Gonyosoma prasinum (BLYTH, 1854)
Can you confirm these amateur observations of Gonyosoma prasinum?
|Higher Taxa||Colubridae, Colubrinae, Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes)|
|Common Names||E: Green Trinket Snake, Green Bush Rat Snake, Green Ratsnake|
G: Grüne Strauchnatter, Grüne Spitzkopfnatter
|Synonym||Coluber prasinus BLYTH 1854: 291|
Gonyosoma gramineum GÜNTHER 1864 (fide SMITH 1943)
Coluber prasinus — BOULENGER 1894: 59
Elaphe prasina — SMITH 1930
Elaphe prasina — SMITH 1943
Elaphe prasina — TWEEDIE 1950
Elaphe prasina — GRANDISON 1978: 288
Gonyosoma prasina — DOWLING & JENNER 1988
Elaphe prasina — SCHULZ 1996: 201
Gonyosoma prasina — DAS 1997
Elaphe prasina — MANTHEY & GROSSMANN 1997: 344
Elaphe prasina — COX et al. 1998: 53
Gonyosoma prasinum — DAVID et al. 2004
Gonyosoma prasinum — UTIGER et al. 2005
Elaphe prasina — ZHAO 2006
Gonyosoma prasinum — ZIEGLER et al. 2007
Elaphe prasina — DAS & YAAKOB 2007
Rhadinophis prasina — BURBRINK 2007
Elaphe prasina — STUART & HEATWOLE 2008
Gonyosoma prasinum — NGUYEN et al. 2009
Rhadinophis prasinus — SCHULZ 2011
Rhadinophis prasina — ZAHER et al. 2012
Rhadinophis prasinus — DAS 2012
Rhynchophis prasinus — WALLACH et al. 2014: 655
Gonyosoma prasinum — CHEN et al. 2014
Gonyosoma prasina — CHAN-ARD et al. 2015: 168
Gonyosoma prasinus — FELDMAN et al. 2015
Gonyosoma prasinum — BOUNDY 2020
|Distribution||India (Darjeeling, Assam, Arunachal Pradesh [A. Captain, pers. comm.], Mizoram), NW Myanmar (= Burma)|
Type locality: “Asám” [= Assam, India, but could be any part of north-eastern India]
gramineum: Type locality: “probably from Khasya” [= Khasi Hills, Meghalaya]
|Types||Syntypes: ZSI 7669 and ZSI 7671|
Lectotype: BMNH 1918.104.22.168 (formerly IMC 7670 & BMNH 1822.214.171.1245), longest syntype 940 mm (W. Robinson), designated by Cox et al. (2013: 221), fide Wallach et al. 2014: 655. This is in error; this specimen does not belong to the original series of syntypes of Coluber prasinus but is the holotype of Gonyosoma gramineum (fide David et al. 2022).
Holotype: NHMUK 19126.96.36.199 (probably male) [gramineum]
|Diagnosis||Description (holotype, ZSI 7669, female): Body elongate, distinctly laterally compressed; head elongate, triangular, slightly narrowed anteriorly, rather thick posteriorly, flattened anteriorly, moderately distinct from the relatively thick neck; snout long, rather flattened, rounded from dorsal view, truncated from lateral view, not projecting beyond the lower jaw, 2.15 times as long as the horizontal eye diameter; no canthus rostralis; nostril lateral, large, vertically ovoid, piercing the upper posterior edge of the prenasal; eye large, its diameter about 1.6 times greater than the distance between its lower edge and the lower margin of the lip, with a round pupil; tail long, slender, cylindrical, tapering and prehensile.|
Measurements.—SVL: 627 mm; TaL: 222 mm; TL: 849 mm; ratio TaL/TL: 0.261.
Head. HL: 24.5 mm; HW: 12.4 mm; SnL: 8.4 mm; DE-h: 3.9 mm; DE-v: 3.7 mm; DE-Lip: 2.5 mm; InNar-D: 5.4 mm; InOrb-D: 9.2 mm.
Body scalation. Dorsal scales in 21–19–15 rows, feebly keeled on 4th upper rows of each side plus the vertebral row, scales of the 1st–5th DSR smooth; scales of 1st DSR only barely enlarged; 203 ventral plates, distinctly angulate with a strong lateral keel; 107 subcaudal scales, all paired, angulate and laterally keeled; cloacal plate entire.
Head scalation. Arrangement of upper head scales complete, including 2 internasals, 2 prefrontals, 2 supraoculars, 1 frontal, and 2 parietals. Rostral well developed, wider than high, visible from above but barely separating internasals; a large nasal on each side, rectangular, much elongate, divided in its middle by the large nostril and a suture below the nostril, both parts pentagonal; internasals short but wide, more or less pentagonal, distinctly wider than long, in contact with each other along a long suture; prefrontals large, hexagonal, bent ventrolaterally and going low downward on the side of the snout, in contact with the loreal, about twice longer than internasals; one supraocular on each side, entire, subtriangular, broad, widening posteriorly, twice longer than wide and much narrower than the frontal; frontal bell-shaped, its round apex pointing backward, large but squat, slightly longer than wide, about 1.9 times longer than prefrontals; parietals large, long and wide and distinctly longer than frontal; 1/1 loreal scale, small, subrectangular, much elongate; 9/9 SL, 1st–4th SL tall, 1st–2nd in contact with the nasal, 2nd–3rd in contact with the loreal, 4th–6th entering orbit, 8th SL largest; 1/1 preocular, large, longer than high, reaching the upper head surface and touching the frontal as a wedge between the supraocular and the prefrontal; 2/2 small postoculars; 2+2 / 2+2 temporals; 10/10 IL, first pair in contact behind the mental, 1st–5th IL in contact with anterior chin shields, 6th IL largest; mental triangular, small; anterior chin shields shorter than posterior chin shields.
Coloration and pattern. The dorsum and sides of the body are uniform bluish-brown, somewhat paler on the lower sides on 1st and 2nd DSR. The tail is uniform bluish-brown as is the body.
The head is uniform deep greenish-blue above; rostral and region of the nasal and loreal paler, more yellowish-green; anterior supralabials pale greenish-blue, paler than the crown; other supralabials behind the level of the eye are pale bluish-green; temporal area ultramarine-blue. The chin and throat are pale greenish-yellow. The iris is greenish-grey; the pupil is black.
The venter is pale greenish-yellow anteriorly, more pale green posteriorly, darker bluish-green on the outer parts of ventral plates; keels of ventrals cream, forming on each side of the venter a pale line extending from the neck to the vent. The ventral surface of the tail is as the venter anteriorly quickly turning to dark reddish-brown. See also (Fig. 2A–e), David et al. 2022.
For a description of the Holotype of Gonyosoma gramineum see David et al. 2022: 181.
|Comment||Distribution: Possibly in Bhutan (Lenz 2012). Erroneously reported for the Andaman Islands (DAS 1999). Populations from N Thailand, West Malaysia, Laos, Vietnam, China (Yunnan, Guizhou, Sichuan, Hainan) are now considered to be G. coeruleum (David et al. 2022). “Probably” in Nepal, e.g. fide Schleich & Kästle (2002) but without specific records (David et al. 2022).|
Synonymy: mostly following SMITH 1943 and David et al. 2022.
Nomenclature: Rhadinophis is male and thus the name has to be “prasinus”.
Habitat: not arboreal (Harrington et al. 2018).