Effect of low dissolved oxygen on aquatic life stages of the caddisfly Clistoronia magnifica (Limnephilidae)

Embryos, larval stages (instars I–V), pupal stages, and pharate adults of the caddisfly Clistoronia magnifica (Limnephilidae) were exposed to a range of dissolved oxygen (DO) concentrations (0.9–8.3 mg/L) for 4–88 days in the laboratory. Some embryos suspended growth at low DO, resuming growth and hatch when DO was increased. Embryos and larvae all had 96-h EC50 values (50% mortality at 96 h) of about 2.0 mg/L DO. The statistical Effect and No-Effect Thresholds for larvae exposed through two molts from instars I–III were 1.6 and 2.4 mg/L, respectively. At DO concentrations below 4.6 mg/L, egg hatch, larval development, molting success, time of molting, pupation, and adult emergence were delayed.