The brown-banded water snake grows to a maximum total length (including tail) of 78 cm (31 inches).
Dorsally, it is olive or gray-brown, with dark brown, black-edged crossbands, which narrow at the sides, and are usually confluent with the black crossbands of the belly. There is a large dark rhomboid on the nape. Ventrally, it is yellowish (in alcohol) with black crossbands or black spots.
The
dorsal scales are strongly keeled, even on the occiput and nape, and are arranged in 19 rows.
Ventrals are 102–130 in number, the
anal scale is divided, and the 61-94
subcaudals are paired and keeled.[4]
H. angulatus has been reported to be "facultatively viviparous".[3]
Venom
H. angulatus is a non-front-fanged colubroid (NFFC),[6] venomous snake, its venom causes rapid death in mice with an injection of 0.4 mg/kg (intraperitoneally).[7]
There is an urgent need for training of the medical team in the snake identification, clinical management of snakebite, and the existence of a human-snake conflict involving NFFC species in Bolivia.[6]
References
^Nogueira, C.; Gonzales, L.; Cisneros-Heredia, D.F.; Gagliardi, G.; Catenazzi, A.; Schargel, W.; Rivas, G.; Murphy, J. (2019).
"Helicops angulatus". IUCN Red List of Threatened Species. 2019: e.T15178420A15178466. Retrieved 2 December 2021.
^Boulenger, G.A. 1893. Catalogue of the Snakes in the British Museum (Natural History), Volume I., Containing the Families ... Colubridæ Aglyphæ, part. London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xiii + 448 pp. + Plates I-XXVIII. (Helicops angulatus, pp. 278-279).
^
abVillca-Coraniad, Huber; Nieto-Arizaad, Beatriz; Leónad, Raúl; Rocabadoa, José A.; Chippauxabd, Jean-Philippe; Urracd, Félix A. (30 October 2021). "First reports of envenoming by South American water snakes Helicops angulatus and Hydrops triangularis from Bolivian Amazon: A one-year prospective study of non-front-fanged colubroid snakebites". Toxicon. 202: 53–59.
doi:
10.1016/j.toxicon.2021.09.003.
PMID34562494.
S2CID237636615.
Boos, Hans E.A. (2001). The snakes of Trinidad and Tobago. College Station, Texas: Texas A&M University Press.
ISBN1-58544-116-3.
Freiberg, M.A. 1982. Snakes of South America. Hong Kong: T.F.H. Publications.189 pp.
ISBN0-87666-912-7. (Helicops angulatus, p. 99).
Linnaeus, C. 1758. Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio Decima, Reformata. Stockholm: L. Salvius. 824 pp. (Coluber angulatus, new species, p. 217). (in
Latin).