Nassarius snail attack?

3crazyboies

New member
I recently purchased sea hare . He can only be safe on LR or glass. when he is on the sand all the snails (10) go after it. does anyone know why? I have to help him out
 
Nassarius snail are carnivours once they get hungry and tired of cleaning the tank they hunt. Told the LFS store that after I lost a few clams and some fish they diddnt believe me till it happened to them. They can eat fish if u have the giant type, they small ones do damage too.
 
Nassarius snail are carnivours once they get hungry and tired of cleaning the tank they hunt. Told the LFS store that after I lost a few clams and some fish they diddnt believe me till it happened to them. They can eat fish if u have the giant type, they small ones do damage too.

Sounds like you are talking about a Nassarius look-alike. Nassarius are obligate scavengers. According to Ron Shimek:

Nassarius are whelks that have gut and behavioral specializations that seem to prevent them from attacking live prey. They, however, have many near relatives that are not as "fastidious."

From here: http://forum.marinedepot.com/Topic48287-11-1.aspx?Highlight=nassarius+obligate
 
Dr. Shimek's excellent work on Nassarius involved Atlantic species, and as far as I know never included the Indo-Pacific species that are repeatedly implicated in the deaths of aquarium animals. The species that are most often accused of killing snails, clams, and other animals are the ones sold as "Giant Tongan Nassarius," usually Nassarius arcularius and Nassarius coronatus, although a couple other species may be sold under that name. The sellers typcially identify their large snails as Nassarius distortus, which they usually aren't. Interestingly enough, the snails pictured in the marinedepot thread referenced above are the true Nassarius distortus. Thus, there are apparently at least three species of Nassarius with questionable feeding habits. "Obligate scavenger" sounds like a name you'd call something that you wanted to BELIEVE wouldn't kill anything else in your tank. If I were an obligate cannibal, and could readily eat you if someone bonked you on the head and killed you, I'm no less well equipped to eat you if you are still alive. In fact, I might not even be able to tell the difference: if these snails can eat a clam or sea hare when they are "sick" or "dying" they can certainly do the same to a healthy animal that is in a vulnerable position (i.e., where they can't close, or hide, or burrow, or climb, or whatever). I doubt they check pulses to see if an animal is dead before they eat them.

It doesn't surprise me at all that your Nassarius might go after a soft-bodied animal like a sea hare.

Cheers,



Don
 
Fair enough, Don, though I believe Dr. Shimek's theory was that a dead or dying animal releases a chemical that acts as an attractant to the snail and that the snail won't eat without it (to the point of starving to death in tanks of live food).

Thanks for the correction!
 
Heh, I think that might have been my theory, but I also proposed that stress chemicals may "smell" the same, whether the animal is dying or just adapting to a new tank. Whichever the case, it seems like the larger Nassarius species are capable of killing, if they are inclined to. I've never really seen the small species do anything objectionable, although it's certainly possible that they might.

Cheers,


Don
 
My nassarius have been generally well behaved but they did attack and kill a Lettuce sea slug, Tridachia crispate that I put in my tank. Just as in the original post the slug was fine as long as he was on the rock but when he made a dash for the glass across the sand the snails attacked and made short work of him. This is the only living animal I have seen them go after in the six months I have had them in the tank.
I do however have one question about their behavior, initially they would completely conceal themselves in the sand bed with only their snorkel sticking out. As time has went on they bury themselves less and less. They will only partially cover themselves in the sand now to the point were most have Coraline growing on their shells. Is this because they have become comfortable (IE. feel non threatened) in the tank? I'm sure that burying themselves in the sand is an expenditure of a fair amount of energy and if they don't have to they are like most other creatures, they will take the easy way out.
 
Now I'm curious about my nassarius snails. What species might they be? They have very white shells, and a large light colored foot with some spots on the dorsal side. They have a small pointy operculum that sits on the back of their foot just behind the shell. Their shells are about half to three quarters of an inch long. Should I be concerned?
 
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