by Open Science Repository Veterinary Medicine
The crude extract of the plant Ocimum gratissimum was used to control the parasites Argulus spp. infestation on Nile tilapia Oreochromis niloticus by in vitro and in vivo tests, which permitted to determine plant’s efficacy, LC50 values, and the delay of antiparasitic effect. For that, the randomized design were performed into petri dishes using the crude extract of the African’s plant O. gratissimum against the parasites Argulus spp. for in vitro test toxicity, and into raceways for in vitro and in vivo tests of this plant against O. niloticus. The crude extract of the plant O. gratissimum had toxic effect to the parasite Argulus spp. with a LC50 value of 197.66 mg / L with 95 % confidence interval of 194.65 – 200.01 mg / L. For the Nile tilapia O. niloticus, the LC50 value was 1271.22 mg / L with 95 % confidence interval of 1251.20 – 1291.20 mg / L. The 36 hours 100 % efficacy of the crude extract of O. gratissimum was obtained at the concentration of 800 mg / L. The plant, O. gratissimum, had anti-parasitic effects after bath treatments, which can prevent for 3 months against high infestation of Nile tilapia by parasite Argulus spp.
Keywords: Oreochromis niloticus, Argulus spp., treatment, Ocimum gratissimum.