Aj. Reinecke et Sa. Reinecke, THE INFLUENCE OF HEAVY-METALS ON THE GROWTH AND REPRODUCTION OF THE COMPOST WORM EISENIA-FETIDA (OLIGOCHAETA), Pedobiologia, 40(5), 1996, pp. 439-448
Earthworms of the species Eisenia fetida were exposed to metal salts o
f cadmium, manganese, copper, lead and zinc to determine the effects o
f heavy metals on growth and reproduction. Since ultrastructural damag
e of spermatozoa was obtained after exposing the worms to heavy metals
, the aim was also to relate this phenomenon to reproductive performan
ce. The results showed that E. fetida responded differently to differe
nt heavy metals. The concentration ratio for cadmium was the highest a
nd worm growth and reproduction were severely affected. The worms grew
well in the lead contaminated environment and produced cocoons at the
same rate as the control worms. The hatchability of these cocoons wer
e, however, much lower. This phenomenon corresponded the with occurren
ce of extensive ultrastructural spermatozoon abnormalities, especially
of the acrosome region, providing some indication that lead toxicity
affects reproductive performance at this level. Worms exposed to zinc,
manganese and copper grew slower than control worms, matured later an
d produced fewer or no cocoons. The hatching success of the coccons pr
oduced in the zinc contaminated substrate was not as severely affected
as those from the lead exposure.