Genetic structure of Rhinoceros Rock Iguanas, Cyclura cornuta, in the Dominican Republic, with insights into the impact of captive facilities and the taxonomic status of Cyclura on Mona Island

Hispaniola is the second largest island in the Caribbean and harbors an extensive amount of biodiversity. The geologic history and resulting complex topography of the island has led to significant differentiation across various taxonomic groups. Hispaniola is the only Caribbean Island with two species of Rock Iguanas, genus Cyclura. Rhinoceros Rock Iguanas (C. cornuta) are wide-ranging across Hispaniola, occurring in isolated pockets, primarily in low elevation xeric areas. To better understand the population structure of this species, we used a combination of mtDNA and nuclear markers to elucidate the genetic variation of wild populations across 13 sampling regions in the Dominican Republic (DR), as well as neighboring Mona Island, home to a Cyclura population of uncertain taxonomic status. Further, we evaluate the origin of iguanas in captive facilities throughout the DR. Our data reveal a high degree of genetic diversity across wild populations within the DR and shed light on the taxonomic status of the Mona island population. Further, novel genetic diversity is found in captive facilities, most likely resulting from interbreeding between individuals from genetically distinct populations within the captive facilities. Our results suggest that the captive facilities may pose a threat to wild populations and increased regulation of these facilities is needed.