INDUCED BREEDING OF Cirrhinus reba (HAM.) AND Labeo bata (HAM.)

Information on artificial breeding of Cirrhinus reba and Labeo bata is not common in Bangladesh. There are reports on serious decline of natural abundance of these species and are considered threatened under present environmental situation. The species should be brought under culture systems to protect them from being dwindled. For optimizing the breeding technique, the experiment was conducted. Nine pairs of male and female of each species were used. The females of both the species were divided into three treatment groups (T1, T2 and T3). Weight of reba female and male ranged from 110 to 140g and 80 to 105g respectively, the same for bata ranged from 310 to 388g and 180 to 260g for female and male respectively. The females of C. reba were injected a first dose of 0.5, 1.0 and 1.5 mg PG kg-1 body weight followed by a second dose of 4.0, 4.5 and 5.0 mg PG kg-1 body weight respectively after 6 hours of the first dose. The doses for L. bata were 0.5, 1.0 and 1.5 mg PG kg-1 body weight as first, followed by a second dose of 4.5, 5.0 and 5.5 mg PG kg-1 body weight. A single dose for males of C. reba was 1.5 mg PG kg-1 body weight and for L. bata 2.0 mg PG kg-1 body weight. Single pair mating was performed under semi-natural conditions in nine separate hapas with continuous showering at a temperature range of 27-28 0C. The highest average fertilization and hatching of C. reba were obtained at 87.88% and 81.47% respectively and that of L. bata were 86.19% and 75.00% respectively from T2.The percentage of fertilization and hatching obtained against the comparatively low doses of hormone in this experiment was considered noteworthy.