Biological cost of tolerance to heavy metals in the mosquito Anopheles gambiae
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Date
2010-06
Authors
Mireji, P. O.
Keating, J.
Hassanali, A.
Mbogo, C. M.
Muturi, M. N.
Githure, J.I.
Beier, J.C.
Journal Title
Journal ISSN
Volume Title
Publisher
National Institute of Health
Abstract
The global rate of heavy metal pollution is rapidly increasing in different habitats. Anopheles malaria vector species appear to tolerate many aquatic habitats with metal pollutants, despite their normal proclivity for ‘clean’ water (i.e., generally water free of organic matter). Investigations were conducted to establish whether there are biological costs for tolerance to heavy metals in Anopheles gambiae Giles sensu stricto (Diptera: Culicidae), and to assess the potential impact of heavy metal pollution on mosquito ecology. Anopheles gambiae s.s. were selected for cadmium, copper or lead tolerance through chronic exposure of immature stages to solutions of the metals for three successive generations. Biological costs were assessed in the fourth generation by horizontal life table analysis. Tolerance in larvae to cadmium (as cadmium chloride, CdCl2), copper (as copper II nitrate hydrate, (Cu (NO3)2. 2·5H2O) and lead (as lead II nitrate, (Pb (NO3)2), monitored by changes in LC50 concentrations of the metals, changed from, 6.07, 12.42 and 493.32 μg/L to 4.45, 25.02 and 516.69 μg/L, respectively, after 3 generations of exposure. The metal- selected strains had a significantly lower magnitude of egg viability, larval and pupal survivorship, adult emergence, fecundity and net reproductive rate than the control strain. The population doubling times were significantly longer and the instantaneous birth rates lower in most metal- selected strains relative to the control strain. Our results suggest that although An. gambiae s.s. displays the potential to develop tolerance to heavy metals, particularly copper, this may occur at a significant biological cost, which can adversely affect its ecological fitness
Description
Article
Keywords
Anopheles gambiae, biological cost, cadmium, copper, heavy metals, lead, tolerance
Citation
Mireji, P. O., Keating, J., Hassanali, A., Mbogo, C. M., Muturi, M. N., Githure, J. I., & Beier, J. C. (2010). Biological cost of tolerance to heavy metals in the mosquito Anopheles gambiae. Medical and Veterinary Entomology, 24(2), 101-107.