Oyster? Clam? Tridakna? Please, help me with ID.

[Natalya]

Hi, all!
Recently I've found in my aquarium new creature.
It sit in hole inside big alive stone and I can't make good photo with it, sorry.
She (or maybe he ) has a mantle and hides it when she/he is afraid.
Her/his form is interesting: like seed with spike. And her/his cockleshell with small needles around edge and tini needles which cover cockleshell (instead of waved wrinkles) .

It is not a tridacna. It is not oyster.
I can't understand who is this :sad2:

Please, help me.

 

[j_mazzy]

Looks really cool, I hope it's a good one

 

[j_mazzy]

ttt

 

[pagojoe]

Hard to be sure, but from the pic it looks to be an oyster species, maybe Lopha frons. They can have tight zigzags, or broader ones. It should be harmless in any case.

Cheers,


Don

 

[Natalya]

j_mazzy, thank you for good words
pagojoe, many thanks for information, but... I can't find any familiar picture in
https://www.google.it/search?q=Loph...X&ved=0ahUKEwjiirrrsMDNAhXGB8AKHQyiAL4QsAQIJA

My creature have thick foundation and thin top.
Please, see my pictures.
At the Pic1 her/his normal state. At the Pic.2 she/he is afraid, that's why she hidden her mantle and moved to the left (for hiding in stone).

 

[pagojoe]

Like this?

https://www.google.com/search?q=arc...biw=1517&bih=714&dpr=0.9#tbm=isch&q=ark+shell

 

[pagojoe]

 

[Natalya]

Pagojoe, thanks for your help.
Cover of shell looks like in picture. But form is not
Because usually top of it (tridakna, oyster etc) is as arc and foundation is less.
In my creature's case top is almost spike and foundation is bigger than top.
...
But, maybe this (it is from your reference) http://shells.tricity.wsu.edu/ArcherdShellCollection/Imageslarge/Arca_tortuosa2.jpg

if it stay verticaly!
Maybe it is Barnea manilensis inornata, but I can't find information about it's mantle.
It looks like this in the picture

 

[pagojoe]

Yes, I can't think of any family with that type of periostracum other than family Arcidae. However, there are many variable species in that family. I can't really see enough of the shell in the photo to tell what the overall shape is. Barnea may have a dark leathery periostracum, although much of it may be eroded. I don't know if it has the spikes like your animal, though. The only way to get a positive identification may be to remove it from its hiding place .

 

[pagojoe]

Here is a link to photos of many of the Arcidae. Unfortunately, most no longer retain the periostracum. Still, you may be able to find one with a shape similar to yours:

http://www.conchology.be/?t=65&family=ARCIDAE

Cheers,



Don

 

[Natalya]

Incredible variaty! :spin2:
Thank a lot for your help, Don

Have a nice day!