Phylogeographical analysis and phylogenetic inference based on the cytochrome b gene in the genus Caiman (Crocodylia: Alligatoridae) in Central and South America.

The genus Caiman is one of the most taxonomically conflicted among crocodilians. Caiman crocodilus has four subspecies: Caiman crocodilus crocodilus , Caiman crocodilus fuscus , Caiman crocodilus chiapasius and Caiman crocodilus apaporiensis , but some studies recognize Caiman yacare as a subspecies of C. crocodilus or as a C. crocodilus–C. yacare complex. In Argentina, Caiman latirostris and C. yacare are present and included in sustainable use programmes, although they have hardly been studied at the genetic level. The present study had two main objectives: (1) to study the genetic diversity, structure and phylogeny of C. yacare and C. latirostris in Argentina; and (2) to perform a phylogenetic analysis of the genus Caiman throughout its entire distribution. The results show high haplotype diversity for both species but low nucleotide diversity for C. latirostris. Phylogenetic analysis shows a clear separation between both species but, surprisingly, a well-differentiated clade belonging to the Chaco region was observed. The phylogenetic analysis exhibited clades made up of the sequences of each Caiman species, with some inconsistencies: in the clade of C. crocodilus , one sequence of C. yacare is included, and one clade is observed including sequences from C. c. fuscus and C. c. chiapasius. These data indicate the need to undertake interdisciplinary studies to clarify the taxonomic status of these crocodilian species. [ABSTRACT FROM AUTHOR]