Saturday, August 22, 2015

[Herpetology • 2015] Cryptotriton xucaneborum • Biogeography and Evolution of Central American Cloud Forest Salamanders (Caudata: Plethodontidae: Cryptotriton), with the Description of A New Species


Cryptotriton xucaneborum
Rovito, Vásquez-Almazán, Papenfuss, Parra-Olea & Wake, 2015
Figure 6. (A) Holotype of Cryptotriton xucaneborum in life. (B) Ventral view of holotype showing dark grey ventral coloration.(D) View of type locality of C. xucaneborum, showing small forest fragment surrounded by agricultural land. (E) Habitat where holotype of C. xucaneborum was collected.

The cloud forests of Mesoamerica are notable for their high endemism, and plethodontid salamanders provide a striking example of divergence and microendemism across cloud forest blocks at a regional level. Salamanders that make use of arboreal bromeliad microhabitats in the cloud forest appear to be especially prone to divergence driven by natural habitat fragmentation, and are expected to show high endemism at small spatial scales. We use a multilocus dataset to investigate the biogeographic history and relationships among species of a small genus of salamander, Cryptotriton, restricted to the cloud forests of Nuclear Central America. We use a morphological data set along with a coalescent species delimitation method to reveal the presence of at least one undescribed species from an isolated cloud forest in eastern Guatemala. Biogeographic analyses show that Cryptotriton has a different biogeographic history than another clade of cloud forest-restricted salamanders in the same region, perhaps indicating that each genus restricted the spatial expansion and diversification of the other through preemptive occupancy. Our results suggest that isolation across relatively short geographic distances has led to range fragmentation and deep divergence between species. Exploration of remaining patches of cloud forest likely will continue to reveal undetected diversity.

Keywords: bolitoglossine salamander; Chiapas; Guatemala; Honduras; microendemism; molecular phylogenetics; morphology; species delimitation; species tree


Cryptotriton xucaneborum, new species
Sierra de Xucaneb Hidden Salamander
Salamandra Escondida de la Sierra de Xucaneb
Cryptotriton veraepacis McCranie and Rovito, 2014 (part)
Cryptotriton veraepacis Vásquez-Almazán et al. 2009 (part)
Cryptotriton veraepacis Lynch and Wake, 1978 (part)

........  DOI: 10.1111/zoj.12268

Figure 6. (A) Holotype of Cryptotriton xucaneborum in life. (B) Ventral view of holotype showing dark grey ventral coloration. (C) Ventral view of an individual of Cryptotriton veraepacis (USAC 1920) showing lighter grey ventral coloration. (D) View of type locality of C. xucaneborum, showing small forest fragment surrounded by agricultural land. (E) Habitat where holotype of C. xucaneborum was collected.

Habitat and distribution. – Known only from two localities separated by 22 km in the Sierra de Xucaneb, Alta Verapaz, Guatemala. The species may occur at a few other points of relatively high elevation in the Sierra de Xucaneb, but extensive deforestation in most areas has eliminated what may have once been suitable habitat for the species. The holotype was found in an arboreal bromeliad, while the four paratypes from Chelemhá were found active at night on vegetation 1–2 m above the ground. The forest at Finca Volcán represents a transition from lower elevation forest to cloud forest, with relatively few bromeliads and other epiphyte growth, and is classified as subtropical rainforest (Holdridge, 1967), while habitat at Chelemhá is lower montane rain forest (Holdridge, 1967) with typical cloud forest vegetation and extensive epiphyte cover. The only syntopic species of salamander known to occur with Cryptotriton xucaneborum is Bolitoglossa helmrichi, which occurs at both known sites.


Sean M. Rovito, Carlos R. Vásquez-Almazán, Theodore J. Papenfuss, Gabriela Parra-Olea and David B. Wake. 2015. Biogeography and Evolution of Central American Cloud Forest Salamanders (Caudata: Plethodontidae: Cryptotriton), with the Description of A New Species. Zoological Journal of the Linnean Society. 175(1); 150–166.  DOI: 10.1111/zoj.12268

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