• Gyracanthocephala
  • Neoechinorhynchida

The Eoacanthocephala are a class of scratch worms with mandatory change of host, the parasites than adult intestinal parasites almost exclusively in fish and usually have aquatic life cycles. These are usually very small species with average body lengths of a few millimeters.


As with the Archiacanthocephala the females possess a dorsal and a ventral ligament bag in Pseudocoel whose walls do not melt in contrast to those of Palaeacanthocephala. Protonephridia are not present. The main tribes of the epidermal Lakunensystems are dorsal and ventral, while they are the representatives of the Palaeacanthocephala laterally, ie on the body sides. The males have only one large cement gland. In ligament several very large nuclei are present.

Way of life

The Eoacanthocephala have an aquatic life cycle. The definitive hosts are mainly fish, rarely come amphibians and reptiles as hosts in question. As intermediate hosts the animals use mainly small crustaceans, here preferably several ostracods ( Ostracoda ), and aquatic insect larvae. So parasitized about Neoechinorhynchos Rutili in various freshwater fish, including the Rutilus spp, while the larvae ( Acanthor ) ostracods and mud fly larvae infested.


The following are the orders and families of Eoacanthocephala be listed:

  • Gyracanthocephala
  • Neoechinorhynchida Neoechinorhynchidae Neoechinorhynchus
  • Paratenuisentis


Cited evidence

The information in this article originate for the most part the limits given in literature sources, in addition, the following sources are cited: