ABSTRACT:

 Two experiments were carried out to study the effect of dietary supplements of methionine on the growth and food utilization of mudlish Clarias anguillaris. In both studies C. anguillaris fingcrlings {17.20g and 1.02g. initial mean weight respectively) were fed full fat soybean diets supplemented with traded levels of L-and D. L-methionine and the growth was monitored for 12 and 14 weeks respectively. Growth rate and food utilization were significantly higher (P<0.05) when they were fed soybean diets supplemented with 0.2% L-and D, L-rnethionine than 0.4, 0.6 and 0.8%. An increase in t11e level of L- and D, L-metllionine beyond 0.2% resulted in a significam reduction in the growth rate of the fish. Growth and food utilizatinn were better in fish fed the casein and fish meal positive control diets than the 0.2% supplemented soybean diets. The unsupplemented soybean diets were poorly utilized by the mudfish fingerlings. The size disparity of fingerlings had no effect on the dietary requirement for the L-and D, L- methionine. Since the less expensive D. L-methionine can substitute L-methionine in the diet, the use of D, L-methionine in dietary supplements is more cost effective than the use of L- methionine.