June 5, 2012 at 9:47 am #16575
I found this critter (or hundreds of them to be exact) off the coast of Rhodes. I identified it as a cone snail, perhaps Conus ventricosus or similar. I’ve understood that all cone snails are predators and venomous. They have a barbed stinger that they use to poke at their prey or enemies.
However, what happened with this snail is that when I picked it up, it soon stung me with this odd appendage it had in the rear end of its shell. First I thought it was the poison stinger it had used, but I later read that the stinger is located in the animal’s mouth, not in the tail end.
So the question is: what is this barbed appendage that the critter used to poke my thumb? It is not well seen in the image, but the "tail" is hard, barbed and crescent-shaped and not visible unless the animal lashes out. The animal also used it to turn itself into correct position, if I placed it on its "back". The whip of the tail was very fast (I always thought that snails are slow!). What is the primary use of the "tail"? Self-defense? Correcting the animal’s position? Attack? Also, is the real stinger supposed to be inside that sack-like structure that is located between the eyes? How easily does one get stung? Should one avoid stepping on a cone snail if walking along the ocean floor? (I know that handling the more exotic cone snails can be dangerous, even fatal – but what about these common ones?)
Someone with knowledge of marine mollusca please help me out, this thing has bothered me for quite a while and all Google has to offer me is that they have a poisonous, barbed mouth-piece (specialized radula). But nobody says anything about pointy and nasty tail!
p.s. Note how the animal gives me an evil eye! I didn’t know that water snails have so well-developed eyes… land snails don’t have anything as complex, right? Just long stalks with light-sensing knobs at the end?
June 9, 2012 at 1:39 pm #111515DarbyParticipant
If you do an image search, you’ll see that the narrow end of the shell is the anterior end of the snail.
June 11, 2012 at 8:47 am #111535quote Darby:
Umm, yeah. Did I say otherwise somewhere? 🙂
Anyway, the animal has a barbed "tail" that is located in the wide/posterior end of the shell ("rear end", as I put it). The eyes and mouth parts an be seen in the narrow/anterior end of the snail, and that is where I assume the real radula-derived poison stinger should also be located. But I was wondering what is this other poking device the animals has, something that I failed to discover by googling? According to my quick observations the snail seemed to use it at least for self defense, but is that the real or only purpose of it?
June 12, 2012 at 1:40 am #111546DarbyParticipant
Sorry, the picture has us looking at the anterior end, so I figured you might have it wrong-way ’round. Is the brown structure across the shell opening from the thumbnail the structure you’re talking about? Hard to tell if it’s part of the shell makings or sticking to the shell…
June 12, 2012 at 6:08 am #111549
Yeah, that brown structure is the "spike" I’m talking about. My best guess is that it is part of the animal’s foot, perhaps the end of it has evolved to form such a structure that is visible in the picture. It is not part of the shell, as far as I know.
Heck, I should’ve dissected one to find out! 😛
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