Emergency

[dmck]

My, once healthy, now I'm not sure, clam has a tear in the mantle, allowing me to see right through to the back of the shell...is this the beginning of the end? Can I do something to help...

[Reefcherie]

dmck,

I don't have any first hand experience with this happening, but I took a look at what Daniel Knop had to say about mantle lacerations in his "Giant Clams" book. He attributes most to either parasitizing crabs or harassment by fish. If the culprit can be removed and/or the clam protected from further damage, an otherwise healthy clam can often heal itself.

What fish and crabs do you have in your tank? How big is the clam and how big is the tear in the mantle? Up until this point, had the clam been displaying full mantle and coloration every day, and reacting quickly to sudden movement near it?

Cheri

[dmck]

Thanks.

There are a few small hermits (blue mostly), and there's one fish, a Sohal Tang, which doesn't seem to touch the clam, but causes it to close a lot when swimming nearby...so is it the frequent opening and closing...?

Otherwise it looks more or less normal.

[Reefcherie]

I don't think frequent closing/opening will cause the mantle to tear - or at least I've never heard of that. My experience with that is that the clam eventually gets used to the fish swimming near it and stops reacting all the time. If the clam doesn't get used to it and has to exert all its energy to the reflexive closing frequently, I would expect that to affect the clam's health - though I don't see how that would cause a tear in the mantle. Is moving the clam out of that Sohal's swimming pattern possible?

You might try watching at night with a flashlight for a rogue crab.

How big is the clam and how big is the tear in the mantle?

The only other thing I can think of that might help a little would be for you to feed DTs if you haven't been. Though the clam should be able to get nutrition using the symbiotic algae in its mantle (as long as the clam is at least around 3" long), if it is already stressed by an injury, I would think that it couldn't hurt to help it out with some DTs.

Cheri

[dmck]

Thanks again.

The clam can be moved to another spot. I feed the tank in general using Two Little Fishies Marine Snow, which a local coral shop had recommended.

The clam is about 3.5 inches, and the tear is barely visible, maybe 1/4 - 3/8"....

Behavior seems fairly normal - but that's hard to tell.

[Gary Majchrzak]

What species clam is damaged? I've seen T. derasa with large size gashes heal up nicely. Maxima and crocea might be another story. I would recommend feeding phytoplankton.

[Reefcherie]

Originally posted by dmck
I feed the tank in general using Two Little Fishies Marine Snow, which a local coral shop had recommended.


Although Two Little Fishes lists clams among the organisms that will benefit from its Marine Snow product, I don't believe there is any live component to it. IMO, live phytoplankton is the way to go for clams (and other filter feeders). DTs may be available locally for you or several online retailers carry it. It is also possible to culture your own phytoplankton. If that is of interest to you, do a search here on RC and you'll get lots of information on how that is done.

Cheri

[dmck]

I'm pretty sure it is a crocea...blue/green/purple mantle, very deep colours.

[zenya]

Found my old thread I posted while back when my T.derasa had same problem.
Sadly it did not recovered and I never found the culprit. if clam is healthy and its nutritional needs are met,it should recover from this. There are many cases of different species of Tridacnas recovering from injuries like this.
Good luck to you and yes,I agree completely that feeding live phytoplankton is best for the clam.
Here's the link with some pics in them
http://reefcentral.com/forums/showthread.php?s=&threadid=106227

[3_high_low]

My Max recovered from a 1/2" gash in the mantle. I never did figure out how it got there but it's doing fine to this day. GL with yours.