~ Freshwater Clams ~

11/07/02	11/07/02
11/12/02	The clams are actually fun to watch too. They have a foot that they extend and retract to burrow into the rocks or sand.
They suck water in through that slit at the bottom, (incurrent siphon) then they blow it out the top (excurrent siphon).	01/26/03
01/09/03	The clam occasionally blows a cannon like shot of stuff out of the top hole. When the newt is watching, he gets a facefull. (See text below)
The gill filaments function in respiration, and they fuse to form sheets of tissue that function as a net or sieve. The cilia move particles toward and into various "food or rejection grooves". These food grooves sort the particles by density and size. Acceptable foods, such as phytoplankton, are small and light. The food is transferred to grooves going into the mouth, while rejected particles, often sediment particles which are heavy or larger, are shunted into grooves leading to the bottom edge of the gills. Here they are wrapped up in mucus to form a small mucoid blob and dropped off the edge of the gill as a piece of "pseudofeces." Pseudo- or "false" - feces look much like the real thing and accumulate with actual feces in the bottom of the clam’s mantle cavity. Periodically the clam claps its shells together blowing both the feces and the pseudofeces out of the excurrent siphon. - Ronald L. Shimek, Ph. D.