EFFECTS OF WATER-QUALITY ON SURVIVAL AND REPRODUCTION OF 4 SPECIES OFPLANARIA (TURBELLARIA, TRICLADIDA)

In a series of bioassays, four planarian species - Dugesia dorotocepha la (Woodworth), Dugesia tigrina (Girard), Cura foremanii (Girard), Den drocelopsis vaginatus (Hyman) - were evaluated against six water quali ty parameters (hardness, temperature, salinity, pH, dissolved organics , and dissolved oxygen) for effects on species survival and asexual re production. No significant (P<0.05) effects were determined on surviva l and asexual reproduction of three species exposed to various levels of hardness. Dugesia tigrina was determined to have a significant incr ease in asexual reproduction with an increase in hardness. Dissolved o xygen was determined to be a critical parameter affecting both surviva l and reproduction of the species evaluated. Dugesia dorotocephala and D. tigrina were determined to be the most adaptable and tolerant of t he species evaluated.