Japan is home to several types of venomous snakes. Most of these – sea snakes (umihebi) and coral snakes, both of which belong to the same family as cobras – are restricted to the sub-tropical Ryukyu island system and other southern islands. Most of the family of vipers are also restricted to these areas, with the most infamous being the “habu” (Trimeresurus flavoviridis). The snakes have a reputation for being aggressive, and such is the local fear of this snake, mongooses were introduced to Okinawa from India as a control method. This proved to be a complete failure – day-active mongooses rarely encounter the night-active habu, instead preferring to prey upon Okinawa’s bird life.
Until a few years ago, one of the drawcards of Okinawa’s tourist industry was habu-mongoose fighting – pit vipers were pitted against mongooses in actual death matches. This practice is now illegal (and not just to prevent my punning about it!) but there is said to be at least one place that now pits snakes against mongooses in a swimming competition!!
In addition to the habu (波布 or 飯匙倩), there are several snakes containing habu as part of their names – himehabu (姫波布), sakishimahabu (先島波布) and tokarahabu (吐噶喇波布) – and they are all of the genus Trimeresurus.
Apparently, there is a bounty on these snakes in Amamioshima.
Returning to mainland Japan, we find two relatives of the habu – the Tsushima mamushi , or Tsushima island pit viper (Gloydius
tsushimaensis) and the Nihon mamushi (Gloydius blomhoffii), popularly known as the Japanese mamushi or Japanese copperhead.
As its name suggests, the Tsushima mamushi (対馬蝮) is found only on Tsushima Island. The Nihon mamushi (日本蝮) is found all over mainland Japan and its range also extends into Korea and China.
Along with the habu, mamushi are sometimes caught and pickled in shochu or awamori and the concoction drunk as tonic. I’ve also talked to people who claim that the mamushi is excellent eating. “Do you want fries with that?”
Although highly venomous and potentially deadly, the mamushi is feared much more than should be reasonably justified. Says fellow blogger and occasional hiking partner Ian “Goat” on his blog:
They’re rarely lethal — Australia has earthworms more dangerous — but this venomous pit-viper looms large in the urban-Japanese fear of nature. You hear about them all the time, though I’ve never met anyone who’s seen one
Which brings us to the last of the venomous snakes of Japan. This one is special to me because it is the only venomous snake I’ve personally encountered in the wild.
The tiger keelback (Rhabdophis tigrinus) or yamakagashi (山楝蛇) was until fairly recently not known to be venomous. Its fangs are located in the back of its mouth, making it difficult to inject its venom into a human. Another recent discovery was that the yamakagashi also has a gland on the back of its neck which secretes a toxic irritant in the manner of toads – no doubt a defense against the crows, hawks, tanuki and four-striped snakes that prey upon it.