Monday, October 20, 2014

[Herpetology • 2014] Description of Four New West African Forest Geckos of the Hemidactylus fasciatus Gray, 1842 complex, revealed by coalescent species delimitation

Fig. 1. [A] Living specimen of Hemidactylus fasciatus (not collected) from Liberia;
[B] Living specimen of Hemidactylus kyaboboensis sp. n. from the type locality.

Fig. 6. [A] Living specimen of Hemidactylus ituriensis (AMNH 10273) from Akenge;
[B] Living specimen of Hemidactylus coalescens sp. n. (ZFMK 87679, holotype) from the type locality;
and [C] uncollected living specimen of Hemidactylus biokoensis sp. n. from Bioko Island
(Reserva científica de la Caldera de San Carlos, 3°14’2.39”N, 8°37’38.60”E.).

The gecko Hemidactylus fasciatus is widespread in rainforest regions of equatorial Africa, from Guinea to Cameroon. Recently, this taxon was identified as a cryptic complex of at least five species, using multilocus genetic data and coalescent models for species delimitation. Here, we provide the formal descriptions of four new species from tropical West and Central Africa. As typical for cryptic species, the new species are genetically distinct, but difficult to distinguish using external morphology. However, coloration, shape of the body crossbands, and body size, are important distinguishing characters for this complex.

We provide a new taxonomy for this complex that includes the following forest gecko species: H. fasciatus is now restricted to West Africa occurring eastwards to the Dahomey Gap, Hemidactylus kyaboboensis sp. n. is known only from within the Dahomey Gap, H. eniangii sp. n. is distributed from the Dahomey Gap to western Cameroon, H. coalescens sp. n. occurs from central Cameroon to southern Gabon, H. biokoensis sp. n. is restricted to Bioko Island, and H. ituriensis, herein recognized as full species, is known from several localities in eastern Africa.

Key words: Africa, rainforest, Sauria, Gekkonidae, Hemidactylus fasciatus complex, Hemidactylus ituriensis.

Fig. 7. Species tree for the Hemidactylus fasciatus species group based on a coalescent-based Bayesian analysis of 1,087 single nucleotide polymorphisms (Leaché et al. 2014). Posterior probabilities are shown on branches. Museum specimen records were downloaded from the HerpNET database, and geographic distribution was predicted using Maxent. Populations with uncertain taxonomic placement are indicated with “?”. Type localities are: [A]= H. kyaboboensis sp. n.; [B]= H. eniangii sp. n.; [C]= H. biokoensis sp. n.; and [D]= H. coalescens sp. n.

Philipp Wagner, Adam D. Leaché & Matthew K. Fujita. 2014. Description of Four New West African Forest Geckos of the Hemidactylus fasciatus Gray, 1842 complex, revealed by coalescent species delimitation. Bonn zoological Bulletin. 63 (1): 1–14