Fig. 9.

White spot syndrome. (a) Carapace from a juvenile Litopenaeus vannamei that is presenting typical white spots on its inner side due to infection by WSSV. (Photo courtesy of Mr. Diego Buenaventura, Guayaquil, Ecuador, 1999); (b) Transmission electron micrograph (TEM) of semi-purified WSSV virions concentrated from the hemolymph of an experimentally infected juvenile L. vannamei. Intact virions have a tail-like appendage that extends from the envelope; (c) TEM of a nucleocapsid showing the 90° arrangement of the capsid subunits on its surface; and (d) schematic showing in a cut-away view the outer envelope, the inner nucleocapsid, and the principal proteins associated with each. (d was modified from Vlak et al., 2005).