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

Abstract

Abstract-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 g Cu/L, 24 g Co/L, and the mixture of 1.0 g Cu/L and 0.9 g Co/L, whereas rainbow trout avoided at least 1.6 g Cu/L, 180 g Co/L, and the mixture of 2.6 g Cu/L and 2.4 g Co/L. Chinook salmon were also more sensitive to the toxic effects of Cu in that they failed to avoid Ն44 g Cu/L, whereas rainbow trout failed to avoid Ն180 g Cu/L. Furthermore, following acclimation to 2 g Cu/L, rainbow trout avoided 4 g 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.

Effect of Acute Copper Sulfate Exposure on Olfactory Responses to Amino Acids and Pheromones in Goldfish (Carassius auratus)

“…Olfactory neurons possess a unique capacity to regenerate, a property that has been used to reveal the cellular component of olfaction in fish (4), amphibians (5), snakes (6), birds (7), and mammals (8,9). Furthermore, some chemicals, such as heavy metals and pesticides, even at sublethal concentrations, are able to disturb a broad range of olfaction-dependent behavior and cause long-lasting damage to the sensory epithelium (10)(11)(12); this has been used to provoke degeneration and regeneration of olfactory neurons.…”

“…Salmonid fishes tend to avoid relatively low concentrations of copper, whereas at high concentrations fish become anosmic (10). Chronic exposure to copper causes impaired avoidance of conspecific alarm cues in Iowa darters (Etheostoma exile) (15) and Colorado pike minnows (Ptychocheilus lucius) (16).…”

Cadmium disrupts behavioural and physiological responses to alarm substance in juvenile rainbow trout (Oncorhynchus mykiss)

“…Several studies have illustrated the sensitivity of olfaction to toxicants, including cadmium (Brown et al, 1982;Stromberg et al, 1983), copper (Hara et al, 1976;Brown et al, 1982;Rehnberg and Schreck, 1986;Julliard et al, 1995;Hansen et al, 1999), diazinon (Moore and Waring, 1996) and mercury (Hara et al, 1976;Brown et al, 1982;Rehnberg and Schreck, 1986). It has recently become apparent that olfactory disruption by sublethal toxicant exposure may consequently disturb olfaction-mediated predator avoidance behaviours of fish.…”

Changes in the olfactory mucosa of the black bullhead Ictalurus melas induced by exposure to sublethal concentrations of sodium dodecylbenzene sulphonate

“…Many studies have demonstrated that morphological alterations induced by several aquatic contaminants (generally heavy metals and pesticides, but also detergents) are accompanied by reduced electric activity, recordable as electroolfactogram (EOG) or electroencephalogram (EEG), in the ORC and olfactory bulb respectively (Bardach et al 1965, Sutterlin et al 1971, Hansen et al 1999b). Other studies have confirmed the relationship between the impairment of olfactory discrimination and behaviour (Rehnberg & Schreck 1986, Hidaka & Tatsukawa 1989, Saglio & Trijasse 1998, Hansen et al 1999a). Detergents at sublethal doses are in fact able to affect feeding behaviour, conspecific attraction, and locomotory activity (Bardach et al 1965, Olsén & Höglund 1985, Barbieri et al 1998.…”