Oxybelis koehleri JADIN, BLAIR, ORLOFSKE, JOWERS, RIVAS, VITT, RAY, SMITH & MURPHY, 2020
Can you confirm these amateur observations of Oxybelis koehleri?
|Higher Taxa||Colubridae, Colubrinae, Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes)|
|Common Names||E: Köhler’s Vine Snake|
|Synonym||Oxybelis koehleri JADIN, BLAIR, ORLOFSKE, JOWERS, RIVAS, VITT, RAY, SMITH & MURPHY 2020|
Oxybelis aeneus — DUMÉRIL & BIBRON 1854: 819
Dryophis acuminata – GÜNTHER 1858: 156 (part)
Dryophis (Coluber) acuminatus — GÜNTHER 1860: 233 (part)
Dryiophis acuminata — COPE 1878: 34
Oxybelis acuminata – BOULENGER 1896: 192
Oxybelis acuminatus — BOCOURT 1897
Oxybelis acuminatus — BARBOUR 1916
Oxybelis acuminatus — STUART 1935: 53
Oxybelis aeneus aeneus – BOGERT & OLIVER 1945: 381
Oxybelis aeneus – KEISER 1974: 7
|Distribution||Guatemala, Honduras, El Salvador, Nicaragua, Costa Rica|
Type locality: Guatemala: El Arenal (circa 560 m, 14° 53′ 1.788′′ N, 89° 46′ 31.799′′ W) of the Municipio Cabañas in the Department of Zacapa
|Types||Holotype: UTA R-46846 (ENS 9858), a female. Collected by a local between Feb and May 1998, preserved 24 Aug 1998.|
Paratypes: UTA R-44838 Nicaragua: Jinotega, El Paraiso Km 152.5, carretera Jinotega-Matagalpa, 1490 m; UTA R-46865 Honduras: Comayagua, Playitos: Aldea “Lo de Reina”, 785 m. UTA R-53176–77 Honduras: Gracias a Dios, Mocorón, 30–50 m.
|Diagnosis||Diagnosis: A vine snake with (1) three upper labials (4–5–6) bordering the orbit; (2) black spots or bars on anterior body, brown uniform brown with little black pigment; (3) labials white and underside of head red–brown with a medial red–brown stripe in females; (4) eye diameter greater than preocular length; (5) second pair of chin shields in contact for most of their length; (6) nine upper labials, three located behind the orbit; (7) snout from above is narrow, tapered, and rounded (snout type A); (8) supraocular is longer than the prefrontal; (9) last upper labial and primary temporal about the same length; and (11) second upper labial does not contact the preocular.|
Variation Rostral is not visible from above and followed by nine plate-like scales on the crown: a pair of internasals, a pair of prefrontals, the frontal, two larger supraoculars, and a pair of parietals. Preoculars extend slightly on to the crown between the prefrontals and supraoculars. The internasals are 75% (r = 0.63–1.0) of the prefrontal length. Average eye diameter is 1.19 (r = 0.83–1.53) the preocular length. In profile, the nasal scale is elongate extending from the edge of the rostral, beyond the preocular scale is short and less than the diameter of the eye. Scales bordering the orbit are the preocular, the supraocular, two small postoculars, and upper labials 4–5–6. Primary temporal contacts both postoculars, the parietal, and two secondary temporals, as well as upper labials 6–7–8–9. Upper labials number nine (rarely eight or ten). The shortest upper labial can be the first or the eighth. The last (usually the ninth) upper labial is the longest. Upper labials 1–2 contact the nasal, 2–3 contact the prefrontal–loreal, 3–4 contact the preocular. Lower labials vary from eight through 10, usually 9; the first four contact the anterior chin shields, a total of six contact both pair of chin shields. The anterior pair of chin shields are shorter (about 60%) than the length of the second pair; the second pair are in contact for most of their length. Dorsal scales are in 17–17–13 rows.
In males, total length ranged from 1135 to 1432 mm (n = 6, x = 1329.83, SD = 106.68), SVL 673–835 mm (n = 7, x = 783.71, SD = 62.55), tail lengths 462–600 mm (n = 7, x = 554.0, SD = 47.75), tail/SVL ratios (n = 7, r = 0.67–0.79, x = 0.71, SD = 0.04). In females, total lengths ranged from 1137 to 1300 mm (n = 8, x = 1221.43, SD = 63.72); tails ranged from 425 to 527 mm (n = 7, x = 478.14, SD = 31.22). Tail/ SVL ratios in females 0.53–0.73, x = 0.65, SD = 0.06.
Ventrals in males vary from 176 to 191 (n = 7, x = 183.83, SD = 4.88); ventrals in females vary from 184 to 191 (n = 7, x = 187.57, SD = 2.26). Subcaudals in males vary from 164 to 186 (n = 5, x = 177, SD = 8.12); in females, subcaudals vary from 176 to 189 (n=5, x=184.8, SD=5.91).
Coloration and pattern: Head usually a uniform brown (it may have some darker pigmented spots), body brown with light mottling and some dark spots anteriorly, posteriorly indistinct transverse blotches that are wide on the vertebral line and narrow laterally; upper labials cream to white and separated from the brown by a black stripe on the dorsal edge of the second labial that extends past the eye to the last labial; lower labials have some red–brown pigmentation; ventral surface of head tan laterally with a red–brown medial stripe that extends from the mental onto the first 15 ventrals. Longitudinal ventral stripes absent. All adult females we have examined (including sequenced material) have a red–orange stripe on the underside of the head and onto the first 12 anterior ventrals, and the coloration is present as spots on some upper labial scales (Fig. 9).
In alcohol, (FMNH 27050) the coloration and pattern are much reduced. The head is gray–brown, the labials are white, and the marking on the lower labials, along with the reddishbrown chin, is usually absent. The ventral side of the head is uniform cream. The dorsum is gray with black lateral spots where the transverse blotches were in life. The ventrals are pale with dense mottling.
Comparison A vine snake with nine upper labials, three of which border the orbit, an eye diameter that is about equal to the length of the internasal, three upper labials in contact with the primary temporal, and the second pair of chin shields in contact for most of their length. Specimens of O. aeneus and those from northern South America have the second pair of chin shields separated for most of their length. Specimens from the western region have an eye diameter that is less than the length of the internasals while those from Panama usually have eight upper labials.
|Comment||Habitat: fully arboreal (Harrington et al. 2018, by implication).|
Distribution: While Jadin et al. 2020 say that the species occurs “from Guatemala to Costa Rica, their map (Fig. 3) doesn’t mention this species but only vaguely refers to “Central American” specimens, which actually do not reach Costa Rica but only N Honduras. Hence the range of this species remains a somewhat unclear.
|Etymology||Named after Gunther Köhler, German herpetologist who has contributed greatly to the knowledge on the systematics and natural history of Central American amphibians and reptiles.|