title: Chronic toxicity of hexavalent chromium to the fathead minnow (Pimephales promelas).
abstract: The chronic effects of hexavalent chromium on the fathead minnow (Pimephales promelas) were investigated. Survival was affected only at the high test concentration of 3.95 mg Cr/L. All chromium concentrations, including 0.018 mg/L, the lowest tested, retarded the early growth of first-generation fish, but this effect was only temporary. Growth of second-generation fish was not affected at concentreations of 1.0 mg/L or lower. Reproduction and hatchability of eggs were not affected at any chromium concentration tested. The maximum acceptable toxicant concentration (MATC) for fathead minnows in hard water (209 mg/L as CaCO3 at pH 7.7) was  based on survival and lies between 1.0 and 3.95 mg Cr/L, respectively. The application factor (MATC/96-hr LC50) is between 0.03 and 0.11.
mesh_terms: D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D002857:Chromium / Q000633:toxicity*; D004531:Eggs; D005260:Female; D005298:Fertility / Q000187:drug effects; D005399:Fishes / Q000502:physiology*; D005618:Fresh Water; D006128:Growth / Q000187:drug effects; D008297:Male; D012098:Reproduction / Q000187:drug effects; D012737:Sex Factors
chemical_list: D002857:Chromium