Egg: oval, with many egg holes and eggshells around it.

Hairiness: the first free swimming period in life history, pear-shaped with cilia. Hairiness is very active, swimming freely in the water, looking for an intermediate host.

Cysticercosis: after entering the snail body, the cilia of the cysticercus are removed to form cysts, and the body wall and protokidney of the cysticercus are preserved, and the body surface can absorb the nutrition of the host for asexual reproduction.

Larvae: oblong, blunt-rounded intestine with mouth, pharynx and no branches, which absorbs nutrients from the host through the intestine or body surface and can reproduce asexually.

Cercaria: the second free life stage in life history, with long tail, mouth, mouth sucker, muscular pharynx and branched intestine, and penetrating gland and protokidney at the front end of the body.

Cysticercosis: oval, no eye spots, mostly parasitic on fish muscles.

Adult: The worm body is soft and flat, narrow at the front and wide at the back, forming oral sucker and abdominal sucker, which is parasitic in the liver, lungs and blood to absorb nutrients.