The Revival of Critically Endangered Rita rita (Ham.)in Bangladesh

To revive the vulnerable catfish, Rita rita, artificial breeding with hormones (carpPG & ovaprim) were conducted. For carpPG, experiment was set under three treatments (T1, T2 and T3) and females were treated at the doses of 90, 100 and 110 mg/kg body weight respectively and males were treated with 40 mg/kg body weight in all cases during the second injection of female proved that the ovulation rate was 100 % in all treatments. The highest fertilization (82.50±6.455 %) and hatching rates (62.75±7.182 %) were observed at the doses of 100 mg carpPG/kg body weight. Another experiment was started with ovaprim where two treatments (T1, T2) against a control were used. Females were treated with 0.5 and 1.0 ml ovaprim/kg body weight respectively and males were treated with 0.5 ml ovaprim/kg body weight in all cases. No ovulation was observed treated with ovaprim. Last experiment was set with 5 days-old larvae reared under two different stocking densities viz. 1 larva and 2 larvae/L of water and fed with chopped tubificid worms ad libitum. There was significant difference between two treatments. Within the period of experiment, embryonic and larval developmental stages were studied.