title: The comparative effects of metals on the hatching of earthworm cocoons.
abstract: To establish the use of Metaphire posthuma as a sensitive model for ecotoxicological studies, the comparative effects of five metals on the hatching profiles of the cocoons of the earthworms, Metaphire posthuma, Eisenia foetida and Perionyx excavatus, were studied. The cocoons of the three species of earthworms were exposed to copper, chromium (III), chromium (VI), lead and zinc at 1.25, 2.5, 5.0 and 10.0 ppm. Viable cocoons were incubated at 20 +/- degrees C by using the immersion method. The results indicated that the inhibition of cocoon hatching was concentration dependent. The normal hatching, delayed hatching and non-viability of cocoons were recorded. At a concentration of 1.25 ppm, there was almost no effect on the hatching of the cocoons of all three species of earthworms, except when exposed to chromium (VI), but higher concentrations (2.5 and 5.0 ppm) caused severe effects. It was concluded that M. posthuma was more sensitive than the other two species, and that it is a suitable model for use in ecotoxicity testing.
authors.affiliation: Cell Biology Division, Industrial Toxicology Research Centre, PO Box 80, M.G. Marg, Lucknow 226 001, India. skgitrc@rediffmail.com
authors.forename: Shrawan K
authors.initials: SK
authors.lastname: Gupta
authors.forename: Richa
authors.initials: R
authors.lastname: Srivastava
authors.forename: Marko
authors.initials: M
authors.lastname: Kuittinen
authors.forename: Neeraj
authors.initials: N
authors.lastname: Mathur
authors.forename: Prem N
authors.initials: PN
authors.lastname: Saxena
mesh_terms: D000818:Animals; D019216:Metals, Heavy / Q000633:toxicity*; D009835:Oligochaeta / Q000187:drug effects*; D012098:Reproduction / Q000187:drug effects; D013045:Species Specificity
chemical_list: D019216:Metals, Heavy