Características zoogeográficas de la ictiofauna litoral de las islas de Cabo Verde y comparación con los archipiélagos macaronésicos

Résumé

Littoral ichtyofauna of the Cape Verde Islands is tropical; Guinean species are clearly dominant, followed by the tropical-subtropical amphiantlantic species, those distributed along the Atlantic and in the Mediterranean, and the circuntropical ones. A remarkable characteristic is the presence of twent}' endemic taxa, indicating the existence of an important process of speciation that seems to be mainly related to isolation and thermal stabilit}'. It is also particular the existence of some Macaronesian elements or exclusive species in the Eastern Atlantic's insular arch that stretches between Azores and Cape Verde. On the contrary, Macaronesian Islands (Azores, Madeira, Salvajes and the Canaries), apart from having a subtropical littoral fish fauna, related to the one in the Atlantic-Mediterranean biogeographic province, present a very low or even non-existent rate of endemism in each archipelago. This characteristic has been linked with the effects of the glacial periods. However, a detailed analysis shows that there are twenty taxa originated in these islands, although some of them are doubted to be valid. Thus, opposing the main opinion, Macaronesian Islands seem to have been a rather important evolutionary centre, though the existence of strong currents has originated a redistribution of most of the new taxa in the insular arch.