Journal of Aquaculture Research & Development

Abstract

Survival, Growth Performance and Changes in Gonads of Oreochromis niloticus (Linnaeus, 1758) Fed with Mango (Mangifera indica) Leaves Meal Diet

Mutlen Melvin*, Zango Paul, Fotio Tchouppe Franck Juve, Kenne Sockeng Yannick and Tomedi Eyango Minette

The aim of the present study was to explore the possible use of Mangifera indica leaf powder as a reproductive inhibitor in Oreochromis niloticus. To this end, 450 juveniles with an average weight of 11.11 g ± 0.61 g were randomly distributed in 15 happas measuring 0.7 m × 0.7 m × 1 m placed in a tarpaulin tank with a usable volume of 12 m³, at a density of 30 juveniles per happa and subjected to natural temperature and light conditions and fed 4 experimental diets, formulated from a control diet to contain Mangifera indica leaf powder at doses of 2 g/kg, 4 g/kg, 6 g/kg and 8 g/kg feed respectively. After 60 days post-treatment, survival and zootechnical growth parameters were assessed. A descriptive examination of the gonads made it possible to determine the impact of the treatment on gonadal development at the end of this phase. The results show that the different treatments had a similar effect on survival (p˂0.05), i.e. an average value of 98.97% ± 0.69%. Comparative analysis of the growth characteristics of control group and group treated with different doses of Mangifera indica leaf powder reveals a significantly greater effect of the dose of 8 g/kg Mangifera indica leaf powder compared with the other treatments applied. On the other hand, analysis of the gonado somatic index at 60 days post-treatment of group treated with different doses of Mangifera indica leaf powder revealed a significantly higher effect of the 4 g/kg dose on the gonado somatic index in both males and females with respective mean values of 0.64 ± 0.08 (males) and 2.47 ± 0.12 (females). With regard to the morphological characteristics of the male and female gonads, gonad atrophy was observed in the entire group treated with the different doses of Mangifera indica powder, which justifies the low gonado somatic index values observed in these different treated batches compared with the control batches. These gonad atrophies observed in the treated group reflect the impact of the different treatments on gonad inhibition. Analysis of the weight and size of the male gonads shows a significantly greater effect of the control batches compared with the treated group, with mean values of 0.54 g ± 0.07 g and 4 mm ± 0.16 mm. In the females, fecundity and egg size were higher in the control group than in those treated with the different doses of Mangifera indica powder, with respective averages of 284 mm ± 3.05 mm and 3 mm ± 0.14 mm. Observations on egg colour showed that the normal olive green colour of Oreochromis niloticus eggs was not maintained in all treatments. The results of this study indicate that Mangifera indica leaves could be used as an alternative ecological method for inhibiting reproduction in Oreochromis niloticus.

Published Date: 2024-03-04; Received Date: 2024-02-03