Thorny-Headed Worms: Acanthocephala

Physical characteristics: Female giant thorny-headed worms are as long as 26 inches (65 centimeters) and are 0.3 to 0.4 inch (8 to 9 millimeters) wide. Males are as long as 4 inches (10 centimeters). The body is grayish brown with deep grooves on the surface. The snout has six spiral rows of six hooks each.

Geographic range: Giant thorny-headed worms live all over the world.

Habitat: Adult giant thorny-headed worms live in hogs, squirrels, moles, hyenas, and dogs. The larvae live in cockroaches and beetles.

Diet: Giant thorny-headed worms absorb nutrients from their hosts.

Behavior and reproduction: Female giant thorny-headed worms release a huge number of eggs that can survive more than three years in the primary host. The larvae develop for four to five months in the Adult giant thorny-headed worms live in hogs, squirrels, moles, hyenas, and dogs. The worms reach adulthood two to three months after entering the primary host. (Illustration by Brian Cressman. Reproduced by permission.) intermediate host. The worms reach adulthood two to three months after entering the primary host.

Giant thorny-headed worms and people: Giant thorny-headed worms cause disease in people and hogs. Hogs become infected when they ingest beetles while rooting for grubs. Humans become infected mainly in rural Asia, where people eat beetles and use them for medicine.

Conservation status: Giant thorny-headed worms are not considered threatened or endangered. ∎