Muscle degeneration associated with cotton shrimp disease of Penaeus indicus

Microsporidian disease of prawns has generally been recognized by the progressive white opacity associated with the musculature. Such microsporidian‐infected prawns are known as ‘cotton shrimp’, ‘milky white’ or ‘chalky white’ prawns. Microsporidians have been reported from prawns of several genera, notably Penaeus , Pandalus and Crangon ( Sprague & Couch 1971 ; Newman, Johnson & Pauley 1976 ). These diseases are highly pathogenic and cause epizootics in feral crustacean populations ( Iverson & Manning 1959 ; Overstreet 1973 ; Lightner, Fontaine & Hanks 1975 ; Sindermann 1990 ).