Big Derasa in trouble!

[Nanook]

I have a big Derasa clam that didn't look good when I got home tonight. It has its body sunken inside the shell and the very white inner shell has some lining schleffing off. If I put my hand over the clam it closes itself tight, but it is all sunken in and does not look good.

I have a large Squamosa, a Maxima and three Croceas that all look fine. No new additions and these clams came from a good friend's established tank with no new clam additions for a couple years.

I did notice the clam looked irritated last night when I fed a lot of Rods Reef and other foods. I don't see any fish picking on it as I watch this evening.

 

[skinz78]

holy cow Nanook, it's a first I get to help a mod out Ok so I do realize you know your stuff, you have to your'e a mod here. But I have to ask all the basic questions.

What are your fish and inverts?
What lighting do you use and have you changed anything on it lately?
What do you dose and how do you do it?
What are your params?
Can you post a pic of the clam?
Anything else that could have stressed it lately, recent additions?

Derasa's look different than other clams do when showing pinched mantle, so I am thinking this may be a possibility.

If it is a fish picking, like I just stated in the two other posts tonite you probably won't see them doing so. They are like kids and know you are watching and to be good.

 

[Nanook]

The tank is 470 gallons, 5ftx5ftx60in.

Fish are Copperband Butterfly (possible suspect), Yellow Tang, 10 anthias, Starry Blenny, a couple damsels, Clarkii clownfish. Inverts are snails and a seahare.

All lighting is 3 months old, four 400w 10K on HQI ballasts, four 110w vho, no changes with lighting schedule.

Calcium reactor, no dosing. Calcium is 550, alk is 10.5, mag 1350, sg 1.026, temp 76-77 degrees.

No recent additions. I will take a picture tomorrow.

Just cause I am a mod doesn't mean I know anything either I'm just a hobbyist.

Thanks for your help.

 

[skinz78]

Hmm, I agree with the copperband. Is there any way you can cover/shield it with something clear and filled with 1/4" holes for circulation. This should keep the fish from getting to it and if it starts to look better then you know you have a nipper. Or if you have anther tank or sump with adequate lighting for a clam can you relocate it to there?


Have you added any clams to the system lately? PM can lie dormant for pieriods of time but it sounds like you have had this clam for quite a while?

 

[Nanook]

No new additions to the tank. This doesn't look like PM, it looks much more sunken in that PM looks like initially. I will see how it looks tomorrow and go from there. Thanks for the help!

 

[skinz78]

One other thought is there any lps or nem's near by that may have long sweeper tenticles that may have stung it?

Or possibly a small aptaisia on the shell, I have seen them do similar harm.

 

[wjgeese]

anything fall into it?
Or, since it sounds like it's been irritated lately, has it been expelling zooxanthellae out its excurrent siphon? If so, maybe your fish are getting a free meal and more by nipping at the siphon? Evidently fish find expelled zoox quite tasty.

 

[Nanook]

The Derasa was dead this afternoon Thanks for all the suggestions and help. I think it was just too far gone and all of a sudden too. I really have no idea what happened to him