Clam closed up, what could be the causes?

[crvz]

I've got two clams in my tank, one crocea and one derasa. They are both on the bottom of my tank, a 58 gallon with 6 T5 overdriven bulbs. Tank parameters are in the norm (salinity ~1.026, calc ~400ppm, alk ~9.6 dkh, nitrate ~2ppm, po4 ~0ppm, temp ~78.5), and I've had the crocea for over six months, derasa around 4 months. The derasa looks great. I had some pyramid snails when I first got the derasa, but at last check (yesterday), I was in the clear on both clams.

Lately (last 4 days or so), though, the crocea has been closed up. Not entirely, but about 80% of the way. I wasnt sure if it was getting too much flow, so I just moved it to a lower flow area, but I wanted to ask around to see what else I should be looking for. Anyone have any ideas?

Thanks,

Chris

 

[Grunt]

What fish do you have in the tank? Any known crabs running around? Have you made any changes in lighting schedules/clam placement/water movement?

 

[crvz]

No big changes before it started "clamming up." Fish include a foxface, sixline wrasse, pair of ocellaris clowns, small hippo tang, and a bicolor blenny. The only new fish are the pair of clowns, but they hang out in one corner of the tank (opposite area as the clam). I do have hermits, but I've not added any in the last 6 months or more. Lighting is the same, water is the same. I'm really stumped. It looks like part of the very edge of the mantle is faded in color, too, but it's not very much (just a few spots, maybe 10% of the perimeter).

Any more details needed that may impact the health of the clam? I perform weekly 15 gallon water changes (~20% total volume), and I've been doing that for over 15 months. Using the same salt. I've got a kalkreactor and autotopoff, as well as a calcium reactor, but they've all been in operation for at least 8 months. Skimmer is an AquaC EV120.

Would love to hear more thoughts.

 

[a4twenty]

<a href=showthread.php?s=&postid=9640860#post9640860 target=_blank>Originally posted</a> by crvz
Lighting is the same, water is the same. I'm really stumped. It looks like part of the very edge of the mantle is faded in color, too, but it's not very much (just a few spots, maybe 10% of the perimeter).

can you post a top down picture of the faded clam?

how old are the bulbs?

what temp. are the bulbs? ( k )

what photo period?

any fading on the mantle can usually be traced back to lack of light. clams get their color from the zooxanthellae algae hosted in their mantle. if they are not receiving enough light the clam will start to lose their zoox and slowly starve to death. ( can take several months...... )

derasas and croceas have very different lighting requirements, here is a link to a really good thread with lots of info.

the crocea will probably be happier if you moved him up closer to the lights. i'm not sure if this has anything to do with the decrease in mantle extension but if you post a picture maybe we can find out


HTH

 

[crvz]

I will try to capture a shot of the clam this evening... I just moved it into a finicky spot for pictures, but I'll do my best.

The 3 of the 6 bulbs are about six months old and the other three are approaching a year (39W T5 bulbs overdriven to about 60-65 watts each, with Icecap SLR reflectors). The clam is about 20" below the bulbs.

The bulbs range in temperature from 6500K to 12000K, and I have only 1 actinic.

3 bulbs are on 10 hours a day and 3 bulbs are on 6 hours a day.

I didnt know about the mantle fading, so that does help, thanks a4twenty. I'll try to get that picture posted this afternoon/evening. Would love to hear any more thoughts!

 

[mbbuna]

bi-color blennies are nippers

 

[crvz]

I'll keep a look out... I've had the blenny before the clam. Could it aquire a taste after this amount of time? I suspect so.

 

[crvz]

Alright, I moved the clam up about 8"... now it's probably about 12" from the lights, though part of some of the bulbs are blocked by rocks. Here is a picture of the clam, and this is about as much as it's been extended for about 5 days now. Unfortunately, there is not enough mantle displayed to see any fading, but i'll see if I can't get another picture later. Sorry about the flash, but I was struggling holding the camera steady where the clam is now. What are everyone's thoughts?

Here it is soon after I got it in June

And here are the two clams last month. They normally were not this close.

 

[Grunt]

It could be getting nipped or annoyed with something, to close up like that. It has new growth on the mantle. Maybe someone else might have some more insight to your problem. Goodluck

I usually replace my lighting before they hit a year old. I don't know if thats affecting your clam or not. Could be possible though.

 

[crvz]

Thanks Grunt, I really need to just sit in front of the tank for 20-30 minutes and see what's happening, if anything. I've got a bigger tank in the garage, and with that will come new bulbs (hopefully in the next couple months), and I'm resigned not to buy new 36" bulbs for this tank. Hopefully I can figure something else out.

Obviously, would still love to hear others thoughts...

 

[Grunt]

Have you noticed any small holes or anything on the underside/bottom?

 

[sdaousa]

Do you have any angel fish in your tank as angels like to snip at everything.

 

[2crazyreefers]

I lost 3 croceas to a bicolor blenny. IMO not clam safe and I would get him out.

 

[crvz]

<a href=showthread.php?s=&postid=9649476#post9649476 target=_blank>Originally posted</a> by Grunt
Have you noticed any small holes or anything on the underside/bottom?

Nope, havent seen any holes. What would that indicate?

<a href=showthread.php?s=&postid=9650744#post9650744 target=_blank>Originally posted</a> by sdaousa
Do you have any angel fish in your tank as angels like to snip at everything.

I had a half-black dwarf angel when I first got the clam, but it instantaneously started nipping on its mantle, so he had to go.

<a href=showthread.php?s=&postid=9651658#post9651658 target=_blank>Originally posted</a> by 2crazyreefers
I lost 3 croceas to a bicolor blenny. IMO not clam safe and I would get him out.

I'm going to have to really watch him sometime today or tomorrow. Thanks for the heads-up. I think it's being bothered by something, as it doesnt seem diseased or anything else. I'll update this thread when/if I figure something out.

 

[Grunt]

I was curious if you have seen holes in the bottom bc I've had large sized bristle worms eating the foot and base of some clams. Also bc of pyramid snails.

Has it attached to the rock since you have moved it?

 

[crvz]

Yes, Grunt, it has attached. I just snapped another picture of it, which is pretty much the same as it has been over the last two weeks now.

So, what are my options? I'd hate to see this clam die. I watched the clam over about twenty minutes, and while nothing is nipping at it, it zips closed whenever a fish draws near. What's funny is that the blenny doesnt really hang on that side of the tank, it's the tang, foxface, and sixline wrasse that swim over the top of it when it's closing up. I'd love to hear more ideas, as I'm out of them...

 

[saltman1]

Hey all I'm tagging along on thisone. My crocea started to close up a few days ago after a few months of being wide open. The only thig i have changed in the tank in the last few weeks was add 12 nassasius (spelling?) snails, the sand bed cleaners. I am thinking this could be the cause?? I picked him up today to make sure nothing was bothering his footing and he had a shell froma hermit crab attached underneath that I pulled off. I will see what happens in the next few days. Any thoughts

 

[saltman1]

Well, I know someone has to know something here....

 

[crvz]

Well good news, everyone. I moved the clam way up in the tank to where fish don't go near it (there's only about 4" to the water surface), and it's looking much better. I moved it on the 14th, and here it is today.

Anyways, thanks for all the suggestions. I dont know if it was just tired of having fish swim by it all the time, or if it was a little starved from being so low in the tank. It's looking good, and still a little "jumpy" if something gets too near, but most of my worry has disappated.

 

[chrisstie]

That's a big difference from the pics before thats awesome!