Mayday - dead clam and weird infestation...

Okay, everything looked fine last night, everyone ate and was light
sensitive and I went to bed. This morning, one of my t.squamosa is dead
and mostly gutted.

Not wanting to leave the carcas in the tank I pulled it out and placed
it a clean plate to investigate. When I set it down a colony of squirmy
things swam out. These things range from about 1/16" to about 1/8" in
length, they seem to scuttle as well as swim. They are clear to white in
color, have feelers and what as well as what look like legs or
appendages for walking - I would call them centipedes if not for the
fact that they live underwater. I flooded the plate with talk water and
have transfered them and the clam's remains to a specimen jar for
observation.

Can anyone help me ID these things? I'm working on photos now, but
they're so small and it's difficult to get them to show up because
they're also almost completly transparent.

Any help would be most appreciated.

mark h