Treatment of zooplankton with neem oil in the laboratory setting

Abstract

An experiment investigating the effects of varying neem oil doses on zooplankton treatment was carried out from march 15 and April 30, 2024 at the fisheries and aquaculture research and application farm integrated kanhé-moyo of Baham (FRAPAIK). its objectives were to contribute to the improvement of specific production zooplankton groups through treatment with different doses of neem oil (azadirachta indica). An experimental device including a T0 control only fertilized with chicken manure, as well as five treatments TN1, TN2, TN3, TN4 and TN5 reated respectively with neem oil at the dose of 1; 0.1; 0.5; 1.5; 2ml /l of water. Each treatment was applied in completely randomized triplicates in 18 transparent breakable aquariums with a capacity of 36 liters. These aquariums are inseminated with phytoplankton three day later pre-fertilized with chicken droppings, and 72 hours later, then with zooplankton at a density of 11ind/l of water with 8 rotifers; and 3 cladocerans. Water quality (physico-chemistry, zooplankton) was analyzed daily. After 45 days of observations, the following results were recorded: The values of the physicochemical parameters of the water (dissolved oxygen,transparency, pH, temperature (did not vary significantly (p<0.05) between treatments. Density, biomass, daily productivity and intrinsic rate biomass increase were significantly different (p<0.05) between the treatments, the highest values of density (2914ind/l) and intrinsic rate biomass increase (911) was recorded in the T0 and lower in batches (1033ind/l) TN3, TN4 and TN5 respectively. As for the biomass and the daily productivity (2128 (µg) and 592(µg)) the highest values were obtained in TN3 and the lowest (295 (µg), 311) respectively in batches T0 and TN4.The use of neem oil at a dose of 0.5ml/l is recommended for mass production of cladocerans.