Figure 1. Juvenile shrimp L. vannamei displaying IMN clinical signs in the form of focal to extensive white necrotic areas of the skeletal muscle in the abdomen. In some of the shrimp, the necrotic muscle may become reddened.

Figure 2. Myonecrosis due to IMNV infection, accompanied by hemocytic infiltration and fibrosis.  As a reference, normal skeletal muscle can be observed in the upper right corner. Mayer-Bennett hematoxy-lin/eosinphloxin stain.  Total magnification: 50x

  Figure 3.  IMNV 40 nm diameter spherical particles isolated from naturally infected shrimp with the disease.  Transmission electron micrograph amplified 60,000 times. Negative PTA stain.