Bothriechis rasikusumorum, 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 rasikusumorum sp. nov.

Figs 22 , 23 , 24

Type material.

Holotype: CZUT-R 349 (Fig. 22 ), adult male collected by Hugo Hernández at Vereda El Regenero, Huila department, Colombia (1.82023, -75.99867; 1616 m).

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

Proposed standard English name.

Shah’s Eyelash-Pitviper.

Proposed standard Spanish name.

Víbora de pestañas de los Shah.

Local Spanish name.

Culebra de tiro.

Diagnosis.

Bothriechis rasikusumorum sp. nov. is diagnosed based on the following combination of characters: (1) supraciliary scales low and granular, or two pointy but not raised; (2) anterior dorsal head scales smooth; (3) gular scales similar in size to chinshields; (4) 5-10 interoculolabials; (5) 2-3 canthals which may be flat or slightly raised forming a ridge along the canthus; (6) loreal not in contact with preocular; (7) yellow morph absent; (8) dorsal bands dark brown or black; (9) opposing kidney shaped dorsal marks absent; (10) black speckles on dorsal scales present; (11) black speckling on ventral surfaces prominent posteriorly; (12) ventral surfaces never entirely white; (13) iris light green, yellow, or reddish brown with black reticulations; (14) 21-23 dorsal scale rows at mid-body; (15) 144-152 ventrals in males, 152-153 in females; (16) maximum total length in males 650 mm, in females 799 mm.

Comparisons.

Bothriechis rasikusumorum 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 most of them by having supraciliaries not raised, a low number of canthals (2-3), a low number of ventral scales, and dorsal and ventral surfaces heavily speckled with black pigment (Figs 22 , 23a ). Bothriechis rasikusumorum sp. nov. resembles B. klebbai sp. nov., but this other species occurs on the northern portion of Colombia’s Cordillera Oriental and is characterized by having less than 152 ventrals in females, a rich reddish-brown iris, a series of paired oblong blotches on each side of the dorsum, and no basal hooks on the hemipenial body (Fig. 21 ). Bothriechis rasikusumorum sp. nov. is also similar to B. schlegelii , but this other species occurs northwest of the known distribution of B. rasikusumorum sp. nov. and is characterized by lacking black speckles on the dorsal and ventral scales in most populations (Figs 12 , 13 ), having two triangular and moderately raised supraciliary scales, and basal hooks that are 3-10X the size of adjacent spines at the base of the hemipenial body (Fig. 14 ).

Hemipenial morphology.

(n = 1; Fig. 24 ) Everted and inflated, the organ is deeply bilobed, calyculate and noncapitate; hemipenial lobes cylindrical, narrower towards the capitulum; in sulcate and asulcate views, lobe crotch ornamented with densely packed small spines that become larger distally; sulcus spermaticus centrolineal, bifurcate and with walls strongly defined, bifurcation occurs below bilobation point and proximal to the base of the hemipenial body; sulcus spermaticus branch runs to lobe tips; distal half of each hemipenal lobe densely ornamented with small calyces with strongly defined spinulate edges. In sulcate view, hemipenial body surface with small spinules medially, but with a pair of enlarged and strongly calcified lateral spines (basal hooks) followed by 4-5 rows of smaller obliquely-arranged mesial spines that become gradually smaller towards each lobe’s capitulum; each hemipenial lobe ornamented with mesial and lateral spines about half the size of the basal hook; the spines in each lobe are replaced distally by calyces with strongly spinulate edges. In lateral view, hemipenial body and lobes with rows of spines, but otherwise non-spiculate; distal half of lobes strongly calyculate. In asulcate view, the center of hemipenial body covered with scattered spinules; hemipenial lobes ornamented with 3 rows of spines.

Description of holotype.

An adult male, SVL 536 mm, tail length 114 mm (21.3% SVL); head length 30.2 mm (5.6% SVL) from tip of snout to angle of jaw; head width 24.2 mm (80.1% head length) taken at broadest point; rostral broader than high (4.2 × 2.3 mm); nasal not entirely divided; incomplete suture between nasal and first supralabial; loreal about 1/3 size of pit, contacting postnasal, 1 canthal, 1 suprafoveal, 2 prefoveals, lacunolabial, and preocular; prefoveals 5/4; subfoveals 2/2; postfoveals 0; prelacunal fused with second supralabial on the right side; sublacunals 2/2 (one of which is small and granular); supralacunal elongated and in contact with 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 8/8 (including lacunolabial); infralabials 11/11, first pair barely fail to meet posteriorly due to stretched skin; mental broader than long (4.2 × 2.3 mm); 1 pair of chinshields; 5 pairs of gulars between chinshields and preventrals; preventrals 1; anterior internasals 2; canthals 3/2; supraciliary scales low and granular with the exception of a pair of raised and triangular scales; supraoculars B-shaped, 2.5 × longer than wide; intersupraoculars 5; anterior dorsal head scales smooth; posterior head scales barely keeled; interrictals 27; dorsal scale rows 23/23/19; ventrals 147; cloacal plate entire; 56 undivided subcaudals; tail prehensile.

Natural history.

Bothriechis rasikusumorum sp. nov. is an arboreal snake that inhabits montane cloud forests and coffee plantations (Erik Gaitan, pers. comm.). Vipers of this species have been seen at night or during the day, either on leaf-litter or on low understory vegetation less than 2 m above the ground.

Venom.

We know of no snakebites caused by this species in Colombia nor any studies on the venom that could be assigned to this species.

Distribution.

Bothriechis rasikusumorum sp. nov. is known from at least 26 localities (listed in Suppl. material 3) along the upper watershed of the Río Magdalena in Huila department, Colombia. The species occurs over an area of approximately 6,578 km2 along the eastern slope of Cordillera Central and on both slopes of Cordillera Oriental at elevations 1,298-2,180 m above sea level (Fig. 3 ).

Etymology.

The specific epithet rasikusumorum is a patronym honoring Rasik Shah (1939-2022), Kusum Shah (1942-present), and their grandson Oscar Shah. The Shah family helped fund the expedition that led to the discovery of this new species.

Conservation status.

We consider Bothriechis rasikusumorum 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 much less than 20,000 km2 (Fig. 3 ) and its habitat is severely fragmented and declining in extent and quality due to deforestation. Although B. rasikusumorum sp. nov. occurs in three protected areas (Parque Nacional Cueva de los Guácharos, Bosque Protector Pompeya, and Reverva Chiyurco), most localities where the species has been recorded (Suppl. material 1) are in forest patches surrounded by a matrix of pastures and plantations. 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 71% of the forest cover throughout the species’ potential distribution area has been destroyed, mostly due to the expansion of the agricultural frontier. One of us (JV) interviewed coffee plantation workers in Huila, who report that they routinely kill these vipers when found. During a 10-night expedition to Huila department, a group of three field biologists led by JV failed to find a single specimen in four of the localities where the species has been reported nearby the city Pitalito.

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 12. Photographs of some specimens of Bothriechis schlegelii from Antioquia department, Colombia, in life. a, c, f. From the live collection at INSV-SR, Serpentario Nacional de Colombia; b, d, e, g. from the live collection at SUA, Serpentario de la Universidad de Antioquia. Photos by Jose Vieira.

Figure 13. Photographs of some specimens of Bothriechis schlegelii in life. a. Adult from Planes de San Rafael, Risaralda department, Colombia; b-f. Adults from Popayan, Cauca department, Colombia, photographed at the Serpentario de la Universidad del Cauca. Photos by Jose Vieira and Amanda Quezada.

Figure 14. Hemipenial architecture of Bothriechis schlegelii in sulcate, lateral, and asulcate views. a. IAVH-R 6055 from Reserva Tesorito, Valle del Cauca department, Colombia; b. IAVH-R 6598 from Popayan, Cauca department, Colombia; c. IAVH-R 5465 from Fresno, Tolima department, Colombia. Photos by Duvan Zambrano.

Figure 21. Hemipenial architecture of Bothriechis klebbai sp. nov. in sulcate, lateral, and asulcate views. a. ICN 2786 and b. ICN 2855 from Virolin, municipio de Charala, Santander department, Colombia; c. UIS-R 4803 from vereda Naranjal, municipio de Coromoro, Santander department, Colombia. Photos by Duvan Zambrano and Elson Meneses Pelayo.

Figure 22. Adult male holotype of Bothriechis rasikusumorum sp. nov. CZUT-R 349 in a. Dorsal and b. Ventral view. Photos by Duvan Zambrano.

Figure 23. Photographs of living specimens of Bothriechis rasikusumorum sp. nov. from Huila department, Colombia. a. La Umbria; b. SUA 4659 Finca Miraflores. Photos by Jose Vieira and Duvan Zambrano.

Figure 24. Hemipenial architecture of Bothriechis rasikusumorum sp. nov. in sulcate, lateral, and asulcate views. ICN 11164 from Parque Nacional Cueva de Los Guacharos, Huila department, Colombia. Photos by Duvan Zambrano.