The following points highlight the eight major diseases of air-breathing fishes.
(1) Fry and fingerlings of stripped murrel have been found to be affected with fin rot and dropsy in nursery. As a remedial method the infected ones are given a bath in either 1% acriflavin or 0.3% formalin solution, for about 10 minutes or till they show sign of distress.
(2) Murrels are generally found encountered with parasites such as Lernaea sp. and Argulus sp. and can be controlled by the application of lime at the rate of 300 kg/hectare.
(3) Singhi has been found to be affected by various bacterial diseases leading to the loss of barbel and development of reddish inflamatory patches from the base of their anal fin and running up to the caudal tip. It can be controlled by the application of terramycin at the rate of 100 mg/kg body weight in their feed, for 7 to 10 days.
(4) Pox disease has been detected in singhi from the small reddish white spot on their body. A bath in potasium permanganate at the rate of 1 mg/litre of water has been found to be effective in the prevention of the disease.
(5) Magur suffering from swollen abdomen has been found to be infected with cestoda. Such affected fishes should be removed from the pond.
(6) In intensive culture, magur has been found suffering from bacterial (generally, Pseudomonas) disease and the symptoms are ulcers, reddish lips and loss of barbels. Controlled methods being application of sulphadiazine in the diet at the rate of 100 mg/kg of feed for one week.
(7) Koi shows non-carcinogenic tumours caused probably by Clostridium sp. The tumour can be cured by the application of terramycin at the rate of 100 mg/ kg of feed for seven days.
(8) In sewage fed ponds, koi has been found to be suffering from lymphocystis, detected from proliferous growth of binding tissue on the fins as well as on the body. Lymphocystis can be cured by the application of terramycin or sulphadiazine at the rate of 100 mg/kg of feed for 7 to 10 days.