Lima Scabra - File Clam

[Stijn]

Hi everybody,

I have been diving since a few weeks in Wakatobi, Indonesia, and one of the amazing things I have seen is the Lima Scabra or file clam.
I have been trying to find out more about this scallops but the only information I find is on how to keep them in a saltwater aquarium, what food to give them, etc...

What I want to know is what do they eat in the ocean, what's te purpose of the lightning on the sides, can they swim, what's the purpose of the tentacles??

It's a fascinating creature, pls help me

 

[archman]

flame scallops are members of the pteriomorph clade, an oddball set of clams that don't seem to share anything 'cept for a distinctive filibranch-type gill. It's shaped like a "W" in cross section. Other pteriomorphs include ark shells, oysters, pen shells, and mussels (no, NOT what people call clams up north!).

Most pteriomorphs are marine, and attach to the bottom by naturally produced cement, or with strands of the tough proteinaceous byssus. Flame scallops, unlike their pals the bay scallops, are stuck to the bottom just like everybody else in the family (actually it's a subclass but who's counting). They are incapable of swimming, and enjoy nestling amonst rock or coral cracks with their shells moderately agape.

This is how they catch food. Those frilly tentacle-things are extensions of the soft mantle tissue, and they are great at catching little bits of particulate matter from the water column. They'll ingest plankton and detritus in this manner.

 

[badassbill]

While they can't "swim"...they can propel backwards by closing rapidly. When they do this is several times in a row, they can move pretty quickly actually. There is also a species of these, it may be them exactly, that has a neon blue light that also surrounds it's opening. Very high on the "neato" factor...and an interesting species.

 

[archman]

While they can't "swim"...they can propel backwards by closing rapidly.

This is true for pectinids (true scallops), but only marginally so for limids like the flame shell. Both possess the distinctive monomyarian adductor muscle, but it's far less developed in limids. That muscle drives the "swimming" power. Limids are undergoing an evolutionary progression towards swimming loss, and have very nearly achieved it.

Your flame shell "nests" using short byssal threads, and these are fairly permanent fixatives. True scallops lack attachment byssus in the adult stage, except for members of the genus Chlamys.

Also unlike many true scallops, Lima and it's pals lack eyes. This is another evolutionary change is response to a loss of escape-swimming behaviour.

 

[drbill]

We have the related species Lima hemphilli (= Lima dehiscens) here in so Cal. I just checked my authoritative guide to our inverts and it had nothing on what they eat. Of course like most bivalves, it filters plankton and organic matter from the water.

Dr. Bill