Epibiotic infestation of luminous bacteria in penaeid shrimp Penaeus indicus (H Milne Edwards) larvae

Abstract

Epibiotic infestation of luminous bacteria was observed in hatchery reared 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 total viable counts in larvae and rearing water respectively were luminescent. Luminous organisms were readily isolated from nearshore water, sand filtered inshore well water, broodstock and Artemia rearing systems. Luminous bacteria isolated from larvae and rearing water were identified as Vibrio harveyi. No larval mortality was observed. Addition of ciprofloxacin at the rate of 0.2 ppm to the rearing water and repeated water exchange for 3 days controlled the infestation.