Developing monosex pearlspot, etroplus suratensis (bloch, 1790) using synthetic hormone

Etroplus suratensis (Bloch 1790) fries from the same brood were collected and reared at 15ppt salinity. The 30 days old fries with 0.01±0g weight and 0.96±0cm Length was used for the study. They were fed with 17α -Methyl Testosterone (MT) administrated feed to study the monosex production and growth. Commercial feed with38% protein and 9% lipid was used for incorporation of hormone. The hormone was thoroughly mixed with micro feed to achieve tested dosages of 0, 20, 40, and 60 mg/kg MT. The duration of the experiment was 60 days of which first 28 days hormone mixed feed was used. During the period of hormonal administration the fries were fed 6 times a day. The results showed significant difference in masculinization (P<0.05).Hormone administration showed in sex conversion with an average male population of 96.7% in 60mg dosage followed by 40mg with 80%. However the control gave almost the 1:1 ratio with 46% males. Growth didn’t show much variation between the treatment and had highest weight gain in T3 60mg/kg (1.48±0.22) followed by Control (1.18±0.17) and least observed from T1 20mg (1.11±0.13). The average survival rate was highest in Control 91.1% followed by T2 40mg 85.6%. The highest specific growth rate recorded of 8.91±0.04 in the treatment T3 60mg and lowest in T1 20mg/kg with 8.40±0.21.So, this study reveals the potential of producing all male pearlspot seed production and thereby increased growth and productivity.