Adenovirus-Like Particles Associated with a Disease of Cultured White Sturgeon, Acipenser transmontanus

Juvenile white sturgeon, Acipenser transmontanus, suffering from a chronic mortality had enlarged nuclei particularly in the epithelium of the straight intestine and spiral valve. These nuclei were often five times larger than those of uninfected cells and contained numerous virus particles with an average diameter of 74 nm. Although nuclear changes induced by the virus are similar to those described for certain members of the Herpesviridae, the virion morphology and absence of an envelope were, however, more characteristic of the Adenoviridae. Attempts to isolate the virus using established cell lines from selected freshwater fish and two lines recently developed from white sturgeon were unsuccessful. Nuclear enlargement indicating virus infection was, however, observed in juvenile sturgeon receiving intraperitoneal injections of homogenates of viscera from infected fish.