Phylogenetic and biogeographic analyses of Greater Antillean and Middle American Cichlidae.

Abstract

Unlike other cichlids, the Middle American and Greater Antillean Cichlidae are not present on former Gondwanan fragments. This has led to many conjectures about the age and historical biogeography of this notable disjunct distribution. A phylogenetic approach is used to resolve the complex biogeographic history and taxonomic problems of this group. In a combined analysis incorporating morphological data and sampling from 3.5 kb of molecular characters (16S, COI, cyt <italic>b</italic>, S7, TMO-4C4) from 109 species (including about 80 of the 115 Middle American taxa) two large clades of Middle American cichlids are recovered, one of which is sister to a Greater Antillean clade. Divergence times based on rates of molecular evolution from a phylogenetic analysis of nuclear genes (S7, TMO-4C4) and mitochondrial genes (COI, 16S) estimate that the separation of Middle American and South American cichlids took place around the end of the Cretaceous, a period when a landbridge connecting South America and the Yucatan Peninsula started to breakup. An Eocene divergence time was estimated for Greater Antillean and Middle American cichlids, consistent with the geological separation of Cuba and Hispaniola from the Yucatan Peninsula. A morphological phylogenetic analysis of 41 Neotropical cichlids using 89 morphological characters finds that the taxonomic sections (sub-genera) once used to reflect putative clades within <italic>Cichlasoma</italic> poorly document natural groups. The name <italic>Nandopsis</italic> is restricted to the Greater Antillean clade. A taxonomic revision concludes that <italic> Nandopsis vombergi</italic> lacks diagnostic features and is a junior synonym of <italic>Nandopsis haitiensis</italic>. The Miocene Haitian fossil, <italic> Nandopsis woodringi</italic>, is a member of <italic>Nandopsis</italic> as evidenced by synapomorphies shared with that group. Based on combined analyses <italic> Herichthys, Thorichthys, Nandopsis</italic> and <italic>Caquetaia</italic> are recovered as monophyletic but <italic>Parachromis, Vieja, Amphilophus, Archocentrus</italic> and <italic>Tomocichla</italic> are not. Recent dispersal of Middle American cichlids to South American appears to be more prevalent than the reverse. Several species including the endemic South American <italic> Cichlasoma festae, C. ornatum</italic> and <italic>C. facetum</italic> are phylogenetically Middle American. Marine dispersal hypotheses are not employed for any disjunct distribution of cichlids because vicariance hypotheses are better able to explain the biogeographic patterns, both temporal and phylogenetic.