MASS LARVAL MORTALITIES IN INDIAN RIVER PRAWN MACROBRACHIUM MALCOLMSONII UNDER HATCHERY CONDITIONS AND THEIR CONTROL BY APPLICATION OF ANTIBIOTICS
D.R. Kanaujia, B.K. Das, A.N. Mohanty-1998
Journal of Aquaculture in the Tropics 13 (3): 171-179
Abstract:
A seed production experiment of Macrobrachium malcolmsonii in an air-lift biofilter recirculatory system showed 100 per cent mortality at early larval stages between II and V instar within 6-15 days of rearing in 13 trials and in advanced stages of the larval and post-larval (PL) rearing in one trial. Microbial studies indicated maximum bacterial count (2.54 x 10^3/ml) in larval rearing medium and a comparatively lower count (1.48 x 10^3/ml) in the biofilter medium. Bacterial flora comprising 65-72% Bacillus, 15-30% Pseudomonas spp., 5-13% Kurthia. These were found to be most sensitive to Ampicillin, Chloramphenicol and Oxytetracycline and resistant to Streptomycin, Erythromycin, Tetracycline, Nalidixic acid, Bacitracin, Penicillin and Gentamycin. Ampicillin was found to be more effective in controlling bacterial population in the larval rearing medium. The application of Oxytetracycline, Chloramphenicol and Ampicillin each at 1 ppm in the rearing medium could control larval diseases and proved most effective as curative as well as preventive measures to larval diseases.
(Central Institute of Freshwater Aquaculture, P.O. Kausalyaganga, Via. Bhubaneswar 751002 (Orissa), India)