title: Part 2: Sensitivity comparisons of the mayfly Centroptilum triangulifer to Ceriodaphnia dubia and Daphnia magna using standard reference toxicants; NaCl, KCl and CuSO4.
abstract: Criteria for establishing water quality standards that are protective for 95% of the native species are generally based upon laboratory toxicity tests. These tests utilize common model organisms that have established test methods. However, for invertebrates these species represent mostly the zooplankton community and are not inclusive of all taxa. In order to examine a potential under-representation in emerging aquatic invertebrates the US Environmental Protection Agency has cultured a parthenogenetic mayfly, Centroptilum triangulifer (Ephemeroptera: Baetidae). This study established a 48h acute and a 14-day short-term chronic testing procedure for C. triangulifer and compared its sensitivity to two model invertebrates, Ceriodaphnia dubia and Daphnia magna. Toxicity tests were conducted to determine mortality and growth effects using standard reference toxicants: NaCl, KCl and CuSO4. In 48-h acute tests, the average LC50 for the mayfly was 659mgL(-1) NaCl, 1957mgL(-1) KCl, and 11μgL(-1) CuSO4. IC25 values, using dry weight as the endpoint, were 228mgL(-1) NaCl, 356mgL(-1) KCl and 5μgL(-1) CuSO4. C. triangulifer was the most sensitive species in NaCl acute and chronic growth tests. At KCl concentrations tested, C. triangulifer was less sensitive for acute tests but was equally or more sensitive than C. dubia and D. magna for growth measurements. This study determined C. triangulifer has great potential and benefits for use in ecotoxicological studies.
authors.affiliation: The McConnell Group, 26 W. MLK Blvd., Cincinnati, OH 45268, United States.
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Struewing
authors.affiliation: U.S. Environmental Protection Agency, 26 W. MLK Blvd., Cincinnati, OH 45268, United States. Electronic address: Lazorchak.jim@epa.gov.
authors.forename: James M
authors.initials: JM
authors.lastname: Lazorchak
authors.affiliation: The McConnell Group, 26 W. MLK Blvd., Cincinnati, OH 45268, United States.
authors.forename: Paul C
authors.initials: PC
authors.lastname: Weaver
authors.affiliation: U.S. Environmental Protection Agency, 26 W. MLK Blvd., Cincinnati, OH 45268, United States.
authors.forename: Brent R
authors.initials: BR
authors.lastname: Johnson
authors.affiliation: Stroud Water Research Center, Avondale, PA, United States.
authors.forename: David H
authors.initials: DH
authors.lastname: Funk
authors.affiliation: North Carolina State University, Raleigh, NC, United States.
authors.forename: David B
authors.initials: DB
authors.lastname: Buchwalter
mesh_terms: D000818:Animals; D019327:Copper Sulfate / Q000633:toxicity*; D003621:Daphnia / Q000187:drug effects*; D065133:Ephemeroptera / Q000187:drug effects*; D011189:Potassium Chloride / Q000633:toxicity*; D012015:Reference Standards; D012965:Sodium Chloride / Q000633:toxicity*; D018675:Toxicity Tests / Q000592:standards*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; D012965:Sodium Chloride; D011189:Potassium Chloride; D019327:Copper Sulfate
keywords: Comparative toxicity; CuSO(4); KCl; Mayfly; NaCl