EFFECTS OF THE INSECT GROWTH-REGULATOR (S)-METHOPRENE ON THE EARLY-LIFE STAGES OF THE FATHEAD MINNOW PIMEPHALES-PROMELAS IN A FLOW-THROUGH LABORATORY SYSTEM
Dh. Ross et al., EFFECTS OF THE INSECT GROWTH-REGULATOR (S)-METHOPRENE ON THE EARLY-LIFE STAGES OF THE FATHEAD MINNOW PIMEPHALES-PROMELAS IN A FLOW-THROUGH LABORATORY SYSTEM, Journal of the American Mosquito Control Association, 10(2), 1994, pp. 211-221
This study assessed the effect of the insect growth regulator (IGR) (S
)-methoprene on fathead minnow (Pimephales promelas) early life stages
. Newly spawned (less-than-or-equal-to 24 h) minnow eggs were continuo
usly exposed to (S)-methoprene concentrations of 13, 23, 48, 84, and 1
60 mug/liter for 37 days in a 2-liter proportional diluter system. No
significant reductions (P > 0.05) were detected at any test concentrat
ion for hatchability, fry survival, or total survival when compared to
controls. Significant reductions (P less-than-or-equal-to 0.05) in le
ngth and weight were detected at the 2 highest mean measured test conc
entrations compared to controls. The maximum acceptable toxicant conce
ntration (MATC) limits, the no-observed effect concentration (NOEC), a
nd the lowest observed effect concentration (LOEC), based on analyses
of fry length and weight, were 48 and 84 mug/liter, respectively. The
point estimate MATC value (the geometric mean of the NOEC and LOEC) wa
s calculated to be 63.5 mug/liter.