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Malacostraca
Malacostraca is the second largest of the six classes of pancrustaceans behind insects, containing about 40,000 living species, divided among 16 orders. Its members, the malacostracans, display a great diversity of body forms and include crabs, lobsters, spiny lobsters, crayfish, shrimp, krill, prawns, isopods, amphipods, mantis shrimp, and many other less familiar animals. They are abundant in all marine environments and have colonised freshwater and terrestrial habitats. They are segmented animals, united by a common body plan comprising 20 body segments (rarely 21), and divided into a head, thorax, and abdomen. Etymology The name Malacostraca is . The word was used by Aristotle, who contrasted them with oysters, in comparison with which their shells are pliable. It was applied to this taxon by French zoologist Pierre André Latreille in 1802. He was curator of the arthropod collection at the National Museum of Natural History in Paris. This scientific name is misl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mantis Shrimp
Mantis shrimp are carnivorous marine crustaceans of the order Stomatopoda (). Stomatopods branched off from other members of the class Malacostraca around 400 million years ago, with more than 520 extant species of mantis shrimp known. All living species are in the suborder Unipeltata, which arose around 250 million years ago. They are among the most important predators in many shallow, tropical and subtropical marine habitats. Despite being common in their habitats, they are poorly understood, as many species spend most of their lives sheltering in burrows and holes. Dubbed "sea locusts" by ancient Assyrians, "prawn killers" in Australia, and now sometimes referred to as "thumb splitters" due to their ability to inflict painful wounds if handled incautiously, mantis shrimp possess powerful raptorial appendages that are used to attack and kill prey either by spearing, stunning, or dismembering; the shape of these appendages are often used to classify them into groups: extant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eumalacostraca
Eumalacostraca is a subclass of crustaceans, containing almost all living malacostracans, or about 40,000 described species. The remaining subclasses are the Phyllocarida and possibly the Hoplocarida. Eumalacostracans have 19 segments (5 cephalic, 8 thoracic and 6 abdominal). This arrangement is known as the "caridoid facies", a term coined by William Thomas Calman in 1909. The thoracic limbs are jointed and used for swimming or walking. The common ancestor is thought to have had a carapace, and most living species possess one, but it has been lost in some subgroups. Caridoid facies Calman identified the following features as distinguishing eumalacostracan crustaceans: "Carapace enveloping the thoracic region; movably stalked eyes; biramous first antenna; scale-like exopod on the second antenna; natatory exopods on the thoracic limbs; elongate, ventrally flexible abdomen; tail fan formed by the lamellar rami of the uropods on either side of the telson." Classification Martin and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphipoda
Amphipoda () is an order (biology), order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods () range in size from and are mostly detritivores or scavengers. There are more than 10,700 amphipod species currently recognized. They are mostly marine animals, but are found in almost all aquatic environments. Some 2,250 species live in fresh water, and the order also includes the terrestrial Talitridae, sandhoppers such as ''Talitrus saltator'' and ''Arcitalitrus sylvaticus''. Etymology and names The name ''Amphipoda'' comes, via Neo-Latin ', from the Greek language, Greek root (linguistics), roots 'on both/all sides' and 'foot'. This contrasts with the related Isopoda, which have a single kind of thoracic leg. Particularly among Angling, anglers, amphipods are known as ''freshwater shrimp'', ''scuds'', or ''sideswimmers''. Description Anatomy The body of an amphipod is divided into 13 segments, which can be tagmosis, grouped ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Krill
Krill ''(Euphausiids)'' (: krill) are small and exclusively marine crustaceans of the order (biology), order Euphausiacea, found in all of the world's oceans. The name "krill" comes from the Norwegian language, Norwegian word ', meaning "small Fry (biology), fry of fish", which is also often attributed to species of fish. Krill are considered an important trophic level connection near the bottom of the food chain. They feed on phytoplankton and, to a lesser extent, zooplankton, and are also the main source of food for many larger animals. In the Southern Ocean, one species, the Antarctic krill, makes up an estimated biomass (ecology), biomass of around 379 million tonnes, making it among the species with the largest total biomass. Over half of this biomass is eaten by whales, Pinniped, seals, penguins, seabirds, squid, and fish each year. Most krill species display large diel vertical migration, daily vertical migrations, providing food for predators near the surface at night an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leptostraca
Leptostraca (from the Greek words for ''thin'' and ''shell'') is an order of small, marine crustaceans. Its members, including the well-studied '' Nebalia'', occur throughout the world's oceans and are usually considered to be filter-feeders. It is the only extant order in the subclass Phyllocarida. They are believed to represent the most primitive members of their class, the Malacostraca, and first appear in the fossil record during the Cambrian period. Description Leptostracans are usually small, typically long, but the largest species ('' Nebaliopsis typica'') can reach 4 cm, and the Silurian '' Ceratiocaris'' could grow to 75 cm. They are distinguished from all other members of their class in having seven abdominal segments, instead of six. Their head has stalked compound eyes, two pairs of antennae (one biramous, one uniramous), and a pair of mandibles but no maxillipeds. They are the only malacostracans with a carapace that comprises two valves. It covers the head an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lobster
Lobsters are Malacostraca, malacostracans Decapoda, decapod crustaceans of the family (biology), family Nephropidae or its Synonym (taxonomy), synonym Homaridae. They have long bodies with muscular tails and live in crevices or burrows on the sea floor. Three of their five pairs of legs have claws, including the first pair, which are usually much larger than the others. Highly prized as seafood, lobsters are economically important and are often one of the most profitable commodities in the coastal areas they populate. Commercially important species include two species of ''Homarus'' from the northern Atlantic Ocean and Scampi (other), scampi (which look more like a shrimp, or a "mini lobster")—the Northern Hemisphere genus ''Nephrops'' and the Southern Hemisphere genus ''Metanephrops''. Distinction Although several other groups of crustaceans have the word "lobster" in their names, the unqualified term "lobster" generally refers to the clawed lobsters of the fam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecdysis
Ecdysis is the moulting of the cuticle in many invertebrates of the clade Ecdysozoa. Since the cuticle of these animals typically forms a largely inelastic exoskeleton, it is shed during growth and a new, larger covering is formed. The remnants of the old, empty exoskeleton are called exuviae. After moulting, an arthropod is described as ''teneral'', a ''callow''; it is "fresh", pale and soft-bodied. Within one or two hours, the cuticle hardens and darkens following a Tanning (leather), tanning process analogous to the production of leather. During this short phase the animal expands, since growth is otherwise constrained by the rigidity of the exoskeleton. Growth of the limbs and other parts normally covered by the hard exoskeleton is achieved by transfer of body fluids from soft parts before the new skin hardens. A spider with a small abdomen may be undernourished but more probably has recently undergone ecdysis. Some arthropods, especially large insects with tracheal respira ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caridea
The Caridea, commonly known as caridean shrimp or true shrimp, from the Greek word καρίς, καρίδος (karís, karídos, “shrimp”), are an infraorder of shrimp within the order Decapoda. This infraorder contains all species of true shrimp. They are found widely around the world in both fresh water, fresh and seawater, salt water. Many other animals with similar names – such as the mud shrimp of Axiidea and the boxer shrimp of Stenopodidea – are not true shrimp, but many have evolved features similar to true shrimp. Biology Carideans are found in every kind of aquatic habitat, with the majority of species being marine. Around a quarter of the described species are found in fresh water, however, including almost all the members of the species-rich family Atyidae and the Palaemonidae subfamily Palaemoninae. They include several commercially important species, such as ''Macrobrachium rosenbergii'', and are found on every continent except Antarctica. The marine species ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oyster
Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but not all oysters, are in the superfamily Ostreoidea. Some species of oyster are commonly consumed and are regarded as a delicacy in some localities. Some types of pearl oysters are harvested for the pearl produced within the mantle. Others, such as the translucent Windowpane oysters, are harvested for their shells. Etymology The word ''oyster'' comes from Old French , and first appeared in English during the 14th century. The French derived from the Latin , the feminine form of , which is the Latinisation (literature), latinisation of the Ancient Greek () 'oyster'. Compare () 'bone'. Types True oysters True oysters are members of the family Ostreidae. This family includes the edible oysters, which mainly belong to the genera '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aristotle's Biology
Aristotle's biology is the theory of biology, grounded in systematic observation and collection of data, mainly zoology, zoological, embodied in Aristotle's books on the science. Many of his observations were made during his stay on the island of Lesbos, including especially his descriptions of the marine biology of the Pyrrha lagoon, now the Kalloni#Bay and lagoon, Gulf of Kalloni. His theory is based on Hylomorphism, his concept of form, which derives from but is markedly unlike Plato's theory of Forms. The theory describes five major biological processes, namely metabolism, temperature regulation, information processing, embryogenesis, and inheritance (biology), inheritance. Each was defined in some detail, in some cases sufficient to enable modern biologists to create mathematical models of the mechanism (biology), mechanisms described. Aristotle's method, too, resembled the style of science used by modern biologists when exploring a new area, with systematic data collection ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
