Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Some observations on experimental infections of pigs with the thorn-headed worm, Macracanthorhynchus hirudinaceus.

Abstract

The maximum duration of adult infection in pigs with Macracanthorhynchus hirudinaceus is about 10 months. Two or three months lapse after infection before the adult phase is reached. A female may produce 260, 000 eggs daily, while a gravid female may contain at one time 10 million embryonated eggs. The site of election is the jejunum about 23 to 43 feet from the pylorus. The males range from 5.3 cm. to 10.8 cm., the females measure from 21.6 cm. to 45.7 cm. R.T.L.