by standard experiments designed to isolate and characterize specific anion and cation currents for example cl u2212 currents are studied in isolation by using nmdg cl bath and pipette solutions specific current types are characterized further by performing a limited series of pharmacological inhibitor studies the intracellular ca 2 and atp dependence of all currents observed will be assessed excretory cell fluid transport as discussed earlier excretory cells are present albeit at low frequency in the inventors 39 mixed cultures the appearance of the cells is similar to that described by buechner et al 1999 they typically have one or two well developed processes a single highly refractile canal like structure extends from the tip of the processes across the cell body this structure is the excretory canal a number of observations indicate that the excretory cell is a secretory cell responsible for elimination of fluid and waste products from the pseudocoelomic space for example exposure of worms to hypotonic media causes increased fluid secretion and excretion nelson amp riddle 1984 animals swell with fluid and die when excretory cells are laser ablated nelson amp riddle 1984 mutations in various genes leads to the formation of large fluid filled cysts in excretory cell tubular.