Abstract. Variations in species richness of local assemblages may be explained by local ecological processes or large-scale evolutionary and biogeographical processes. In Anolis lizards, species with different ecomorphs can coexist by occupying different niches. In addition, several species with the same ecomorph (e.g., trunk-ground) can coexist, and the number of trunk-ground anole species varies among local species assemblages. In this study, we assessed the importance of ecological interactions, number of speciation events, and range expansion for local and regional species diversity of these lizards. We examined the species richness and thermal microhabitat partitioning (considered to be a measure of ecological interaction) of 12 trunk-ground anole species in 11 local assemblages in Cuba. The results indicated that the phylogenetic structure of trunk-ground anole lizard assemblages was random. However, there was an overdispersion of preferences for thermal microhabitat use, which indicates that differences in microhabitat use are likely to occur within assemblages. We suggest that the number of speciation events within regions and the number of sympatrically coexisting species increases species richness at the local level. Migration appeared to be limited, leading to the range expansion of only three species with different thermal requirements. The thermal niches of species were conserved within Anolis allogus clade, whereas species within the Anolis homolechis and Anolis sagrei clades tended to change their thermal niches. Our results suggest that the species composition and richness in local assemblages could be explained by evolutionary history (the number of speciation events and limits to range expansion) and ecological processes (habitat partitioning). Of the ecological factors, the number of thermal (microhabitat use) and structural niches (e.g., vegetation) could limit the potential number of coexisting species within a local assemblage.
There are 196 species of amphibians known from the West Indies, 188 of which are native. With only a few exceptions, all of those native species are endemic to single islands or island banks and most are restricted to a small region within an island such as a single mountain top. The native species are members of the following families: Aromobatidae (1 species), Bufonidae (12 sp.), Hylidae (9 sp.), Eleutherodactylidae (161 sp.), Leptodactylidae (3 sp.), and Strabomantidae (2 sp.). The recent Global Amphibian Assessment found that 84% of West Indian amphibian species are threatened and that 71% are in the two highest threat categories, Endangered and Critically Endangered. The remote areas where many species occur constrain monitoring efforts, but remarkably, 49 species (26% of all native species) have not been observed in at least 10 years and 31 species (16%) in at least 20 years. Much-needed surveys will almost certainly find some of those species, but five species have not been found despite intensive search efforts, and are likely extinct -for unknown reasons. Small distributions and declining habitat area and quality were the most important considerations in determining conservation status. Many species are contained within national parks and other protected areas, but the effectiveness of the protected areas varies from essentially no protection to moderately good protection. Unfortunately, most of the critically endangered species occur in countries (e.g., Haiti) where protected areas have low effectiveness. Deforestation and habitat modification continue to be the most serious and widespread threats, although the impacts of an introduced fungal pathogen and climate change are being carefully monitored. For unexplained reasons, the largest conservation agencies, The Nature Conservancy and Conservation International, have yet to establish programs of any significance in countries of the Caribbean region (e.g., Haiti) where the biodiversity crisis is the most severe. Nearly all of the biological data used in determining the conservation status of species comes from the field of systematics and taxonomy rather than ecology, yet this fact has yet to be fully appreciated by the culture of conservation.
Two of the earliest examples of successful invasive amphibians are the greenhouse frog ( Eleutherodactylus planirostris ) and the Cuban treefrog ( Osteopilus septentrionalis ) in Florida. Although both are generally assumed to be recent introductions, they are widespread on Caribbean islands and also have been proposed as natural colonizers. We obtained nucleotide sequence data for both species and their closest relatives in their native and introduced ranges. Phylogenetic analyses trace the origin of E. planirostris to a small area in western Cuba, while O. septentrionalis is derived from at least two Cuban sources, one probably a remote peninsula in western Cuba. The tropical-to-temperate invasion began with colonization of the Florida Keys followed by human-mediated dispersal within peninsular Florida. The subtropical Keys may have served as an adaptive stepping stone for the successful invasion of the North American continent.
Cuba has the highest diversity of snakes in the genus Tropidophis, representing 53 % of all the known species. Tropidophis steinleini sp. nov. is described from the eastern region of Cuba, raising the number of species to 17 in this archipelago. The new species is most closely related to T. wrighti, T. spiritus and T. morenoi. We discuss the phylogenetic relationships of this new species and other species of the genus in Cuba, based on molecular data, and classified them within three species groups according to the obtained tree topology.
Species of Anolis lizards of the West Indies that naturally inhabit hot and open areas also tend to thrive in urban areas. In this study, transcriptome was sequenced for nine species of Cuban Anolis lizards that are closely related to each other, but inhabit different thermal microhabitats. Using PAML and HyPhy software, we attempted to identify genes and amino acid sites under positive selection in the common ancestral branch of A. porcatus and A. allisoni, and the branch of A. sagrei, which inhabit hot and open areas, and thrive in urban areas. Although there were no genes where positive selection was commonly detected on both of the tested branches, positive selection was detected in genes involved in the stress response (e.g., DNA damage and oxidative stress) and cardiac function, which could be related to adaptive evolution of tolerance to heat or ultraviolet radiation, on both branches. These findings suggest that adaptive evolution of the response to stress caused by heat or ultraviolet radiation might have occurred in ancestors of Anolis species inhabiting hot and open areas and might be related to the current thriving in urban areas of them.
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