Saturday, April 24, 2021

[Herpetology • 2021] Cyrtodactylus hantu & C. miriensis • Genetically diverse yet morphologically conserved: Hidden Diversity Revealed among Bornean Geckos (Gekkonidae: Cyrtodactylus)

Intraspecific variation and interspecific overlap in live individuals of the Cyrtodactylus pubisulcus complex. 
 (B–C) C. pubisulcus s.s.; (E–F) C. hantu sp. nov.; and (H–I) C. miriensis sp. nov.

 Davis, Das, Leaché, Karin, Brennan, Jackman, Nashriq, Chan & Bauer, 2021 
The appreciation of cryptic biological diversity, and the pace at which it is recognized, has greatly increased with the use of molecular systematic techniques. The gekkonid genus Cyrtodactylus Gray, 1827 is one example of a group that has undergone a particularly rapid increase in recognized diversity due to molecular systematic studies. Many of these new species result from recognizing closely related but diagnosable lineages into sister taxa. Our study implements a multi‐faceted approach to delimit cryptic Cyrtodactylus lineages on the Southeast Asian island of Borneo using morphological, ecological, and multilocus genetic data. We use multiple species delimitation models to assess species boundaries and identify clades that warrant further investigation. Unlike most morphologically cryptic species that have recently diverged, we find evidence of cryptic lineages being polyphyletic. Using multivariate statistical analyses, we show minimal phenotypic distinction between putative cryptic species within the C. pubisulcus complex. Despite not finding morphologically diagnostic characters, we demonstrate strong evidence for the specific recognition of C. hantu sp. nov. and C. miriensis sp. nov., which are currently considered conspecific with C. pubisulcus, from Sarawak, Malaysia. Our new concept for C. pubisulcus restricts the geographic range of the species to specific regions in western Sarawak, Malaysia, thus underscoring the need to conserve the limited remaining habitats of these species, as well as the considerable undescribed diversity across Borneo.

ancestral state reconstruction, cryptic species, new species, species delimitation, Squamata

Intraspecific variation and interspecific overlap in live individuals of the Cyrtodactylus pubisulcus complex. 
Upper row (a–c) C. pubisulcus s.s.; middle row (d–f) C. hantu sp. nov.; and lower row (g–i) C. miriensis sp. nov.
Border colors correspond to the map presented in Figure 1

Cyrtodactylus hantu Davis et al., sp. nov. 
(C. sp. nov. Sibu) 
Pelagus Bent‐toed Gecko.

Etymology: The specific epithet hantu is in reference to the Malay word for ghost. We chose this specific epithet for two reasons: (1) the species was found around the Pelagus Resort, a now abandoned resort in the middle of the rainforest that is said to be haunted; (2) the cryptic characteristics of this species have enabled it to hide in plain sight.

Cyrtodactylus miriensis Davis et al., sp. nov. 
(C. sp. nov. Miri)
Miri Bent‐toed Gecko

Etymology: The specific epithet miriensis is in reference to the distribution of the species in the Miri Division of Sarawak.

Ancestral state estimation of Bornean Cyrtodactylus and their closely related congeners. Ancestral estimation performed using a Bayesian approach in the the R package “phytools” (Revell, 2012) with a mitochondrial ND2 ML phylogeny as the input tree.
Light green and dark blue = two banding patterns for medium‐sized rock dwelling, banded; light blue = small to medium‐sized forest dwelling, often blotchy; pink = large‐bodied forest dwelling, often banded; dark green = species that do not fit into these generalized patterns. Focal species in this study are highlighted with a yellow box

Hayden R. Davis, Indraneil Das, Adam D. Leaché, Benjamin R. Karin, Ian G. Brennan, Todd R. Jackman, Izneil Nashriq, Kin Onn Chan and Aaron M. Bauer. 2021. Genetically diverse yet morphologically conserved: Hidden Diversity Revealed among Bornean Geckos (Gekkonidae: Cyrtodactylus). Journal of Zoological Systematics and Evolutionary Research. DOI: 10.1111/jzs.12470