EPIBIOTIC INFESTATION OF LUMINOUS BACTERIA IN PENAEID SHRIMP PENAEUS-INDICUS (EDWARDS,H.MILNE) LARVAE

Epibiotic infestation of luminous bacteria was observed in hatchery re ared mysis larvae of Penaeus indicus. Viable bacterial counts in these larvae and rearing water were 4.30 x 10(6) g(-1) (on wet weight basis ) and 5.10 x 10(5) ml(-1) respectively. About 28.37% and 50.98% of tot al viable counts in larvae and rearing water respectively were lumines cent. Luminous organisms were readily isolated from nearshore water, s and filtered inshore well water, broodstock and Artemia rearing system s. Luminous bacteria isolated from larvae and rearing water were ident ified as Vibrio harveyi. No larval mortality was observed. Addition of ciprofloxacin at the rate of 0.2 ppm to the rearing water and repeate d water exchange for 3 days controlled the infestation.