title: Relative sensitivity of three endangered fishes, Colorado squawfish, bonytail, and razorback sucker, to selected metal pollutants.
abstract: The acute toxicity of four metal pollutants to larval and juvenile stages of endangered Colorado squawfish (Ptychocheilus lucius), bonytail (Gila elegans), and razorback sucker (Xyrauchen texanus) were determined in a water quality representative of that in the Green River, Utah. The rank order of toxicity (96-hr LC50) of the metals to all species and life stages from most toxic to least toxic was mercury (57-168 micrograms/liter) > cadmium (78-168 micrograms/liter) > hexavalent chromium (32,000-123,000 micrograms/liter) > lead (> 170,000 micrograms/liter). In tests with lead, a precipitate formed in all test solutions and no mortalities occurred in these treatments. The larvae of each species were as sensitive or more sensitive than the juveniles to cadmium, hexavalent chromium, and mercury. Overall, the three species exhibited similar sensitivities to cadmium, hexavalent chromium, and mercury. Comparison of test results for the juveniles with toxicity values reported for other freshwater fishes tested in different water qualities indicates that the endangered fishes are more sensitive to cadmium than other cyprinids and centrarchids and less sensitive than salmonids, whereas their sensitivity to hexavalent chromium and mercury is similar to that of other cyprinids, centrarchids, and salmonids.
authors.affiliation: U.S. Geological Survey, Midwest Science Center, Yankton, South Dakota 57078-9214, USA.
authors.forename: K J
authors.initials: KJ
authors.lastname: Buhl
mesh_terms: D000818:Animals; D002104:Cadmium / Q000633:toxicity; D002274:Carcinogens, Environmental / Q000633:toxicity; D002857:Chromium / Q000633:toxicity; D003120:Colorado; D005399:Fishes / Q000502:physiology*; D005618:Fresh Water; D007854:Lead / Q000633:toxicity; D007928:Lethal Dose 50; D008628:Mercury / Q000633:toxicity; D019216:Metals, Heavy / Q000633:toxicity*; D012680:Sensitivity and Specificity; D013045:Species Specificity; D016019:Survival Analysis; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D002274:Carcinogens, Environmental; D019216:Metals, Heavy; D014874:Water Pollutants, Chemical; D002104:Cadmium; D002857:Chromium; C074702:chromium hexavalent ion; D007854:Lead; D008628:Mercury