Life-history effects of arsenic toxicity in clades of the earthworm Lumbricus rubellus.
Exposures of Lumbricus rubellus to a series of arsenic concentrations in soil were used to assess life-stage (juvenile, adult) and genotype specific sensitivities, to calculate population growth rate (λ) and to assess patterns of As accumulation. Significant mortality was seen in juveniles at 125 mg/kg As, while growth and maturation was affected from 36 mg/kg and above. In adults, cocoon production at the highest concentration (125 mg/kg) was significantly reduced. Phylogenetic analysis was performed by comparison of mitochondrial sequences to establish genotypic variation among juveniles. Three clades with more than 7.5% divergent were described, with 70% of earthworms belonging to a single clade. Date of and mass at maturation was significantly different between clades, but clades were not differentially As sensitive. Parameter λ was reduced at 36 mg/kg As and was negative at 125 mg/kg As, suggesting impacts and population stability and potential extinction at environmentally relevant concentrations.
Centre of Ecology and Hydrology, MacLean Building, Benson Lane, Crowmarsh Gifford, Wallingford OX10 8BB, United Kingdom.
C J
CJ
Anderson
P
P
Kille
A J
AJ
Lawlor
D J
DJ
Spurgeon
D000818:Animals; D001151:Arsenic / Q000633:toxicity*; D005838:Genotype; D008018:Life Cycle Stages / Q000187:drug effects*; D009835:Oligochaeta; D010802:Phylogeny; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000633:toxicity*
D012987:Soil; D012989:Soil Pollutants; D001151:Arsenic