摘要

Cichlid fishes in the East African Rift Valley lakes provide an excellent natural laboratory for the study of sexual selection. Lake Malawi has more than 1,000 endemic species with a striking diversity in trophic adaptations and behaviours. What makes this example of adaptive radiation so exciting is that it evolved in a notably short time. Critical behavioural decisions such as choosing a mate profoundly affect an individual's fitness. Sexual selection can depend heavily on visual cues that must be rapidly translated into appropriate behavioural actions that eventually maximize fitness. Female cichlids are able to visually discriminate between males of their own species and closely related species, using body color and possibly other visual cues. Mate choice based on intraspecific color signaling plays a critical role in maintaining biodiversity when species are sympatric and not ecologically differentiated. Furthermore, successful mate choice in these cichlids necessitates acute visual discrimination in a temporally and spatially dynamic light environment. The role of color in cichlids is thus considered central to cichlid diversification in the great lakes of Africa, yet our understanding of the basis for body color and polarization patterns and the functional characteristics of cichlid visual systems remain quite limited.