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The Crustaceans Portal

Abludomelita obtusata.jpg

Crustaceans (Subphylum Crustacea) form a very large group of arthropods, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at 0.1 mm (0.004 in), to the Japanese spider crab with a leg span of up to 14 ft (4.3 m) and a mass of 44 lb (20 kg). Like other arthropods, crustaceans have an exoskeleton, which they moult in order to grow. They are distinguished from other groups of arthropods, such as insects, myriapods and chelicerates by the possession of biramous (two-parted) limbs, and by the nauplius form of the larvae. Most crustaceans are free-living aquatic animals, but some are terrestrial (e.g. woodlice), some are parasitic (e.g. fish lice, tongue worms) and some are sessile (e.g. barnacles). The group has an extensive fossil record, reaching back to the Cambrian, and includes living fossils such as Triops cancriformis, which has existed apparently unchanged since the Triassic period. More than 10 million tons of crustaceans are produced by fishery or farming for human consumption, the majority of it being shrimps and prawns. Krill and copepods are not as widely fished, but may be the animals with the greatest biomass on the planet, and form a vital part of the food chain.

Selected article

Carcinus maenas (Malacostraca: Decapoda: Carcinidae)
Carcinus maenas, the shore crab or green crab, is a common littoral crab, and an important invasive species, listed among the 100 "world's worst alien invasive species". Although native to the Baltic Sea, North Sea and north-east Atlantic Ocean, it has since become established on both east and west coasts of North America, in Argentina, South Africa and Australia. C. maenas is a predator feeding on many organisms, particularly bivalve molluscs (such as clams, oysters, and mussels), polychaetes and small crustaceans. It is primarily nocturnal, although activity also depends on the tide, and crabs can be active at any time of day.

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A medium-sized crab, with claws outstretched, with a yellow body, grading to black in the centre of the carapace.

Selected biography

Edward J. Miers F.Z.S. F.L.S. (1851–1930) was a British zoologist and curator of the crustacean collection at the Natural History Museum in London. He contributed to the scientific reports from the Challenger expedition of 1872–1876, and described 32 new genera and at least 260 new species and subspecies of decapod crustaceans, along with four genera and 72 new species in other orders.

Miers published his Catalogue of the stalk- and sessile-eyed Crustacea of New Zealand in 1876 and revised the Plagusiinae, Hippidae, Majidae, Squillidae and Idoteidae in monographs dated 1878–1881. He also reported on the collections donated by the Admiralty from a number of voyages, including the survey of the coast of Japan by H.M.S. Sylvia (1870–1877), an expedition to view the Transit of Venus in Kerguelen and Rodrigues (1874–1875), a survey of the Galápagos Islands by H.M.S. Petrel, Novaya Zemlya by H.M.S. Isbjorn (1879), Baron Hermann-Maltzan's voyage to Gorée in 1881, and the voyages of H.M.S. Alert to Patagonia and the Strait of Magellan (1881–1882). The upheavals at his workplace and the quantity of work to be done may have taken their toll on Miers, and he was "completely prostrated with illness" for three months.

Miers was still working on material from the Alert expedition, when six boxes containing the crabs from the Challenger expedition arrived, sent by John Murray. Describing these crabs would be Miers' largest taxonomic work, one which was published in 1886 as Report on the Brachyura collected by H. M. S. Challenger during the years 1873–1876 in 1886. Miers' honorarium for this work was £63 (60 guineas).

Selected picture

Nebalia bipes (Leptostraca: Nebaliidae)
Credit: Hans Hillewaert

Nebalia bipes is a species of leptostracan crustacean, and, in 1780, the first species in the order to have been described.

Crustacean lists


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