How do you tell clams apart?
 

well the title says it. I was at a LFS yesterday and he had a few clams. I asked which ones were which and he told me Crocea and Derasa but they all looked the same to me. How does everyoen know the difference between the clams?

thanks

gotta look at their shells, which are different. google tridacna identification. lotsa sites

What he said^^^. After a while you will notice some very common mantel color patterns and shapes that are "somewhat" unique to each species of clam. Between shells, mantels and simply experience in careful observation the ID of them becomes pretty easy.

Telling clams apart
 

Crocea and Derasa are actually the easiest to tell apart. The Derasa has more of a green tint and lined mantel and a smoother shell. The Crocea may or may not have any scutes and tend to be blue to purple in color and more squat in appearence. But these are just generalizations. Just take a look at a Derasa in pics and they pretty much look alike except for the rare exception.

alright thanks ill go ahead and hit google hard!

2018 and I googled "tridacna identification". It brought me here. :/

:lmao::lmao::lmao:

Doing a little research myself a couple weeks back, I found that only maximas have the little "eyes" around the mantle on the outer edge. While they are not eyes, what they are in fact is areas of little to no coloration which allows more light through to the zooanthelle(sp?).

For 2 years I thought I had a squamosa when in fact it was a maxima. LFS I bought it from sold it as a squamosa. In his defense when small other then the "eyes" on the mantle, the shell(scutes on the shell) and byssal opening are almost identical.