STUDY OF ACCLIMATION PROTOCOL AND FECUNDITY OF TILAPIA, OREOCHROMIS MOSSAMBICUS IN SEAWATER.
Rajeev Ranjan-1 and S. Athithan-2
1-2-Dept. of Coastal Aquaculture, Fisheries College and Research Institute, Thoothkudi- 628 008
Tamil Nadu Fisheries University, Tamil Nadu, India
[Corresponding author E-mail1: email@example.com]
Received: 07-03-2016 Accepted: 31-03-2016
Gradual acclimation of tilapia fingerlings, Oreochromis mossambicus from freshwater to seawater was conducted in cement tank under wet laboratory condition. Salinity was increased at a rate of 7 ppt / day, fingerlings were acclimatized to live in almost near seawater condition by the 5th day of experiment.The entire water was exchanged with complete seawater from the 6th day onwards. However, water temperature and dissolved oxygen was maintained at 30.0 ± 1oC and 6.32 ± 0.51 ppm respectively and other parameters maintained within tolerable range. The duration taken to acclimatize the tilapia fingerlings from freshwater to seawater was 5 days. Experiments were also conducted consecutively to determine the fecundity of the tilapia, O. mossambicus in full-strength seawater (36± 1 ppt). Brooder were selected in a ratio of 1:3 (male: female) and stock in cement tank. Eight matured male and twenty four matured female were used in the tank. No significant effect on fecundity was found with respect to the size of male and female brooders. The ratio of 1:3 was found ideal to reduce aggressive behavior during the breeding periods.
Keywords: tilapia, Salinity, temperature, DO