ULTRASTRUCTURAL EXAMINATION OF VIRUS-LIKE PARTICLES IN A MARINE RHIZOPOD (SARCODINA, PROTISTA)

Recent research indicates that bacteriophages are abundant and importa nt for controlling populations in prokaryote microbial communities. Th e number and role of viruses in eukaryotic microbial communities is le ss well known. This report demonstrates the presence of polyhedral vir us-like particles infecting a free-living, marine rhizopod. The virus- like particle appears to cause cell damage and possibly death. It is a ble to replicate within the protist and may be able to spread to other members of the population. A survey of the literature indicates that viruses and virus-like particles are present in other protists, perhap s more commonly than usually reported. If viruses are widely dispersed in eukaryote microbial populations, they could contribute significant ly to cycling in aquatic food webs and have implications for gene tran sfer between marine organisms.