【舌形动物类】
舌形动物类（学名：Pentastomida），又称五口动物类，是动物界的一个分类。属于无脊椎动物，介乎于环节动物和节肢动物之间，均为寄生性动物。其特征是体软、扁而长，无色，透明，无足。身长从数毫米到十数厘米，体表分近百个清晰的节段，内部却并不分节。舌形动物均为雌雄异体的专性寄生物PLOS：牠们的身体没有呼吸系统、Excretory system和循环系统，虫体前端口部突出，呈椭圆形，周围有两对可伸缩的钩，用以附着在寄主组织上。
本物种的名称是因为从其部分物种的外型酷似脊椎动物的舌头，因而为名；而其学名及另一名称「五口动物」的来源，则是因为其口器的五个钩，好像有五个口一样，因而为名。这五个「钩」，其实只有一个为口器，其余四个只是颚足。过往由于对本分类物种的分类不明，单单从外形来判断，所以将其归类到门一层。后来到了2001年，研究证据显示五口动物实为退化了的寄生性节肢动物，本物种生物跟其他物种的关系得到确认，所以被降至归入成为颚足纲的一员，是为舌形亚纲。随著颚足动物的分类被重组，舌形亚纲亦被重新分类，成为了寡甲总纲鱼介形纲的成员Zrzavý et al 1997。
现时本分类有物种约130个，皆为被动式寄生物，其部分解剖结果为退化性。成年的舌虫长约1 ，多数于宿主的呼吸系统黏付着。
==分类==
以下为这是马丁和戴维斯在2001年成立的分类，将五口动物置于甲壳亚门颚足纲。以下包含现存的目、超科、科、属和种：
Armillifer armillatus Wyman, 1848, a 4 cm individual collected from the respiratory system of a python, Python sebae. Specimen deposited in the  Museum für Naturkunde Berlin
Female (right) and male (left) Armillifer sp.
*头行目 Cephalobaenida Heymons, 1935
*Cephalobaenidae Heymons, 1922
::*Cephalobaena Heymons, 1922
:::*Cephalobaena tetrapoda Heymons, 1922
*孔头舌虫目 PorocephalidaLi et al 2012
*Linguatuloidea
:*Linguatulidae Haldeman, 1851
::*Linguatula Frölich, 1789
:::*Linguatula arctica Riley, Haugerud & Nilssen, 1987
:::*Linguatula multiannulata Haffner & Rack in Haffner, Rack & Sachs, 1969
:::*Linguatula recurvata (Diesing, 1850)
:::*Linguatula serrata Frölich, 1789
::*Neolinguatula Haffner & Rack in Haffner, Rack & Sachs, 1969
:::*Neolinguatula nuttalli (Sambon, 1922)
:*Subtriquetridae Fain, 1961
::*Subtriquetra Sambon, 1922
:::*Subtriquetra megacephalum (Baird, 1853)
:::*Subtriquetra rileyi Junker, Boomker & Booyse, 1998
:::*Subtriquetra shipleyi Hett, 1924
:::*Subtriquetra subtriquetra (Diesing, 1836)
*孔头舌虫总科 Porocephaloidea
:*孔头舌虫科 Porocephalidae Sambon, 1922
::*舌虫属 Armillifer Sambon, 1922
:::*Armillifer aborealis Riley & Self, 1981
:::*Armillifer agkistrodontis Self & Kuntz, 1966
:::*Armillifer armillatus (Wyman, 1845)
:::*Armillifer australis Heymons, 1935
:::*Armillifer grandis (Hett, 1915)
:::*Armillifer mazzai (Sambon, 1922)
:::*Armillifer moniliformis (Diesing, 1836)
:::*Armillifer yoshidai Kishida, 1928
::*Cubirea Kishida, 1928
:::*Cubirea annulata (Baird, 1853)
:::*Cubirea pomeroyi (Woodland, 1921)
::*Elenia Heymons, 1932
:::*Elenia australis Heymons, 1932
::*Gigliolella Chabaud & Choquet, 1954
:::*Gigliolella brumpti (Giglioli, 1922)
::*Kiricephalus Sambon, 1922
:::*Kiricephalus clelii Riley & Self, 1980
:::*Kiricephalus coarctatus (Diesing, 1850)
:::*Kiricephalus constrictor Riley & Self, 1980
:::*Kiricephalus gabonensis Riley & Self, 1980
:::*Kiricephalus pattoni (Stephens, 1908)
:::*Kiricephalus tortus (Shipley, 1898)
::*Parasambonia Stunkard & Gandal, 1968
:::*Parasambonia bridgesi Stunkard & Gandal, 1968
:::*Parasambonia minor Riley & Self, 1982
::*Porocephalus Humboldt, 1812
:::*Porocephalus basiliscus Riley & Self, 1979
:::*Porocephalus benoiti Fain, 1960
:::*Porocephalus bifurcatus
:::*Porocephalus clavatus (Wyman, 1845)
:::*Porocephalus crotali Humboldt, 1812
:::*Porocephalus dominicana Riley & Walters, 1980
:::*Porocephalus stilesi Sambon in Vaney & Sambon, 1910
:::*Porocephalus subuliferum (Leuckart, 1860)
:::*Porocephalus taiwana Qiu, Ma, Fan & Lu, 2005
:::*Porocephalus tortugensis Riley & Self, 1979
::*Waddycephalus Sambon, 1922
:::*Waddycephalus calligaster Riley & Self, 1981
:::*Waddycephalus komodoensis Riley & Self, 1981
:::*Waddycephalus longicauda Riley & Self, 1981
:::*Waddycephalus porphyriacus Riley & Self, 1981
:::*Waddycephalus punctulatus Riley & Self, 1981
:::*Waddycephalus radiata Riley & Self, 1981
:::*Waddycephalus scutata Riley & Self, 1981
:::*Waddycephalus superbus Riley & Self, 1981
:::*Waddycephalus teretiusculus (Baird, 1862)
:::*Waddycephalus vitiensis Heymons, 1932
:*Sebekidae Sambon, 1922
::*Alofia Giglioli in Sambon, 1922
:::*Alofia ginae Giglioli in Sambon, 1922
:::*Alofia indica (von Linstow, 1906)
:::*Alofia merki Giglioli 'in Sambon, 1922
:::*Alofia nilotici Riley & Huchzermeyer, 1995
:::*Alofia parva Riley & Huchzermeyer, 1995
:::*Alofia platycephalum (Lohrmann, 1889)
:::*Alofia simpsoni Riley, 1994
:::*Alofia travassosi (Heymons, 1932)
::*Diesingia Sambon, 1922
:::*Diesingia kachugensis (Shipley, 1910)
:::*Diesingia megastomum (Diesing, 1836)
::*Selfia Riley, 1994
:::*Selfia porosus Riley, 1994
::*Leiperia Sambon, 1922
:::*Leiperia australiensis Riley & Huchzermeyer, 1996
:::*Leiperia cincinnalis (Sambon in Vaney & Sambon, 1910)
:::*Leiperia gracilis (Diesing, 1836)
::*Sambonia Noc & Giglioli, 1922
:::*Sambonia clavata (Lohrmann, 1889)
:::*Sambonia parapodum Self & Kuntz, 1966
:::*Sambonia solomenensis (Self & Kuntz, 1957)
:::*Sambonia varani (Self & Kuntz, 1957)
:::*Sambonia wardi (Sambon in Vaney & Sambon, 1910)
::*Agema Riley et al., 1997
:::*Agema silvaepalustris Riley et al., 1997
::*Pelonia Junker & Boomker, 2002
:::*Pelonia africana Junker & Boomker, 2002
::*Sebekia Sambon, 1922
:::*Sebekia cesarisi Giglioli in Sambon, 1922
:::*Sebekia divestei Giglioli in Sambon, 1922
:::*Sebekia johnstoni Riley, Spratt & Winch, 1990
:::*Sebekia microhamus Self & Rego, 1985
:::*Sebekia minor (Wedl, 1861)
:::*Sebekia mississippiensis Overstreet, Self & Vliet, 1985
:::*Sebekia multiannulata Riley, Spratt & Winch, 1990
:::*Sebekia novaeguineae Riley, Spratt & Winch, 1990
:::*Sebekia okavangoensis Riley & Huchzermeyer, 1995
:::*Sebekia oxycephalum (Diesing, 1836)
:::*Sebekia purdieae Riley, Spratt & Winch, 1990
:::*Sebekia trinitatis Riley, Spratt & Winch, 1990
*Raillietiellida Almeida & Christoffersen, 1999
:*Raillietiellidae Sambon, 1922
::*Raillietiella Sambon, 1910
:::*Raillietiella aegypti Ali, Riley & Self, 1982
:::*Raillietiella affinis Bovien, 1927
:::*Raillietiella agcoi Tubangui & Masiluñgan, 1936
:::*Raillietiella ampanihyensis Gretillat, Brygoo & Domergue, 1962
:::*Raillietiella amphiboluri Mahon, 1954
:::*Raillietiella belohaensis McAllister, Riley, Freed & Freed, 1993
:::*Raillietiella bicaudata Heymons & Vitzthum, 1935
:::*Raillietiella boulengeri (Vaney & Sambon, 1910)
:::*Raillietiella bufonis Ali, Riley & Self, 1982
:::*Raillietiella cartagenensis Ali, Riley & Self, 1985
:::*Raillietiella chamaeleonis Gretillat & Brygoo, 1959
:::*Raillietiella colubrilineati (Leuckart, 1860)
:::*Raillietiella congolensis Fain, 1961
:::*Raillietiella crotali Ali, Riley & Self, 1984
:::*Raillietiella freitasi (Motta & Gomes, 1968)
:::*Raillietiella furcocercum (Diesing, 1836)
:::*Raillietiella gehyrae Bovien, 1927
:::*Raillietiella gigliolii Hett, 1924
:::*Raillietiella gowrii Rajalu & Rajendran, 1970
:::*Raillietiella hebitihamata Self & Kuntz, 1960
:::*Raillietiella hemidactyli Hett, 1934
:::*Raillietiella indica Gedoelst, 1921
:::*Raillietiella kochi Heymons, 1926
:::*Raillietiella mabuiae Heymons, 1922
:::*Raillietiella maculatus Rao & Hiregaudar, 1962
:::*Raillietiella maculilabris Ali, Riley & Self, 1984
:::*Raillietiella madagascariensis McAllister et al., 1993
:::*Raillietiella mediterranea (Hett, 1915)
:::*Raillietiella monarchus Ali, Riley & Self, 1984
:::*Raillietiella morenoi Abreu-Acosta et al., 2006
:::*Raillietiella mottae Almeida, Freire & Lopes, 2008
:::*Raillietiella namibiensis Riley & Heideman 1998
:::*Raillietiella orientalis (Hett, 1915)
:::*Raillietiella piscator Nair, 1967
:::*Raillietiella rileyi Krishnasamy et al., 1995
:::*Raillietiella schoutedeni Fain, 1960
:::*Raillietiella scincoides Ali, Riley & Self, 1984
:::*Raillietiella spiralis Hett, 1924
:::*Raillietiella teagueselfi Riley, McAllister & Freed, 1988
:::*Raillietiella tetrapoda (Gretillat, Brygoo & Domergue, 1962)
:::*Raillietiella trachea Riley, Oaks & Gilbert, 2003
:::*Raillietiella venteli (Motta, 1965)
::*Yelirella Spratt, 2010
:::*Yelirella petauri (Spratt, 2010)
*Reighardiida Almeida & Christoffersen, 1999
:*Reighardiidae Heymons, 1926
::*Hispania Martínez et al., 2004
:::*Hispania vulturis Martínez et al., 2004
::*Reighardia Ward, 1899
:::*Reighardia lomviae Dyck, 1975
:::*Reighardia sternae (Diesing, 1864)
==参考文献==
==参看==
* 舌形虫病或人舌形虫病
==外部连结==
*Pentastomida