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The Crustaceans Portal Crustaceans (fromLatin word "crustacea" meaning: "those with shells" or "crusted ones") areinvertebrate animals that constitute one group ofarthropods that are traditionally a part of thesubphylumCrustacea (/krəˈsteɪʃə/), a large, diverse group of mainlyaquaticarthropods including the more familiardecapods (shrimps,prawns,crabs,lobsters andcrayfish),seed shrimps,branchiopods,fish lice,krill,remipedes,isopods,barnacles,copepods,opossum shrimps,amphipods andmantis shrimp. The crustacean group can be treated as a subphylum under thecladeMandibulata. It is now well accepted that thehexapods (insects andentognathans) emerged deep in the crustacean group, with the completed pan-group referred to asPancrustacea. The three classesCephalocarida,Branchiopoda andRemipedia are more closely related to the hexapods than they are to any of the other crustaceans (oligostracans andmulticrustaceans). The 67,000 described species range in size fromStygotantulus stocki at 0.1 mm (0.004 in), to theJapanese spider crab with a leg span of up to 3.8 m (12.5 ft) and a mass of 20 kg (44 lb). Like otherarthropods, crustaceans have anexoskeleton, which theymoult to grow. They are distinguished from other groups of arthropods, such asinsects,myriapods andchelicerates, by the possession ofbiramous (two-parted) limbs, and by theirlarval forms, such as thenauplius stage ofbranchiopods andcopepods. Most crustaceans are free-livingaquatic animals, but some areterrestrial (e.g.woodlice,sandhoppers), some areparasitic (e.g.Rhizocephala,fish lice,tongue worms) and some aresessile (e.g.barnacles). The group has an extensivefossil record, reaching back to theCambrian. More than 7.9 million tons of crustaceans per year are harvested by fishery or farming for human consumption, consisting mostly ofshrimp and prawns.Krill andcopepods are not as widely fished, but may be the animals with the greatestbiomass on the planet, and form a vital part of the food chain. The scientific study of crustaceans is known ascarcinology (alternatively,malacostracology,crustaceology orcrustalogy), and a scientist who works in carcinology is acarcinologist. (Full article...) Selected article Did you know?
Selected biography%2c_working_with_crab_specimens.jpg) For three years, Mary worked on avoluntary basis for her brother, before being granted a clerkship bySpencer Fullerton Baird at theSmithsonian Institution. She continued to work at the museum, largely unaided, and after 28 years, she was promoted to assistantcurator in charge of the Division of Crustacea. Her largest work wasLes crabes d'eau douce ("Freshwater crabs"), published in three volumes in 1904–1906. She wrote or co-wrote 166 papers in total, includingdescriptions of 1147 new species and subspecies, 63 new genera, one subfamily, 3 families and a superfamily, as well as othernomenclatural novelties. The taxa first described by Rathbun include important commercial species such as the Atlantic blue crabCallinectes sapidus, and the tanner crab,Chionoecetes bairdi. She retired on the last day of 1914, but did not stop working until her death. She qualified for aPh.D. atGeorge Washington University in 1917. Selected image
Triops longicaudatus (left: dorsal; right: ventral) is a species oftadpole shrimp which has existed since theTriassic. General imagesThe following are images from various crustacean-related articles on Wikipedia.
Crustacean lists
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