Global wild capture, 1950–2010, in tonnes, of caridean shrimp The most significant commercial species among the carideans is Pandalus borealis, followed by Crangon crangon. The wild capture production of P. borealis is about ten times that of C. crangon.
Arthropod, any member of the phylum Arthropoda, the largest phylum in the animal kingdom, which includes such familiar forms as lobsters, crabs, spiders, mites, insects, centipedes, and millipedes. About 84 percent of all known species of animals are members of this phylum.
The subphylum Chelicerata (New Latin, from French chélicère, from Greek khēlē "claw, chela" and kéras "horn") constitutes one of the major subdivisions of the phylum Arthropoda. It contains the horseshoe crabs, sea spiders, and arachnids (including scorpions and spiders).
Crabs belong to the subphylum Crustacean, the largest group of marine arthropods, which also includes lobster, shrimp, and krill, a shrimp-like crustacean. Crabs move sideways, walking on four pairs of legs, and holding their two legs with claws away from their body.
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 brachiopods and copepods.
Eurypterids, often informally called sea scorpions, are an extinct group of arthropods related to arachnids that include the largest known arthropods to have ever lived. They are members of the extinct order Eurypterida (Chelicerata); which is the most diverse Paleozoic chelicerate order in terms of species.
The subphylum Hexapoda (from the Greek for six legs) constitutes the largest number of species of arthropods and includes the insects as well as three much smaller groups of wingless arthropods: Collembola, Protura, and Diplura (all of these were once considered insects).
An arthropod (/ ˈ ɑːr θ r ə p ɒ d /, from Greek ἄρθρον arthron, "joint" and πούς pous, "foot") is an invertebrate animal having an exoskeleton (external skeleton), a segmented body, and paired jointed appendages. Arthropods form the phylum Euarthropoda, which includes insects, arachnids, myriapods, and crustaceans.
These groups make up the clade Mandibulata, which is currently believed to be the sister group to the rest of arthropods, the clade Arachnomorpha (Chelicerata and Trilobita). Unlike the chelicerae of arachnids, mandibles can often be used to chew food.
Millipede, (class Diplopoda), any member of the arthropod class Diplopoda, distributed worldwide and commonly grouped with several other classes as myriapods. The approximately 10,000 species live in and eat decaying plant matter; some injure living plants, and a few are predators and scavengers.
Myriapoda is a subphylum of arthropods containing millipedes, centipedes, and others. The group contains over 16,000 species, most of which are terrestrial. Although their name suggests they have myriad (10,000) legs, myriapods range from having up to 750 legs (the millipede Illacme plenipes) to having fewer than ten legs.
Sea spiders, also called Pantopoda or pycnogonids, ('pycno-' closely packed, 'gonid' gonidia) are marine arthropods of class Pycnogonida. They are cosmopolitan, found in oceans around the world. There are over 1300 known species, with a leg span ranging from 1 mm (0.04 in) to over 70 cm (2.3 ft).
Arthropods range in size from the microscopic crustacean Stygotantulus up to the Japanese spider crab. Arthropods' primary internal cavity is a hemocoel, which accommodates their internal organs, and through which their haemolymph – analogue of blood – circulates; they have open circulatory systems.
Springtail, (order Collembola), any of approximately 6,000 small, primitive, wingless insects that range in length from 1 to 10 mm (0.04 to 0.4 inch). Most species are characterized by a forked appendage attached at the end of the abdomen and held in place under tension from the tenaculum, a clasplike structure formed by a pair of appendages.
Spiders are air-breathing arthropods that have eight legs and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other orders of organisms. Spiders are found worldwide on every continent except for Antarctica, and have become established in nearly every habitat with the exceptions of air and sea colonization. As of November 2015, at least 45,700 spider species, and 113 families have been recorded by taxonomists.