等足目
软甲纲的一目节肢动物
等足目（学名：Isopoda），又名等足类或等脚类，是一目甲壳类，其下包括了潮虫及球潮虫。等足目的化石纪录可以追溯至3亿年前的石炭纪[3][4]。
等足目 化石时期：石炭纪–现代
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| Eurydice pulchra：一种在沙质岸边出没的肉食性等足目物种。 | |
科学分类 
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| 界： | 动物界 Animalia |
| 门： | 节肢动物门 Arthropoda |
| 亚门： | 甲壳亚门 Crustacea |
| 纲： | 软甲纲 Malacostraca |
| 亚纲： | 真软甲亚纲 Eumalacostraca |
| 总目： | 囊虾总目 Peracarida |
| 目： | 等足目 Isopoda Latreille, 1817[1] |
| 亚目 | |
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语源
特征
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等足目是体型较细小的甲壳类，有七对大小及形态相似的脚，体型由300微米至50厘米不等。[5]它们的腹背一般都是扁平的，但在深海或地下水中的物种很多时都会不同。[5]等足目没有明显的甲壳，只在头部有壳。[6]气体交换是由似鳃的腹肢开始至身体后部。陆地生活的等足目很多时都有像肺部的结构，往往在底部显而易见。[5]若有眼睛，都是无柄的。[6]与异足目一样，它们最后的腹节与尾节融合，组成腹尾节。[6]胸部的第一节则与头部融合。胸部附器是单枝的，而腹肢则是二枝的。[6]
生态
约有4500种等足目是生活在水中的，大部份分布在海床。[3]约有500种是淡水的，其馀5000种是属于潮虫亚目，远比陆生的其他甲壳类成功。[3]在深海中以栉水虱亚目较为丰富，差不多完全排除了其他等足目，成功发展辐射适应。[3]
一些等足目发展成寄生生态。上虾亚目是完全寄生的，而扇肢亚目则是部份寄生。例如缩头鱼虱（Cymothoa exigua）是寄生在墨西哥笛鲷中，它会吃了墨西哥笛鲷的舌头，并且取而代之，是已知唯一在功能上取代主体的寄生方式。[7]
多样化及分类
等足目属于囊虾总目，有特制的育幼袋孵蛋。根据2001年的分类，当时约有11437个物种，分别分类在11个亚目[5][8]。
- Acanthaspidiidae
- Ianthopsis Beddard, 1886
- Iolanthe Beddard, 1886
- Mexicope Hooker, 1985
- Mexicope kensleyi Hooker, 1985
- Mexicope maletensis Riehl & Schienbein, 2024[9]
- Mexicope sushara Bruce, 2004
- Mexicope westralia Just, 2001
- 纺锤水虱科 Aegidae
- Agnaridae
- Alloniscidae
- Amphisopidae
- Amphisopodidae
- Ancinidae
- Antarcturidae
- Abyssarcturus Kussakin & Vasina, 1995
- Acantharcturus Schultz, 1981
- Antarcturus
- Caecarcturus Schultz, 1981
- Chaetarcturus Brandt, 1990
- Cylindrarcturus Schultz, 1981
- Fissarcturus Bathyweddellensis, 2007
- Fissarcturus Brandt, 1990
- Fissarcturus Rossi, 2007
- Fissarcturus Sandwichi, 2007
- Furcarcturus Baltzer, Held & Wägele, 2000
- Glaberarcturus Kussakin & Vasina, 1998
- Globarcturus Kussakin & Vasina, 1994
- Halearcturus Poore, 2015
- Litarcturus Brandt, 1990
- Marmachius Poore, 2012
- Mixarcturus Brandt, 1990
- Oxyarcturus Brandt, 1990
- Tuberarcturus Brandt, 1990
- Xiphoarcturus Pereira, Roccatagliata & Doti, 2019
- 背尾水虱科 Antheluridae
- Anthuridae
- Anuropidae
- Archaeoniscidae
- Archeoniscidae
- Arcturidae
- Arcturididae
- Armadillidae
- 球木虱科 Armadillidiidae
- Armadilliidae
- Asconiscidae
- 栉水虱科 Asellidae
- Atlantasellidae
- Atlantidiidae
- 澳洲水虱科 Austrarcturellidae
- Balloniscidae
- Barybrotidae
- Basserolidae
- 异深水虱科 Bathynataliidae
- Bathynomidae
- Bathytropidae
- Berytoniscidae
- Bisilvestriidae
- 鳃虱科 Bopyridae
- Brasileirinidae
- Buddelundiellidae
- Cabiropidae
- 大尾水虱科 Calabozoidae
- Capitoniscidae
- Chaetilidae
- Chaetiliidae
- 漂水虱科 Cirolanidae
- 珊瑚水虱科 Corallanidae
- Crinoniscidae
- Cryptoniscidae
- Cryptothiridae
- Cumoechidae
- Cylisticidae
- 缩头鱼虱科 Cymothoidae
- Cyproniscidae
- Dajidae
- Delatorreiidae
- Dendrotionidae
- Desmosomatidae
- Detonidae
- Dubioniscidae
- Echinothambematidae
- 内虱科 Entoniscidae
- Entophilidae
- Eubelidae
- Excorallanidae ，为Corallanidae的异名
- Expanathuridae
- Gnathidae
- 巨颚水虱科 Gnathiidae
- Gnathostenetroididae
- Hadromastacidae
- Halophilosciidae
- Haplomunnidae
- Haploniscidae
- Hekelidae
- Hemioniscidae
- Holidoteidae
- Holognathidae
- Hypsimetopidae
- Hyssuridae
- Idoteidae
- Ionidae
- Irmaosidae
- Ischnomesidae
- 寄藻水虱科 Janirellidae
- Janiridae
- Joeropsididae
- Katianiridae
- Keuphyliidae
- Lantoceramiidae
- Lepidocharontidae
- Leptanthuridae
- 海蟑螂科 Ligiidae
- Limnoriidae
- Macrostylidae
- Mesamphisopidae
- Mesoniscidae
- Mesosignidae
- 小角水虱科 Microcerberidae
- Microniscidae
- Microparasellidae
- Mictosomatidae
- 浮游水虱科 Munnidae
- Munnopsidae
- Nannoniscidae
- Olibrinidae
- 海蛆科 Oniscidae
- Diacara Budde-Lund, 1908
- Exalloniscus Stebbing, 1911
- Exalloniscus albus (Dollfus, 1898)
- Exalloniscus beroni Taiti & Ferrara, 1988
- Exalloniscus bicoloratus Taiti & Ferrara, 1988
- Exalloniscus borneanus Taiti & Ferrara, 1988
- Exalloniscus brincki Manicastri & Argano, 1986
- Exalloniscus burmaensis Taiti & Cardoso, 2020
- Exalloniscus caudatus Taiti & Ferrara, 1988
- Exalloniscus coecus (Dollfus, 1898)
- Exalloniscus convexus Taiti & Cardoso, 2020
- Exalloniscus cortii Arcangeli, 1927
- Exalloniscus curvispinatus Li & Jiang, 2024[10]
- Exalloniscus deharvengi Taiti & Cardoso, 2020
- Exalloniscus duospinatus Li & Jiang, 2024[10]
- Exalloniscus japonicus Taiti & Gruber, 2008
- Exalloniscus kampucheaensis Taiti & Cardoso, 2020
- Exalloniscus malaccensis Taiti & Ferrara, 1988
- Exalloniscus maschwitzi Taiti & Ferrara, 1988
- Exalloniscus nepalensis Schmalfuss, 1983
- Exalloniscus papillosus (Budde-Lund, 1912)
- Exalloniscus rotundatus Taiti & Ferrara, 1986
- Exalloniscus schmalfussi Taiti & Cardoso, 2020
- Exalloniscus siamensis Taiti & Cardoso, 2020
- Exalloniscus silvestrii Kwon & Taiti, 1993
- Exalloniscus stilifer Taiti & Cardoso, 2020
- Exalloniscus sumatranus Manicastri & Taiti, 1991
- Exalloniscus taitii Li & Jiang, 2024[10]
- Exalloniscus thailandensis Dalens, 1987
- Exalloniscus tortilis Taiti & Cardoso, 2020
- Exalloniscus triangulus Li & Jiang, 2024[10]
- Exalloniscus tridentatus Li & Jiang, 2024[10]
- Exalloniscus troglophilus Taiti & Gruber, 2008
- Exalloniscus tuberculatus Nunomura, 2000
- Exalloniscus vietnamensis Taiti & Ferrara, 1988
- Hanoniscus Budde-Lund, 1912
- Hiatoniscus Barnard, 1932
- Hora Barnard, 1932
- Krantzia Barnard, 1932
- 海蛆属 Oniscus Linnaeus, 1758
- Oroniscus Verhoeff, 1908
- Phalloniscus Budde-Lund, 1908
- Rabdoniscus Vandel, 1981
- Rodoniscus Arcangeli, 1934
- Sardoniscus Arcangeli, 1939
- Tasmanoniscus Vandel, 1973
- Palaeophreatoicidae
- Paramunnidae
- Paranthuridae
- Paraplatyarthridae
- Parasellidae
- Periscyphicidae
- Philosciidae
- Phoratopodidae
- 坑水虱科 Phreatoicidae
- Phreatoicopsidae
- Phreatoicopsididae
- Plakarthriidae
- 蚁虱科 Platyarthridae
- Pleurocopidae
- Podasconidae
- Ponderellidae
- 鼠妇科 Porcellionidae
- Protognathiidae
- Protojaniridae
- Pseudarmadillidae
- Pseudidotheidae
- Pseudojaniridae
- Pudeoniscidae
- Rectarcturidae
- Rhyscotidae
- Santiidae
- Schoebliidae
- Schweglerellidae
- Scleropactidae
- Scyphacidae
- 扁水虱科 Serolidae
- Spelaeoniscidae
- 团水虱科 Sphaeromatidae
- Sphaeroniscidae
- Stellatoniscidae
- Stenasellidae
- Stenetriidae
- Stenoniscidae
- Styloniscidae
- Tainisopidae
- Tecticipitidae
- Tendosphaeridae
- Thambematidae
- Thermoarcturidae
- Titanidae
- Trachelipodidae
- Tricarinidae
- 毛潮虫科 Trichoniscidae
- Tridentellidae
- Turanoniscidae
- 瘤水虱科 Tylidae
- Urdidae
- Urstylidae
- Vermectiadidae
- Xenarcturidae
- Xenosellidae
- 科的地位未定的属：
- Anhelkocephalon Bill, 1914
- Arctasellus Henry & Magniez, 1995
- Austrorgathona
- Brunnella Polz, 2005
- Chimaeroniscus Williams, Boyko & Moritaki, 2022
- Congloboniscus Jackson, 1938
- Crenisopus Wilson & Keable, 1999
- Cryptocotitus Schultz, 1977
- Cryptolacruma Schädel, Hörnig, Hyžný & Haug, 2021
- Cylisticoides Schmalfuss, 2003
- Debodea Hiller, 1999
- Discosalaputium Schädel, van Eldijk, Winkelhorst, Reumer & Haug, 2020
- Electrolana Schädel, Hyžný & Haug, 2021
- Elocryptus Schultz, 1977
- Ennurensis Collinge, 1915
- Eoarmadillidium Dollfus, 1904
- Eobooralana Schädel, Nagler & Hyžný, 2023
- Gelrincola Schädel, van Eldijk, Winkelhorst, Reumer & Haug, 2020
- Helleria Czerniavsky, 1868
- Jaerella Richardson, 1911
- Kanthyloma Klompmaker, Artal, van Bakel, Fraaije & Jagt, 2014
- Leptaspidia Bate & Westwood, 1868
- Mauritaniscus Vandel, 1958
- Musconiscus Arcangeli, 1930
- Nalocryptus Schultz, 1977
- Nococryptus Schultz, 1977
- Olincera W.E.Leach
- Oniscomorphus Jackson, 1938
- Onocryptus Schultz, 1977
- Osicryptus Schultz, 1977
- Ourachaerus Kinahan, 1859
- Paraleptotrichus Arcangeli, 1927
- Philoscodillo Jackson, 1938
- Platuropodus Pazinato, Haug, Rohn, Adami-Rodrigues, Pirani Ghilardi, Cardoso Langer & Haug, 2021
- Platyburmoniscus Schmidt, 2000
- Potrerillo de Armas & Juarrero de Varona, 1999
- Pseudodiploexochus Taiti, Paoli & Ferrara, 1998
- Reboursia Guinot, Wilson & Schram, 2005
- Rhacura Richardson, 1908
- Rotungus Collinge, 1916
- Squilloides Tchindono & Tchesun, 1993
- Strigoproavus Schollmann, 1993
- Synuropus Richardson, 1901
- Thermaloniscus Bourdon, 1983
- Tole Ortmann, 1901
- Trichopleon Beddard, 1886
- Trisopodoniscus Bourdon, 1981
- Unusuropode Duarte & Santos, 1962
- Urias Richardson, 1911
- Vacuotheca Schädel, Perrichot & Haug, 2019
- Xostylus Menzies, 1962
生长
等足目的幼虫如同其成虫，但却没有最后一对胸足。等足目生长周期中没有了游泳阶段是限制其分布的原因，并形成高度特有性。[3]它们会以两个阶段来脱壳。[5]
参考资料
- ^ Boxshall, Geoff. Isopoda. WoRMS. 2014 [2014-05-08].
- ^ Dreyer, Hermann; Wägele, Johann-Wolfgang. The Scutocoxifera Tax. Nov. and the Information Content of Nuclear ssu rDNA Sequences for Reconstruction of Isopod Phylogeny (Peracarida: Isopoda). Journal of Crustacean Biology. 2002-05, 22 (2): pp. 217–234 [2017-07-17]. （原始内容存档于2019-08-16）.
- ^ 3.0 3.1 3.2 3.3 3.4 Richard Brusca. Isopoda. Tree of Life Web Project. 1997-08-06 [2010-03-27]. （原始内容存档于2016-03-22）.
- ^ Schram, =Frederick R. Isopod from the Pennsylvanian of Illinois. Science. 1970, 169 (3948): 854–5. doi:10.1126/science.169.3948.854.
- ^ 5.0 5.1 5.2 5.3 5.4 5.5 M. Schotte, C. B. Boyko, N. L. Bruce, J. Markham, G. C. B. Poore, S. Taiti & G. D. F. Wilson. World List of Marine, Freshwater and Terrestrial Isopod Crustaceans. World Register of Marine Species. [2009-02-19]. （原始内容存档于2019-10-23）.
- ^ 6.0 6.1 6.2 6.3 S. J. Keable, G. C. B. Poore & G. D. F. Wilson. Australian Isopoda: Families. Australian Museum. 2002-10-02 [2010-03-27]. （原始内容存档于2018-10-10）.
- ^ R. C. Brusca & M. R. Gilligan. Tongue replacement in a marine fish (Lutjanus guttatus) by a parasitic isopod (Crustacea: Isopoda). Copeia. 1983, 3: 813–6. doi:10.2307/1444352.
- ^ Martin, Joel W.; Davis, George E. An Updated Classification of the Recent Crustacea (PDF). Natural History Museum of Los Angeles County. 2001: 132 pp [2010-03-27]. （原始内容存档 (PDF)于2013-05-12）.
- ^ Torben Riehl, Katharina Ellen Schienbein and Constantine Mifsud. 2024. A New Species of Mexicope Hooker, 1985 (Crustacea, Isopoda) — the First Record of Acanthaspidiidae Menzies, 1962 from the Mediterranean Sea. Biodiversity Data Journal. 12: e121508. DOI: 10.3897/BDJ.12.e121508
- ^ 10.0 10.1 10.2 10.3 10.4 Five new species of Exalloniscus Stebbing, 1911 (Crustacea, Isopoda, Oniscidea) from China. Zoosystematics and Evolution. [2024-04-14]. （原始内容存档于2024-10-01）.
