Abstract

Cadmium tolerance in field populations of the midge Chironomus riparius was studied by comparing the effects of chronic cadmium exposure on several life-history parameters using first generation, laboratory-reared animals. Differences between populations of C. riparius were therefore assumed to have a genetic basis. Field populations naturally exposed to metals were less sensitive to cadmium compared to unexposed populations, when larval development time and hatchability of the egg masses were measured. However, larval mortality still increased with cadmium exposure and no differences between exposed and unexposed populations were observed. Furthermore, life-history patterns differed between metal tolerant and nontolerant populations grown under control conditions. Metal tolerant populations were characterized by a high control mortality (50%) or an increased larval development time (with 30%). The results, therefore, indicated the presence of costs of tolerance, while a direct selection on certain life-history characteristics due to metal pollution was absent.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.