Ardeirhynchus
Ardeirhynchus is a monotypic genus of parasitic worms belonging to the family Polymorphidae. Its sole described species is Ardeirhynchus spiralis, which is found in Northern America.
Taxonomy
The genus was described by Dimitrova & Georgiev in 1994. The original description of Ardeirhynchus spiralis was done by Rudolphi in 1809. The National Center for Biotechnology Information does not indicate that any phylogenetic analysis has been published on Ardeirhynchus that would confirm its position as a unique genus in the family Polymorphidae. A phylogenetic tree was created.Description
A. spiralis consists of a proboscis covered in hooks and a long trunk. The genus is distinguished from Arhythmorhynchus, which is the most morphologically similar genus, in three ways: a considerably shorter neck, minute trunk spines, the distribution of groups of hypodermal nuclei in the anterior part of the trunk and in lateral rows along the length of the posterior part of the trunk, the position of the male genital system, and a terminal genital pore.Distribution
The distribution of A. spiralis is determined by that of its hosts. It is found in Bulgaria.Hosts
The life cycle of an acanthocephalan consists of three stages beginning when an infective acanthor is released from the intestines of the definitive host and then ingested by an arthropod, the intermediate host. Although the intermediate hosts of Ardeirhynchus are arthropods. When the acanthor molts, the second stage called the acanthella begins. This stage involves penetrating the wall of the mesenteron or the intestine of the intermediate host and growing. The final stage is the infective cystacanth which is the larval or juvenile state of an Acanthocephalan, differing from the adult only in size and stage of sexual development. The cystacanths within the intermediate hosts are consumed by the definitive host, usually attaching to the walls of the intestines, and as adults they reproduce sexually in the intestines. The acanthor is passed in the feces of the definitive host and the cycle repeats. There may be paratenic hosts for Ardeirhynchus.A. spiralis parasitizes the herons Little bittern and squacco heron. The prevalence in the first host is 1.9% and usually only 1 worm is found. There are no reported cases of A. spiralis infesting humans in the English language medical literature.