The interactive effects of multiple stressors on physiological stress responses and club cell investment in fathead minnows.
Anthropogenic activities have dramatically increased over the past decades, with the consequence that many organisms are simultaneously exposed to multiple stressors. Understanding how organisms respond to these stressors is a key focus for scientists from many disciplines. Here we investigated the interactive effects of two stressors, UV radiation (UVR) and cadmium (Cd) exposure on a common freshwater fish, fathead minnow (Pimephales promelas). UVR is known to influence the density of epidermal club cells (ECCs), which are not only a key component of the innate immune system of fishes, but are also the source of chemical alarm cues that serve to warn other fishes of nearby predators. In contrast, Cd impairs the physiological stress response and ability of fish to respond to alarm cues. We used an integrative approach to examine physiological stress response as well as investment in ECCs. Fish exposed to UVR had higher levels of cortisol than non-exposed controls, but Cd reduced cortisol levels substantially for fish exposed to UVR. Fish exposed to UVR, either in the presence or absence of Cd, showed consistent decreases in ECC investment compared to non-exposed controls. Despite differences in ECC number, there was no difference in the potency of alarm cues prepared from the skin of UVR and Cd exposed or non-exposed fish indicating that UVR and Cd exposure combined may have little influence on chemically-mediated predator-prey interactions.
Department of Biology, University of Saskatchewan, Saskatoon, S7N 5E2 SK, Canada. Electronic address: aditya.manek@usask.ca.
Aditya K
AK
Manek
Department of Biomedical Sciences, WCVM, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada.
Maud C O
MC
Ferrari
Department of Biology, University of Saskatchewan, Saskatoon, S7N 5E2 SK, Canada.
Som
S
Niyogi
Department of Biology, University of Saskatchewan, Saskatoon, S7N 5E2 SK, Canada.
Douglas P
DP
Chivers
D000818:Animals; D002104:Cadmium / Q000633:toxicity; D003530:Cyprinidae / Q000502:physiology*; D013312:Stress, Physiological / Q000502:physiology*; D014466:Ultraviolet Rays / Q000009:adverse effects*; D014874:Water Pollutants, Chemical / Q000633:toxicity
D014874:Water Pollutants, Chemical; D002104:Cadmium
Alarm cue; Cadmium; Cortisol; Epidermal club cells; UV radiation