author(s)
P Das, J Mohanty, MR Badhe, PK Sahoo, KK Sardar and SC Parija

abstract
Vaccination against fish ectoparasite, Argulus siamensis seems to be a better alternative to the harmful chemicals used for its control. A preliminary study was undertaken to assess the protective response induced by whole antigens of Argulus parasite in host fish, rohu (Labeo rohita). The whole antigens of A. siamensis (50 µg protein/fish) along with adjuvant was injected intraperitoneally three times at 14 days interval to rohu and 14 days after last booster, the fishes were challenged with 250 numbers of metanauplii of Argulus to record the load of parasites on host up to 12-days post-challenge. The immunized fish showed 35.42% of low grade infection (1–15 parasites/fish) and 22.92% high grade infection (>30 parasites/fish) as compared to 14.58% and 41.67%, respectively, in control fish. Further, the immunized fish showed reduced haemorrhages on body surface along with higher antibody response (measured through indirect ELISA) as compared to controls. The results indicated possibility of vaccine development against this parasite as method of long term protection.