Tantulocarida | |
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Microdajus sp. | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Superclass: | Multicrustacea |
Class: | Tantulocarida G. A. Boxshall & R. J. Lincoln, 1983 [1] |
Families | |
Tantulocarida is a highly specialised group of parasitic crustaceans that consists of about 33 species, treated as a class in superclass Multicrustacea. They are typically ectoparasites that infest copepods, isopods, tanaids, amphipods and ostracods. [2] [3]
This section needs expansion. You can help by adding to it. (November 2024) |
In the Tantulocarida, animals do not ever present eyes. [4]
The tantulus larvae has a head with a ventral oral disc but no appendages, a six-segmented thorax with six pairs of legs, and a limbless abdomen consisting of one to six segments in addition to a telson. [5]
Members of this subclass are minute – less than 0.3 millimetres (0.012 in) in length and have a dramatic reduction in body form compared to other crustaceans, with an unsegmented, sac-like thorax and a much reduced abdomen. [6] One tantulocarid species, Tantulacus dieteri, is the world's smallest arthropod, with a total body length of only 85 micrometres (0.0033 in). [7]
This section needs expansion. You can help by adding to it. (June 2018) |
The tantulocarid life cycle is unique among crustaceans. The tantulus larva transforms directly from a non-feeding (lecithotrophic) and free-swimming organism into a parasite without any instars. When entering the parasitic stage much of the body, such as the muscles, degenerates, even if the body itself becomes bigger. As a parasite it is permanently attached to its host, and after piercing its host's cuticle with an unpaired stylet, a rootlet system used to absorb nutrients enters through the hole and grow into the host’s tissue. The adult form develops inside the larva, and can become either a sac-like parthenogenetic female, or a fully developed free-living, non-feeding and sexually-reproducing male or female. [8] [9] [10] [11] [12] The eggs inside the parthenogenetic female are eventually released as fully developed tantulus larvae. The finding of what appears to be a benthic non-feeding nauplius larva suggests that eggs produced by sexual females hatch as nauplii instead of tantulus larvae. Both the parthenogenetic and sexual females are semelparous. [13]
Five families are recognised: [14]
Basipodellidae Boxshall & Lincoln, 1983: [15]
Doryphallophoridae Huys, 1991: [16]
Microdajidae Boxshall & Lincoln, 1987: [17]
| Cumoniscidae Nierstrasz & Brender à Brandis, 1923 (formerly family Deoterthridae: [18]
Onceroxenidae Huys, 1991: [19]
|
Copepods are a group of small crustaceans found in nearly every freshwater and saltwater habitat. Some species are planktonic, some are benthic, several 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.
The family Argulidae, whose members are commonly known as carp lice or fish lice, are parasitic crustaceans in the class Ichthyostraca. It is the only family in the monotypic subclass Branchiura and the order Arguloida, although a second family, Dipteropeltidae, has been proposed. Although they are thought to be primitive forms, they have no fossil record.
Cumoniscidae is a family of crustaceans in the class Tantulocarida, classified under the superclass Multicrustacea. The family was previously known as Deoterthridae, but Cumoniscidae was determined to be senior subjective synonym.
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.
Poecilostomatoida is a suborder of copepods. Although it was previously considered a separate order.
Murunducaris is a genus of crustacean in family Parastenocarididae. It contains the following species:
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 endopods of the legs and antennae. The closest relatives of Paralubbockia are the family Oncaeidae. Initially placed among the Poecilostomatoida, Paralubbockia is now considered part of the Cyclopoida.
Stygotantulus is a genus of crustacean with the sole species Stygotantulus stocki. It lives as an ectoparasite on harpacticoid copepods of the families Tisbidae and Canuellidae. It may be the smallest arthropod in the world, at a length of less than 0.1 millimetres (0.004 in). The specific name stocki commemorates Jan Hendrik Stock, a Dutch carcinologist.
Centropagidae is a family of copepods in the order Calanoida. Its members are particularly known as plankton in coastal waters and in fresh water in Australia and southern South America. They are also found on subantarctic islands and in lakes in Antarctica.
Karllangia is a genus of marine copepods. Its name commemorates the Swedish carcinologist Karl Georg Herman Lang. The genus contains five species:
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.
Cletocamptus is a genus of marine and brackish-water copepods, containing the following species:
Tegastidae is a family of copepods, which are characterised by having laterally compressed bodies, a claw-like mandible in the nauplius stage, and by a modified male genital complex. 85 species have been described in 6 genera. Two species of Smacigastes are found at hydrothermal vents, while the remaining species are found in shallow water, associated with algae, bryozoans and cnidarians, such as corals.
Lernaeocera branchialis, sometimes called cod worm, is a parasite of marine fish, found mainly in the North Atlantic. It is a marine copepod which starts life as a small pelagic crustacean larva. It is among the largest of copepods, ranging in size from 2 to 3 millimetres when it matures as a copepodid larva to more than 40 mm as a sessile adult.
Gaussia is a genus of copepods. The genus contains bioluminescent species. It is a "characteristic genus of the mesopelagial", occurring at depths of 0–3,000 metres (0–9,843 ft). The genus Gaussia contains the following species:
Geoffrey Allan Boxshall FRS is a British zoologist, and Merit researcher at the Natural History Museum, working primarily on copepods.
Archidactylina is a genus of copepods that contains only the species Archidactylina myxinicola, and is the only genus in the family Archidactylinidae. It is a parasite of the gill pouches of two species of hagfish found in Japanese waters, Eptatretus okinoseanus and Myxine garmani.
The clade Multicrustacea constitutes the largest superclass of crustaceans, containing approximately four-fifths of all described non-hexapod 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.
Hutchinsoniella macracantha is a species of crustacean known as a horseshoe shrimp. It is the only species in the genus Hutchinsoniella and was first described in 1955 by Howard L. Sanders, having been discovered in Long Island Sound; they were the first example of a new class of crustacean that was given the name Cephalocarida.
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.