2. Materials and methods
2.1. Study area
The site chosen for the study was Vembanad Lake, the largest
estuarine system located on the south west coast of India and theaquaculture farms adjoining the Vembanad Lake (Fig. 1). Vembanad
Lake extends between 9000 and 10400
N and 76000 and
77300
E. The area includes low lying swamps and tidal creeks with
mangroves which support larvae and juveniles of many crustacean
species due to their nutrient rich environment. Cultured crustaceans
collected from the aquaculture farms of Vypin, Panangad,
Kumbalangi, Chellanam and Allepey and wild crustaceans of
estuary and from the seas off Cochin, Kerala state, India were used
in this study.
The specimens were checked for the presence of symptoms of
WSSV before storage. One peapod from the each specimen was
excised and stored at 70 C until use.
2.2. Extraction of viral DNA
The viral DNA was extracted from the tissue of the crustaceans
as described by Otta et al [12]. Total DNA extracted from infected
Penaeus monodon was used as positive control.