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The toxicity of malathion to unionid mussels: Relationship to expected environmental concentrations
Author(s) -
Keller Anne E.,
Ruessler D. Shane
Publication year - 1997
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620160524
Subject(s) - unionidae , malathion , biology , daphnia magna , juvenile , toxicology , acute toxicity , ecotoxicology , toxicity , mussel , bivalvia , zoology , mollusca , ecology , pesticide , chemistry , organic chemistry
The acute toxicity of malathion to glochidia, juvenile, and adult freshwater mussels was determined at pH 7.5 in soft water and at pH 7.9 in moderately hard reconstituted fresh water at 25°C and 32°C. Nine species were tested in one or more life stages. Glochidia tests were conducted for 4, 24, or 48 h, while juvenile and adult exposures lasted 96 h. Overall, Utterbackia imbecillis was the least sensitive species for all exposure conditions and life stages. The LC50 values for glochidia tested at 25°C ranged from 7 mg/L for Lampsilis siliquoidea (4 h) to 324 mg/L for U. imbecillis (48 h). At 32°C, glochidia LC50s were 119 mg/L for Villosa lienosa (48 h) and 374 mg/L for U. imbecillis (24 h). Tests with juvenile mussels produced 96‐h LC50s ranging from 24 mg/L for Lampsilis straminea claibornensis at 25°C to 219 mg/L for U. imbecillis at 25°C. The 96‐h LC50s for three species of adult mussels were greater than the highest malathion exposure concentration of 350 mg/L. These values are considerably higher than the reported 48‐h LC50 of 1 μg/L for Daphnia magna and the 96‐h LC50 of 0.76 μg/L for Gamarus fasciatus but are similar to 96‐h LC50s for some fish. Expected environmental concentrations should not be lethal to unionids.