Portal:Crustaceans

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The Crustaceans Portal

Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are a part of the subphylum Crustacea (/krəˈsteɪʃə/), a large, diverse group of mainly aquatic arthropods including decapods (shrimps, prawns, crabs, lobsters and crayfish), seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, opossum shrimps, amphipods and mantis shrimp. The crustacean group can be treated as a subphylum under the clade Mandibulata. It is now well accepted that the hexapods (insects and entognathans) emerged deep in the Crustacean group, with the completed pan-group referred to as Pancrustacea. The three classes Cephalocarida, Branchiopoda and Remipedia are more closely related to the hexapods than they are to any of the other crustaceans (oligostracans and multicrustaceans).

The 67,000 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 3.8 m (12.5 ft) and a mass of 20 kg (44 lb). Like other arthropods, crustaceans have an exoskeleton, which they moult 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 their larval forms, such as the nauplius stage of branchiopods and copepods.

Most crustaceans are free-living aquatic animals, but some are terrestrial (e.g. woodlice, sandhoppers), some are parasitic (e.g. Rhizocephala, fish lice, tongue worms) and some are sessile (e.g. barnacles). The group has an extensive fossil record, reaching back to the Cambrian. More than 7.9 million tons of crustaceans per year are harvested by fishery or farming for human consumption, consisting mostly of shrimp 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. The scientific study of crustaceans is known as carcinology (alternatively, malacostracology, crustaceology or crustalogy), and a scientist who works in carcinology is a carcinologist. (Full article...)

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Homarus gammarus (Malacostraca: Decapoda: Nephropidae)

Homarus gammarus, known as the European lobster or common lobster, is a species of clawed lobster from the eastern Atlantic Ocean, Mediterranean Sea and parts of the Black Sea. It is closely related to the American lobster, H. americanus. It may grow to a length of 60 cm (24 in) and a mass of 6 kilograms (13 lb), and bears a conspicuous pair of claws. In life, the lobsters are blue, only becoming "lobster red" on cooking. Mating occurs in the summer, producing eggs which are carried by the females for up to a year before hatching into planktonic larvae. Homarus gammarus is a highly esteemed food, and is widely caught using lobster pots, mostly around the British Isles.

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... that, despite its name, the freshwater crab Potamon ibericum (pictured) does not live in Iberia?
... that when the sea anemone Adamsia palliata grows on the exterior of a gastropod shell, it is capable of enlarging the shell to better accommodate the hermit crab Pagurus prideaux inside?
... that Jurellana tithonia, dating from the Jurassic, is the earliest known porcelain crab?
... that several pelagic gooseneck barnacles were once found attached to an American crocodile?

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Michèle de Saint Laurent (December 9, 1926 – July 11, 2003) was a French carcinologist. She was born on December 9, 1926 at Fontainebleau, near Paris. She studied general biology at the University of Paris under Pierre-Paul Grassé, earning her Diplôme de Licence in 1954. She started undertaking scientific research even before finishing her degree, and the resulting paper brought her into contact with staff at the Muséum national d'histoire naturelle in Paris. From 1955 until 1960, she worked at the Centre National de la Recherche Scientifique (CNRS), at their laboratory at Banyuls-sur-Mer; thereafter, she returned to the Paris museum.

The first major focus of Michèle de Saint Laurent's work was the systematics of hermit crabs. She also investigated other decapod crustaceans, particularly the Thalassinidea. As a result of this work, she was invited in 1974 to visit the Smithsonian Institution and was given an unidentified specimen which had been caught by the Albatross expedition in 1908. She and Jacques Forest realised that it represented a living relative of the Glypheoidea, a group previously thought to have been extinct since the Eocene. They described the new genus together in 1975, as Neoglyphea. De Saint Laurent's later work included a new classification of crabs (involving the recognition of a new section, Eubrachyura), and three new superfamilies (Axioidea, Enoplometopoidea and Retroplumoidea), as well as various works on the decapods of hydrothermal vents.

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Credit: Gideon Pisanty

Ocypode cursor is a species of ghost crab that lives on sandy beaches in the Atlantic Ocean and Mediterranean Sea.

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General images

The following are images from various crustacean-related articles on Wikipedia.

Image 1Abludomelita obtusata, an amphipod (from Crustacean)
Image 2Copepods, from Ernst Haeckel's 1904 work Kunstformen der Natur (from Crustacean)
Image 3Eryma mandelslohi, a fossil decapod from the Jurassic of Bissingen an der Teck, Germany
Image 4The large ostracod Herrmannina from the Silurian (Ludlow) Soeginina Beds (Paadla Formation) on eastern Saaremaa Island, Estonia (from Ostracod)
Image 5Porcellio scaber and Oniscus asellus (Peracarida: Isopoda) (from Malacostraca)
Image 6Articulated ostracod valves in cross-section from the Permian of central Texas; typical thin section view of an ostracod fossil (from Ostracod)
Image 7Leptostraca such as Nebalia bipes retain the primitive condition of having seven abdominal segments. (from Malacostraca)
Image 8Body structure of a typical crustacean – krill (from Crustacean)
Image 9Zoea larva of the European lobster, Homarus gammarus
Image 10Odontodactylus scyllarus (Hoplocarida: Stomatopoda) (from Malacostraca)
Image 11A shed carapace of a lady crab, part of the hard exoskeleton
Image 12Daphnia pulex (Cladocera: Daphniidae) (from Branchiopoda)
Image 13Grapsus grapsus, a terrestrial crab (from Malacostraca)
Image 14Artemia salina (Anostraca: Artemiidae) (from Branchiopoda)
Image 15Anatomy of Cypridina mediterranea (from Ostracod)
Image 16Ostracod swimming motions (in real time) (from Ostracod)
Image 17Squilla empusa,
a mantis shrimp (from Malacostraca)
Image 18Decapods, from Ernst Haeckel's 1904 work Kunstformen der Natur (from Crustacean)
Image 19Eggs of Potamon fluviatile, a freshwater crab
Image 20Ostracod (from Ostracod)
Image 21Cancer pagurus (Eucarida: Decapoda) (from Malacostraca)
Image 22Norway lobsters on sale at a Spanish market