Routes of immunostimulation vis-a-vis survival and growth of Penaeus monodon postlarvae

The present study was carried out to obtain the performance of booster doses of immunostimulants given through different routes. Postlarvae of tiger shrimp Penaeus monodon (PL30) were immunostimulated via immersion and oral routes using heat-killed Vibrio anguillarum. Bath (10(6) CFU/ml for 1 h), bath and in-feed (initially immersed in 10(6) CFU/ml for 1 h followed by two feedings with 10(5) CM/feeding), and in-feed alone were used as the routes of immunostimulation. A booster dose was given in each of the treatment groups at 20 days postpriming (dpp). Growth and survival were studied following priming and booster until 60 dpp. The survival of shrimps in bath+feed treatment was significantly (P<0.05) higher than the bath treatment. However, initial bath priming followed by booster through feed or bath significantly (P<0.05) enhanced the growth and survival of the postlarvae compared to the primed or the control. Growth was the best with booster (bath+in-feed)-treated larvae, followed by other booster-treated and primed groups, while it was the least in control groups. The booster dose of immunostimulation, in general, is advantageous in inducing growth and protective response in shrimp, and among the modes, the in-feed route of administration may be more practical as well as productive. (C) 2005 Elsevier B.v. All rights reserved.