unknown bivalve

[diocrisseashells1000]

Hello collectors,

this are bivalves found in the Philippines
#1. its very fragile and crispy, i drop it accidentally when i try to take a picture of it, found empty dead in 8 ft. deep coral debris.

#1.    <!-- m --><a class="postlink" href="http://www.flickr.com/photos/63645283@N06/sets/72157627563320039/&nbsp;">http://www.flickr.com/photos/63645283@N ... 039/&nbsp;</a><!-- m -->   65-70mm.

#2. the flesh is still inside, (preserved).

        <!-- m --><a class="postlink" href="http://www.flickr.com/photos/63645283@N06/sets/72157627687329900/&nbsp;">http://www.flickr.com/photos/63645283@N ... 900/&nbsp;</a><!-- m -->     17mm.

Cheers,
Diocris.

[dave r]

The first looks to be one of the 'Wing oysters' Pteriidae with the 'tails' broken off. I do not know the second one.

[diocrisseashells1000]

Hello Dave,
                  I think #1 has a Pinnidae features. it does not have pearly nacreous and pallial lines as seen in pteriidae specie, it looks like Pinna rudis but different in shape, no scales and spine, and the internal color is more intense than outside, and the location is different.I might be correct in the family name,but the specie name is still unknown, ( :'( sad to say its already broken,)
                #2 would this might be a coquina specie ? i found it along with this kind of specie in a sandy bottom.

Diocris.

[dave r]

You may be right about the Pinnidae, at first I thought an Atrina species but I thought of Streptopinna saccata. That is an incredibly variable species and your falls withing the forms I have seen.
As to the other, I do not think it is a Coquina (Donax) species, but I do think it could be Mesodesmatidae, maybe an Atactodia species?

[diocrisseashells1000]

#1. Streptopinna saccata, it is somehow looks like it before the accident except mine has a roundly triangular edge, but as you said the shape is very variable. Your identification accepted.

#2. Mesodesmatidae, Atactodea sp. I will consider it.

Many thanks sir Dave for your great help.
Diocris.