Differences in neurobehavioral responses of chinook salmon (Oncorhynchus tshawytscha) and rainbow trout (Oncorhynchus mykiss) exposed to copper and cobalt: behavioral avoidance

• Published in: Environmental toxicology and chemistry 1999-09, Vol.18 (9), p.1972-1978
• Main Authors: Hansen, J.A, Marr, J.C.A, Lipton, J, Cacela, D, Bergman, H.L
• Format: Article
• Language: English
• Subjects: Agnatha. Pisces; Animal, plant and microbial ecology; Applied ecology; behavior; Behavioral avoidance; Biological and medical sciences; Chinook salmon; Cobalt; contaminants; Copper; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on vertebrates; Fundamental and applied biological sciences. Psychology; Oncorhynchus mykiss; Oncorhynchus tshawytscha; Rainbow trout
• ISSN: 0730-7268; 1552-8618
• DOI: 10.1002/etc.5620180916

Behavioral avoidance of copper (Cu), cobalt (Co), and a Cu and Co mixture in soft water differed greatly between rainbow trout (Oncorhynchus mykiss) and chinook salmon (O. tshawytscha). Chinook salmon avoided at least 0.7 microgram Cu/L, 24 microgram Co/L, and the mixture of 1.0 microgram Cu/L and 0.9 microgram Co/L, whereas rainbow trout avoided at least 1.6 microgram Cu/L, 180 microgram Co/L, and the mixture of 2.6 micrograms Cu/L and 2.4 micrograms Co/L. Chinook salmon were also more sensitive to the toxic effects of Cu in that they failed to avoid greater than or equal to 44 microgram Cu/L, whereas rainbow trout failed to avoid greater than or equal to 180 microgram Cu/L. Furthermore, following acclimation to 2 microgram Cu/L, rainbow trout avoided 4 microgram Cu/L and preferred clean water, but chinook salmon failed to avoid any Cu concentrations and did not prefer clean water. The failure to avoid high concentrations of metals by both species suggests that the sensory mechanism responsible for avoidance responses was impaired. Exposure to Cu concentrations that were not avoided could result in lethality from prolonged Cu exposure or in impairment of sensory-dependent behaviors that are essential for survival and reproduction.