Jareeporn Ruangsri, Amornrat Phongdara, Poonsook Prasertsan, and Kitjakarn Supamattaya

pp. 239 - 252

Abstract

Immunological responses of black tiger shrimp (Penaeus monodon) were induced under laboratory
conditions by injecting white spot syndrome virus (WSSV) and yellow head virus (YHV). The survivors
from WSSV and YHV infection showed improvement in their immunity against the re-challenging by both
viruses. The WSSV survivors showed higher capability than that of YHV survivors in developing the
immunity. The highest relative percent survival (RPS) against WSSV and YHV noted after a 43-day period
of WSSV injection was 67 and 37.5%, respectively. While the RPSs against both viruses after periods of 46
and 60 days of the YHV injection were 37.5 and 12.1%. Similarly, an in vitro neutralization activity of plasma separated from the survivors with WSSV injection showed preference of virus being eliminated over the
plasma from YHV injection.
Blood parameters for survivors with WSSV injection for 43 days showed an increase in phenoloxidase activity, while the YHV injected survivors exhibited higher level of total hemocytes and phenoloxidase
activity. Histopathological examinations in survivors revealed changes of lymphatic tubes into spheroids
higher than those in normal individual.