title: Acute and chronic toxicity of azinphos-methyl to two estuarine species, Mysidopsis bahia and Cyprinodon variegatus.
abstract: The acute and chronic toxicity of azinphos-methyl (Guthion) was evaluated for two estuarine species in the laboratory. Mysids (Mysidopsis bahia) and sheepshead minnows (Cyprinodon variegatus) were selected as the representative invertebrate and vertebrate estuarine test species, respectively. The toxicological endpoints determined for each species included the 96-h LC50, the no-observed-effect concentration (NOEC), the maximum acceptable toxicant concentration (MATC), and the acute-to-chronic ratio. The 96-h LC50 value derived for sheepshead minnows (2.0 microg/L) was seven times higher than the 96-h LC50 value (0.29 microg/L) derived for mysids. The MATCs were 0.024 microg/L and 0.24 microg/L for the mysid and the sheepshead minnow, respectively. The estimated acute-to-chronic ratios were 12 for mysids and 8.3 for sheepshead minnows.
authors.affiliation: U.S. Environmental Protection Agency Region 6, 1445 Ross Avenue, Dallas, Texas 75202, USA.
authors.forename: M G
authors.initials: MG
authors.lastname: Morton
authors.forename: F L
authors.initials: FL
authors.lastname: Mayer
authors.forename: K L
authors.initials: KL
authors.lastname: Dickson
authors.forename: W T
authors.initials: WT
authors.lastname: Waller
authors.forename: J C
authors.initials: JC
authors.lastname: Moore
mesh_terms: D000818:Animals; D001387:Azinphosmethyl / Q000633:toxicity*; D003530:Cyprinidae / Q000254:growth & development*; D033364:Decapoda / Q000187:drug effects*; D007306:Insecticides / Q000633:toxicity*; D007928:Lethal Dose 50; D012623:Seawater
chemical_list: D007306:Insecticides; D001387:Azinphosmethyl