Mapping the chemistry of the Earth's mantle

The Earth's mantle makes up about 85% of the Earth's volume and is made of solid rock. But exactly what rock types is the mantle made of, and how are they distributed throughout the mantle? An international team of researchers—including ...

What may be the largest source of abiotic methane gas on Earth

Methane (CH4), the chief constituent of natural gas, is one of the most widely used "clean" fuels. Although methane is usually considered to originate from organic matter, recently, more and more evidence shows that methane ...

Mars: Could life itself have made the planet uninhabitable?

Four billion years ago, the solar system was still young. Almost fully formed, its planets were starting to experience asteroid strikes a little less frequently. Our own planet could have become habitable as long as 3.9 billion ...

Surface waves help map the interior of Mars

Researchers have observed seismic waves propagating along the surface of a planet other than Earth for the first time. The marsquakes that resulted from two large meteorites that hit Mars were recorded by NASA's InSight lander ...

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Crustacean

Thylacocephala? Branchiopoda

Remipedia Cephalocarida Maxillopoda

Ostracoda

Malacostraca

Crustaceans (Crustacea) form a very large group of arthropods, usually treated as a subphylum, 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 12.5 ft (3.8 m) and a mass of 44 lb (20 kg). 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 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. The scientific study of crustaceans is known as carcinology (alternatively, malacostracology, crustaceology or crustalogy), and a scientist who works in carcinology is a carcinologist.

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