title: Time-specific and population-level differences in physiological responses of fathead minnows (Pimephales promelas) and golden shiners (Notemigonus crysoleucas) exposed to copper.
abstract: The influence of exposure time on gill Na+/K+ ATPase activity and metabolic rate in populations of fathead minnows (Pimephales promelas) and golden shiners (Notemigonus crysoleucas) hatcheries in Ohio (OH) and Pennsylvania (PA) when exposed to sublethal concentrations of copper (Cu) was examined. The pattern of change in gill Na+/K+ ATPase activity was similar in all species/populations and results support expectations based on the concept of acclimation. In all populations, Na+/K+ ATPase activity declined significantly compared to reference values within 24 h, recovered by 48 h, and then continued to increase before exceeding reference values by 192 h. With the exception of PA fathead minnows, Na+/K+ ATPase activities returned to reference levels by 384 h. Although metabolic rates of individual fish were not strongly correlated with Na+/K+ ATPase activities, the pattern of change in mean values of these physiological parameters was very similar. However, OH populations of both fathead minnows and golden shiners demonstrated much more dramatic changes in metabolic rate compared to PA fish. At 24 h, metabolic rate of PA fathead minnows had decreased by 16% compared to the reference value whereas the OH population had decreased by 31%; metabolic rate of PA golden shiners declined by 23% compared to 59% in OH shiners at 24 h. Similar differences were observed in the maximum metabolic rates achieved at 192 h. While the increased sensitivity of OH fish to Cu is not readily explainable by genetic or environmental factors, results suggest the need for considering population level differences when evaluating the physiological effects of toxicants.
authors: Pennsylvania State University--Greater Allegheny, 4000 University Drive, McKeesport, PA 15132, USA. jdp12@psu.edu
authors: John D
authors: JD
authors: Peles
authors: David H
authors: DH
authors: Pistole
authors: Mickey C
authors: MC
authors: Moffe
mesh_terms: D000818:Animals; D003300:Copper / Q000633:toxicity*; D003530:Cyprinidae / Q000502:physiology*; D004734:Energy Metabolism / Q000187:drug effects*; D005398:Fisheries; D005880:Gills / Q000187:drug effects* / Q000201:enzymology; D009820:Ohio; D010414:Pennsylvania; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; D003300:Copper; D000254:Sodium-Potassium-Exchanging ATPase