Mabuya unimarginata Cope

Castiglia, Riccardo, Annesi, Flavia, Bezerra, Alexandra M. R., García, Andrés & Flores-Villela, Oscar, 2010, Cytotaxonomy and DNA taxonomy of lizards (Squamata, Sauria) from a tropical dry forest in the Chamela-Cuixmala Biosphere Reserve on the coast of Jalisco, Mexico, Zootaxa 2508, pp. 1-29 : 19-20

Mabuya unimarginata Cope (Central American mabuya)

Specimens analysed: one female from Chamela (MZFC 21804).

Distribution: from Jalisco on the Pacific coast and from Veracruz on the Gulf of Mexico south to Guatemala, Belize, Honduras, El Salvador, Nicaragua, Costa Rica, and Panama.

Subspecies: no subspecies have been described.

Karyotype: the karyotype of M. unimarginata is here described for the first time ( Fig. 12 ). It has 2n = 32 with 18 macro- and 36 microchromosomes. Among the macrochromosomes it can be possible to identify two groups of chromosomes. The first group consists of four pairs of large biarmed chromosomes. The second group includes five pairs of smaller chromosomes arranged as three submetacentric pairs of and two acrocentric pairs. The karyotype here described is distinctive among the Neotropical species of Mabuya already studied. In fact, the species that share the same chromosomal number ( M. caissara and M. macrorhyncha ) have the macrochromosomal complement constituted of all metacentric chromosomes while M. unimarginata have two pairs of acrocentrics macrochromosomes (pairs 8 and 9) ( Colus & Ferrari 1988). The presence of acrocentric chromosomes in M. unimarginata could be a characteristic specific to this species.

DNA taxonomy: a fragment of the cyt b sequence (350 bp) was aligned with the other sequences available in GenBank (belonging to Costa Rica, Guatemala, Honduras, Mexico, Guerrero, Mexico and Oaxaca) ( Miralles et al. 2009). The specimens from Chamela represents the northernmost locality sampled for the species. The phylogenetic relationships among haplotypes do not reveal any geographic pattern. However, the genetic divergence observed within this species is high. The divergence ranges from 4% to 10%. The haplotype from Chamela is also divergent respect to all the others (6.3–9.5%). These values are of the same magnitude found among different species in Mabuya (min–max: 4.08–17.51, Miralles et al. 2009). These data suggest that M. unimarginata may constitute a species complex ( Miralles et al. 2009). Alternatively, it can constitute a rare but not unique case of a species showing a high divergence in mtDNA (e.g Jesus et al. 2006). For this species we also sequenced a fragment of the 16S rDNA (502bp). A phylogenetic tree was built with other representative species of Mabuya from South America (dataset by Mausfeld et al. 2002.) including a sequence by M. unimarginata from Honduras ( Honda et al. 2003). The results show a divergence of 3.2% between the samples of M. unimarginata from Chamela and Honduras. Interestingly these sequences are also very similar to the Mabuya mabouya sequence from Tobago, with 3.4% divergence. The three sequences cluster together but the two haplotypes belonging to M. unimarginata do not cluster together because of the internal position of Mabuya mabouya . The simplest explanation for this pattern is that perhaps the haplotype from Tobago belongs to M. unimarginata and not to M. mabouya . These two species are very similar in morphology and cannot be easily recognized in the field. If this is the case, this finding represents the first report of M. unimarginata from Tobago.

Figures

FIGURE 12. Karyotype of Mabuya unimarginata female (2 n = 32).