A NEW BACULOVIRUS OF CULTURED SHRIMPS

By means of ultrathin section, negative staining and sucrose gradient ultra-centrifugation, a new baculovirus has been discovered and purifi ed in lymphoid organs and such tissues as muscles of the shrimps which have been spontaneously attacked by diseases and artificially infecte d. With a diameter of 96-112 nm, this is the thickest baculovirus of s hrimps ever known. In the center is the high-density nucleus. Between the capsid and the envelope is a broad space, which is not found in an y of the baculoviruses of the prawns ever reported. On the surface of the purified nucleocapsid, there is a subunit of the spiral arrangemen t, which is also characteristic of this virus. It has not been observe d and found in the epithelial cells of the livers, intestines and chee ks, which is quite different from the fact that prawn baculoviruses in fect a certain epithepilial cell of the above-mentioned ones without e xception. The viruses only multiplicate inside the core of target cell s, which will not form occluded bodies or inclusion bodies. It is a ne w virus which has never been reported. It is called lymphoid cell nucl ear baculovirus (LNBV).