Eoacanthocephala is a

class Class or The Class may refer to: Common uses not otherwise categorized * Class (biology), a taxonomic rank * Class (knowledge representation), a collection of individuals or objects * Class (philosophy), an analytical concept used differently ...

parasitic Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson ha ...

worm Worms are many different distantly related bilateral animals that typically have a long cylindrical tube-like body, no limbs, and no eyes (though not always). Worms vary in size from microscopic to over in length for marine polychaete worm ...

s, within the

phylum In biology, a phylum (; plural: phyla) is a level of classification or taxonomic rank below kingdom and above class. Traditionally, in botany the term division has been used instead of phylum, although the International Code of Nomenclatu ...

Acanthocephala Acanthocephala (Greek , ', thorn + , ', head) is a phylum of parasitic worms known as acanthocephalans, thorny-headed worms, or spiny-headed worms, characterized by the presence of an eversible proboscis, armed with spines, which it uses to p ...

. They feed on any aquatic cold-blooded creature such as turtles and fish. Their proboscis spines are arranged radially, with no

protonephridia The nephridium (plural ''nephridia'') is an invertebrate organ, found in pairs and performing a function similar to the vertebrate kidneys (which originated from the chordate nephridia). Nephridia remove metabolic wastes from an animal's body. Neph ...

, and with persistent ligament sacs in female. The only reliable way to identify the group is that they only have one

cement gland Cement glands are small organs found in Acanthocephala that are used to temporarily close the posterior end of the female after copulation. Cement glands are also mucus-secreting organs that can attach embryos or larvae to a solid substrate. Th ...

. This is a primitive characteristic and hence the name. The class contains 2

orders Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...

: * Gyracanthocephala Van Cleave, 1936 * Neoechinorhynchida Southwell and Macfie, 1925

References

*Robert L. Usinger; Storer. 1951. General Zoology. Sixth edition. McGraw-Hill, Inc. Page-437.
ITIS - Report: Eoacanthocephala".
''www.itis.gov''. Retrieved 2022-10-15. Acanthocephalans {{Acanthocephalan-stub