Myxozoans that infect fish, such as Myxobolus
cerebralis ("whirling disease" of salmonids) and
HofereUus (=Mitraspora) carassii (kidney enlargement
disease of goldfish), are all members of the
class Myxosporea, and have a multicellular spore
with polar capsules and polar filaments that
facilitate adherence of the spore to the intestinal
mucosa. 5 The mode of transmission is unknown
for most myxosporeans. As with microsporeans,
treatment is unrewarding for clinical disease,
although experimentally malachite green, nitrofurans,
toltrazuril and fumagillin have some
anti-myxozoan activity. TM