Squamosa Clam with open mouth

[Alex Carciofi]

Hi
I have a squamosa clam for 4 months now. Recently it began to keep its mouth open all day long. The pic below shows the clam:

http://www.sonora.com.br/aquario/images/tridacnas.jpg


I know that this can be a bad sign. Can you tell me the possible cause of this behavior?

Alex

[herefishiefishie]

A few thoughts:

Does the clam ever close the inhalant siphon (the mouth)?

Does the clam react to being shaded, or to being touched?

The color looks good. How long have you had this clam? Is the clam being harrassed by anything else in the tank? Are there any little rice-grain-like snails on the bottom the the clam?

Do you have sufficient oxygenization in the water?

Note that the inhalant siphon is usually at least slightly open, and almost never completely closed. However, it should not usually be gaping.

Does anyone here have the Knop book and can look up an answer to this one?

[Alex Carciofi]

The inhalant siphon used to be closed, looking like a thin slit. In the last few days it is always open, though, and the gap has about 1 cm.

The clam reacts readly to being shaded and touched.

I have the clam for 4 months. I think the clam is not being harrassed by anything.

One thing: should the inhalant syphon be abobe the exhalant? Or the contrary? Or their relative position do not matter?

Alex

[herefishiefishie]

The inhalant siphon being open might not be anything. Sometimes my clams have them open for a while, and it closes up again.... I would observe for a while to see how it goes.

I don't think the relative position of the siphons matters. At least, I've never given it a thought nor heard anyone else mention it. An interesting question, though.

[DeepBlue]

HFF, Alex

I just reviewed all the symptoms in Knop's book covering Environmental Damage, Infectious Diseases, and Damage from Macroparasites and Fish. (Chapter 5, Secs. I, II, III, pgs 79 - 119)

Found nothing to the effect of a constantly open inhalant siphon. Other than bleaching, tissue damage to the mantle, or holes in the shell, the only other major indicators I found were the clam being partially or completely closed all the time. Another behavior was the lack of retractive reaction to shading or being touched, this is a sign of low temperature.

Sorry I couldn't be of more help.

[chuey]

My squamosa looks like that all the time. No problems so far.