clam mantel shrinking

[volivier]

my 3" crocea clam is pulling away from one end of itself so I can see the white shell. It used to fall over the sides largley and beautiful. I have 3 400W 10K metal halides and 2 72" actinic. I did cut back on my lighting from 8 hours MH to 5-6 hrs due to some algae growth. Could this be the cause? All other water tests are the same as they've always been, my nitrates are at 20 as usual, calcium 420, phosphates are .5 though. I just started testing the phosphate so I can't say if this is how my water has always been or not. I've had the clams for arounds 2 months now, the other is doing fine. One is on the left end and the other in the middle of my tank mid range.

[davidsreef]

In my opinion your nitrates are a little high. Crocea clams can be the most difficult clams to keep, so I would try to bring the nitrates down. Also clam under 3" should be spot fed cause their mantle isn't large enough to absorb all of the light needed for their energy needs. Since yours in 3" it is right on the line of feeding / not feeding, so use your judgement if you wish to spot feed. The problem with that is it could cause water quality issues.
Just my 2 cents.
Oh, what size tank?

[volivier]

Originally Posted by davidsreef

In my opinion your nitrates are a little high. Crocea clams can be the most difficult clams to keep, so I would try to bring the nitrates down. Also clam under 3" should be spot fed cause their mantle isn't large enough to absorb all of the light needed for their energy needs. Since yours in 3" it is right on the line of feeding / not feeding, so use your judgement if you wish to spot feed. The problem with that is it could cause water quality issues.
Just my 2 cents.
Oh, what size tank?

135, my signature has some info about my tank. I had stopped feeding DT to it, I thought it was big enough for my 400 watts to take care of, is dt what you feed?

[davidsreef]

Hehe. Now I see your tanks specs (duh). Sorry. I personally have never had a clam under 4 in. so I can't say from my own experience if 3 in. is enough. Most posts I have read say 3 in. is enough, others say 3.5, so believe what you want. If your clam isn't able to produce enough energy from the mantle, it probably should still be target fed. How tall is your tank? THat can play an effect, but since you have so much light, I can't imagine you having a problem there. I have never used DT's myself, although I would love to get a hold of some (its hard to find good food like that around NW Wisconsin). I feed my fish/corals homemade food similar to E.B. recipe found in his book or on the net. I do not target feed my clams, altough I assume they are able to consume at least a minimal amount of food.
Are there any pests on the clam shell? My crocea would retract its mantle a bit cause of very small bristle worms that would hide in the scutes of the shell and irritate the mantle. Once the bristle worms left, the clam is fine now.
Again, all of this is JMHO.

[volivier]

Originally Posted by davidsreef

Hehe. Now I see your tanks specs (duh). Sorry. I personally have never had a clam under 4 in. so I can't say from my own experience if 3 in. is enough. Most posts I have read say 3 in. is enough, others say 3.5, so believe what you want. If your clam isn't able to produce enough energy from the mantle, it probably should still be target fed. How tall is your tank? THat can play an effect, but since you have so much light, I can't imagine you having a problem there. I have never used DT's myself, although I would love to get a hold of some (its hard to find good food like that around NW Wisconsin). I feed my fish/corals homemade food similar to E.B. recipe found in his book or on the net. I do not target feed my clams, altough I assume they are able to consume at least a minimal amount of food.
Are there any pests on the clam shell? My crocea would retract its mantle a bit cause of very small bristle worms that would hide in the scutes of the shell and irritate the mantle. Once the bristle worms left, the clam is fine now.
Again, all of this is JMHO.

my digital camera is w/my daughter at the high school, when she gets home I'll try to attach a photo. It is kind of fuzzy, can't tell what it is, not really a color to it. I will look closer ASAP, my purple tang does like to swim right by it and irritates it, but surely not enough to make it retract? I did have an acropora frag near that end of the clam, I moved it last night in case it was engaging in some chemical warfare.

[davidsreef]

I can't imagine that the tang is irritating the clam enough for it to retract. I am not sure if the acro would irritate it or not, but moving it is probalby better for both, just as long as the clam isn't moved too often. From my experience its best to let them be, they will move until they are happy and then try to attach there (unless your clam is attached to a rock then it can't move much, just a little bit).

[Casey]

Yes get us a pic when you can would help alot.

[volivier]

ok, it shrunk up a little with the flash, but you can see the left end is receding, after I fed some dt last night it extended some, but this morning it is receded again.

[Casey]

Yea that doesnt look good have you looked under him for snails? You might have to do a freshwater bath.

[volivier]

Originally Posted by Casey

Yea that doesnt look good have you looked under him for snails? You might have to do a freshwater bath.

can't move him, it is attached to the rock

[Casey]

Originally Posted by volivier

can't move him, it is attached to the rock

Yes you can just wiggle him back and forth till he lets go.I do it all the time.