Hybridization between Crocodylus acutus and Crocodylus moreletii in the Yucatan Peninsula II. Evidence from Microsatellites

Detecting and quantifying hybridization between endangered or threatened taxa can provide valuable information with regards to conservation and management strategies. Hybridization between members of the genus Crocodylus has been known to occur in captivity and in some wild populations. We tested for hybridization among wild populations of American crocodile (C. acutus) and Morelet’s crocodile (C. moreletii) in the Yucatan Peninsula by comparing Bayesian assignment tests, based on microsatellite data, to mitochondrial and morphological assignments. Skin clips from 83 individuals were taken for genetic identification, and a total of 32 individuals (38.6%) exhibited some evidence of hybridization by combined morphological, mitochondrial and microsatellite analyses. The majority of hybrids were classified as F2 hybrids and backcrosses to C. moreletii. Most of the introgression occurs in two national biosphere reserves located on the northern and eastern coasts of the Yucatan Peninsula. P