Abstract:

The endangered riverine catfish, locally known as Pangas (Pangasius pangasius Hamilton; Pangasiidae), is a very important catfish of Bangladesh. Though it is also distributed in India, Myanmar and Pakistan the induced breeding technique of the species has not been established. To save this fish from extinction, the experiment was conducted with 23 broods of P. pangasius (10 females and 13 males) weighing 4.2 kg on an average to establish a suitable breeding technique. Three breeding trials were conducted. Four different doses viz. 9, 10, 11 and 12 mg·kg-1 body weight of acetone dried carp pituitary gland (PG) were tested. Though all the four doses resulted in 100% ovulation in females, the dose of 10 mg·kg-1 body weight of PG demonstrated the best result in consideration to fertilization and hatching rates of eggs. Hatching of fertilized eggs occurred between 28 and 32 hours of incubation at 26 to 28°C. Hatching rate was highest (65%) in the second trial. Newly hatched larvae were planktonic and transparent. Feeding of larvae started between the third and fourth days after hatching. A number of larvae died at the free swimming stage and many died at the first feeding stage. The majority died within 10 days of hatching. Only 3 larvae survived after 10 days out of the thousands that hatched. These larvae preferred tubificid worms.

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Date 2004/06/01

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