{{Short description|Order of crustaceans}} {{Automatic taxobox | image = Copepodkils.jpg | image_caption = Unidentified species of copepod in the order Calanoida. | display_parents = 2 | parent_authority = [[Wilhelm Giesbrecht|Giesbrecht]], 1882&nbsp;<ref name="Martin & Davis">{{cite book |url=http://atiniui.nhm.org/pdfs/3839/3839.pdf |title=An Updated Classification of the Recent Crustacea |author=J. W. Martin & G. E. Davis |year=2001 |publisher=[[Natural History Museum of Los Angeles County]] |url-status=dead |archive-url=https://web.archive.org/web/20190908234116/https://atiniui.nhm.org/pdfs/3839/3839.pdf |archive-date=8 September 2019}}</ref> | taxon = Calanoida | authority = [[Georg Ossian Sars|Sars]], 1903 | subdivision_ranks = Families | subdivision = See text }}

'''Calanoida''' is an [[order (biology)|order]] of [[copepod]]s, a group of arthropods commonly found as [[zooplankton]]. The order includes around 46 families with about 1800 species of both marine and [[fresh water|freshwater]] [[copepod]]s between them.<ref name="Mauchline"/>

== Description == Calanoids can be distinguished from other planktonic copepods by having first [[antenna (biology)|antennae]] at least half the length of the body and [[Arthropod leg#Biramous and uniramous|biramous]] second antennae.<ref name="Mauchline"/> However, their most distinctive anatomical trait is the presence of a joint between the fifth and sixth body segments.<ref name="IZ">{{cite book|author=Barnes|first=Robert D.|title=Invertebrate Zoology|publisher=Holt-Saunders International|year=1982|isbn=0-03-056747-5|location=Philadelphia, Pennsylvania|page=692}}</ref> The largest specimens reach {{convert|18|mm}} long, but most do not exceed {{convert|0.5|-|2.0|mm|2|abbr=on}} long.<ref name="Mauchline"/>

== Classification == The order Calanoida contains the following families:<ref>{{Cite web |title=WoRMS - World Register of Marine Species - Calanoida |url=https://www.marinespecies.org/aphia.php?p=taxdetails&id=1100 |access-date=8 December 2024 |website=www.marinespecies.org}}</ref>

{{Div col|colwidth=13em}} * [[Acartiidae]] * [[Aetideidae]] * [[Arctokonstantinidae]] * [[Arietellidae]] * [[Augaptilidae]] * [[Bathypontiidae]] * [[Calanidae]] * [[Candaciidae]] * [[Centropagidae]] * [[Clausocalanidae]] * [[Diaixidae]] * [[Diaptomidae]] * [[Discoidae]] * [[Epacteriscidae]] * [[Eucalanidae]] * [[Euchaetidae]] * [[Fosshageniidae]] * [[Heterorhabdidae]] * [[Hyperbionycidae]] * [[Kyphocalanidae]] * [[Lucicutiidae]] * [[Megacalanidae]] * [[Mesaiokeratidae]] * [[Metridinidae]] * [[Nullosetigeridae]] * [[Paracalanidae]] * [[Parapontellidae]] * [[Parkiidae]] * [[Phaennidae]] * [[Pontellidae]] * [[Pseudocyclopidae]] * [[Pseudocyclopiidae]] * [[Pseudodiaptomidae]] * [[Rhincalanidae]] * [[Rostrocalanidae]] * [[Ryocalanidae]] * [[Scolecitrichidae]] * [[Spinocalanidae]] * [[Stephidae]] * [[Sulcanidae]] * [[Temoridae]] * [[Tharybidae]] * [[Tortanidae]] {{Div col end}}

== Ecology == Calanoid copepods are the dominant animals in the [[plankton]] in many parts of the world's oceans, making up 55–95% of plankton samples.<ref name="Mauchline">{{cite book|author=Mauchline|first=John|chapter-url=https://books.google.com/books?id=fbsrq6CvYkAC&pg=PA4|title=The Biology of Calanoid Copepods|publisher=[[Elsevier]]|year=1998|isbn=978-0-12-105545-5|series=Advances in Marine Biology|volume=33|pages=1–15|chapter=Introduction}}</ref> They are therefore important in many food webs, taking in energy from [[phytoplankton]] and [[algae]] and 'repackaging' it for consumption by higher [[trophic level]] predators.<ref name="Mauchline"/> Many commercial fish are dependent on calanoid copepods for diet in either their [[larva]]l or adult forms. [[Baleen whale]]s such as [[bowhead whale]]s, [[sei whale]]s, [[right whale]]s and [[fin whale]]s rely substantially on calanoid copepods as a food source.<ref name="Mauchline"/>

== References == {{Reflist}}

== External links == *{{Commons category-inline|Calanoida}} *{{Wikispecies-inline|Calanoida}} * [https://web.archive.org/web/20111004050233/http://www.tafi.org.au/zooplankton/imagekey/copepoda/calanoida/ Calanoida fact sheet – guide to the marine zooplankton of south eastern Australia] * [http://www.miljolare.no/data/ut/art/?lang=eng&or_id=1879 Classification of Calanoida] * [https://web.archive.org/web/20130618054223/http://www.crustacea.net/crustace/calanoida/ Key to calanoid copepod families]

{{Plankton}} {{Taxonbar|from1=Q478553|from2=Q15875987}} {{Authority control}}

[[Category:Calanoida| ]] [[Category:Crustacean orders]]