Resistant to heat. Monomer. Excretory gland, ventriculus, and the luminal epithelium of the intestine of the larvae. Causes an allergic reaction in human. Binds to IgE and IgG4. A.simplex is a fish parasite that, when accidentally ingested by humans, may cause allergic reactions in sensitized individuals. Belongs to the SXP/RAL-2 family.