Abstract:

This is the first report on the successful hatchery larval rearing of the silver pomfret Pampus argenteus (Euphrasen) based on eggs stripped from the wild gravid fish during the 1998 and 1999 spawning periods. The result of this investigation shows that males always outnumber the females in the population. The present investigation also confirms that spawning initiates in May and reaches a peak in June and July when the water temperature is between 28 to 30oC. Gonadal maturity stages in relation to day time have been investigated for the first time and show that gravid female occurs in the early day time period up to 15:00 h and proceeds to attain full ripe ovulated fish in the evening hours. Spawning occurs in the late evening hours. Among the eggs collected, the viable floating eggs varied from 38.6 to 44.0% and egg hatching ranged from 36.5 to 51.8% during the 1998 and 1999 spawning periods. The mean egg diameter was 1.12±0.02 mm and the newly hatched larval size was 2.40±0.10 mm. The egg hatching time was 15 h at 29 to 30oC. Egg hatching was significantly high (P0.05) between stocking densities of 20,30 and 40 larvae l-1. Up to 1.5% larval survival was observed. Larval survival declined during the June to August culture period but was not significantly different (P>0.05) from the June-July culture period. A number of biological and environmental factors have been identified to be associated with low larval survival in the hatchery. The results demonstrate the possibility of producing silver pomfret under hatchery culture conditions. However, further research is required to enhance larval survival towards realizing commercial farming of this species.

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Date 2002/06/01

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