Saturday, August 16, 2014

Gymnophthalmus underwoodi on Tobago

The shiny lizard, Gymnophthalmus underwoodi, is one of those reptiles that is widespread and probably common,  but not particularly easy to find. It is small, lives in burrows or under objects, and is active only when the sun is shining - when it can significantly raise its body temperature. Its distribution ranges from Venezuela, the Guyanas, and Brazil northward into the Lesser Antilles. It has been reported as far north as Antigua. Humans may, at least in part, be responsible of its island distribution.The shiny lizard is frequently associated with lawns and gardens and as people transport their favorite plants from palace to place these tiny lizards may move with them. Additionally it is a unisexual species which provides the advantage of not needing a mate. In fact, G. underwoodi is one of four species in a complex of cryptic species (the others are: G. cryptus, G. leucomystax, and G. specious). Kiziran & Cole (1999) found G. cryptus is the ancestor of G. underwoodi.


Hardy (1982) commented on the lack of specimens of Gymnopthalmus underwoodi from Tobago, Cole et al did find find specimens from Tobago, nor did Murphy (1997). Yet some publications and websites have included Tobago in the distribution- the IUCN red list is an excellent example. It presence on Tobago would seem reasonable given its presence in Trinidad and Venezuela and the Antilles. However, a HerpNet search did not show any specimens from Tobago.

On 6 June 2013 Rick Lehtinen collected a single specimen of G. underwoodi in from of the Vegetable King in Castara, Tobago. Thus confirming its presence on the island. The specimen is deposited in the UWIMZ. Since that date the species has become quite abundant on the northeastern end of the island.


Literature

Cole, CJ, et al. Gymnophthalmus (Reptilia Teiidae) in the neotropics: genetics origin and systematics. American Museum Novitates (2994): 1-29

Hardy, J. D. 1982. Biogeography of Tobago, West Indies, with special reference to amphibians and reptiles, a review. Bulletin of the Maryland Herpetological Society 18(2):37–142.

Kizirian DA. Cole CJ. 1999. Origin of the Unisexual Lizard Gymnophthalmus underwoodi (Gymnophthalmidae) Inferred from Mitochondrial DNA Nucleotide Sequences. Molecular Phylogenetics and Evolution 11:394–400.

Murphy, J. C. 1997. Amphibans and reptiles of Trinidad ad Tobago. Krieger Publishing, Malabar, FL.

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