Embryonic and larval development of spotted murrel, Channa punctatus (Bloch)

Abstract

Induced breeding experiments of spotted murrel, Channa punctatus (Bloch) were conducted in mature males and females by administrating a single intramuscular injection of ovaprim at a dosage of 0.3ml/Kg body weight. Spawning was observed 23-24 hrs after the injection at ambient temperature and the fertilized eggs were buoyant, non-adhesive, and straw yellow in colour with diameter ranging between 0.9mm and1.10 mm. Incubation period was 24-25 hrs. The hatchlings were transparent and measured 2.7-2.9mm, with a large oval head, a well-defined yolk sac and short tail and the larvae attained free normal movement when 36 hrs old. The yolk got fully absorbed within 3 days and by this time mouth formation was complete and the larvae started feeding. The post larvae were observed to start aerial respiration on 17th day. After 20 days the length of fry ranged between 7.5 and 7.8mm and resembled the adult in its external features. Length of the fingerlings ranged from 18.3-21.0mm after 35 days and appeared just like an adult in all respects except sexual maturity.