Arhythmorhynchus is a genus of parasitic worms in Acanthocephala (thorny-headed worms, also known as spiny-headed worms) belonging to the family Polymorphidae. Taxonomy The genus was described by Lühe in 1911. The National Center for Biotechnology Information does not indicate that any phylogenetic analysis has been published on any Arhythmorhynchus species that would confirm its position as a unique genus in the family Polymorphidae.
Description Arhythmorhynchus species consist of a proboscis covered in hooks and a long trunk. Species The genus Arhythmorhynchus contains many species.
Arhythmorhynchus capellae (Yamaguti, 1935) Arhythmorhynchus comptus Van Cleave & Rausch, 1950 Arhythmorhynchus distinctus Baer, 1956 Arhythmorhynchus eroliae (Yamaguti, 1939) Arhythmorhynchus frassoni (Molin, 1858) Arhythmorhynchus frontospinosus (Tubangui, 1935) Arhythmorhynchus jeffreyi Schmidt, 1973 Arhythmorhynchus johnstoni Golvan, 1960 Arhythmorhynchus limosae Edmonds, 1971 Arhythmorhynchus petrotschenkoi (Schmidt, 1969) Atrashkevich, 1979 Arhythmorhynchus plicatus (von Linstow, 1883) Arhythmorhynchus pumilirostris Van Cleave, 1916 Arhythmorhynchus rubicundus (Molin, 1859) Arhythmorhynchus siluricola Dollfus, 1929 Arhythmorhynchus suecicus Lundström, 1942 Arhythmorhynchus teres Van Cleave, 1921 Arhythmorhynchus tigrinus Moghe & Das, 1953 Arhythmorhynchus trichocephalus (Leuckart, 1876) Arhythmorhynchus tringi Gubanov, 1952 Arhythmorhynchus turbidus (Van Cleave, 1937) Arhythmorhynchus uncinatus (Kaiser, 1893) Arhythmorhynchus villoti Golvan, 1994 Arhythmorhynchus xeni Atrashkevich, 1978
Distribution The distribution of Arhythmorhynchus is determined by that of its hosts. The species of this genus are found in Europe and Northern America. Hosts
The life cycle of an acanthocephalan consists of three stages beginning when an infective acanthor (development of an egg) is released from the intestines of the definitive host and then ingested by an arthropod, the intermediate host. The intermediate hosts of Arhythmorhynchus 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 (hosts where parasites infest but do not undergo larval development or sexual reproduction) for xx.
Arhythmorhynchus parasitizes animals. There are no reported cases of Arhythmorhynchus infesting humans in the English language medical literature.
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