A phylogeny of the genus Limia (Teleostei: Poeciliidae) suggests a single-lake radiation nested in a Caribbean-wide allopatric speciation scenario

Abstract

The Caribbean is one of the most important biodiversity hotspots on the planet due to the high level of species diversity and endemism in plants and animals. As elsewhere, adaptive radiations in the Caribbean lead to many speciation events within a limited period and hence are particularly prominent biodiversity generators. The general prediction from Island Biogeography that relates species richness to island size is valid for livebearing fishes in general in the Greater Antilles, where larger islands have higher numbers of species mainly due to in situ speciation. A prime example of this speciation process can be seen in the genus Limia, endemic to the Greater Antilles. Within Hispaniola, nine species have been described from a single isolated site, Lake Miragoâne, pointing towards extraordinary sympatric speciation in Limia. Few studies have examined the evolutionary history of the fishes found in Lake Miragoâne. Here, we address the gaps in present knowledge by providing a preliminary phylogeny of Limia and testing whether the species found in Lake Miragoâne may originated from an in situ radiation. We targeted the mitochondrial cytochrome b gene, a well-established marker for lower-level taxonomic relationships for which we obtained almost complete sequences for 13 species. The general topology of the phylogenies we produced are in concordance with other published phylogenies of Limia. There is also strong support that the species found in Lake Miragoâne in Haiti are indeed monophyletic (BS=97; PP=1.0), confirming the hypothesis of a recent local radiation. Within Lake Miragoâne, speciation is likely extremely recent, leading to incomplete lineage sorting in the mtDNA. Future studies are needed using multiple unlinked genetic markers to disentangle the relationships within the Lake Miragoâne clade.

Annotated list of livebearing fishes (Cyprinodontiformes: Poeciliinae) from Lake Miragoane in Southwestern Haiti, Hispaniola

“…Collected fishes were euthanized using MS 222 and then preserved in ethanol 75% for further species identification in the laboratory based on morphometric and meristic characters with emphasis in the analysis of the gonopodium tip in males. Additionally, we also preserved some individuals in ethanol 95% for molecular studies (Spikes et al, 2020). All fishes were collected with the authorization of the Ministry of Environment of Haiti as part of a survey of the native freshwater fish fauna of the lake.…”