U. Schulteoehlmann et al., MARISA CORNUARIETIS (GASTROPODA, PROSOBRANCHIA) - A POTENTIAL TBT BIOINDICATOR FOR FRESH-WATER ENVIRONMENTS, Ecotoxicology, 4(6), 1995, pp. 372-384
The ramshorn snail Marisa cornuarietis (L., 1767) exhibits imposer (oc
currence of male parts in addition to the female genital duct) under t
he influence of TBT (tributyltin) in laboratory experiments and accumu
lates this biocide in a time- and concentration-dependent manner. A co
mparison of BCF (bioconcentration factors) demonstrates that this limn
ic species accumulates more TBT than marine species. Evidence is given
that TBT causes hormonal disorders which are responsible for imposer
development. The testosterone/oestradiol quotient reflects the imposer
development which can be described by a classification scheme differe
ntiating four stages in Marisa cornuarietis. In the background of the
constantly increasing organotin concentration in the limnic environmen
t Marisa cornuarietis could be a well-suited bioindicator for TBT poll
ution. No other limnic species with a lower threshold concentration fo
r measurable TBT effects is reported within the literature.