Bothriechis khwargi, Arteaga & Pyron & Batista & Vieira & Meneses Pelayo & Smith & Barrio Amorós & Koch & Agne & Valencia & Bustamante & Harris, 2024

Arteaga, Alejandro, Pyron, R. Alexander, Batista, Abel, Vieira, Jose, Meneses Pelayo, Elson, Smith, Eric N., Barrio Amoros, Cesar L., Koch, Claudia, Agne, Stefanie, Valencia, Jorge H., Bustamante, Lucas & Harris, Kyle J., 2024, Systematic revision of the Eyelash Palm-Pitviper Bothriechis schlegelii (Serpentes, Viperidae), with the description of five new species and revalidation of three, Evolutionary Systematics 8 (1), pp. 15-64 : 15

Bothriechis khwargi sp. nov.

Figs 17 , 18

Type material.

Holotype: UIS-R 4294 (Figs 17 , 18b ), adult female collected by Elson Meneses-Pelayo on November 15, 2017 at Finca la Esperanza, vereda Sogamoso, municipio de Betulia, Santander department, Colombia (7.00600, -73.421608; 1195 m).

Paratypes: All labeled Bothriechis khwargi sp. nov. in Suppl. material 1.

Proposed standard English name.

Khwarg’s Eyelash-Pitviper.

Proposed standard Spanish name.

Víbora de pestañas de Khwarg.

Diagnosis.

Bothriechis khwargi sp. nov. is diagnosed based on the following combination of characters: (1) two triangular and moderately raised supraciliary scales; (2) anterior dorsal head scales keeled; (3) gular scales much smaller than chinshields; (4) 7-14 interoculolabials; (5) 3-4 canthals, some of which with raised triangular projections; (6) loreal in contact with preocular in ~1/3 of specimens; (7) yellow morph absent; (8) dorsal bands absent, faint, or restricted to top of dorsum in juveniles; (9) opposing kidney shaped dorsal marks absent; (10) black speckles on dorsal scales absent; (11) black speckling on ventral surfaces absent; (12) ventral surfaces entirely white in most individuals; (13) iris pale green or straw yellow; (14) 21-23 dorsal scale rows at mid-body; (15) 144-153 ventrals in males, 145-154 in females; (16) maximum total length in males 219 mm, in females 610 mm.

Comparisons.

Bothriechis khwargi sp. nov. is compared to other species of the genus previously subsumed under B. schlegelii sensu lato (differences summarized in Table 2 ). It differs from all of them by having two triangular and moderately raised supraciliary scales, anterior head scales keeled, gular scales much smaller than chinshields, entirely pale white belly in most individuals, and dorsal bands faint or absent. Bothriechis khwargi sp. nov. resembles B. torvus , but this other species does not occur along the slopes of the Cordillera Oriental and is characterized by having thin pink bands on the dorsum (Fig. 15 ). Bothriechis khwargi sp. nov. occurs in sympatry with B. klebbai sp. nov. along the upper slopes of the Serranía De Los Yariguíes, but it differs from this other species by being smaller in body size, having an entirely white belly, pale greenish iris, keeled anterior dorsal head scales, gulars much smaller than chinshields, and by lacking black speckling on dorsal and ventral surfaces (Fig. 18 ).

Description of holotype.

An adult female, SVL 511 mm, tail length 99 mm (19.4% SVL); head length 31.7 mm (6.2% SVL) from tip of snout to angle of jaw; head width 21.8 mm (68.8% head length) taken at broadest point; rostral broader than high (3.0 × 2.6 mm); nasal divided and not fused with first supralabial; loreal about same size of pit, contacting postnasal, 1 canthal, 1 prefoveal, supralacunal, lacunolabial, and preocular; prefoveals 4/4; subfoveals 3/3; postfoveals 0; prelacunal fused with second supralabial; sublacunals 1/1; supralacunal elongated and barely reaches orbit; preoculars 1/1 (2/2 if supralacunal is considered a preocular); suboculars 1/1; postoculars 1/1; loreal pit large, directed anteriorly, located slightly below line drawn from center of eye to naris; supralabials 9/8 (including lacunolabial); infralabials 11/12, first pair meet posteriorly; mental broader than long (4.0 × 1.4 mm); 1 pair of chinshields; 5 pairs of gulars between chinshields and preventrals; preventrals 2; anterior internasals 2; canthals 3/3; supraciliary scales low and granular with the exception of a pair of low, but triangular and pointed scales; supraoculars bean-shaped, 2.3 × longer than wide; intersupraoculars 8; anterior dorsal head scales lightly keeled; posterior head scales strongly keeled; interrictals 25; dorsal scale rows 23/23/19; ventrals 154; cloacal plate entire; 54 undivided subcaudals; tail prehensile.

Natural history.

Bothriechis khwargi sp. nov. is an arboreal snake that inhabits evergreen foothill forests. Vipers of this species have been seen at night or during the day, either at ground level or on low understory vegetation. EMP and CLBA found one individual at 1 m above the ground in a fern foraging at night.

Venom.

We know of no snakebites caused by this species in Colombia.

Distribution.

Bothriechis khwargi sp. nov. is known from at least 19 localities (listed in Suppl. material 3) along the western foothills of Colombia’s Cordillera Oriental. The species occurs over an area of approximately 14,697 km2 and has been recorded at elevations 167-1,800 m above sea level (Fig. 3 ). Approximately 29% of the predicted area of distribution of B. khwargi sp. nov. overlaps with that of B. klebbai sp. nov., and we found evidence of sympatry between the two species at elevations above 1,700 m on the western slopes of the Serranía de los Yariguíes. UIS-R 4447 is a B. klebbai sp. nov. and was found just 3.7 km airline distance from a photographic record of an B. khwargi sp. nov.

Etymology.

This species is named in honor of Dr. Juewon Khwarg, in recognition of his support of the discovery and protection of new species of vipers in the Andes of Colombia. Khwarg is a conservationist with a special love for the lesser-known reptiles of the unexplored regions of the tropics.

Conservation status.

We consider Bothriechis khwargi sp. nov. to be included in the Vulnerable category following the IUCN criteria B1a, b (i, iii, iv) ( IUCN 2012), because the species’ extent of occurrence is estimated to be less than 20,000 km2 (Fig. 3 ) and its habitat is severely fragmented and declining in extent and quality due to deforestation. Although B. khwargi sp. nov. occurs in one national park ( Serranía de los Yariguíes) and a privately protected area (Reserva Natural Reinita Cielo Azul), most localities where the species has been recorded (Suppl. material 3) are in heavily human-modified areas. Based on the species distribution model presented in Fig. 3 in combination with maps of vegetation cover of Colombia ( IDEAM 2014), we estimate that nearly 79% of the forest cover throughout the species’ potential distribution area has been destroyed, mostly due to the expansion of the agricultural frontier.

Figures

Figure 3. Distribution of species of Bothriechis previously subsumed under B. schlegelii sensu lato. Each colored area is a geographic representation of the suitable environmental conditions for one of the clades recovered in the phylogeny of Fig. 2. Lime green shade in southeastern Panama represents overlap between between B. nigroadspersus and B. torvus.

Figure 15. Photographs of some specimens of Bothriechis torvus in life. a. Adult and b. Juvenile (same individual) from Morromico Reserve, Choco department, Colombia; c. TH 145 adult female from Morromico Reserve, Choco department, Colombia; d. Adult and e. Juvenile from Uraba, Antioquia department, Colombia. Photos by Jose Vieira.

Figure 17. Female holotype of Bothriechis khwargi sp. nov. UIS-R 4294 in a. Dorsal and b. Ventral view. Photos by Johan Cordon-Rangel.

Figure 18. Photographs of some specimens of Bothriechis khwargi sp. nov. in life. a. UIS-R- 4921 female from Quebrada La Boquerona, vereda La Putana, municipio de Betulia, Santander department b. UIS-R 4294 female holotype from Finca La Esperanza, vereda Sogamoso, municipio de Betulia, Santander department, Colombia. Photos by Jose Vieira and Elson Meneses Pelayo.