Thursday, September 16, 2021

[Herpetology • 2021] Chilabothrus ampelophis • A Small New Arboreal Species of west Indian Boa (Serpentes: Boidae) from southern Hispaniola

Chilabothrus ampelophis 
Landestoy, Reynolds & Henderson, 2021

 DOI: 10.3099/MCZ67.1 

Thirteen species of West Indian boas (Chilabothrus) are distributed across the islands of the Greater Antilles and Lucayan Archipelago. Hispaniola is unique among this group of islands in having more than two species of Chilabothrus—three are currently recognized. Here we describe a fourth species from Hispaniola, a newly discovered distinctive species of small boa from the dry forest of the Barahona Peninsula, southwestern Dominican Republic, near the border with Haiti. This new species resembles in body size and in other aspects its closest relative Chilabothrus fordii (Günther 1861), with which it appears to be allopatric. The new species, which we describe as Chilabothrus ampelophis sp. nov., differs from C. fordii in body, head, and snout shape; in scalation; in both coloration and color pattern; and in phylogenetic uniqueness. Some relevant meristic characters from C. ampelophis sp. nov. fall between C. fordii and C. gracilis (Fischer, 1888), accentuating the morphological and likely ecological differences from its sister species C. fordii. The discovery of this new species is especially important as it appears to be among the smallest boid (Boidae) species, has an arboreal specialization, and is found in a very restricted and highly threatened habitat.

Figure 5. Head shape and scutellation in dorsal view of
A, Chilabothrus fordii (MNHNSD 23.3904).
B-F, type series of Chilabothrus ampelophis sp. nov.: MNHNSD 23.3900, KUH 352337, MNHNSD 23.3902, MNHNSD 23.3901, MCZ R-197400, respectively.
Head-scale formula is indicated by light shading (intersupraocular or frontal scales) and numbers (3-1-2; F = frontal); dark shading highlights supraocular scales. Scale bars = 5 mm.

Figure 2. Chilabothrus ampelophis sp. nov.
Clockwise from top: KUH 352337 (5 December 2020), MNHSD 23.3901 (19 November 2020), MNHSD 23.3901 (19 November 2020).

Figure 6. Head and snout profiles of left, Chilabothrus ampelophis sp. nov. (MCZ R-197400) and right, C. fordii (MNHNSD 23.3906).
Note the flat head and protruding eyes and supraoculars above the level of frontal region in C. ampelophis; this region is convex with a gradually tapering snout in C. fordii.

Figure 7. Dorsal patterns of A, Chilabothrus ampelophis sp. nov. (MNHNSD 23.3901) and B, C. fordii (MNHNSD 23.3906).
Note the differences in coloration and shape of the primary elements: basically and predominantly a zigzag in C. ampelophis and ovate to subcircular blotches in C. fordii. Sizes are not to scale.

Chilabothrus ampelophis sp. nov.
Hispaniolan Vineboa

Etymology. The epithet is from ancient greek ampelos, meaning vine, in allusion to the slender body and head shape, which is rather unusual for the genus, and for the relative abundance of vines in the dry rocky habitat at the type locality. The suffix -ophis refers to a snake, hence the epithet is translated as ‘‘vinesnake.’’ 

Figure 8. Habitat of Chilabothrus ampelophis sp. nov. in the southwestern corner of the Dominican Republic.
A, aerial drone photo from March 2021 showing general habitat consisting of forested rolling hills from 200-to 400-m elevation where all specimens of C. ampelophis sp. nov. were found.
B and C, photos showing habitat characteristics of the type locality for C. ampelophis sp. nov.
D, agricultural encroachment along the foothills of the type locality.