舌形動物類（學名：Pentastomida），又稱五口動物類，是動物界的一個分類。屬於無脊椎動物，介乎於環節動物和節肢動物之間，均為寄生性動物。其特徵是體軟、扁而長，無色，透明，無足。身長從數毫米到十數厘米，體表分近百個清晰的節段，內部卻並不分節。舌形動物均為雌雄異體的專性寄生物：牠們的身體沒有呼吸系統、排泄系統和循環系統，蟲體前埠部突出，呈橢圓形，周圍有兩對可伸縮的鉤，用以附著在寄主組織上。
本物種的名稱是因為從其部分物種的外型酷似脊椎動物的舌頭，因而為名；而其學名及另一名稱「五口動物」的來源，則是因為其口器的五個鉤，好像有五個口一樣，因而為名。這五個「鉤」，其實只有一個是真的口器、其餘四個只是顎足。過往由於對本分類物種的分類不明，單單從外形來判斷，所以將其歸類到門一層。後來到了 2001 年，研究證據顯示五口動物實為退化了的寄生性節肢動物，本物種生物跟其他物種的關係得到確認，所以被降至歸入成為顎足綱的一員，是為舌形亞綱。隨著顎足動物的分類被重組，舌形亞綱亦被重新分類，成為了寡甲總綱魚介形綱的成員。

現時本分類有物種約 130 個，皆為被動式寄生物，其部分解剖結果為退化性。成年的舌蟲長約 1 至 14 公分（0.4 至 5.5 英寸） ，多數於宿主的呼吸系統黏付著。



分類

以下為這是馬丁和戴維斯在 2001 年成立的分類，將五口動物置於甲殼亞門顎足綱。以下包含現存的目、超科、科、屬和種：


* 頭行目 Cephalobaenida Heymons, 1935

　
: 
* Cephalobaenidae Heymons, 1922

　
: : 
* _Cephalobaena_ Heymons, 1922

　
: 
* _Cephalobaena tetrapoda_ Heymons, 1922


* 孔頭舌蟲目 Porocephalida

　
: 
* 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)


* 孔頭舌蟲總科 Porocephaloidea

　
: 
* 孔頭舌蟲科 Porocephalidae Sambon, 1922

　
: 
* 舌蟲屬 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)



參考文獻



參看


* 舌形蟲病或人舌形蟲病



外部連結


* 維基物種上的相關資訊：舌形動物類