Document Detail


Joint effects of density dependence and toxicant exposure on Drosophila melanogaster populations.
MedLine Citation:
PMID:  17658601     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Risk assessment of environmental contaminants is usually based on experiments on well-fed individuals held at low population densities. However, field populations are often subject to resource limitation. Individuals who are already stressed by crowding or food limitation may show greater susceptibility to toxicants. But density dependence could also reduce population-level impacts as toxicant-related mortalities may reduce competition for resources. This study examines the joint effects of toxicants and food availability on populations of Drosophila melanogaster. The interactions between the effects of food limitation and toxicant stress were dose dependent and strongly influenced by toxicity mechanisms. In food-limited conditions, a compensatory effect often occurred, with toxicant exposure having a lower proportional impact than at higher food levels. This provides further evidence that density-dependent population processes can produce an assimilative capacity for the effects of toxicants. But synergistic food-toxicant effects were also common and the interaction often switched between synergistic and compensatory at different toxicant concentrations and food supplies. There is no simple "less-than-additive", "additive" or "more-than-additive" relationship between density and toxicant effects, even for a single toxicant.
Authors:
Yue Gui; Alastair Grant
Publication Detail:
Type:  Journal Article     Date:  2007-07-20
Journal Detail:
Title:  Ecotoxicology and environmental safety     Volume:  70     ISSN:  1090-2414     ISO Abbreviation:  Ecotoxicol. Environ. Saf.     Publication Date:  2008 Jun 
Date Detail:
Created Date:  2008-04-21     Completed Date:  2008-10-31     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7805381     Medline TA:  Ecotoxicol Environ Saf     Country:  United States    
Other Details:
Languages:  eng     Pagination:  236-43     Citation Subset:  IM    
Affiliation:
Centre for Ecology, Evolution and Conservation, University of East Anglia, Norwich NR4 7TJ, UK. guiyue2002@yahoo.com.cn
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MeSH Terms
Descriptor/Qualifier:
Animals
Cadmium / toxicity*
Diflubenzuron / toxicity*
Drosophila melanogaster / drug effects*,  physiology
Environmental Pollutants / toxicity*
Female
Food Deprivation
Larva / drug effects,  physiology
Nicotine / toxicity*
Phenylcarbamates / toxicity*
Population Density
Chemical
Reg. No./Substance:
0/Environmental Pollutants; 0/Phenylcarbamates; 35367-38-5/Diflubenzuron; 54-11-5/Nicotine; 72490-01-8/fenoxycarb; 7440-43-9/Cadmium

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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