Non-Occluded Baculo-like Virus, the Causative Agent of Yellow Head Disease in the Black Tiger Shrimp (Penaeus monodon).

Abstract

A new non-occluded baculo-like virus was detected from black tiger shrimp (Penaeus monodon) with yellow head disease in the southern part of Thailand. Virus particles observed in necrotic tissues of gills and lymphoid organ were bacilliform in shape, ranging from 150-200 nm in length and 40-50 nm in diameter, and were enveloped singly by a trilaminar unit membrane. From the experimental infection trials, it was assumed that this virus was the most virulent among the viruses which have been known in the black tiger shrimp, to date. Pathogenicity and some characters of the virus as well as pathological changes caused by this virus were described.