IMMERSION OF 17 �?Ž�?± -METHYLTESTOSTERONE DOSE&DURATION ON TILAPIA MASCULINIZATION


Thirty-five Nile Tilapia eggs (Oreochromis L. 1758) fry were selected randomly and placed in a 1L plastic container incubator. These were then immersed either in 0, 250 or 500mg/L of 17a-methyltestosterone (MT) for 6, 12, 24, 48, 72 and 96h separately. The controls were made using eggs and fry from the same age group, but only in ethanol (250mL/L), for the same duration. They were then washed, nursed in plastic containers (10L) and glass aquaria (100L), and water was added according to their growth. The animals were given 40% protein pellets from 62 to 65 days of age. They were then dissected using the acetocarmine squash method for gonadal sexual determination. Both the 250mg/L and 500mg/L of MT inducing (P

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