|Limidae, the file clams, have oval, circular or triangular shells with small "ears" or extensions on either side of the hinge. The sculpture can be smooth, ribbed and/or scaly. The mantle of the organism generally has long sticky tentacles. The file clams can swim like the scallops by flapping their shells and ejecting a stream of water. They swim with their hinge forward, unlike the scallops that swim with the hinge at the back. They can also attach to substrates or build a nest of shell and coral pieces held together by a tangle of byssal threads. There are 7 species found in Texas waters.