Polymorphida

Polymorphida are an order of thorny-headed worms (phylum Acanthocephala). The adults of these parasitic platyzoans feed mainly on fish and aquatic birds.

This order contains 5 families:


 * Centrorhynchidae Van Cleave, 1916
 * Isthomosacanthidae Smales, 2012
 * Plagiorhynchidae Meyer, 1931
 * Pyriprobosicidae
 * Polymorphidae Meyer, 1931