Alaria arisaemoides adult

These flukes are about 5 mm long. The anterior 2/3 of this species is the fore-body (top of photo) and the posterior 1/3 is the hind-body. The oral sucker is visible. The dark tribocytic organ fills the middle and anterior portion of the fore-body. Lateral bands of vitellaria are present in the posterior half of the fore-body. Many eggs are present in the uterine coils at the posterior of the fore-body, and the uterus continues to the genital pore at the posterior end of the body.

The hind-body contains the two large testes, located in tandem. There may appear to be an anterior and posterior pair of testes, but each "pair" is simply a single, curved testis.