The dorsal color pattern of R. tigrinus is olive-drab green, with black and bright orange crossbars or spots from the neck down the first third of the body. The belly is whitish. The average total length (including tail) is usually 60–100 cm (24–39 in).[5]
The diet of R. tigrinus consists mainly of small vertebrates, especially frogs and toads. It forages using both chemical (smell/tongue) and visual cues to find its prey.[6]Rhabdophis tigrinus has specialized nuchal glands on the back of the neck [7] that are used to store cardiotonic steroids (bufadienolides) sequestered from the toads in their diet [8]. Rhabdophis tigrinus are resistant to the toxic effects of these chemicals [9]. This is different from their venom, which is produced in oral glands and is not known to contain bufadienolides or other sequestered toxins. Female Rhabdophis tigrinus can pass sequestered chemicals to their offspring, both by deposition in egg yolk and by transfer across the egg membranes within the oviduct, late in gestation [10].
Defensive behavior
Rhabdophis tigrinus has two rows of glands in its neck that provide protection from predators by releasing steroidal toxins that are sequestered from ingested poisonous toads, referred to as kleptotoxisism.[11] When this species is challenged at cooler temperatures it tends to demonstrate passive anti-predator responses such as flattening the neck and body and lying still, while at higher temperatures it more frequently flees instead.[12] This snake thus appears to rely more heavily on the deterrence provided by these glands at low ambient temperatures.[12] Although venomous, few deaths have been recorded due to its tendency to display one of these other behaviors as opposed to striking. This hesitancy to strike at a predator in turn may be because its fangs are located in the back of the mouth, making a successful strike on a large object difficult.[13]
^Breuer, Hans; Murphy, William Christopher (2009–2010). "Rhabdophis tigrinus formosanus". Snakes of Taiwan. Archived from the original on 5 June 2013. Retrieved 7 October 2012.{{cite web}}: CS1 maint: multiple names: authors list (link)
^Sawai Y, Honma M, Kawamura Y, Saki A, Hatsuse M (2002). "Rhabdophis tigrinus in Japan: Pathogenesis of envenomation and production of antivenom". Toxin Reviews. 21 (1–2): 181–201. doi:10.1081/TXR-120004746. S2CID84284824.
Further reading
Boie H (1826). "Merkmale einiger japanischen Lurche". Isis von Oken19: 202–216. (Tropidonotus tigrinus, new species, pp. 205–207). (in German and Latin).
Boulenger GA (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. (Tropidonotus tigrinus, pp. 249–250).
Stejneger L (1907). Herpetology of Japan and Adjacent Territory. United States National Museum Bulletin 58. Washington, District of Columbia: Smithsonian Institution. xx + 577 pp. (Natrix tigrina, new combination, pp. 272–280, Figures 242–242 + Plate XIX, figures 1–2).
