ID this clam, possible hybrid?

[Turtlesteve]

I got this clam last year, it was sold to me as a crocea for $45. When i got it I posted an ID request with photos and the general consensus was t. maxima, however it shares characteristics of both species.

Pic #1:

 

[Turtlesteve]

Pic #2

 

[Turtlesteve]

Pic #3

 

[cromax]

That is a crocea. 100% born and bred croc.

It looks like a big nice one, too.
Don't let the scutes on the shells fool you. Croceas can have them too. The primary characteristics you should look for are: Shell thickness and mantle shape. Crocea shells are very thick to make up for the decreased "shell corrugations".

But for me, the dead giveaway is always the mantle. You can't mistake a crocea mantle for anything else.

If it looks like a crocea and acts like a crocea...........


:bigeyes:

 

[OrionN]

What make you think that it was a hybrid? It looks like a 100% Crocea to me. A beautiful one too.
Minh Nguyen

 

[manderx]

when i'm not sure, i like to look at the underside. the opening is a night-day indicator for me. nice clam for 45 bucks.

 

[Project Reef]

What the heck is a hybrid clam?? LOL

Nice Crocea, looks very nice actually.

 

[RonN]

A Crocea for sure

 

[RonN]

A Crocea for sure

 

[Turtlesteve]

Thanks, yes it was the scutes on the shell confusing me. All of the other crocea i had seen were completely devoid of shell scutes.

Someone else actually suggested a possible hybrid, so that's why I added it to the poll.

 

[Real Reefs]

Turtlesteve a picture of the scutes from the top may demonstrate more clearly what has got you guessing that it may be a hybrid. I have both maxima's and crocea's and I aggree with you that the shell does demonstrate a type of hybrid shell.

 

[Squidman]

Great pics Turtle Steve. I have alomost exactly the same clam and the same question. I'm certain it is a crocea, but the first row of scutes it grew were big enough to rival those of my squamosa's. I have never seen a crocea or even a picture of a crocea with scutes like ours have (except yours). Nice looking clam either way and thanks for asking the question.

 

[AQUAN8TOR]

Definitely a crocea, like everyone else said. The shell is also very typical. In Knop's Giant Clams book, there is discussion on the lack of scutes in many croceas because of their more frequent tendency, as compared to other tridacnids, to bore into rocks. The scutes act as a file, or sandpaper. Also, croceas, in my experience, seem to have scutes that are much more brittle than other clam species. My own croceas have scutes only around the top 4-5 growth rings, and almost all are chipped or cracked.

 

[AQUAN8TOR]

Just realized I didn't finish my thought. The reason in my opinion yours (and mine, too) exhibit scales is that there are lots of captive propagated clams available now, far more than when Knop's book were written, anyway, and captive raised clams are never allowed to bore into rocks, so therefore, the clams never file down their scutes during their mantle contractions. All opinion and theory, helped by the very good book by Daniel Knop. Very technical in some aspects, which I like. I LIKE CLAMS!!! (all kinds...)