RELATIONSHIPS AMONG INCREASE IN BIOMASS, PLANKTONIC PRODUCTIVITY AND PHYSICO-CHEMISTRY OF PONDS STOCKED WITH Zn+Pb+Mn MIXTURE STRESSED FISH
S. Abbas1* and M. Javed2
1Institute of Molecular Biology and Biotechnology, The University of Lahore, Lahore, Pakistan
2Department of Zoology, Wildlife and Fisheries, University of Agriculture, Faisalabad-38040, Pakistan
*Corresponding author’s e-mail address: sidraabbas2012@hotmail.com
ABSTRACT
A group of fish species viz. Cirrhina mrigala, Labeo rohita, Catla catla, Hypophthalmichthys molitrix and Ctenopharyngodon idella were exposed to the sub-lethal Zn+Pb+Mn mixture concentrations in glass aquaria, for a period of 90 days. The other group of fish species was not given any stress. After metals mixture exposure, stressed and control groups were stocked in out-door earthen ponds, separately. Both the groups were reared for fourteen fortnights under semi-intensive pond culture system. Correlation and regression analyses on increase in fish biomass, dry weights of planktonic biomass and physico-chemical variables of pond’s water were performed, on fortnightly data. In stressed fish pond, light penetration and chloride contents had exerted significantly direct while total ammonia, temperature and dissolved oxygen showed significant but inverse influence on increase in fish biomass. However, in control, only variable light penetration exhibited direct relationship with increase in fish biomass. Temperature and chloride contents exhibited direct impacts on planktonic productivity of metals mixture stressed fish. However, in control, temperature, total ammonia and phosphates showed direct relationship with pond productivity. It was also found that dependence of increase in fish biomass on dry weights of planktonic biomass was higher in control than stressed pond.
Keywords: Metals, regression, fish yield, planktonic biomass, physico-chemical parameters.
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