Luis M. Díaz

First Report of Chytridiomycosis in a Dying Toad (Anura: Bufonidae) from Cuba: A New Conservation Challenge for the Island

Infection by the chytrid fungus Batrachochytriumdendrobatidis was detected in a male Bufo longinasus dunni, a small toad endemic to central Cuba. The individual was severely infected and in decaying condition. Sections of the skin were examined through standard histological procedures. Several stages of the fungus were confirmed and are illustrated in this contribution. Implications for amphibian conservation in Cuba are discussed.

Relative importance of habitat use, range expansion, and speciation in local species diversity of Anolis lizards in Cuba

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 n

Factors affecting interspecific differences in genetic divergence among populations of Anolis lizards in Cuba

BackgroundGeographical patterns and degrees of genetic divergence among populations differ between species, reflecting relative potentials for speciation or cladogenesis and differing capacities for environmental adaptation. Identification of factors that contribute to genetic divergence among populations is important to the understanding of why some species exhibit greater interpopulation genetic divergence. In this study, we calculated the mean pairwise genetic distances among populations as species’ average genetic divergence by a phylogeny using nuclear and mitochondrial genes of 303 individuals from 33 Cuban Anolis species and estimated species ages by another phylogeny using nuclear and mitochondrial genes of 51 Cuban and 47 non-Cuban Anolis species. We identified factors that influence species’ differences in genetic divergence among 26 species of Anolis lizards from Cuba. Species ages, environmental heterogeneity within species ranges, and ecomorph types were considered as factors affecting average genetic divergences among populations.ResultsThe phylogenies presented in this study provide the most comprehensive sampling of Cuban Anolis species to date. The phylogeny showed more conservative evolution of Anolis ecomorphs within Cuba and identified twig anoles as a monophyletic group. Subsequent Phylogenetic Generalized Least Squares (PGLS) analyses showed that species age was positively correlated with species’ average genetic divergence among populations.ConclusionAlthough previous studies have focused on factors affecting genetic divergence within species, the present study showed for the first time that species differences in genetic divergence could be largely affected by species age.