An experimental study on the culture of fry of Oreochromis mossambicus (Peters) in a peaty swamp in Sri Lanka using cowdung and poultry manure as fertilizer

Abstract

Growth rates of fry of Oreochromis mossambicus were studied in a dug-out pond in Muthurajawela swamp, which had been fertilized with cowdung and poultry waste. This swamp is characterized by waters with very low pH, low dissolved oxygen and low values of primary productivity. The addition of fertilizer increased the gross primary production from 0.18 g C/m 2-day to 1.08 g C/m 2-day in about 40 days, with pH and dissolved oxygen values becoming favourable for growth of fry. The average growth rate of 0.04 g/day was comparable to the growth rates attained in favourable habitats in Sri Lanka.