BACULOVIRUS INFECTIONS IN THE MUD CRAB, SCYLLA-SERRATA, AND A FRESH-WATER CRAYFISH, CHERAX-QUADRICARINATUS, FROM AUSTRALIA

Two nonoccluded baculoviruses, one from Cherax quadricarinatus, a parastacidean crayfish, and one from Scylla serrata, a brachyuran crab, were found in juvenile, subadult and adult animals in Australia. Neither virus caused clinical disease and with both, the distribution of infected, hypertrophied hepatopancreatic epithelial cells was focal. Cherax baculovirus (CBV) produced amorphous, eosinophilic intranuclear inclusions. Cylindrical nucleocapsids averaged 34 × 154 nm in size. Virions ranged from 172 to 220 nm in length and envelopes were loosely attached. Scylla baculovirus (SBV) produced basophilic intranuclear inclusions in hepatopancreas epithelial cells. Cylindrical nucleocapids averaged 24 × 205 nm in size. The 44 × 253 nm virions often had unilateral or apical expansions of their envelope containing a thin filament-like structure. SBV virions were aligned in regular arrays, particularly at the inner surface of the nuclear membrane. Virions were present budding through the nuclear membrane, acquiring another envelope, and having a diameter ranging from 75 to 80 nm. © 1992.