Palliolisentis

Palliolisentis is a genus in Acanthocephala (parasitic thorny-headed worms, also known as spiny-headed worms).

Taxonomy
The type species is Palliolisentis quinqueungulis. The National Center for Biotechnology Information does not indicate that any phylogenetic analysis has been published on Palliolisentis that would confirm its position as a unique order in the family Quadrigyridae.

Description
Palliolisentis has a cylindrical Proboscis armed with 6–12 longitudinal rows of hooks and a trunk with single field of spines.

Species
The genus Palliolisentis Machado-Filho, 1960 contains three species:


 * Palliolisentis ornatus Machado-Filho, 1960
 * Palliolisentis polyonca Schmidt and Hugghins, 1973
 * Palliolisentis quinqueungulis Machado-Filho, 1960 (type species)

Distribution
The distribution of Palliolisentis species is determined by that of its hosts.

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 most Palliolisentis species are not known. 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 are passed in the feces of the definitive host and the cycle repeats.

There are no reported cases of any Palliolisentis species infesting humans in the English language medical literature.