Reproductive Biology Of Channa Punctatus (Bloch) From Paddy Field Of Sivasagar, Assam

Generally Channa punctatus females are relatively smaller in size and have bulging abdomen while males possess, pin head like black dots on the ventral region of the body. The six different maturity stages have been recorded. The immature and maturing specimens were encountered from October-February, while developing, mature and gravid fish were recorded in February-March and spent fishes were recorded in between April and September. The gonadosomatic ratio (GSR) was increased gradually from February onwards reaching its maximum in April (10.81) and decline from June and July and thereafter it again increased in August (3.38) and September (4.57) and reached it minimum during November (1.34) and January (1.17). Size at first maturity (M50) was observed for female and males at length group of 9.0-15.0 cm. The mean ova diameter of maturing was recorded was 0.34 (±0.03) mm; developing was 0.52 (± 0.16) mm; mature ova was 0.79 (±0.18) mm; gravid was 0.92 (±0.25) mm. Absolute fecundity was ranged from 2423 to 6466 and the number of eggs increases as the fishes gain in weight and length. Again, the relative fecundity varied from 104 to 216 and the value is found to be comparatively high in the younger size groups. The relationship of fecundity with total length, total weight and ovary weight has been calculated. C. punctatus are heterochronal breeder having two peak breeding season in April and September and it may be inferred that C. punctatus spawn twice in a year with double spawning peak. Spawning season was over by August and December onwards.