Effect of aqua-drugs and chemicals on shrimp health and production in Khulna, Bangladesh

Present study was conducted in three different Upazilas viz., Batiaghata, Dacope and Rupsha of Khulna district, Bangladesh from August 2016 to May 2017. Data were collected through personal contact, farms and market survey and discussion with shrimp farmers and drug sellers. Farmers of the research areas used Oxolinic acid, Renamucin, Oxytetracucline, Lime, Salt, Formalin, Eco-solution, Basudin and Timsen to treat the viral, bacterial and fungal diseases. Average recovery of 55-60% and 35-40% were recorded from bacterial and fungal diseases of shrimp respectively, but there was no recovery in case of viral diseases. Shrimps of nontreated ghers were affected by WSSV, Black gill disease, Black spot disease, Zoothumnium and external fouling but almost no disease were observed in aqua drugs-treated ponds. Histological findings showed that shrimp muscles and hepatopancreas in drug treated ponds and ghers had some pathological changes like necrosis, vacuums and hemorrhages which were severe in winter season, whereas, normal structure of muscle and hepatopancreas were observed during summer season. Production of shrimp in the study areas was recorded 6916 Kg/ha in probiotics and aqua-drugs treated ponds, whereas, 543 Kg/ha in non-treated ghers. From the present study it could be concluded that aqua-drugs and chemicals have positive effect on shrimp health and production except some pathological changes in the investigated organgs of shrimp especially during winter season.