Monday, February 8, 2021

[Herpetology • 2021] Calamaria alcalai • A New Species of Reed Snake, Genus Calamaria (Colubridae: Calamariinae), from Mindoro Island, Philippines

Calamaria alcalai
 Weinell, Leviton & Brown, 2021

Philippine Journal of Systematic Biology. 14(2)

We describe a new species of reed snake of the genus Calamaria Boie 1827, from Mindoro Island, Philippines. The new species differs from all other species of Calamaria by having the following combination of characters: a high number of subcaudal scale pairs (> 40 in males, > 30 females) and ventrals + subcaudals (> 205 in males, > 210 in females); mental scale not contacting chin shields; dorsal surface of head, body, and tail uniformly dark brown; and ventral surface of body (extending to include part or all of first longitudinal row of dorsals) uniformly pale (yellow or white in life). The new species is likely most closely related to Calamaria schlegeli Duméril, Bibron, and Duméril 1854, which also has a high number of subcaudal scales compared to other Calamaria species. The new species is the second Calamaria species known from Mindoro Island and the eighth known from the Philippines, and its presumed distant relationship from other Philippine Calamaria suggests an additional colonization of the Philippines by this genus from continental Asia. 

Keywords: biodiversity, biogeography, Calamaria alcalai new species, Serpentes, Squamata, systematics

In life photograph of Calamaria alcalai, new species (male paratype), KU 335918, Municipality of Sablayan, Occidental Mindoro Province, Philippines.
Photo: Scott Travers.

Calamaria alcalai, new species
 Alcala's Reed Snake

Diagnosis: The new species differs from all other southeast Asian species by having the following combination of characters: prefrontal scales large, bordering rostral scale; internasal scales absent; 13 longitudinal rows of dorsal scales throughout length of body; subcaudal scales > 30 pairs (females), > 40 pairs (males); mental scale not in contact with chin shields; preocular scale present; prefrontal scale not in contact with eye. Color pattern in life: dorsal surface of head, body, and tail maroon or light maroon; ventral surface of head and anterior of body yellow; ventral surface of posterior of body and tail pale cream; boundary between dorsal and ventral body coloration on first longitudinal row of dorsal scales light yellow to cream. Color pattern in ethanol: dorsal surface of head, body, and tail uniformly dark brown; ventral surface of head, body, and tail pale yellow or cream.

Etymology: The species epithet alcalai is a patronym in the genitive singular, honoring Dr. Angel C. Alcala, for his numerous contributions on the systematics, biogeography, and ecology of amphibians and reptiles of the Philippines—and, in general, for his influential promotion of conservation and sustainable management of the archipelago’s terrestrial and marine biodiversity. 

Map of the Philippines (a), and Mindoro Island (b) with elevation indicated by incremental shading (see key); red star = type locality of Calamaria alcalai, new species; blue circle = additional locality; both within the Municipality of Sablayan. Gray shading indicates areas ~ 120 m below sea level that are presumed to have been exposed land during Pleistocene glacial maxima, and represent the hypothesized limits of Pleistocene Aggregate Island Complexes (PAICs), including the distinct Mindoro PAIC, which encompasses small islands to the south; light blue color indicates large, present day lakes. In (a), B.I. = Babuyan Island Group, R.I. = Romblon Island Group.

Jeffrey L. Weinell, Alan E. Leviton And Rafe M. Brown. 2021.  A New Species of Reed Snake, Genus Calamaria (Colubridae: Calamariinae), from Mindoro Island, Philippines.  Philippine Journal of Systematic Biology. 14(2). DOI 10.26757/pjsb2020b14006.