Sinonatrix aequifasciata (BARBOUR, 1908)
Can you confirm these amateur observations of Sinonatrix aequifasciata?
|Higher Taxa||Colubridae (Natricinae), Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes)|
|Common Names||Asiatic Water Snake|
|Synonym||Natrix aequifasciata BARBOUR 1908: 317|
Natrix aequifasciata — MELL 1931 
Sinonatrix aequifasciata — ROSSMAN & EBERLE 1977
Sinonatrix aequifasciata — VOGEL et al. 2004
Sinonatrix aequifasciata — NGUYEN et al. 2009
Sinonatrix aequifasciata — WALLACH et al. 2014: 677
|Distribution||China (Guangxi, Guangdong, Hong Kong, Hainan, Fujian, Guizhou, Hunan, Jiangxi, Sichuan, Zhejiang),|
N Vietnam (Hoa Binh, Vinh Phuc, Lao Cai, Ha Giang, Cao Bang southwards to Nghe An, Ha Tinh), Laos
Type locality: “Mt. Wuchi”, now Mt. Wuzhi, Hainan Island, People’s Republic of China).
|Types||Holotype: MCZ 7101|
|Comment||Specimens from Yunnan have been redescribed as S. yunnanensis.|
Description.- Body stout, cylindrical; head oval, strongly elongate, rather narrow, barely distinct from neck; snout long, accounting for 29.2 % of total head length, 2.0 as long as horizontal diameter of eye, slightly flattened, narrowing at its tip which is nearly blunt when seen from above, rounded seen from side, with no defined canthus rostralis; nostril dorsolateral, directed upwards; eye large, its diameter much greater than distance between its inferior margin and upper lip edge; pupil rounded; tail long, cylindrical and clearly progressively tapering. Maxillary teeth 23, gradually enlarged posteriorly. Snout-vent length 485 mm; tail length 152 mm; total length 637 mm. Ventrals (3 preventrals) + 149 ; subcaudals 78, all paired; anal divided. Dorsal scale rows 19-19-17, strongly keeled except those in outermost row which are smooth. Dorsal scale rows reduction:
left: 3rd + 4th -> 3rd (ventral 89)
right: 3rd + 4th -> 3rd (ventral 90)
Rostral twice as wide as high; internasals subtriangular, longer than wide, distinctly anteriorly narrowed; prefrontals only slightly larger than internasals, reaching loreal; one large, undivided supraocular on each side; nasal rectangular, much longer than high, divided into two parts, with a dorsolateral nostril piercing upwards near upper edge of the limit between nostril parts; one subrectangular, gothic-shaped loreal; 9/9 supralabials, 5th entering orbit, 4th and 6th separated from orbit by only a small scale, 7th largest; 1/1 preocular; no subocular; 3/3 postoculars; 2 + 2 + 3 temporals on both sides; 10/9 infralabials.
In life and preservative, dorsal and upper tail surfaces are dark grey, marked on each side of body with 21 and on each side of tail with 13 wide, regular, distinct vertical black bands encircling body, which are strongly constricted in their middle at mid-height of flanks; wider lower and upper parts of each band marked with an oval blotch of dorsum ground colour, giving the appearance of conspicuous, broad rounded X-shaped markings on each flank, the X more or less contacting each other by their upper branches on the vertebral line; bands immediately behind head and towards the tail end indistinct. Head uniformly dark olive grey, without any marking. Venter dirty whitish yellow, darker towards tail, marked with irregular double (sometimes single) black bands coming from lateral X-shaped markings, separated by a more or less wide amount of venter ground colour [from VOGEL et al. 2004].