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Decapods
The Decapoda or decapods, from Ancient Greek δεκάς (''dekás''), meaning "ten", and πούς (''poús''), meaning "foot", is a large order (biology), order of crustaceans within the class Malacostraca, and includes crabs, lobsters, crayfish, Caridea, shrimp, and Dendrobranchiata, prawns. Most decapods are scavengers. The order is estimated to contain nearly 15,000 extant species in around 2,700 genera, with around 3,300 fossil species. Nearly half of these species are crabs, with the shrimp (about 3,000 species) and Anomura including hermit crabs, king crabs, porcelain crabs, squat lobsters (about 2500 species) making up the bulk of the remainder. The earliest fossils of the group date to the Devonian. Anatomy Decapods can have as many as 38 appendages, arranged in one pair per body segment. As the name Decapoda (from the Greek language, Greek , ', "ten", and , '':wikt:-pod, -pod'', "foot") implies, ten of these appendages are considered legs. They are the pereiopods, foun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crustacean
Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), 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 , to the Japanese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
