Large Tridacna Clam ID - I'm stumped

[wjgeese]

Do you have any links to identification of this type of derasa? I so far have found pictures of similar morphs on the forums, but have not found any non-forum post showing the difference. Even Giant Clams in the Sea and the Aquarium by James Fatheree is of no help. Also, the way I see it, is there is no real way to know if it is hybridization without some sort of DNA testing and comparison with known derasa and known gigas. Until I see evidence supporting the argument that it is not a hybrid, I can't discount that possibility. I have read multiple scientific articles which suggest that hybridization may be possible, but none which definitively say it happens. Also, there are quite a few articles (non-scientific) which explain that it probably happens.
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Right now the clam is coloring up nicely and is indeed showing the classic short lines that other derasas have. So far I'm not convinced wither way. All I DO know is that others have had the same morph.

 

[wjgeese]

No I do not have any extensive reference list to back up my speculations other than being in the hobby and into clams for 30 yrs. I suspect that eventually this type of derasa that you have will eventually be recognized as a subspecies (much like the tear drop maximas recently were). But this will rely on DNA footprinting. Given the strong presence of these 'holy' derasas in the 90s -- for almost 10+ yrs, I really find it hard to believe that they are truly hybrids. More likely a regional specific difference in morphology.Just my $0.02. I believe most of these came out of Tonga.

 

[Bongo Shrimp]

The possibility of it being a sub-species is an interesting idea. I wish it were easier to get DNA tests of these things.

 

[ta_billy]

Very interesting tridacna. I have been an avid fan of tridacnas for years and have keep most species with varying degrees of success. Two successes being deresa and gigas. I looked back at some of my old photos and referenced my copy of Daniel Knop's Giant Clams, and this clam appears to be a classic case of a deresa/gigas hybrid, imho.

I am also very, very envious of your find ;-)

 

[joshky]

Whatever it is, it's awesome. Great find man! :beer:

 

[Stevenliu9]

I double the Derasa/Gigas hybrid

 

[Bongo Shrimp]

Here's a new pic. The colors are flooding back, the nips have almost completely healed and the shell has begun growing. The shell growth is most evident on the very bottom part of the shell right at the hinge where a decent chip occurred (not pictured).

I still don't care what species it is although I was told by James Fatherree that it is T. derasa.

 

[JRR1285]

Amazing looking clam.

 

[Bongo Shrimp]

Amazing looking clam.

Thank you!

 

[wakesetter]

Deresa, hands down.

I have grown out handfuls of deresa and gigas. The first pic looked like it could maybe be a hybrid, the newer pic makes it very clear that it is a deresa. Looks like it was just stressed and under lit in the first pic.

Either way, nice clam you have there sir.

 

[Bongo Shrimp]

Thanks. It'd hard to tell in the new pic cause of the lighting, but the windows in the mantle are still there.

 

[ta_billy]

Agreed. It's starting to look like a pure Deresa now. Lesson learned.

 

[Bongo Shrimp]

Update time! Yes, we already know he's a derasa but look how far he's come! Here he is with his buddies who were also rescued.

 

[PfenWendt]

Let me know if you want to sell/ship one I'd be veryyyyy much so interested in any of those! Very nice clams, i am jealous for sure

 

[Bongo Shrimp]

Let me know if you want to sell/ship one I'd be veryyyyy much so interested in any of those! Very nice clams, i am jealous for sure

Thank you.

They are not for sale and I am not interested in offers. Thank for the interest though.

 

[ca1ore]

Looks a lot more like a deresa in the most recent pictures.

 

[Bongo Shrimp]

Update time! Yes, we already know he's a derasa but look how far he's come! Here he is with his buddies who were also rescued.

Looks a lot more like a deresa in the most recent pictures.

Did you read my update post?

 

[ca1ore]

Did you read my update post?

You mean the one sentence? Maybe two. Yes, I even understood them. Just observing that it does indeed look like a pretty standard deresa now; as opposed to looking a bit odd initially.

 

[Bongo Shrimp]

You mean the one sentence? Yes, I even understood it. Just observing that it does indeed look like a pretty standard deresa now; as opposed to looking a bit odd initially.

Interesting.

Anyways it still has the "holes" in the mantle but they are only visible if you look up close.