I need help with a Clam Foot Question

[COB650]

I have a Crocea clam 4 inch. I woke up today to find some type of white meaty thing on the strainer of my maxi 1200. I pulled it off and I believe it to be my clams foot? Am I right? It's white long and at one end heart shaped. Along one side is a bunch of fine loose tissue. The heart shaped end is kind of hard and the rest of it is smooshy. Is this an indicator that my clam is going to die soon? The clam looks fine and reacts to light changes. no pinching, but it is gaping but I thought that was regular with Crocea clams. The clam is placed 7 inches from the top of the tank and no strong current is being directed towards it.

100 Gal
2 175 watt halides
PH 8.1-8.0
DKH 8-10
calcium 500+
working a berlin skimmer

Any Ideas???

 

[Reefcherie]

Is it possible for you to pick the clam up and examine it? If it is still attached to the rock, I don't see how what you found could be the clam's foot and if the foot was missing, I would expect the clam to be doing quite poorly.

If you can post a picture of what you call "gaping," we'll be able to tell you if that is normal or not.

Cheri

 

[COB650]

Found my answer

Found my answer

Thanks to clam direct I have found that it is quite normal for clams to shed their byssal threads/foot. It is noted that gaping is common place among the Crocea species.

Thanks for replying

 

[Reefcherie]

That is interesting to hear...I've been keeping clams for a couple of years now - I currently have 10 of them - and have never seen that happen. Barry certainly has more experience than I do though, so I'm sure he's seen it all. My T. croceas also do not typically gape, though they will do so for a short period of time and never show a large gape unless very stressed.

If your clam remains reactive, the mantle looks great, and the gaping is moderate, that will be fine.

Cheri

 

[Snail Guy]

COB650,

This peaked my interest. It's well known that certain families of gastropods (such as Cypraea, Stomatella, Harpa) will release part of their foot (autotomy), primarily as a defense mechanism. Though I have never heard of bivalves releasing their foot. So, I inquired about this on Conch-L (a listserver for those interested in shells). Response, thus far, is that autotomy is not known in bivalves.

A more general question for all the clam keepers out there...how often do you note the foot? Is it often? Is it mainly with younger clams settling down? How about with adults already settled into place. I'd love to know more about this.

Cheers,
Bob

 

[holeinone1972]

Clams release their byssal attachment generally from stress. Is this a new clam?

Croceas do have a tendency to be a little more open in their incurrent syphon than do other Tridacnid species. But, it should not we wide open. I tell folks that their clam's incurrent siphon should resemble a coin slot, closed fairly tight. A crocea should be loosely closed, but if the opening is an oval or wide open, it is probably stressed out.

Rob

 

[Reefcherie]

Thanks for jumping on Rob! I wanted to say that stress was probably involved if byssal attachment was shed, but didn't know if there were other circumstances that would do it.

So many people ask about gaping and are unsure what is "normal" vs not. I like your description! I also higly recommend Daniel Knop's book, "Giant Clams" for all clam owners. There are plenty of pictures in there of what "normal" of each type of clam should look like, as well as tons of information.

Cheri

 

[COB650]

thanks all for replying

thanks all for replying

Thanks again for replying to my thread.

The clam is new, about 5 days old in my tank now. The color hasn't faded and the mantle has not shrunk.

What concerns me is the gaping. Since the inhalant siphon is wide open as you stated. Oddly this happens only when I turn on my lights. As of right now I have very low lighting from a window hitting my tank and the mantle is extended not fully but very good. The inhalant siphon as you said looks like a coin slot. When lights come on the mantle extends another half inch but the inhalant siphon expands and gapes.

The color of the clam is blue to purple and lead me to believe this clam needs high lighting as with most Crocea species. But do you think I am giving it too much lighting? It's about 7 inches from the top with two 175 watt metal halides?

I wish I could take a picture of the clam. I can, but I can't resize the picture with my current software. I will hopefully be getting photoshop today.

Thanks again for replying and by all means keep the suggestions coming.

 

[COB650]

Crocea pic

Crocea pic

Here is my gaping Crocea

 

[COB650]

not the best of pictures, but they won't let me post jpegs so pdf is the best I can do.

 

[Barry N.]

I also higly recommend Daniel Knop's book,

October 1997 Daniel wrote in "Aquarium Frontier: One the Half Shell.

"Generally, clams can live even without a byssal gland. Some will expel it when their weight is sufficient to keep them on the substrate by gravity".

I have seen shed their byssal on several occasions and the clam lives on. Now on the other hand if the byssal is ripped out or torn, then a bacteria infection can lead to death. Expel it different than ripped or torn out.