Efficacy of Velvet Bean (Mucuna pruriens) seeds Ethanolic Extract on Survival, Growth Performance and Sex Reversal of Nile Tilapia, Oreochromis niloticus (Linnaeus, 1758)

Abstract

The present study was conducted to evaluate the efficacy of Mucuna pruriens seeds ethanolic extract on survival, growth performance and masculinization of Oreochromis niloticus juvenile. To this end, 600 O. niloticus juveniles with an average weight of 8.43 ± 0, 52 g were randomly distributed in 20 happas measuring 0.7 × 0.7 × 1 m placed in a 28 m3 tarpaulin tank at a density of 50 juveniles per happa and subjected to natural temperature and light conditions. Offsprings were fed with 5 experimental feeds including 02 controls (negative control (no treatment) and positive control (treatment with 17a – methyltestosterone at 60 mg/kg feed)) and 03 based on M. pruriens seeds ethanolic extract at doses of 0.15; 0.20 and 0.30 g/Kg feeds. After 60 days post-treatment, survival and zootechnical growth parameters were assessed. The study employed the standard acetocarmine squash technique of gonads to analyze the sex reversal percentage. Phytochemical screening revealed the presence of phenolic compounds, flavonoids, alkaloids, tannins saponins and steroids in M. pruriens seeds ethanolic extract. The result showed that total survival rates in all treatments and controls were ranging from 96. 47 ± 2.41% to 82 ± 1.12% (p<0.05). Indeed fishes from group treated at 0.20 g/kg of M. pruriens seeds ethanolic extract obtained the highest survival rates (96,47 ± 2,41%), while the lowest was obtained from fishes from control group (untreated group) with an average value of 82 ± 1.12%. Comparative analysis of the growth characteristics of control group and group treated with different doses of M. pruriens seeds ethanolic extract (0.15; 0.20 and 0.30 g/kg) reveals a significantly greater effect (p<0.05) of treatment based on M. pruriens seeds ethanolic extract at 0.20 g/kg and treatment with 17a – methyltestosterone at 60 mg/kg feed compared with the other treatments applied in terms of Average Weight Gain(20,01 ± 6,33 g (MP 0.20) and 21,65 ± 6,24 0 g (MT)), Average Daily Gain (0,35 ± 0,09 g/d (MP 0.20) and 0,36 ± 0,02 g/d (MT)), Specific Growth Rate (6,98 ± 0,06 %/d (MP 0.20) and 6,93 ± 0,35 %/d (MT)) and Average Fish Length (10,22 ± 1,14 cm (MP 0.20) and 10,9 ± 1,03 cm (MT)). A comparative analysis of the sex ratio of treated group with M. pruriens seeds ethanolic extract revealed that the treatment at 0.20 g/kg was the most effective dosage that ensured a maximum male ratio (88.37 ± 1.53%., p<0.05). These findings highlight the potential of M. pruriens seeds ethanolic extract as a viable alternative to synthetic steroid hormones for achieving masculinization in Nile tilapia. Keywords Nile tilapia; Mucuna pruriens; Sex reversal; Survival; Growth performance 17a-MT