Monday, May 28, 2012

Two New Cryptic Species of Pit Vipers in the Genus Cerrophidion from Central America

Top: Cerrophidion sasai. Bottom: C. wilsoni. Photos: Eric Smith UTA 
The discovery of cryptic species has become increasingly frequent with the application of molecular phylogenetic analyses, particularly for species with broad geographic distributions. Now, Jadin et al. (2012) have described two new species of Central American montane pit vipers in the genus Cerrophidion, that had been previously confused with C. godmani, a widely distributed highland species found throughout Central America. The authors provide evidence based on both molecular phylogenetic analyses and morphological data that C. godmani represents three deeply divergent lineages and note that it is possibly polyphyletic. These three lineages are relatively conserved in their morphology and tend to be highly variable among individuals, but morphological characters were available to diagnose them as evolutionarily distinct.

The Costa Rica montane pitviper, Cerrophidion sasai has a known range that includes parts of two mountain ranges which together cover portions of Costa Rica and Panama. The species occurs in both the Cordillera Central and the Cordillera de Talamanca. C. sasai uses lower montane and montane forest habitats as well as disturbed highland habitats.

The Honduran Montane pitviper, Cerrophidion wilsoni, inhabits lower montane rainforest between 1400 and 3491 m and may occur in nearby premontane rainforest and pine-oak forest as low as 1220 m and all known populations of C. wilsoni occur within the borders of Honduras and El Salvador but the highland areas that support populations of C. wilsoni in Honduras and El Salvador also extend into eastern Guatemala and the authors suggest the species very likely occurs in that country.

Five species of Cerrophidion are now known to occur in Neotropical montane habitats between ca. 1200 and 3500 m in elevation Two of these species (C. petlalcalensis and C. tzotzilorum) are endemic to Mexico and are restricted to geographically small ranges The third, C. godmani, is restricted by the authors to Guatemala and Mexico.

Jadin, R.C., Townsend, J.H., Castoe, T.A. and Campbell, J.A. (2012), Cryptic diversity in disjunct populations of Middle American Montane Pitvipers: a systematic reassessment of Cerrophidion godmani. Zoologica Scripta. doi: 10.1111/j.1463-6409.2012.00547.x

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