MERCURY TOXICITY IN TWO INTERTIDAL TROPICAL MARINE MOLLUSCS
MERCURY TOXICITY IN TWO INTERTIDAL TROPICAL MARINE MOLLUSCS
Date
1983
Authors
EKANATH, A. E
MENON, N. R
Journal Title
Journal ISSN
Volume Title
Publisher
Society of Fisheries Technologists (India) Cochin
Abstract
Lethal and sub-lethal effects of mercury have been studied in Perna viridis and
Modiolus carvalhoi. For P. viridis LC30 is 1.0 p.p.m. at 48 hand 0.23 p.p.m. at 96 h.
Recorded LC50 values forM. carvalhoi are 0.5 p.p.m. and 0.19 p.p.m. at 48 hand 96 h
respectively. The results document that these two species, although inhabiting the
same area in the tidal belt, exhibit clear differences in mercury resistance. It is further
shown that the duration of exposure affects mortality rates. In sub-lethal concentration,
between 0.01 and 0.10 p.p.m. decrease in pedal-gland activity is conspicuous in P. viridis.
At concentrations•much below LC50 values (at 96 h), although some animals are
alive, pedal-gland activity is totally suspended, supporting the assumption that shellclosure
ability plays a minor role in byssus thread production. In M. carvalhoi total
cessation of p~dal gland activity occurred at 0.09 p.p.m. of mercury.
Description
Keywords
MERCURY TOXICITY,INTERTIDAL, TROPICAL ,MARINE MOLLUSCS
Citation
Fishery Tech 20(2):84-89