Wed 11 Oct 2006
The Tiger Keelback or Japanese Water Snake (yamakagashi) is such a beautiful snake, with red and black spots along its body, but it is also poisonous. Apparently there are not too many cases of people being killed because the snake is relatively quiet and tries to escape rather than attack. This snake does not have the usual front “fangs” we associate with poisonous snakes, but instead has poisonous molars (i.e. at the back of the mouth). It also has poison glands located on its neck from which, as an anti-predator mechanism, it sprays poison into its attacker’s eyes. I didn’t know this piece of information until after I researched about the snake, but I didn’t notice anything spray out when I picked it up. I will be more careful next time!!
It took quite a while to catch this snake. I saw one sliding through the grass at the side of a small ditch, but it escaped before I got near to it. Then I spotted another and tried to grab it, missing it by inches. I’m not quite sure how many snakes there were at this location, but there seemed to be quite a few because I made four separate attempts in different places before I finally caught one. It was either several snakes or the same one that popped up in different places along a 50m stretch of the ditch!
This species of snake eats frogs and toads.
Reptilia: Colubridae: Rhabdophis tigrinus
Tiger Keelback or Japanese Water Snake = yamakagashi
October 18th, 2006 at 5:39 pm
Hi Nigel,
Very interesting site you have here. I’m also very interested in nature (especially reptiles and amphibians) and also live in Japan. I’m curious about the imformation you posted about poison glands that spray on the neck of the Yamakagashi. I have handled many of these and I’ve never seen or read about such poison glands. Is it possible that they are a bad smelling scent gland? As they do produce a bad smelling odour that sticks to your hands for quite a while. Would it be possible for you to let me know the source of your research on these glands?
Cheers,
Sean
October 21st, 2006 at 6:31 pm
Hi Sean,
Thanks for your comment.
I read about this poison gland in a children’s reptile book and checked it on Japanese Wikipedia. Link:
http://ja.wikipedia.org/wiki/%E3%83%A4%E3%83%9E%E3%82%AB%E3%82%AC%E3%82%B7
Sorry I don’t have anything more scientific than this as a reference.
I don’t know what you’re getting on your hands when you touch these snakes, but it seems like it might be the toxic secretion being described. I guess it’s only bad if you get it in your eyes, so washing your hands might be a good idea (I’m sure you do that anyway!!)
All the best,
Nigel
November 9th, 2006 at 1:02 am
These things rarely bite and when they do, chew. Because of that, they seem safe but their venom, should they get it into you, is truly nasty. Worse than the mamushi.
http://kamimoku.com/snakes.html
http://www2.gol.com/users/nhavens/htmlfile/snakes-e.html
November 11th, 2006 at 1:23 pm
Hi Douglas,
Thanks so much for this useful information.
Worrying… I will *definitely* be careful the next time I handle one of these snakes.
Best wishes,
Nigel
June 8th, 2007 at 4:30 am
Hello,
I’d love to use one of your images in my publication. Please contact me if possible.
Thank you
Arlete
June 9th, 2007 at 10:25 pm
Hi Arlete,
I’m very interested in supplying an image. Please email me directly:
stott@hyu.bbiq.jp
Thanks for your interest,
Nigel
April 27th, 2009 at 12:47 am
Hello Nigel,
Thank you for the information on the Yamakagashi. I have been watching your site for a while. I first saw it while living in Puerto Vallarta, Mexico, and was researching Japanese Insects. Now I live with my Japanese husband in Fukuoka, but we are moving to Nishimera in Miyazaki, so I figured I should make sure there weren’t any dangerous creatures I should be aware of. Thank you very much for your lovely site. Perhaps someday our families can go hiking together. I would love to go hiking with you guys. Please visit us if you come to Nishimera!
July 11th, 2010 at 5:34 pm
Hi !i just experienced very scary situation, with them.
You guys said that they don’t attack, but i am sure today we both just didn’t run in the same direction.usually i had seen them dead on the road killed by cars.is my first time to see them alive. the story is funny … drunk too much caffe and was on the middle of my sanpo,so wanted to … i almost did but i saw something on the level of my eyes moving odd left right, very fast.
start running, you can imagine… was so scary.
believe me they are very fast.
the next weird thing was that i wanted to go home but the everytime i step forward the snake rise.
so i just wait until get lost.
that very day i saw 3 snakes the same in radius under 1km.
The scary thing was that i didn’t know how i should react in this kind of situation.No more caffe for me before sanpo if i ever go …
again.
Location Chiba, katsuura
July 13th, 2010 at 11:34 am
Hi Mary,
Yes, we’re very lucky to have so many snakes in Japan! I think that they are amazing creatures and I love being able to find them on almost every hike (or sanpo!) during the summer.
If you are frightened of something, it’s usually best to avoid running, especially in the mountains, because it’s so easy to fall down and injure yourself. The wait-and-watch technique is fine with these kinds of snake. And, believe me, they want to avoid you just as much as you want to avoid them. But please try not to be scared and please try to admire them as beautiful living things.