Sea Cucumber with Parasitic Snail

[mollymonticello]

I bought a what I think is a Pentaca anceps sea cucumber on Thursday. I found a tiny pink snail (size of a grain of rice) on the cucumber and pulled it off with tweezers. it was really stuck on there, and when I grasped it, it seemed to burrow in.

I am a curious person and am wondering if anyone knows what species of snail this is and anything about it.

Here is the snail I found on it:

<img src="http://i197.photobucket.com/albums/aa65/mollymonticello/IMG_6384.jpg?t=1238301553">

Here is the snail on the cucumber (click on thumbs to see big picture):

<a href="http://s197.photobucket.com/albums/aa65/mollymonticello/?action=view&current=snailoncucumber.jpg" target="_blank"><img src="http://i197.photobucket.com/albums/aa65/mollymonticello/th_snailoncucumber.jpg" border="0" alt="Pentaca anceps Pink and Green Sea Cucumber" ></a>

Should I be overly concerned that there are more of these snails and that they will stress my cucumber out to the point of it dying and as a result nuking my tank?

I've read that this particular species isn't as likely to poison a tank as their sea apple cousins. Just in case this thing goes nuclear, I have polyfilters and fresh carbon in my Fluval 405, 20 gallons of new water, and a Hydor performer skimmer.

It's been extending its feeding arms and I don't see any obvious damage to its skin. Here is the cucumber as of a few minutes ago:

<a href="http://s197.photobucket.com/albums/aa65/mollymonticello/?action=view&current=IMG_6381.jpg" target="_blank"><img src="http://i197.photobucket.com/albums/aa65/mollymonticello/th_IMG_6381.jpg" border="0" alt="Pentaca anceps Pink and Green Sea Cucumber" ></a>

Edit: I just fed it some tiny pieces of mysis and it was eating them. I think it's fine.

 

[pagojoe]

I can't tell you for certain which species it is, since I've never worked on ID'ing a red one, but I can tell you what family it's in, and I'll give you a guess on the genus. It's in the family Eulimidae, most of which are parasitic on echinoderms. I wouldn't worry too much about finding the snail on your cucumber, as many of the ones you find in the ocean have eulimids attached. They apparently don't do much harm or they'd have killed off all their hosts already. I don't really think they dig in so much as they "glue" themselves to the host animal, at least in the case of the ones which parasitize holothurians (sea cucumbers). If you try to pull one off, you usually end up stretching out an elastic thread that attaches the snail to the cucumber, and if you release it, it snaps the snail back to its host. As you probably noticed, the shells are extremely smooth and slippery, even when they are dry. The surface is so smooth, in fact, that it's difficult to pick one up with your fingers.

Identifying them is a big problem, since most of them were named from their shells, and many of the shells are almost identical, even if the animals are very different. A few have colors and patterns, but the majority are translucent white or transparent, and most of the visible color is the animal color rather than the shell color. Sometimes the empty shells are stained the color of the animal, though, so that can be a hint.

Your snail is probably in the genus Melanella, as are many of the cucumber parasites, and if yours isn't Melanella araeosomae, it's pretty close:

http://www.gastropods.com/6/Shell_18366.shtml

Cheers,



Don

 

[mollymonticello]

Thanks a lot, Don. I'm borrowing a better camera tonight, so I'll try to get a closer pic of that snail. It's really pretty. I've been keeping it in a jar in the hopes that I'll get a better picture.

I've been feeding my cucumber Liquid Life "bio-plankton." http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=11456 Do you think that's good food for them? I'm reluctant to try foods that are not frozen or refrigerated. Does anyone know how different is it from Kent Marine Chromaplex? http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=7361

Most sites say they eat baby brine shrimp, but I read that sea apples and filter feeding sea cucumbers only eat very tiny phytoplankton and even baby brine shrimp are too big (and zooplankton, besides).