Are LA/DD blue squamosa clams really maxima clams?

[cypho]

How do you tell a maxima and a squamosa apart? Squamosa clams have a more symmetrical shell and a much smaller byssal opening.

I have 4 squamosa clams - or at least that is what I thought until recently. 3 of them were purchased locally and one of them was purchased from LA/DD as a "Indonesian Cultured Blue Squamosa Clam".

When cleaning the tank last week I noticed something odd. My newest clam (the one from LA/DD) finally released the rubble it was holding onto and I could get a good look at the shell. And it looks very different than my other 3 squamosas.

Here is the byssal openings of my 4 clams. One of these does not look like the others.

And here are shell profiles. Look at the distance from the hinge to the right/left edge. On Squamosa clams the two distances will be about the same. On Maxima clams one side will be longer than the other. And again, one clam stands out as clearly different than the others.

I sent LA an email telling them that I think they misidentified the clam along with the 2 shell pictures (pics 4 & 8 above) as evidence. They wrote back this morning confirming that they are sticking with their original ID - Squamosa. I'm curious what you all think. Is the new clam a Maxima? Or is LA right and it is a squamosa? Or are we both wrong and it is a hybrid of the two species.

And if they have ID'd my clam incorrectly, is this a systematic error. If anyone reading this has a LA blue squamosa, what does it's shell look like? Are all of their the LA/DD "blue squamosa" clams really just overpriced maxima clams?

 

[saltyfilmfolks]

IMO

A maxima has a much larger byssal opening. As it's a rock borer.

The chutes can get worn and will have different growth patterns dependnh on where they are due to flow etc so they are not always a good indicator.

 

[cypho]

IMO

A maxima has a much larger byssal opening. As it's a rock borer.

The chutes can get worn and will have different growth patterns dependnh on where they are due to flow etc so they are not always a good indicator.

Based on that do you think the LA/DD clam ( pics 4&8 ) is maxima or squamosa?

That clam has a much larger byssal opening than the other 3, but I don't have a maxima to compare it to.

 

[saltyfilmfolks]

Check this out.
http://www.advancedaquarist.com/2012/2/inverts
The difference between the two clams is quite dramatic.

 

[cypho]

Check this out.
http://www.advancedaquarist.com/2012/2/inverts
The difference between the two clams is quite dramatic.

Are you saying that clam #4 looks very similar or very different than the maximas in that link?

I think it looks more like the maximas in that link. But that is contrary to what I was told by LA/DD and that is why I am looking for additional opinions.

 

[saltyfilmfolks]

Are you saying that clam #4 looks very similar or very different than the maximas in that link?

I think it looks more like the maximas in that link. But that is contrary to what I was told by LA/DD and that is why I am looking for additional opinions.

No, I'm saying the difference between a Squami and maxima is very noticeable. And I think you have a squami.

 

[hart24601]

Looks like a squamosa to me. Yes it's a bit different than your others but I would never think it was a maxima.

 

[cypho]

No, I'm saying the difference between a Squami and maxima is very noticeable. And I think you have a squami.

Looks like a squamosa to me. Yes it's a bit different than your others but I would never think it was a maxima.

Thanks,

I do hope you are right. Here are the 4 clams from above. The 2nd on the left is the LA/DD clam (the one that is almost solid blue without the spotting). If it really is a squamosa it is the coolest one I've ever seen. I suppose I'll know if he gets big like his brothers or if they leave him in the dust.

 

[Overboard]

Hmmm, that mantle sure looks like a Maxima. Maybe one of the Cocos cultured clams that LA DD sells? I would have said squammie at first, but I have seen quite a few maximas with that profile to the shell. The large polynesians in particular. Not a true maxima, but I have a large Ningaloo (Noae now, I think), and it has that profile.

I caught a presentation by James Fatherree on clams at MACNA and he, at least, feels that there are virtually zero hybrids. All his research indicated hybrid larvae just don't survive long.

Did you send pictures of the mantle to LA DD? If it really is a Maxima, I would assume it was just an honest mistake on their part.

Would be interesting to see what Fatherree would say if you could figure out how to contact him. MACNA is this week, but I don't think he is a speaker this year.

Good luck!

 

[hart24601]

Can you get a close up of the inhalent siphon?

Looking at James book it says squamosa has branching tentacles and Maxima's don't.


But what a stunning collection. Absolutely gorgeous. You must go through all like nobody's business.

Consider clam qt for new ones. I had a great collection and got a small ORA blue squamosa and it had some.pathogen that wiped out my clams, I tried just about everything but clam diseases just are not that well known.


Also the incredible variations in the same species and some species phenotypes being re-classified as new species there will always be some impossible to 100% ID specimens short of DNA analysis.

 

[cypho]

Hmmm, that mantle sure looks like a Maxima. Maybe one of the Cocos cultured clams that LA DD sells? I would have said squammie at first, but I have seen quite a few maximas with that profile to the shell. The large polynesians in particular. Not a true maxima, but I have a large Ningaloo (Noae now, I think), and it has that profile.

I caught a presentation by James Fatherree on clams at MACNA and he, at least, feels that there are virtually zero hybrids. All his research indicated hybrid larvae just don't survive long.

Did you send pictures of the mantle to LA DD? If it really is a Maxima, I would assume it was just an honest mistake on their part.

Would be interesting to see what Fatherree would say if you could figure out how to contact him. MACNA is this week, but I don't think he is a speaker this year.

Good luck!

I also assumed honest mistake on their part - that's why I sent them the pictures (including a pic of the mantle). But they stuck with their original ID.

Yes the mantle is very maxima like. That's why I did not post the mantle in the OP. I did not want people basing their options on the mantle which from everything I read is the least reliable feature for making an ID. If the shell is plausibly squamosa, I am willing to give LA DD the benefit of the doubt.

 

[Overboard]

I will be at MACNA and there is a speaker (not Fatherree) on clams. I will try and ask him after his talk. I can show the pictures off my phone.