EVALUATION OF ADAPTIVE PLASTICITY IN WILD Sarotherodon Galilaeus AND Coptodon Zillii IN CONCRETE POND

Abstract

This experiment evaluates the adaptive plastic responses of wild Sarotherodon galilaeus and Coptodon zillii from Tagwai Dam Reservoir in concrete pond. Fifteen (15) adult samples of each species were collected via baited Malian traps and transferred to the experimental facility at Bosso Campus Fish Farm, Federal, University of Technology, Minna. The samples were held in hapas-in-concrete-pond for 243 days (8-months). somatic and breeding data such as: mean survival rates: 0.27 (27%) and 0.33 (33%), mean final body weights gain: 76.62 ± 26.48 and 43.92 ± 17.08, breeding (fry produced): 201 and 379, progressive breeding trendline (polynomial) equation: y=15.56x2-160.58x+387.86, R²=0.7861 and y=10.143x2-101.21x+230.71, R²=0.7534 were calculated for S. galilaeus and C. zillii, respectively. Survivorship was low (<50 %) for both species in contrast to growth performance (weight gain) by which S. galilaeus was significantly (p<0.05) better. Statistical significances were determined by means of Independent-Samples t-test analysis in IBM SPSS 21. The length-weight regression analysis showed b>3.0 (positive allometric growth) for both species with high regression coefficient (R2 > 90 %). The condition factor (K) for S. galilaeus and C. zillii were 3.07g/cm3 and 3.45g/cm3, respectively, are good indications of wellbeing of the species in captivity. The survival, growth, and breeding in the captive fishes are precursors to the aquaculture potentials of local strains of S. galilaeus and C. zillii. A comprehensive study of the adaptation processes of the species are hereby recommended