Abstract |
Continuous flow, laboratory microcosms were used to measure the effects of pH, phenol, and NaCl on the survival of the life stages of Chironomus attenuatus, the caloric content of third and fourth instar larvae and adults, the lipid and protein-nitrogen content of fourth instar larvae, and the interaction among the various responses. Each experiment consisted of 24 treatment combinations with a 3 x 4 x 2 factorial arrangement in a completely randomized design with two replications of each treatment. Treatment variables were pH at 6.2, 7.2, and 8.2; phenol at 0, 10, 20, and 30 mg/l; and NaCl at 0 and 600 mg/l. pH had a significant effect on the survival of all life stages of C. attenuatus. Increasing phenol levels resulted in a nearby linear increase in caloric content. Sodium chloride affected the lipid content of fourth instar larvae. The lipid content was higher with NaCl present in the media than without NaCl. Interaction had a significant effect on all responses except survival of third and fourth instar larvae. (Author) |