Derasa?

Dubin

New member
Is this a Derasa and is it ok for it to be on the sand?

ClamSide.jpg

Clam.jpg

ClamTopDown2.jpg
 

SNAKEMANVET

PREMIUM MEMBER
I don't think that is a dersea,my dersea shell is smooth and don't have the scutes like that one.Maybe a crocea or maximas.Let someone with more exp id it for you.
 

DSR

New member
It is not a maxima for certain. I am thinking crocea because of the retained scutes (they usually grind them away, but not always). The shell looks more like a crocea to me.

The best way to tell is to turn the clam over and look at the bottom. If it is a crocea, then it doesn't like sand and you should check carefully for snails.

How long have you had it? Could just be the picture/lighting, but it don't look like it is doing too good. Can you post your tank information and water parameters.
 

evsalty

hmmmmmm
That is def not a crocea. Look at the first pic and see the waviness of the shell. Aside from color it looks like the dersa that you posted pics of DSR. Croceas also extend their mantle quite a bit.

I am no expert thogh but I do know that it is NOT a crocea.
 

DSR

New member
Also the edges are different than you would expect to see on a derasa... I still think it is a crocea, but I am open to being wrong. With regard to mantle extension, that is why I asked how long in tank, as it doesn't look all that healthy (could be picture quality though).
 

evsalty

hmmmmmm
Re: Derasa?

I am refering to how the folds go all the way down to the bottom of the shell. Most croceas that I have seen and mine that I own plus on the same page your pic is from do not have folds down that far. My other thing is the complete lack of mantle extension even though it is spreading open quite a bit. Also croceas usually are similar size from top to bottom and from front to back while his is def longer then it is tall.

<a href=showthread.php?s=&postid=15436973#post15436973 target=_blank>Originally posted</a> by Dubin

ClamSide.jpg



This pic is also from the reefkeeping page about croceas. Notice how there is no waveiness or folds along the shell above the bysil (sp?) opening.
tn_pedal_jpg.jpg
 

IFbettas

New member
That is 100% a derasa. No doubt about it. Derasas often develop low profile ridges along their shells when in captivity. My derasa is doing the same thing. Look in Fatheree's book, Giant Clams in the Sea and the Aquarium, in the part on derasas and clam identification.
 

Dubin

New member
DSR, I took the pictures with my iPhone so it could easily be the quality of the picture. My water paramaters are good and that clam has been in my tank for about a year and a half. I don't know if this would make any difference but the picture was taken about 10 minutes after the lights came on, he opens up more than that throughout the day!
 

DSR

New member
yep. that does make a difference. I was afraid that something was wrong with it. You know I had never noticed that the folds stop before they get to the byssal opening. That is interesting. I just have never seen one (my own included) the had scutes like that. Very interesting.
 

IFbettas

New member
They don't really make "scutes" but just ridges like what can be seen on that ones shell. I have seen several derasas with folds like that. They don't do it often in the wild but it happens in captivity (just like how croceas make scutes in captivity).
 

evsalty

hmmmmmm
<a href=showthread.php?s=&postid=15438909#post15438909 target=_blank>Originally posted</a> by DSR
yep. that does make a difference. I was afraid that something was wrong with it. You know I had never noticed that the folds stop before they get to the byssal opening. That is interesting. I just have never seen one (my own included) the had scutes like that. Very interesting.
It was yours that made me think yes on dersa...:smokin:
 

Dubin

New member
So it's ok for it to be on the sand? It's been there for over a year, but I was just wondering if it would do better on some rock or something, or does it not matter either way?
 

IFbettas

New member
Derasas are fine being on the sand unattached once they get some size on them. How big is it? Eventually derasas can't make byssal threads anymore once they get bigger because they fill in their byssal opening. Then they just stay upright from their own weight. When they are still small (under 6 inches or so) they prefer to be attached to something. You can put it on a small rock and then bury the rock under the sand so you don't have to look at it. If it has been unattached this long I think it should remain that way so you don't stress it out.
 

IFbettas

New member
Yup its a derasa, and a nice one too! I'm waiting for my little 3 inch one to get that size and hopefully huge some day.
 

DSR

New member
Got home last night and checked out my derasa and no scutes at all, very smooth. But the folds go all the way down to the umbro. Had never noticed that before thanks for point that out.
 
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