# Tanaidacea > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Tanaidacea > Markdown URL: https://mediated.wiki/source/Tanaidacea.md > Source: https://en.wikipedia.org/wiki/Tanaidacea > Source revision: 1327022140 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{Short description|Order of crustaceans}} {{Automatic taxobox | oldest_fossil = Carboniferous | image = Tanaissus_lilljeborgi.jpg | image_caption = ''Tanaissus lilljeborgi''
(a tanaid from the [North Sea](/source/North_Sea)) | taxon = Tanaidacea | authority = [Dana](/source/James_Dwight_Dana), 1849 | subdivision_ranks = Suborders | subdivision = *[Anthracocaridomorpha](/source/Anthracocaridomorpha) † *[Apseudomorpha](/source/Apseudomorpha) *[Tanaidomorpha](/source/Tanaidomorpha) }} The [crustacean](/source/crustacean) order '''Tanaidacea''' (known as '''tanaids''') make up a minor group within the [class](/source/class_(biology)) [Malacostraca](/source/Malacostraca). There are about 940 species in this order. ==Description== Tanaids are small, shrimp-like creatures ranging from {{convert|0.5|to|120|mm|in|sigfig=2}} in adult size, with most species being from {{convert|2|to|5|mm|in|sigfig=1}}. Their carapace covers the first two segments of the [thorax](/source/thorax). There are three pairs of limbs on the thorax; a small pair of [maxilliped](/source/maxilliped)s, a pair of large clawed [gnathopod](/source/gnathopod)s, and a pair of [pereiopod](/source/pereiopod)s adapted for burrowing into the mud. The remaining six thoracic segments each bear a pair of pereiopods,{{cite book |last1=Holdich |first1=D. M. |last2=Jones |first2=J. A. |title=Tanaids: keys and notes for the identification of the species |date=1983 |publisher=[Cambridge University Press](/source/Cambridge_University_Press) |location=Cambridge, New York |isbn=9780521272032 |pages=3–9}} and each of the first five [abdominal](/source/abdomen) segments normally carry [pleopod](/source/pleopod)s. The final segment is fused with the [telson](/source/telson) and carries a pair of [uropod](/source/uropod)s. The [gill](/source/gill)s lie on the inner surface of the carapace. The thoracic limbs wash water towards the mouth, filtering out small particles of food with the mouthparts or maxillipeds. Some species actively hunt prey, either as their only food source, or in combination with filter feeding. ==Habitat== Most are marine, but a handful are also found in [freshwater](/source/freshwater). They live buried in bottom sediments, sometimes in self-built tubes. ==Life cycle== Tanaids do not undergo a true [planktonic stage](/source/plankton). The early developmental period is spent while young are within the [marsupium](/source/Brood_pouch_(Peracarida)) of the mother. Subsequently, post-larvae, called [manca](/source/manca)s, emerge as [epibenthic](/source/benthos) forms. Some species are [hermaphroditic](/source/hermaphrodite).{{cite book |author= Barnes, Robert D. |year=1982 |title= Invertebrate Zoology |publisher= Holt-Saunders International |location= Philadelphia, PA|pages= 768–769|isbn= 0-03-056747-5}} ==Taxonomy== The oldest representatives of the group are known from the [Carboniferous](/source/Carboniferous), with modern forms emerging during the [Mesozoic](/source/Mesozoic).{{Cite journal |last1=Pazinato |first1=Paula G. |last2=Müller |first2=Patrick |last3=Haug |first3=Joachim T. |date=2023-01-31 |title=New species of Tanaidacea from Cretaceous Kachin amber, with a brief review of the fossil record of tanaidacean crustaceans |url=https://fr.pensoft.net/article/99995/ |journal=Fossil Record |volume=26 |issue=1 |pages=39–50 |doi=10.3897/fr.26.99995 |issn=2193-0074|doi-access=free }} The order Tanaidacea is divided into the following sub-orders, superfamilies and families:{{cite web |author=WoRMS |year=2018 |title=Tanaidacea |publisher=[World Register of Marine Species](/source/World_Register_of_Marine_Species) |url=http://www.marinespecies.org/aphia.php?p=taxdetails&id=1133 |accessdate=May 7, 2018}} {{Div col|colwidth=29em}} * '''Suborder''' [Anthracocaridomorpha](/source/Anthracocaridomorpha) † *** Family [Anthracocarididae](/source/Anthracocarididae) † Brooks, 1962 emend. Schram, 1979 *** Family [Niveotanaidae](/source/Niveotanaidae) † Polz, 2005 * '''Suborder''' [Apseudomorpha](/source/Apseudomorpha) ** Superfamily [Apseudoidea](/source/Apseudoidea) Leach, 1814 (incl. former superfamily Jurapseudoidea{{Cite journal|author1=Richard W. Heard |author2=Andrés G. Morales-Núñez |author3=María de Lourdes Serrano-Sánchez |author4=Marco A. Coutiño |author5=Ricardo Barragán |author6=Francisco J. Vega |year=2020 |title=A new family, genus and species of Tanaidacea (Crustacea; Apseudomorpha) from the Lower Cretaceous (Aptian) of Chiapas, Mexico: Systematic revisions, including designation of two new Paleozoic families, and paleoenvironmental observations |journal=Journal of South American Earth Sciences |volume=102 |article-number=102609 |doi=10.1016/j.jsames.2020.102609 |doi-access=free }}) *** Family [Apseudellidae](/source/Apseudellidae) Gutu, 1972 *** Family [Apseudidae](/source/Apseudidae) Leach, 1814 *** Family [Eucryptocaridae](/source/Eucryptocaridae) Heard et al. 2020 *** Family [Gigantapseudidae](/source/Gigantapseudidae) Kudinova-Pasternak, 1978 *** Family [Jurapseudidae](/source/Jurapseudidae) † Schram, Sieg & Malzahn, 1986 *** Family [Kalliapseudidae](/source/Kalliapseudidae) Lang, 1956 *** Family [Metapseudidae](/source/Metapseudidae) Lang, 1970 *** Family [Numbakullidae](/source/Numbakullidae) Gutu & Heard, 2002 *** Family [Ophthalmapseudidae](/source/Ophthalmapseudidae) Heard et al. 2020 *** Family [Pagurapseudidae](/source/Pagurapseudidae) Lang, 1970 *** Family [Pagurapseudopsididae](/source/Pagurapseudopsididae) Gutu, 2006 *** Family [Parapseudidae](/source/Parapseudidae) Gutu, 1981 *** Family [Protoapseudoidae](/source/Protoapseudoidae) Heard et al. 2020 *** Family [Sphaeromapseudidae](/source/Sphaeromapseudidae) Larsen, 2012 *** Family [Sphyrapodidae](/source/Sphyrapodidae) Gutu, 1980 *** Family [Tanzanapseudidae](/source/Tanzanapseudidae) Bacescu, 1975 *** Family [Whiteleggiidae](/source/Whiteleggiidae) Gutu, 1972 *** Genus ''[Palaeotanais](/source/Palaeotanais)'' † Reiff, 1936 ** Superfamily [Cretitanaoidea](/source/Cretitanaoidea) † Schram, Sieg, Malzahn, 1983 *** Family [Cretitanaidae](/source/Cretitanaidae) † Schram, Sieg & Malzahn, 1986 * '''Suborder''' [Tanaidomorpha](/source/Tanaidomorpha) ** Superfamily [Neotanaoidea](/source/Neotanaoidea) Sieg, 1980 *** Family [Neotanaidae](/source/Neotanaidae) Lang, 1956 ** Superfamily [Paratanaoidea](/source/Paratanaoidea) Lang, 1949 *** Family [Agathotanaidae](/source/Agathotanaidae) Lang, 1971 *** Family [Akanthophoreidae](/source/Akanthophoreidae) Sieg, 1986 *** Family [Alavatanaidae](/source/Alavatanaidae) † Vonk & Schram, 2007 *** Family [Anarthruridae](/source/Anarthruridae) Lang, 1971 *** Family [Colletteidae](/source/Colletteidae) Larsen & Wilson, 2002 *** Family [Cryptocopidae](/source/Cryptocopidae) Sieg, 1977 *** Family [Heterotanoididae](/source/Heterotanoididae) Bird, 2012 *** Family [Leptocheliidae](/source/Leptocheliidae) Lang, 1973 *** Family [Leptognathiidae](/source/Leptognathiidae) Sieg, 1976 *** Family [Mirandotanaidae](/source/Mirandotanaidae) Blazewicz-Paszkowycz & Bamber, 2009 *** Family [Nototanaidae](/source/Nototanaidae) Sieg, 1976 *** Family [Paratanaidae](/source/Paratanaidae) Lang, 1949 *** Family [Pseudotanaidae](/source/Pseudotanaidae) Sieg, 1976 *** Family [Pseudozeuxidae](/source/Pseudozeuxidae) Sieg, 1982 *** Family [Tanaellidae](/source/Tanaellidae) Larsen & Wilson, 2002 *** Family [Tanaissuidae](/source/Tanaissuidae) Bird & Larsen, 2009 *** Family [Tanaopsidae](/source/Tanaopsidae) Błażewicz-Paszkowycz & Bamber, 2012 *** Family [Teleotanaidae](/source/Teleotanaidae) Bamber, 2008 *** Family [Typhlotanaidae](/source/Typhlotanaidae) Sieg, 1984 ** Superfamily [Tanaidoidea](/source/Tanaidoidea) Nobili, 1906 *** Family [Tanaididae](/source/Tanaididae) Nobili, 1906 {{div col end}} ==References== {{Portal|Crustaceans}} {{Reflist}} ==External links== {{Wikispecies-inline}} {{Malacostraca}} {{Taxonbar|from=Q72506}} {{Authority control}} Category:Tanaidacea Category:Crustacean orders --- Adapted from the Wikipedia article [Tanaidacea](https://en.wikipedia.org/wiki/Tanaidacea) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Tanaidacea?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.