VIRUS-LIKE PARTICLES IN POLYSPOROPLASMA-MUGILIS (PROTOZOA, MYXOSPOREA), PARASITIC IN A MARINE FISH (LIZA-AURATA L)

Virus-like particles (VLP) were observed in the capsulogenic cells of the spores of Polysporoplasma mugilis, a myxosporean parasite in the t runk kidney of Liza aurata. Transmission electron microscopy revealed icosahedral, electron-dense cored VLP of 18-20 nm in diameter. By thei r ultrastructural characteristics and cytoplasmic position, these VLP are related to the Picornaviridae. The VLP were densely packed inside membraned vacuoles. VLP were found neither in other developmental stag es, nor in other parts of the spore, nor in the host tissue. This is t he third record of VLP in protozoans parasitic in fish, and the first one from the Myxosporea. Copyright (C) 1996 Australian Society for Par asitology.