Derasa?

[Dubin]

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

http://i415.photobucket.com/albums/pp232/Dubi3071/ClamSide.jpg
http://i415.photobucket.com/albums/pp232/Dubi3071/Clam.jpg
http://i415.photobucket.com/albums/pp232/Dubi3071/ClamTopDown2.jpg

[SNAKEMANVET]

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]

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]

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]

http://reefkeeping.com/issues/2007-10/jf/images/shells1.jpg

The Crocea's shell has distict folds in it just as the derasa does.

here is a picture of derasa shell
http://img89.imageshack.us/img89/5318/img02291vu.jpg

[DSR]

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).

[Cracken]

however the colloration looks alot like a derasa not crocea

[evsalty]

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

http://i415.photobucket.com/albums/pp232/Dubi3071/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.
http://reefkeeping.com/issues/2007-10/jf/images/tn_pedal_jpg.jpg

[IFbettas]

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]

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]

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]

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]

<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]

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]

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.

[Dubin]

It's just shy of 6 inches from end to end. Thanks for your help IFbettas, and everybody else!

[cakemanPA]

I was thinking that it had more of a Squamosa look to it.

[Dubin]

It's definitely not a Squamosa, pretty sure it's a Derasa : )

[IFbettas]

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]

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.

[evsalty]

<a href=showthread.php?s=&postid=15443170#post15443170 target=_blank>Originally posted</a> by DSR
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. Dersas live in the rocks while young I believe so it would make sense that the grind there shell smooth in the rock work. Once living in the sand though they would have nothing to grind against. I could be completely off base on this though.

[IFbettas]

Derasas never live "in" the rocks the way a crocea or maxima lives, but rather when they are small they stay attached on a rock until they get bigger. They just naturally grow without scutes in the wild, but that can change in captivity.

[Dubin]

Yeah it didn't have the scutes when I bought it. In the year and a half i've had it, it developed the two scutes it has.

[IFbettas]

The 3 inch one I bought a couple months ago is now making scutes on its new growth. As soon as it got into my tank it changed its growth pattern. My crocea also started making scutes when I got it a year ago, but that is way more common.

[Zuska]

the top down pic looks like a squamosa because of the color patterns.

[OrionN]

That is a Derasa. In aquarium minor scutes can form even with Gigas

[fishgeek12]

derasa!

[scapes]

derasa all the way

[FreakonaReef]

Deresa clams have a smooth shell. I think it's a T. Squamosa

[a4twenty]

no doubt about it, derasa :)

[OrionN]

<a href=showthread.php?s=&postid=15553319#post15553319 target=_blank>Originally posted</a> by a4twenty
no doubt about it, derasa :)
We actually agree on something:D

[a4twenty]

<a href=showthread.php?s=&postid=15553434#post15553434 target=_blank>Originally posted</a> by OrionN
We actually agree on something:D


i was shocked too http://i200.photobucket.com/albums/aa240/a4twenty/smilies/Heristical.gif