Sg. Cheung et Ryh. Cheung, EFFECTS OF HEAVY-METALS ON OXYGEN-CONSUMPTION AND AMMONIA EXCRETION IN GREEN-LIPPED MUSSELS (PERNA-VIRIDIS), Marine pollution bulletin, 31(4-12), 1995, pp. 381-386
Physiological responses (oxygen consumption and ammonia excretion) of
the green-lipped mussel (Perna viridis) exposed to four concentrations
of Cd (0.15, 0.32, 0.70 and 1.50 ppm) and four concentrations of Zn (
0.60, 1.29, 2.79 and 6.00 ppm) were monitored for 21 days. Changes occ
urred in the ammonia excretion rates and O:N ratios with individual mu
ssels experiencing different metal concentrations over time. Oxygen co
nsumption rate decreased significantly with time for Cd-exposed indivi
duals and also decreased significantly with the interaction between th
e concentration of Zn and time for Zn-exposed individuals. Although lo
w O:N ratios (<30) were obtained in most of the treatments, no predict
able correlation was found between concentrations of metals and values
of O:N obtained. The value of using O:N ratio as a stress index is qu
estioned.