Chronic Dual Exposure (Waterborne+Dietary)
Effects of Cadmium, Zinc and Copper on Growth and their
Bioaccumulation in Cirrhina
mrigala
Muhammad Javed
Department of Zoology & Fisheries, University of
Agriculture, Faisalabad, Pakistan *Corresponding author: javeddr1@hotmail.com
Abstract
During this research endeavor, the chronic
effects of dual exposure (waterborne+dietary) of cadmium (Cd), zinc (Zn) and
copper (Cu) on the growth performance and tissue-specific bioaccumulation of
metals in three age groups (60-, 90- and 120-day) of
Cirrhina mrigala were determined. The exposure of all metals caused
significant effects on the weight and total length gains in all three age groups
of fish. Fish growth was significantly affected due to Cu, followed by Cd and Zn
exposures. However, growth of treated fish was significantly lesser than control
(un-stressed). Fish condition factor did not change significantly due to
treatments. Zn exposure induced significantly better feed intake in fish than Cd
and Cu treatments. Feed conversion efficiency (FCE)
of fish varied significantly due to treatments that changed with age also.
Exposure of fish to metals caused significant alterations in fish feeding
patterns that caused profound effects on fish growth and FCE. Therefore, fish
growth has been found reliable end point in chronic dual exposure of Cd, Zn and
Cu to predict various processes associated with fish bioenergetics. The chronic
dual exposure of metals resulted into significantly inconstant buildup of Cd, Zn
and Cu in fish body organs also. In general, all metals exhibited their
bioaccumulations in fish that followed the order: liver > kidney > gills >
muscles > fins > skins > bones. The 60-dayfish displayed significantly higher
propensity to accrue all metals while Zn accumulation was significantly higher
than both Cd and Cu in the fish body.