Fish act as the main hosts for the adults of spiny-headed worms in the class Eocanthocephala, with crustaceans and aquatic insects acting as intermediate hosts.
In a species of spiny-headed worm, males use their cements on each other, trying to gum up their rivals.
Flukes, tapeworms, spiny-headed worms and roundworms are the four main types of internal parasites.
The larvae of spiny-headed worms develop in various species of crustaceans or insects.
This spiny-headed worm uses the spines on its head to attach to the small intestine of a fish.