What's on my clam?

[LCDRDATA]

We have a crocea clam we purchased last August (birthday present for wife). It slowly lost color over time, which we determined to be insufficient light; we purchased a new light fixture and color was coming back fine. Now the color is fading again. As I was feeding this evening, I noticed this on the edge of the shell/mantle:

I'm not entirely sure if it's a snail or what. The circle under the arrow seems to be very similar to a snail's operculum, and it appears (as I think you can see in the upper photo) that a small tentacle-like extension is coming out from behind the round plate - which I did observe to move. Hopefully in the second photo you can see the curved "shell"(?) this seems to be living in

I noticed the object some time back - it was smaller then and didn't show any sign of being anything but another bump on the shell.

What is this? What is the likelihood this is responsible for the color loss? Is it parasitic or otherwise harmful, or benign? If it is harmful, what can I do about it without hurting the clam? THANKS!

PS last params -

pH 8.3
alk 2.5 meq (7 dKH)
ammo 0
nitrate 0 < NO3 < 2.5
phos 0 < PO4 < 0.03
calc 390
mag 1260

 

[a4twenty]

sorry can't really see it in the pics, does it have an ugly face????

from your description and a couple guesses, it could be a vermetid snail.

here's some pics from google.

if it is you may have to remove him rather than kalk because of his location. if it doesn't look like that then please try to post a better pic.

 

[LCDRDATA]

I haven't been able to see a face - given its location it is generally hidden from view when the mantle is at all extended. I believe it can come farther out than is shown in the picture but I haven't actually seen it extended.

from your description and a couple guesses, it could be a vermetid snail...if it is you may have to remove him rather than kalk because of his location.

I looked at a number of the hits from google, and most of the vermetids described there would be much smaller than this guy, and generally straight like your standard little tiny feather duster worms. I'm guessing a little bit now, but as best I can compare and measure I'd say the round opening was about 1/2 cm in diameter, and the larger organism somewhere around 2 cm or so in diameter around the whorls.

As to dealing with it, this is a little unclear, but what I believe you are saying is that, rather than killing it with kalk paste (a la aiptasia removal) I'd have to get in there physically because it's so close to the mantle - is that correct? If it is a vermetid snail, would it be likely to bother the clam other than local irritation, and if that's not apparent, is it still recommended to remove it? If it needs physical removal, can it be crushed and pulled off piecemeal, or would that potentially release some toxin that would kill my whole tank? - stranger things have happened (and still do) in this hobby.

I should say the clam doesn't show any obvious localized irritation, ie, the mantle that goes over this critter doesn't appear any different at that location than anywhere else on the clam. IF it isn't bothering the clam, barring some other reason I have no problem with it remaining where it is, especially since you generally can't even see it.

I've got a couple of other photos, although I was trying to post the best of the set - would more distinct but slightly less focused help? Or I can try to get better pics tomorrow.

 

[a4twenty]

look at the first pic from that link, that is what i am talking about. a hard shell attached to the clams shell, swirled on top of itself with a hole in the end. the critter will poke his ugly face out when comfortable. here's a pic of one i had as a hitchhiker on a gigas, the shell is hard to see but he is out.

if he isn't bothering the clam then no you don't have to remove him but we need to find what is bothering the clam. how about some more info on the system and a few pics of the full clam and more of the critter if you don't think it is a vermetid.

 

[TIMMAH]

I have this same critter on my clam. I personally dont attribute it to whatever this is though. if you will notice the size of the shell(?) that it lives in, you will probably see that it is actually quite long. the one on my clam has been there for atleast a year that im aware of. I have never seen any discontent from the clam in this area.

 

[mscarpena]

Your alk is on the low end. I like mine around 4.0-4.5. Also calcium is on the low end. When you say you bought a new light what is it, where is the clam positioned, and when did you upgrade the light. A large change in light will shock the clam and can cause bleaching.

 

[LCDRDATA]

Sorry for the delay in responding - what with Valentine's Day yesterday there were other organisms in the house that took priority. I'm going to run my chemistry tests here shortly, and can post updated params once that's done. My alk doesn't seem to want to change - I don't think I've gotten it above about 3.5 meq for more than a day or two. And that was only once. It normally wants to stabilize around 2.5 meq (where it was the last time I tested). I don't know why that is but I'm hesitant to add much higher doses of buffer. As I said, we'll see where we are in a bit. I've been dosing a bit more calcium, so I'll see where that is as well.

We got the new light about a week before Christmas, specifically because the clam wasn't getting enough, even though it's relatively high in the tank. I tried to increase the level relatively quickly but without bleaching the clam. It seemed I was successful, and by the middle of last month the clam's color had noticeably improved. Unfortunately I'm fighting a brown jelly in a couple of my corals right now - I don't think that should hurt the clam directly but if the tank is stressed (?) the clam might be reacting to that - I think. Anyway when I get new params I'll post them.

 

[LCDRDATA]

OK, here are my current params:

SG - 1.026
pH - 8.2
Alk - 3.5 meq (9.8 dKH)
NO3 = 0
PO4 = 0
Ca = 450
Mg = 1290

I'm debating a ~5% water change; I mixed it up and started aerating about 8 hours ago, so I think I should wait until tomorrow; any opinions?

 

[emmanuel]

<a href=showthread.php?s=&postid=14402235#post14402235 target=_blank>Originally posted</a> by LCDRDATA
OK, here are my current params:

SG - 1.026
pH - 8.2
Alk - 3.5 meq (9.8 dKH)
NO3 = 0
PO4 = 0
Ca = 450
Mg = 1290

I'm debating a ~5% water change; I mixed it up and started aerating about 8 hours ago, so I think I should wait until tomorrow; any opinions?

test your water change water mine using reefcrystals always changes bucket to bucket this time its
alk 10 dkh
calcium 350
magnesium 1050
I always have a problem keeping magnesium up now i know why I do water changes every 2 weeks now I dose the water before adding it

 

[emmanuel]

also I saw something on melevs reef about snails(whelcks) that eat clams slowly
http://www.melevsreef.com/pics/0504/baby_maxima.html