Poecilostomatoida are an suborder of

copepods Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat. Some species are planktonic (inhabiting sea waters), some are benthic (living on the ocean floor), a number of species have p ...

. Although it was previously considered a separate order, recent research showed it to be nested within the Cyclopoida

Description

The classification of these copepods has been established on the basis of the structure of the mouth. In poecilostomatoids the mouth is represented by a transverse slit, partially covered by the overhanging labrum which resembles an upper lip. Although there is variability in the form of the mandible among poecilostomatoids, it can be generalized as being falcate ( sickle-shaped). The

antennule Antennae ( antenna), sometimes referred to as "feelers", are paired appendages used for sensing in arthropods. Antennae are connected to the first one or two segments of the arthropod head. They vary widely in form but are always made of one o ...

s are frequently reduced in size and the

antenna Antenna ( antennas or antennae) may refer to: Science and engineering * Antenna (radio), also known as an aerial, a transducer designed to transmit or receive electromagnetic (e.g., TV or radio) waves * Antennae Galaxies, the name of two collid ...

e modified to terminate in small hooks or claws that are used in attachment to host organisms.

Life cycle

As with many crustaceans, larval development is metamorphic with immature forms differing greatly from those of adults. Embryos are carried in paired or single sacs attached to first abdominal somite (as seen in the illustration of the female ''

Sapphirina darwinii ''Sapphirina darwinii'' is a species of parasitic copepod. It is widespread and common in the Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It i ...

'' above right).

Ecology

Most poecilostomatoid copepods are

ectoparasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...

s of saltwater fish or invertebrates (including among the latter

mollusks Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

and echinoderms). They usually attach to the external surface of the host, in the throat-mouth cavity, or the gills. One family of poecilostomatoid copepods, however, have evolved an

endoparasitic Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has c ...

mode of life and live deep within their hosts' bodies rather than merely attaching themselves to exterior and semi-exterior surface tissue. In addition to typical marine environments, poecilostomatoid copepods may be found in such very particular habitats as anchialine caves and deep sea vents (both

hydrothermal vents A hydrothermal vent is a fissure on the seabed from which geothermally heated water discharges. They are commonly found near volcanically active places, areas where tectonic plates are moving apart at mid-ocean ridges, ocean basins, and hotspot ...

and cold seeps). Here, many primitive associated copepods belonging to the Poecilostomatoida and Siphonostomatoida and have been found. Representatives of one Poecilostomatoida family have successfully made the transition to

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...

habitats and host animals therein. Oncaea venusta

List of families

There are over sixty families currently recognized within the group: * Abrsiidae * Anchimolgidae * Anomoclausiidae *

Antheacheridae Antheacheridae is a family of cyclopoid copepods in the order Cyclopoida The Cyclopoida are an order of small crustaceans from the subclass Copepoda. Like many other copepods, members of Cyclopoida are small, planktonic animals living both in ...

* Anthessiidae *

Bomolochidae Bomolochidae is a family (biology), family of copepods parasitic on marine fishes. Most species parasitize the gills of fish, but some species live in the nostrils or on the eyes of their hosts. The family contains just over 150 species from the ...

* Bradophilidae * Catiniidae * Chondracanthidae *

Clausidiidae Clausidiidae is a Family (biology), family of parasitic copepods in the order (biology), order Cyclopoida, containing the following genera: *''Cemihyclops'' Karanovic, 2008 *''Clausidium'' Kossmann, 1875 *''Conchyliurus'' Bocquet & Stock, 1957 * ...

* Clausiidae * Corallovexiidae *

Corycaeidae Corycaeidae is a family of cyclopoid copepods in the order Cyclopoida. There are about 10 genera and more than 70 described species in Corycaeidae. Genera These 10 genera belong to the family Corycaeidae: * '' Agetus'' Krøyer, 1849 * '' Coryca ...

Echiurophilidae ''Echiurophilus'' is a genus of cyclopoid copepods in the family Echiurophilidae, the sole genus of the family. There are at least two described species in ''Echiurophilus''. Species These two species belong to the genus ''Echiurophilus'': * '' ...

Entobiidae ''Entobius'' is a genus of crustaceans belonging to the monotypic family Entobiidae. The species of this genus are found in Western Europe and Northern America. Species: *''Entobius euelpis'' *''Entobius hamondi'' *''Entobius loimiae'' *''E ...

Erebonasteridae Erebonasteridae is a family of crustaceans belonging to the order Cyclopoida. Genera: * '' Ambilimbus'' Ivanenko, Defaye & Huys, 2005 * '' Centobnaster'' Huys & Boxshall, 1990 * '' Erebonaster'' Humes, 1987 * '' Nansennaster'' Martínez Arbizu ...

* Ergasilidae * Eunicicolidae * Gadilicolidae * Gastrodelphyidae *

Herpyllobiidae Herpyllobiidae is a family of cyclopoid copepods in the order Cyclopoida. There are about 6 genera and more than 20 described species in Herpyllobiidae. Genera These six genera belong to the family Herpyllobiidae: * ''Eurysilenium'' M. Sars, 187 ...

Intramolgidae ''Intramolgus'' is a monotypic genus of crustaceans belonging to the monotypic family Intramolgidae. The only species is ''Intramolgus arcticus''. The species is found in the White Sea. References {{Taxonbar, from=Q18606932 Cyclopoida ge ...

Iveidae Iveidae is a family of copepods belonging to the order Cyclopoida. Genera: * '' Ive'' Mayer, 1879 * ''Ubius ''Ubius'' is a monotypic genus of copepods Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every f ...

* Jasmineiricolidae * Kelleriidae *

Lamippidae Lamippidae is a family of copepods belonging to the order Cyclopoida. Genera: * ''Enalcyonium'' Olsson, 1869 * ''Gorgonophilus'' Buhl-Mortensen & Mortensen, 2004 * ''Isidicola'' Gravier, 1914 * ''Lamipella'' Bouligand & Delamare Deboutteville, 1 ...

* Leaniricolidae *

Lichomolgidae Lichomolgidae is a family of copepods Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat. Some species are planktonic (inhabiting sea waters), some are benthic (living on the ...

* Lubbockiidae *

Macrochironidae Macrochironidae is a family of copepods belonging to the order Cyclopoida. Genera: * ''Macrochiron'' Brady, 1872 * ''Oncaeola'' Kramer, 1895 * ''Paramacrochiron'' Sewell, 1949 * ''Pseudomacrochiron'' Reddiah, 1969 * ''Sewellochiron'' Humes, 1969 ...

* Makrostrotidae *

Mesoglicolidae ''Mesoglicola'' is a monotypic genus of crustaceans belonging to the monotypic family Mesoglicolidae. The only species is ''Mesoglicola delagei''. The species is found in Western Europe. References {{Taxonbar, from=Q18607495 Cyclopoida C ...

* Myicolidae * Mytilicolidae * Nereicolidae *

Octopicolidae ''Octopicola'' is a genus of crustaceans belonging to the monotypic family Octopicolidae. The genus has almost cosmopolitan distribution. Species: *''Octopicola huanghaiensis'' *''Octopicola regalis'' *''Octopicola stocki'' *''Octopicola su ...

Oncaeidae Oncaeidae is a family of copepods, containing the following genera: *'' Archioncaea'' Böttger-Schnack & Huys, 1997 *'' Conaea'' Giesbrecht, 1891 *'' Epicalymma'' Heron, 1977 *'' Monothula'' Böttger-Schnack & Huys, 2001 *''Oncaea ''Oncaea'' ...

Paralubbockiidae ''Paralubbockia longipedia'' is a species of copepod, and the only member of the family Paralubbockiidae. The family is characterised by the ventral position of the fifth legs, the possession of a separate maxillary palp, and the form of the e ...

* Philichthyidae * Philoblennidae * Phyllodicolidae * Pionodesmotidae * Polyankyliidae *

Pseudanthessiidae Pseudanthessiidae is a family of cyclopoid copepods in the order Cyclopoida. There are about 7 genera and more than 60 described species in Pseudanthessiidae. Genera These seven genera belong to the family Pseudanthessiidae: * '' Mecomerinx'' H ...

* Rhynchomolgidae * Sabelliphilidae *

Saccopsidae Saccopsidae is a family of copepods belonging to the order Cyclopoida. Genera: * ''Euchonicola'' Boxshall, O'Reilly, Sikorski & Summerfield, 2019 * ''Euchonicoloides'' Boxshall, O'Reilly, Sikorski & Summerfield, 2019 * ''Lanassicola'' Boxshall, ...

Sapphirinidae Sapphirinidae is a family of parasitic copepods in the order Cyclopoida. Description Males come in a variety of bright and flashy colors. In contrast, the females are transparent. The reason for this sexual dimorphism is that males need to at ...

Serpulidicolidae Serpulidicolidae is a family of crustaceans belonging to the order Cyclopoida. Genera: * ''Abyssotaurus'' Brenke, Fanenbruck & George, 2018 * ''Parangium'' Humes, 1985 * ''Rhabdopus'' Southward, 1964 * ''Rhynchopus (crustacean), Rhynchopus'' Sto ...

Shiinoidae Shiinoidae is a Family (biology), family of parasitism, parasitic copepods found on marine Teleost, teleosts. Description The family Shiinoidae consists of nine species of morphologically unusual copepods that parasitize marine teleosts. The b ...

* Spiophanicolidae *

Splanchnotrophidae Splanchnotrophidae is a family of cyclopoid copepods in the order Cyclopoida. There are about 7 genera and more than 30 described species in Splanchnotrophidae. Genera These seven genera belong to the family Splanchnotrophidae: * ''Arthurius'' H ...

* Strepidae * Synapticolidae * Synaptiphilidae * Taeniacanthidae * Telsidae * Thamnomolgidae * Tuccidae * Umazurcolidae *

Urocopiidae ''Urocopia'' is a genus of cyclopoid copepods in the family Urocopiidae, the sole genus of the family. There are at least three described species in ''Urocopia''. Species These three species belong to the genus ''Urocopia'': * ''Urocopia deeveya ...

* Vahiniidae * Ventriculinidae *

Xarifiidae Xarifiidae is a family of cyclopoid copepods in the order Cyclopoida. There are about 5 genera and more than 90 described species in Xarifiidae. Genera These five genera belong to the family Xarifiidae: * ''Botegokika'' Ho, Cheng & Dai, 2013 * ' ...

Xenocoelomatidae Xenocoelomatidae is a family of cyclopoid copepods in the order Cyclopoida. There are at least two genera and four described species in Xenocoelomatidae. Genera These two genera belong to the family Xenocoelomatidae: * '' Aphanodomus'' C. B. Wi ...

References

External links

* * {{Taxonbar, from=Q2344407 Copepods Arthropod suborders