The Archiacanthocephala are a class of scratch worms with mandatory change of host, which parasitize than adult intestinal parasites in terrestrial vertebrates, especially in birds. It is about 150 medium to large species with body lengths of a few centimeters to 70 centimeters in the giant scratches ( Macracanthorhynchus hirudinaceus ), who lives in the intestines of pigs and can attack as accidental hosts also the people.
The Archiacanthocephala are mainly defined by their size and their limited on terrestrial vertebrates host range. They have a proboscis elongated to spherical shape and have no thorns on the trunk. The hooks on the proboscis are spirally arranged with all types and have a species-specific number and shape. The proboscis sheath is located at the trunk base, its wall may be one or two coats. As anatomical features lie in them the main stems of the epidermal Lakunensystems dorsal and ventral, while they are the representatives of the Palaeacanthocephala laterally, ie on the body sides.
The females have a dorsal and a ventral ligament bag in Pseudocoel whose walls do not melt in contrast to those of Palaeacanthocephala. Protonephridia found only in the particularly large species of Oligacanthorhynchidae. Most of the males have eight cement glands and only a few nuclei in the syncytial ligament.
The eggs of the Archiacanthocephala are oval and have no bulges at the Eipolen.
Way of life
The Archiacanthocephala are the only group within the scratch worms a complete terrestrial life cycle, so they are not of aquatic intermediate hosts dependent. The definitive hosts are mainly birds and mammals as intermediate hosts are insects and Myriapoda in question. Thus, for example, the larvae of various scarab beetles, especially May, June or rose beetle, the intermediate hosts of the giant scratch dar.
The Archiacanthocephala involve a number of species in several orders and families:
- Moniliformida Moniliformidae moniliformis
- Oligacanthorhynchidae Macracanthorhynchus
The information in this article originate for the most part the limits given in literature sources, in addition, the following sources are cited: