Life cycle of Diphyllobothrium latum.

Duration: 17 min

Genre: Educational

Year Published: 1966

Creator: Communicable Disease Center

Format: 16mm

Color: B&W

Sound: sound

Description: This audiovisual traces the life cycle of the broad tapeworm Diphyllobothrium latum from the embryonated egg stage to the full grown adult worm. Animation, diagrams and microscopic views are used to achieve this purpose. The small larvalstage within the crustacea, the final larval stage within the fish host, and the adult worm in the human host are described in detail. Microscopic views illustrate the development of the embryonated egg into the coracidium. After the coracidium is ingested by the first aquatic host, the ciliated envelope ruptures. It later matures into a grown procercoid with six hooks. The final larval stage within the second host (fish host) is characterized by the development of the procercoid into a worm about five centimeters in length, cylindrical and with anterior grooves. Diagrams illustrate the lodging of the young worm in the human small intestines, and its development into a full grown worm, which can be as long as thirtyfeet. The program concludes with a description of the anatomical features of the adult Diphyllobothrium latum.