Weird Bivalve ID Request

[XFeathersx]

Hello, I just got this bivalve from a friend who doesn't know what it is either. He said it was attached to a rock he got, and that it's some type of scallop because it has opened and has blue striped soft tissue on the inside. It's just started opening for me. It's certainly pretty, with a nice iridescence. Does anyone have any ideas of what it is?

 

[shakacuz]

@ISpeakForTheSeas

 

[ISpeakForTheSeas]

Hello, I just got this bivalve from a friend who doesn't know what it is either. He said it was attached to a rock he got, and that it's some type of scallop because it has opened and has blue striped soft tissue on the inside. It's just started opening for me. It's certainly pretty, with a nice iridescence. Does anyone have any ideas of what it is?

I'm still learning bivalve taxonomy, and I'm not sure what exactly you have there, but I can tell you that's not a scallop.

The long, thin shape and hooked umbo by the external ligament would lead me to thinking it's a Solenid or Pharid (Razor/Knife Clam) species of some kind; however, none of those species that I'm aware of would be attached to a rock (they're burrowers).

 

[ISpeakForTheSeas]

I'm still learning bivalve taxonomy, and I'm not sure what exactly you have there, but I can tell you that's not a scallop.

The long, thin shape and hooked umbo by the external ligament would lead me to thinking it's a Solenid or Pharid (Razor/Knife Clam) species of some kind; however, none of those species that I'm aware of would be attached to a rock (they're burrowers).

Recently learned a bit more about bivalves and was reminded of this thread - I would guess this is an Isognomon species; a Tree Oyster.