Monogeneans: Monogenea

Physical characteristics: Adult Polystoma integerrimum (abbreviated to P. integerrimum) worms are about three-eighths of an inch (10 millimeters) long. The attachment organ has six muscular suckers, one pair of large hooks, and sixteen small hooks. There also are suckers around the mouth.

Geographic range: P. integerrimum lives in Europe.

Habitat: P. integerrimum lives in the bladders of common frogs.

Diet: P. integerrimum eats blood.

Behavior and reproduction: Adult P. integerrimum worms do not make eggs while their host frogs are living on land during most of year. When the frogs enter water to spawn in spring, the worms lay their eggs. The larvae that hatch invade the gills of frog tadpoles, or the frog's early water-dwelling stage. When the tadpoles change into frogs, the worms travel through the digestive tract and possibly the skin to the host's bladder, where they mature. A single egg that stays Polystoma integerrimum lives in the bladders of common frogs. (Illustration by Barbara Duperron. Reproduced by permission.) in an adult worm develops and hatches, and the larva stays in the host of its parent, increasing the parasite infection in the host.

Polystoma integerrimum and people: P. integerrimum has no known importance to people.

Conservation status: P. integerrimum is not threatened or endangered. ∎