Polyarthra | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Copepoda |
Superorder: | Podoplea |
Order: | Polyarthra Lang, 1944 |
Polyarthra is an order of copepods belonging to the class Copepoda. [1] [2]
There are two families recognised in the order Polyarthra: [1] [2]
Herring are forage fish, mostly belonging to the family of Clupeidae.
Copepods are a group of small crustaceans found in nearly every freshwater and saltwater habitat. Some species are planktonic, some are benthic, a number of species have parasitic phases, and some continental species may live in limnoterrestrial habitats and other wet terrestrial places, such as swamps, under leaf fall in wet forests, bogs, springs, ephemeral ponds, puddles, damp moss, or water-filled recesses of plants (phytotelmata) such as bromeliads and pitcher plants. Many live underground in marine and freshwater caves, sinkholes, or stream beds. Copepods are sometimes used as biodiversity indicators.
Pseudophyllid cestodes are tapeworms with multiple "segments" (proglottids) and two bothria or "sucking grooves" as adults. Proglottids are identifiably pseudophyllid as the genital pore and uterine pore are located on the mid-ventral surface, and the ovary is bilobed ("dumbbell-shaped").
Harpacticoida is an order of copepods, in the subphylum Crustacea. This order comprises 463 genera and about 3,000 species; its members are benthic copepods found throughout the world in the marine environment and in fresh water. A few of them are planktonic or live in association with other organisms. Harpacticoida represents the second-largest meiofaunal group in marine sediments, after nematodes. In Arctic and Antarctic seas, Harpacticoida are common inhabitants of sea ice. The name Harpacticoida comes from the Greek noun harpacticon and the suffix -oid and means reminiscent of a predator.
Siphonostomatoida is an order of copepods, containing around 75% of all the copepods that parasitise fishes. Their success has been linked to their possession of siphon-like mandibles and of a "frontal filament" to aid attachment to their hosts. Most are marine, but a few live in fresh water. There are 40 recognised families:
Calanoida is an order of copepods, a group of arthropods commonly found as zooplankton. The order includes around 46 families with about 1800 species of both marine and freshwater copepods between them.
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 the sea and in freshwater habitats. They are capable of rapid movement. Their larval development is metamorphic, and the embryos are carried in paired or single sacs attached to first abdominal somite.
Dracunculus medinensis is a nematode that causes dracunculiasis, also known as guinea worm disease. The disease is caused by the female which, at around 80 centimetres in length, is among the longest nematodes infecting humans. In contrast, the longest recorded male Guinea worm is only 4 cm.
Poecilostomatoida is a suborder of copepods. Although it was previously considered a separate order, recent research showed it to be nested within the Cyclopoida.
Cyclopidae is a family of copepods containing more than half of the 1,200 species in the order Cyclopoida in over 70 genera.
Monstrilloida is an order of copepods with a cosmopolitan distribution in the world's oceans. The order contains a single family, Monstrillidae. The name of the first ever described genus Monstrilla is derived from latin, meaning "tiny monster", because the lack of usual diagnostic features of copepods puzzled early taxonomists.
The San Francisco Estuary together with the Sacramento–San Joaquin River Delta represents a highly altered ecosystem. The region has been heavily re-engineered to accommodate the needs of water delivery, shipping, agriculture, and most recently, suburban development. These needs have wrought direct changes in the movement of water and the nature of the landscape, and indirect changes from the introduction of non-native species. New species have altered the architecture of the food web as surely as levees have altered the landscape of islands and channels that form the complex system known as the Delta.
Forage fish, also called prey fish or bait fish, are small pelagic fish which are preyed on by larger predators for food. Predators include other larger fish, seabirds and marine mammals. Typical ocean forage fish feed near the base of the food chain on plankton, often by filter feeding. They include particularly fishes of the order Clupeiformes, but also other small fish, including halfbeaks, silversides, smelt such as capelin and goldband fusiliers.
Syndinium is a cosmopolitan genus of parasitic dinoflagellates that infest and kill marine planktonic species of copepods and radiolarians. Syndinium belongs to order Syndiniales, a candidate for the uncultured group I and II marine alveolates. The lifecycle of Syndinium is not well understood beyond the parasitic and zoospore stages.
Gelyella is a genus of freshwater copepods. They live in groundwater in karstic areas of southern France and western Switzerland. The two species are the only members of the family Gelyellidae and, although previously placed in the order Harpacticoida, a new order, Gelyelloida, was erected for this family alone.
Misophrioida is an order of copepods, containing the following families:
The clade Multicrustacea constitutes the largest superclass of crustaceans, containing approximately four-fifths of all described crustacean species, including crabs, lobsters, crayfish, shrimp, krill, prawns, woodlice, barnacles, copepods, amphipods, mantis shrimp and others. The largest branch of multicrustacea is the class Malacostraca.
Diphyllobothriidea is an order of Cestoda (tapeworms). Members of this order are gut parasites of vertebrates. They infect mammals as their definitive hosts and use either copepods or both copepods and fish as in the broadfish tapeworm as intermediate hosts.
Longipedia is a genus of marine copepods of the family Longipediidae, order Canuelloida.
Mesocyclops longisetus is a species of freshwater copepod in the family Cyclopidae. Two subspecies are accepted, Mesocyclops longisetus curvatus Dussart, 1987, and Mesocyclops longisetus longisetus. It has a neotropical distribution.