Got Another Strange Hitchhiker

[Donya]

I will try to get a picture soon if the description alone doesn't work. These "things" rode in on a snail, and I only spotted them after adding the snail to the tank. I don't want to stress the snail by taking it out for photos in the same day.

These things are about the diameter of a pea, most smaller. They look vaguely like the top half a scallop shell, only comming out the front are 2 short feelers and a proboscis that can stretch out at least as far as the shell is long. I havn't seen the "body" of these animals move much, but the proboscis wiggles around quite fast. I figure it must be some sort of mollusk/gastropod, but I can't find a match in any of my books or on the web. Does the description ring a bell for anyone?

 

[Donya]

Wonderful...looks like I have Linkia shells. They only problem is, they are supposedly starfish parasites and I have no starfish. They are adhered to a snail around the sutures and I can't pry them off. Is there a chance these could be parasitising the larger snail? They could well have drilled small holes in the shell..I can't pick them off so I can't tell, but I would think they'd go elsewhere looking for a starfish if that was really their prefered host.

 

[Donya]

Tragically I know what they are now. They killed my Strombus made me want to quit the whole thing when I saw that, I was very attached to that snail. They are a type of parasite related to the Linckia shell, but parasitic on snails. They drill their own shells right through the host's shell onto the soft tissue. They are impossible to get off until the host dies....and then when they do come off, they expose huge areas of soft tissue. The worst part is their proboscis...it comes off like a tick's head, left embedded in the host. I just pulled one off and the proboscis is wiggling its way out of the dead host now.

If any of you happen to see one of these things on a snail you're about to get, DON'T GET IT!!! I will be lucky to avoid having these things spread to the rest of my snails

 

[Navarre]

A nice 6 line wrasse would deal with these usually. Its very hard keeping to 1 type of creature tank (like snails) as they have no predator to their parasites etc. Things like amphipods and small parasetic inverts like this are usually dealt a stunning blow by predators such as wrasses etc. remove these from the equasion and you suddenly have no defence and now run the risk of an epidemic.

I have a similr problem with majanoe anenomes. I have no known predator in my system and they are running rampant all over my liverock. )

 

[Donya]

A wrasse might be able to nip them off prior to the drilling, but once those things are drilled in...their shell actually grows out under the host's shell so they are impossible to pry off without the use of a metal tool, and it risks damage to the host. I tried to pick them off while the host was alive and failed for that reason. When they were removed, it exposed large areas of organ tissue which would mean death for the host anyway. The organs had been badly damaged by the proboscises (probosces?). Unfortunately the parasites were already drilled in and stuck fast at the time I got the host so I doubt anything would have saved it in the end.

I dug out all my snails last night to check them for the same thing...the coast is clear so far. I lost 2 Astreas a couple days before the Strombus died to what appears to have been the same thing (drill holes), but no other evidence. I may have gotten lucky and eliminated it by removing the Strombus when I did, since it had some other un-drilled parasites on it that were looking for places to settle in. I'm keeping a close eye out on all the other snails in the mean time.

I take it a citrus/clown goby probably wouldn't help much?

 

[Navarre]

Nah they arent really parasite crunchers. Wrasses perform great cleaning duties and leopard wrasse/sixline wrasses spend their entire day examining liverock for anything that shows signs of life and is edible

 

[Donya]

Newb question...I saw something labeled as a 5-line wrasse at the store, that looked like a black & yellow color equivalent of the pictures I'm finding of 6-line wrasses. Is one a color variant of the other, or was I seeing a completely different fish?