Aplousobranchia is an order of sea squirts in the class

Ascidiacea Ascidiacea, commonly known as the ascidians or sea squirts, is a paraphyletic class in the subphylum Tunicata of sac-like marine invertebrate filter feeders. Ascidians are characterized by a tough outer test or "tunic" made of the polysacchari ...

, first described by Fernando Lahille in 1886. They are colonial animals, and are distinguished from other sea squirts by the presence of relatively simple pharyngeal baskets. This provides the etymology of their name: in

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

, () means "simple". The posterior part of the abdomen contains the heart and gonads, and is typically larger than in other sea squirts.

Taxonomy

Order Aplousobranchia * Family Clavelinidae Forbes & Hanley 1848 ycnoclavellidae Kott 1990**'' Clavelina'' Savigny 1816 [''Bradiclavella'' Zirpolo 1925; ''Chondrostachys'' Macdonald 1858; ''Dendroclavella'' Oka 1927; ''Podoclavella'' Herdman 1890; ''Rhodozona'' Van Name 1902; ''Stereoclavella'' Herdman 1890; ''Synclavella'' Caullery 1900] **''Euclavella'' Kott 1990 **''Nephtheis'' Gould 1856 [''Oxycorynia'' Drasche 1882] **''Pycnoclavella'' Garstang 1891 [''Archiascidia'' Julin 1904] * Family Diazonidae Garstang 1891 **'' Diazona'' Savigny 1816 'Aphanibranchion'' Oka 1906; ''Syntethys'' Forbes & Goodsir 1851; ''Diagonum'' Troschel 1842; ''Diagoma'' Wade 1842** '' Pseudodiazona'' Millar 1963 'Patridium'' Kott 1975** '' Pseudorhopalaea'' Millar 1975 ** '' Rhopalaea'' Philippi 1843 'Rhopalona'' Roule 1886; ''Rhopalopsis'' Herdman 1890** '' Tylobranchion'' Herdman 1886 * Family Didemnidae Giard 1872 iplosominae Giard 1872**'' Atriolum'' Kott 1983 **''Clitella'' Kott 2001 **'' Coelocormus'' Herdman 1886 **'' Didemnum'' Savigny 1816 [''Didemnoides'' Drasche 1883; ''Diplosomoides'' Herdman 1886 non Lahille 1890; ''Hypurgon'' Sollas 1903; ''Leptoclinum'' Milne-Edwards 1842; ''Sarcodidemnoides'' Oka & Willey 1892; ''Tetradidemnum'' Della Valle 1881] **''Diplosoma (tunicate), Diplosoma'' Macdonald 1859 [''Arenadiplosoma'' Menker & Ax 1970; ''Astellium'' Giard 1872; ''Lioclinum'' Verrill 1871; ''Pseudodidemnum'' Giard 1872; ''Pseudodiplosoma''] **'' Leptoclinides'' Bjerkan 1905 'Askonides'' Kott 1962**'' Lissoclinum'' Verrill 1871 'Diplosomoides'' Lahille 1890 non Herdman 1886; ''Echinoclinum'' Van Name 1902; ''Polysoma'' Kott 1983**'' Polysyncraton'' Nott 1892 **'' Trididemnum'' Della Valle 1881 'Didemnoides'' Lahille 1890 non Drasche 1884; ''Didemnopsis'' Hartmeyer 1903* Family Euherdmaniidae Ritter 1904 **'' Euherdmania'' Ritter 1904 'Herdmania'' Ritter 1903 non Lahille 1888* Family Holozoidae Berrill 1950 **''Colella'' Herdman 1886 ''

nomen nudum In Taxonomy (biology), taxonomy, a ''nomen nudum'' ('naked name'; plural ''nomina nuda'') is a designation which looks exactly like a scientific name of an organism, and may have originally been intended to be one, but it has not been published ...

'' ** '' Distaplia'' Della Valle 1881 'Celulophana''; ''Holozoa'' Lesson 1832; ''Julinia'' Calman 1894; ''Leptobotrylloides'' Oka 1927** '' Hypsistozoa'' Brewin 1953 ** '' Hypodistoma'' Tokioka 1967 ** '' Neodistoma'' Kott 1990 ** '' Polydistoma'' Kott 1990 ** '' Protoholozoa'' Kott 1969 ** '' Pseudoplacentela'' Sanamyan 1993 ** '' Sycozoa'' Lesson 1832 'Cyathocormus'' Oka 1913** '' Sigillina'' Savigny 1816 'Atapozoa'' Brewin 1946; ''Atopozoa'' Brewin 1956; ''Hyperiodistoma'' Michaelsen 1930* Family Placentelidae Kott 1992 **'' Placentela'' Redikorzev 1913 'Homoedistoma'' Redikorzev 1927; ''Sigillinaria'' Oka 1933* Family Polycitoridae Michaelsen 1904 **'' Archidistoma'' Garstang 1891 ** '' Brevicollus'' Kott 1990 ** '' Cystodytes'' Drasche 1884 ** '' Eucoelium'' Savigny 1816 ** '' Eudistoma'' Caullery 1909 'Distoma'' Savigny 1816 non Retzius 1786; ''Paessleria'' Michaelsen 1909** ''Exostoma'' Kott 1990 ** '' Millarus'' Monniot & Monniot 1988 ** '' Polycitor'' Renier 1804 'Paradistoma'' Caullery 1909; ''Tetrazona'' Michaelsen 1930** '' Polycitorella'' Michaelsen 1924 ** ''Rhombifera'' Peres 1956 non Barrande 1867 * Family Polyclinidae Milne-Edwards 1841 ynoicidae**'' Aplidiopsis'' Lahille 1890 **'' Aplidium '' Savigny 1816 [''Haploidium'' Agassiz 1846; ''Amaroecium'' Milne-Edwards 1841; ''Circinalium'' Giard 1872; ''Fragarium'' Giard 1872; ''Heterotrema'' Fiedler 1889; ''Parascidia'' Milne- Edwards 1841; ''Polyclinoides'' Drasche 1883; ''Sidnyum'' Savigny 1816] ** ''Morchellioides'' Herdman, 1886 ** ''Morchellium'' Giard 1872 ** ''Neodictyon'' Sanamyan 1988 ** ''Polyclinella'' Harant 1931 ** '' Polyclinum'' Savigny 1816 'Glossophorum'' Lahille 1816** '' Sidneioides'' Kesteven 1909 ** '' Synoicum'' Phipps 1774 [''Atopogaster'' Herdman 1886; ''Lissamaroucium'' Sluiter 1906; ''Macroclinum'' Verrill 1871; ''Polyclinopsis'' Gottschaldt 1894; ''Psammaplidium'' Herdman 1886; ''Glossoforum'' Lahille 1886] * Family Protopolyclinidae Kott 1992 **''Condominium (tunciate), Condominium'' Kott 1992 ** ''Monniotus'' Millar 1988 ** ''Protopolyclinum'' Millar 1960 * Family Pseudodistomidae Harant 1931 ** '' Anadistoma'' Kott 1992 ** '' Citorclinum'' Monniot & Millar 1988 ** '' Pseudodistoma'' Michaelsen 1924 * Family Ritterellidae Kott 1992 **'' Dumus'' Brewin, 1952 **'' Pharyngodictyon'' Herdman 1886 **'' Ritterella'' Harant 1931 * Family Stomozoidae Kott 1990 **'' Stomozoa'' Kott 1957 * Family Vitrumidae Kott 2009 ** '' Vitrum'' Kott 2009

References

* {{Authority control Tunicate orders Taxa named by Fernando Lahille