title: The impact of temperature on the acute toxicity of arsenate and arsenite to rainbow trout (Salmo gairdneri).
abstract: This research investigated the influence of temperature (5 or 15 degrees C) on the acute toxicity of waterborne arsenite and arsenate to rainbow trout. Trout exposed to arsenate at 5 degrees C had a 144-hr LC50 (95% fiducial limits) of 114.1 (106.7 to 121.9) mg liter-1, twice the value of 58 (50.6 to 66.4) mg liter-1 evident in fish exposed at 15 degrees C. Temperature had no effect on the toxicity of arsenite; 144-hr LC50's at 5 and 15 degrees C were 17.7 (16.5 to 18.9) and 20.7 (19.9 to 21.5) mg liter-1, respectively. When fish were exposed to 70 mg liter-1 arsenate for 72 hr, those held at 15 degrees C had mean whole-body arsenic levels that were five times higher than the levels in fish held at 5 degrees C. There were, however, essentially no differences in the patterns of arsenic uptake between 5 and 15 degrees C when the fish were exposed to arsenate at 0.7 or 1.2 of the 144-hr LC50 at each temperature, a strategy which compensates for (eliminates) temperature as a modifier of toxicity. Fish which were held in arsenate-free water after the 72-hr arsenate exposure depurated significantly more arsenic at 15 degrees C than at 5 degrees C. Despite this, it is apparent that enhanced uptake at 15 degrees C was the overriding factor controlling the differences in the expression of arsenate toxicity at the two temperatures.
authors.affiliation: Department of Biology, University of Waterloo, Ontario, Canada.
authors.forename: S M
authors.initials: SM
authors.lastname: McGeachy
authors.forename: D G
authors.initials: DG
authors.lastname: Dixon
mesh_terms: D000818:Animals; D001149:Arsenates / Q000633:toxicity*; D001151:Arsenic / Q000633:toxicity*; D018053:Arsenites; D007928:Lethal Dose 50; D012474:Salmon / Q000378:metabolism*; D013696:Temperature
chemical_list: D001149:Arsenates; D018053:Arsenites; C015001:arsenite; D001151:Arsenic