The Dibothriocephalus Latus has for its host some kind of fish, usually the pike. It is the largest of the tapeworms, measuring from 5 to 9 meters in length and having at times as many as 4000 segments. The growth after infection is very rapid.

The head is long, flattened, and has two groove-like suckers on its sides. The neck is thin, gradually increasing in diameter.