Harpacticoida is an
order
Order, ORDER or Orders may refer to:
* A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica
* Categorization, the process in which ideas and objects are recognized, differentiated, and understood
...
of
copepod
Copepods (; meaning 'oar-feet') are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (living in the water column), some are benthos, benthic (living on the sedimen ...
s, in the
subphylum
In zoological nomenclature, a subphylum is a taxonomic rank below the rank of phylum.
The taxonomic rank of " subdivision" in fungi and plant taxonomy is equivalent to "subphylum" in zoological taxonomy. Some plant taxonomists have also used th ...
Crustacea
Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...
. This order comprises 463
genera
Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...
and about 3,000
species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
; its members are
benthic
The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". ...
copepod
Copepods (; meaning 'oar-feet') are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (living in the water column), some are benthos, benthic (living on the sedimen ...
s found throughout the world in the marine environment (most families) and in
fresh water
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salt (chemistry), salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include ...
(essentially the
Ameiridae
Ameiridae is a family of crustaceans belonging to the order Harpacticoida
Harpacticoida is an Order (biology), order of copepods, in the subphylum Crustacean, Crustacea. This order comprises 463 genus, genera and about 3,000 species; its membe ...
,
Parastenocarididae
Parastenocarididae is a family of copepods in the order Harpacticoida adapted to life in groundwater
Groundwater is the water present beneath Earth's surface in rock and Pore space in soil, soil pore spaces and in the fractures of stratum, ro ...
and the
Canthocamptidae
Canthocamptidae is a family (biology), family of copepods. Most of the 700 species are confined to fresh water, although there are also marine species. It contains the following genera:
*''Afrocamptus'' Chappuis, 1932
*''Antarctobiotus'' Chappui ...
). A few of them are
plankton
Plankton are the diverse collection of organisms that drift in Hydrosphere, water (or atmosphere, air) but are unable to actively propel themselves against ocean current, currents (or wind). The individual organisms constituting plankton are ca ...
ic or live in association with other organisms. Harpacticoida represents the second-largest
meiofauna
Meiobenthos, also called meiofauna, are small benthic invertebrates that live in marine or freshwater environments, or both. The term ''meiofauna'' loosely defines a group of organisms by their sizelarger than microfauna but smaller than macrof ...
l group in
marine sediment
Marine sediment, or ocean sediment, or seafloor sediment, are deposits of insoluble particles that have accumulated on the seafloor. These particles either have their origins in soil and Rock (geology), rocks and have been Sediment transport, ...
s, after
nematode
The nematodes ( or ; ; ), roundworms or eelworms constitute the phylum Nematoda. Species in the phylum inhabit a broad range of environments. Most species are free-living, feeding on microorganisms, but many are parasitic. Parasitic worms (h ...
s. In Arctic and Antarctic seas, Harpacticoida are common inhabitants of
sea ice
Sea ice arises as seawater freezes. Because ice is less density, dense than water, it floats on the ocean's surface (as does fresh water ice). Sea ice covers about 7% of the Earth's surface and about 12% of the world's oceans. Much of the world' ...
. The name Harpacticoida comes from the Greek noun ''harpacticon'' (rapacious predator) and the suffix ''-oid'' (akin to) and means ''reminiscent of a predator'' .
Harpacticoids are distinguished from other copepods by the presence of only a very short pair of first
antennae. The second pair of antennae are biramous, and the major joint within the body is located between the fourth and fifth body segments. They typically have a wide
abdomen
The abdomen (colloquially called the gut, belly, tummy, midriff, tucky, or stomach) is the front part of the torso between the thorax (chest) and pelvis in humans and in other vertebrates. The area occupied by the abdomen is called the abdominal ...
, and often have a somewhat worm-like body.
Families
53 families are currently recognised in the Harpacticoida:
*
Adenopleurellidae
Adenopleurellidae is a family of crustaceans belonging to the order Harpacticoida
Harpacticoida is an Order (biology), order of copepods, in the subphylum Crustacean, Crustacea. This order comprises 463 genus, genera and about 3,000 species; i ...
*
Aegisthidae
*
Ameiridae
Ameiridae is a family of crustaceans belonging to the order Harpacticoida
Harpacticoida is an Order (biology), order of copepods, in the subphylum Crustacean, Crustacea. This order comprises 463 genus, genera and about 3,000 species; its membe ...
*
Ancorabolidae
*
Arenopontiidae
*
Argestidae
*
Balaenophilidae
*
Canthocamptidae
Canthocamptidae is a family (biology), family of copepods. Most of the 700 species are confined to fresh water, although there are also marine species. It contains the following genera:
*''Afrocamptus'' Chappuis, 1932
*''Antarctobiotus'' Chappui ...
*
Chappuisiidae
*
Cletodidae
Cletodidae is a family of copepods belonging to the order Harpacticoida
Harpacticoida is an Order (biology), order of copepods, in the subphylum Crustacean, Crustacea. This order comprises 463 genus, genera and about 3,000 species; its members ...
*
Cletopsyllidae
Cletopsyllidae is a family of crustaceans belonging to the order Harpacticoida
Harpacticoida is an Order (biology), order of copepods, in the subphylum Crustacean, Crustacea. This order comprises 463 genus, genera and about 3,000 species; its ...
*
Cristacoxidae
Cristacoxidae is a family of crustaceans belonging to the order Harpacticoida
Harpacticoida is an Order (biology), order of copepods, in the subphylum Crustacean, Crustacea. This order comprises 463 genus, genera and about 3,000 species; its m ...
*
Cylindropsyllidae
Cylindropsyllidae is a family of copepods belonging to the order Harpacticoida
Harpacticoida is an Order (biology), order of copepods, in the subphylum Crustacean, Crustacea. This order comprises 463 genus, genera and about 3,000 species; its ...
*
Dactylopusiidae
Dactylopusiidae is a family of copepods belonging to the order Harpacticoida
Harpacticoida is an Order (biology), order of copepods, in the subphylum Crustacean, Crustacea. This order comprises 463 genus, genera and about 3,000 species; its me ...
*
Darcythompsoniidae
Darcythompsoniidae is a family (biology), family of copepods, containing four genera. Members of the family have a very wide distribution throughout the tropics, where they live in rotting mangrove leaves. They lack egg sacs and are thought to la ...
*
Ectinosomatidae
*
Hamondiidae
*
Harpacticidae
*
Idyanthidae
*
Laophontidae
*
Laophontopsidae
*
Latiremidae
*
Leptastacidae
*
Leptopontiidae
*
Louriniidae
*
Metidae
*
Miraciidae
Miraciidae is a family (biology), family of copepods in the family Miraciidae.
Subdivisions
The World Register of Marine Species lists the following genera as accepted within Miraciidae, subdivided into three subfamilies.
References
...
*
Nannopodidae
*
Neobradyidae
*
Normanellidae
*
Novocriniidae
*
Orthopsyllidae
*
Parameiropsidae
*
Paramesochridae
*
Parastenheliidae
*
Parastenocarididae
Parastenocarididae is a family of copepods in the order Harpacticoida adapted to life in groundwater
Groundwater is the water present beneath Earth's surface in rock and Pore space in soil, soil pore spaces and in the fractures of stratum, ro ...
*
Peltidiidae
*
Phyllognathopodidae
*
Pontostratiotidae
*
Porcellidiidae
*
Protolatiremidae
*
Pseudotachidiidae
*
Rhizothricidae
*
Rometidae
*
Rotundiclipeidae
*
Superornatiremidae
*
Tachidiidae
*
Tegastidae
*
Tetragonicipitidae
*
Thalestridae
*
Thompsonulidae
*
Tisbidae
*
Zosimeidae
References
External links
Harpacticoida, Guide to the marine zooplankton of south eastern AustraliaTasmanian Aquaculture and Fisheries Institute*
{{Authority control
Crustacean orders