Pentastomida
. Tongueworm is any of a group of parasitic, wormlike animals found in the respiratory system of vertebrates, especially reptiles . Tongueworms cling to the lining of the nasal passageways and lungs where they feed on the blood of the host. Also called pentastomids, tongueworms occur worldwide, although most species are tropical. The body of the tongueworm is highly modified for parasitism, that is, obtaining nourishment from the body of another, usually larger host organism (see Parasite ). Adults of most species are 2 to 13 cm (0.8 to 5.1 in) long. Their mouth is jawless and sometimes projects outward as a trunklike proboscis. The mouth is flanked by two pairs of small, fingerlike projections equipped with claws that are used to attach to the host. The name pentastomid, meaning five-mouthed, derives from the fact that, in some species, these four grasping organs resemble the proboscis and look like additional mouths. The single, true mouth leads to a long, straight gut, the front of