The comparison of adult and juvenile earthworms Eisenia fetida sensitivity to cadmium

The heavy metals pollution of soils pose serious risk to soil dwelling organisms and earthworms, as soil keystone species, are considered to be one of the most sensitive groups of soil invertebrates. Cadmium is a non-essential, strongly toxic element causing severe biochemical, physiological and reproductive effects in many organisms. During the present study our aim was to compare the adult and juvenile earthworms Eisenia fetida sensitivity to cadmium. Adult and juveniles earthworms were exposed to 1-100 μg Cd g-1 of soil. Adult worms were exposed to metals for 4 weeks, juveniles – for 14 weeks. The juveniles E. fetida were found to be more sensitive to Cd than adults. The risk of death of juveniles increased with Cd concentration in soil, but there was no significant mortality of adults at all tested Cd concentrations. The growth of juveniles (measured as weight) was also more affected than that of adults (p< 0.05). The weight of adult earthworms exposed to cadmium tended to show a dose-related decrease though a statistically significant decline was detected only in case of the highest concentration (100 μgCd g-1 soil). Cd severely affected the maturation of juvenile at the highest concentrations, worms did not reach sexual maturity at all. In case of adult worms, Cd inhibited the cocoon production rate in range of 18 – 65 %Aplinkotyros katedraVytauto Didžiojo universiteta