Standardisation of Weaning Protocol for Larvae of Clarias magur (Hamilton, 1822)

Abstract

Clarias magur (Hamilton, 1822) is a highly priced commercially important species targeted for aquaculture diversification in India and South-East Asian countries. Weaning from live to formulated feed during larval rearing is critical for successful seed production. Hence, the present study aimed to standardise the effective weaning age to achieve high growth and survival of C. magur. The 4 days post-hatch (dph) larvae with mean initial length and weight of 7.4 ± 0.83 mm and 4.97 ± 0.35 mg, respectively, were selected, and 2100 larvae were randomly stocked into 21 plastic tubs (100 larvae per tub) for six weaning treatments (W4, W7, W9, W11, W13 and W15 dph) and the control in triplicates. The study was conducted for 21 days and 4 to 24 dph. All larvae in the treatments groups were fed Artemia nauplii ad libitum and a weaning diet fed to apparent satiation according to W4 to W15 schedules. The control group larvae were fed with Artemia nauplii alone. Results revealed that final length and weight, weight gain per cent, daily weight gain and specific growth rate were significantly (P < 0.05) higher in the Artemia nauplii fed control group followed by W15 dph larval group. The survival rate was significantly (P < 0.05) higher for W15 larvae, followed by the control group. The present study indicates that the ideal protocol for C. magur larval fed with Artemia nauplii from 4 dph for weaning to formulated diet was at 15 dph until 24 dph for good growth and survival rates.