Glyptonotus antarcticus | |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Subphylum: | Crustacea |
Class: | Malacostraca |
Superorder: | Peracarida |
Order: | Isopoda |
Family: | Chaetiliidae |
Genus: | Glyptonotus |
Species: | G. antarcticus |
Binomial name | |
Glyptonotus antarcticus | |
Glyptonotus antarcticus is a benthic marine isopod crustacean in the suborder Valvifera. This relatively large isopod is found in the Southern Ocean around Antarctica. It was first described by James Eights in 1852 and the type locality is the South Shetland Islands. [1]
Glyptonotus antarcticus has a typical maximum length of 9 cm (3.5 in), [2] but may rarely reach up to 20 cm (8 in). [3] [4] This is large for an isopod, most of which are between 0.5 and 1.5 cm (0.2–0.6 in) in length. [5] It has two pairs of compound eyes, a large pair on the dorsal surface and a smaller pair on the ventral surface. Glyptonotus antarcticus has only five ommatidia, which is unusual for crustaceans and insects. [6] It is thought that the latter are useful when the animal is swimming, which it does in an upside-down position. [6] With the exception of the eyes, certain mouthparts and feet, the whole surface of the animal has minute cuticular outgrowths of feathery hairs and knobbly scales. It is thought that these may help to prevent attachment of Foraminifera and marine larval organisms on the body surface. [7]
Glyptonotus antarcticus is native to the Southern Ocean around Antarctica, where it occurs in large numbers. [2] It lives on the seabed at depths ranging from the intertidal zone [1] down to more than 600 m (2,000 ft). [2]
Glyptonotus antarcticus is a carnivore and scavenger and is often caught in baited traps on the seabed. It is an opportunistic predator with a mixed diet which includes a high proportion of echinoderms, but it is also cannibalistic. [8] [9] That the available food supply may be fairly constant is shown by the fact that it breeds at any time of year. [8] Females can breed when at least 7.5 cm (3 in) long. [9] The eggs and young are brooded for an extended period—more than 1½ year—in the female's marsupium where they are nourished by a maternal secretion. As typical of Antarctic isopods, there is no pelagic larval stage. [10]
Given its abundance and the fact that it is relatively easy to keep in aquaria, Glyptonotus antarcticus has become an important model organism used as a research object in ecological, biochemical and physiological studies. [2] [11] [12] A 2005 genetic study suggested that Glyptonotus antarcticus may in fact represent several distinct species. [2]
The compound eyes of arthropods like insects, crustaceans and millipedes are composed of units called ommatidia. An ommatidium contains a cluster of photoreceptor cells surrounded by support cells and pigment cells. The outer part of the ommatidium is overlaid with a transparent cornea. Each ommatidium is innervated by one axon bundle and provides the brain with one picture element. The brain forms an image from these independent picture elements. The number of ommatidia in the eye depends upon the type of arthropod and range from as low as 5 as in the Antarctic isopod Glyptonotus antarcticus, or a handful in the primitive Zygentoma, to around 30,000 in larger Anisoptera dragonflies and some Sphingidae moths.
Isopoda is an order of crustaceans that includes woodlice and their relatives. Isopods live in the sea, in fresh water, or on land. All have rigid, segmented exoskeletons, two pairs of antennae, seven pairs of jointed limbs on the thorax, and five pairs of branching appendages on the abdomen that are used in respiration. Females brood their young in a pouch under their thorax.
Bathynomus giganteus is a species of aquatic crustacean, of the order Isopoda. It is a member of the giant isopods (Bathynomus), and as such it is related—albeit distantly—to shrimps and crabs. It was the first Bathynomus species ever documented, and was described in 1879 by French zoologist Alphonse Milne Edwards after the isopod was found in fishermen's nets off the coast of the Dry Tortugas in the Gulf of Mexico.
The superorder Peracarida is a large group of malacostracan crustaceans, having members in marine, freshwater, and terrestrial habitats. They are chiefly defined by the presence of a brood pouch, or marsupium, formed from thin flattened plates (oostegites) borne on the basalmost segments of the legs. Peracarida is one of the largest crustacean taxa and includes about 12,000 species. Most members are less than 2 cm (0.8 in) in length, but the largest is probably the giant isopod which can reach 76 cm (30 in). The earliest known perecaridian was Oxyuropoda ligioides, a fossil of which has been found dating to the Late Devonian of Ireland.
The Valvifera are marine isopod crustaceans. Valviferans are distinguished, however, by the flat, valve-like uropods which hinge laterally and fold inward beneath the rear part of their bodies, covering the pleopods. Some species are omnivorous, and serve as effective scavengers in the economy of the sea.
The Cymothoidae are a family of isopods in the suborder Cymothoida found in both marine and freshwater environments. Cymoithoids are ectoparasites, usually of fish, and they include the bizarre "tongue-biter", which attaches to a fish's tongue, causing it to atrophy, and replaces the tongue with its own body. Ceratothoa oestroides is one of the most devastating ectoparasites in Mediterranean aquaculture. Around 40 genera and more than 380 species of cymothoid are recognised. Species of the Cymothoidae are generally found in warmer waters and rarely in the cool and cold climates.
Ceratoserolis is a genus of isopods in the family Serolidae from the Southern Ocean around Antarctica and some Sub-Antarctic Islands. They prefer to live on soft bottoms and range of least between 24 and 950 m (80–3,120 ft) in depth. They are superficially similar to the unrelated, extinct trilobites and reach up to about 8 cm (3.1 in) in length. They were once considered to be part of the genus Serolis and for a long time only Ceratoserolis trilobitoides was recognized. The validity of the other species has been disputed, but there are some morphological and genetic differences between them and C. trilobitoides, and there are indications that additional, currently unrecognized species of Ceratoserolis exist.
Nichollsia is a genus of isopod crustaceans from India. It comprises two species:
Iais pubescens is a species of marine isopod in the family Janiroidea. It inhabits seashores in a large number of locations in the southern hemisphere and may be found both free-living, and as commensals on larger isopods.
A giant isopod is any of the almost 20 species of large isopods, crustaceans distantly related to shrimp and crabs, which are decapods, in the genus Bathynomus. They are abundant in the cold, deep waters of the Atlantic, Pacific, and Indian Oceans. Bathynomus giganteus, the species upon which the generitype is based, is often considered the largest isopod in the world, though other comparably poorly known species of Bathynomus may reach a similar size. The giant isopods are noted for their resemblance to the much smaller common woodlouse, to which they are related.
The Microcerberidea are a suborder of isopod crustaceans. They are less than 2 mm (0.079 in) long, and live interstitially. They may be found in the eastern Pacific Ocean, and around the coasts of South America, Africa, the Mediterranean Sea, and India.
Chiridotea is a genus of isopod crustaceans in the family Chaetiliidae, containing the following species:
The Chaetiliidae are a family of isopod crustaceans in the suborder Valvifera, comprising these genera:
Aega psora is a species of isopod crustacean that parasitises a number of fish species in the North Atlantic. It is a serious ectoparasite of larger species of fish, particularly when they are injured.
Aega antarctica is a species of isopod crustacean. It is a temporary ectoparasite of fish, feeding on the fish's blood and then dropping to the seabed to digest its meal over a period of several months. It is found in the seas around Antarctica.
Idotea neglecta is a marine isopod in the family Idoteidae. It can be found on algae in the littoral and sublittoral zone of north-west European coasts.
Dynoides indicus is a species of isopod in the family Sphaeromatidae. It can be found in the water near Sri Lanka.
Scutuloidea kutu is a species of marine isopods in the family Sphaeromatidae, first described by Stephenson and Riley in 1996. No subspecies are listed in the Catalog of Life. The name "kutu" was chosen as a metaphor, as the species lives on seaweed.
Scutuloidea maculata is a species of marine isopods in the family Sphaeromatidae, first described by Charles Chilton in 1883. No subspecies are listed in the Catalogue of Life.
Anuropus is a genus of isopods in the suborder Cymothoida. As of 2021, it is the only genus in the family Anuropidae.