Pentastomida

Pentastomida

[‚pen·tə′stäm·ə·də]

(invertebrate zoology)

A class of bloodsucking parasitic arthropods; the adult is vermiform, and there are two pairs of hooklike, retractile claws on the cephalothorax.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Pentastomida

 

(more accurately, Linguatulida), a unique class of parasitic invertebrates, whose place in the system of animal classification is unclear. Members of the class most closely resemble arthropods, and they are usually added to the phylum Arthropoda as an extra class. There are about 60 species, distributed mainly in the tropics.

The body, which reaches 14 cm long, is wormlike, not infrequently ligulate. It consists of a short, unsegmented anterior section and a longer, segmented posterior section. The mouth is on the underside of the anterior section, and along its sides there are two pairs of claws. The animal is covered with a cuticle. Under the skin there is a layer of annular and then longitudinal striated muscles. In most members of the class the ventral nerve cord is concentrated in a subesophageal ganglion. The digestive tract is tubular, and there is an anus at the posterior end of the body. There are no respiratory or circulatory organs. The sexes are separate.

Adult individuals parasitize the lungs and nasal passages of reptiles and mammals. The eggs, which are swallowed by an intermediary host (also a vertebrate), develop into larvae with two pairs of short lateral legs. The larvae then become nymphs, which develop into adults after they are swallowed by the terminal host.

A. V. IVANOV

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.