|
Cranchiidae
The family Cranchiidae comprises the approximately 60 species of glass squid, also known as cockatoo squid, cranchiid, cranch squid, or bathyscaphoid squid. Cranchiid squid occur in surface and midwater depths of open oceans around the world. They range in mantle length from to over , in the case of the colossal squid. The common name, glass squid, derives from the transparent nature of most species. Cranchiid squid spend much of their lives in partially sunlit shallow waters, where their transparency provides camouflage. They are characterised by a swollen body and short arms, which bear two rows of suckers or hooks. The third arm pair is often enlarged. Many species are bioluminescent organisms and possess light organs on the undersides of their eyes, used to cancel their shadows. Eye morphology varies widely, ranging from large and circular to telescopic and stalked. A large, fluid-filled chamber containing ammonia solution is used to aid buoyancy. This buoyancy system is uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colossal Squid
The colossal squid (''Mesonychoteuthis hamiltoni'') is part of the family Cranchiidae. It is sometimes called the Antarctic squid or giant cranch squid and is believed to be the largest squid species in terms of mass. It is the only recognized member of the genus ''Mesonychoteuthis'' and is known from only a small number of specimens. The species is confirmed to reach a mass of at least , though the largest specimens—known only from beaks found in sperm whale stomachs—may perhaps weigh as much as ,e Papa(2019)How big is the colossal squid on display?Museum of New Zealand Te Papa Tongarewa.e Papa(2019)The beak of the colossal squid Museum of New Zealand Te Papa Tongarewa. making it the largest known invertebrate. Maximum total length has been estimated at .Roper, C.F.E. & P. Jereb (2010). Family Cranchiidae. In: P. Jereb & C.F.E. Roper (eds.) Cephalopods of the world. An annotated and illustrated catalogue of species known to date. Volume 2. Myopsid and Oegopsid Squids'. FA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taoniinae
Taoniinae is a subfamily containing ten genera of glass squids. Description Unlike Cranchiinae , the other subfamily within Cranchiidae , Taoniinae all lack cartilaginous strips which extend back from the funnel-mantle point of fusion. Their funnels are free laterally, and they have one to three photophores on the eyes. The largest photophore is crescent-shaped for most genera, but it's triangular in '' Helicocranchia'', a semicircle in '' Bathothauma'', and circular in '' Sandalops''. This is in contrast to glass squids in the subfamily Cranchiinae, which have at least four small photophores which are round or oval in shape. In addition, males lack hectocotyli; these are arms which have evolved to specialize in storage and transfer of spermatophores to females. Taoniinae are also often larger than Cranchiinae and have darker beaks. Another characteristic is that a Taoniinae's caecum, is smaller than its stomach; in Cranchiinae, the caecum is larger than the stomach. Taxono ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferdinand Victor Alphons Prosch
Ferdinand Victor Alphons Prosch (November 25, 1820 in Copenhagen – July 29, 1885) was a Danish doctor, veterinarian and biologist. Prosch's father, Johannes Henrik William Prosch (died 1843) was a secretary in the Danish War Chancery and his mother, Caroline Sophie (née Brement) was French. In 1837 Prosch was a student at the Metropolitan School in Copenhagen and by 1843 he had taken his medical exams. Between 1843 and 1846 Prosch was employed by the University as a prosector, i.e. a preparer of specimens for dissection in the University's Zoological museum. In 1847 he joined the ''Flaaden'' as the ship's doctor on a voyage to Madeira. Guinea, Venezuela and the Caribbean. In 1848 he was the ship's doctor on the frigate ''Havfrue'' ("Mermaid") in the First Schleswig War. After the war practiced as a doctor in Copenhagen and was a teacher of natural history, in which capacity he published the book "Lærer i Naturhistorie, i hvilken Egenskabin" 1851, which at the time was widely ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polarizing Filter (photography)
A polarizing filter or polarising filter (see spelling differences) is often placed in front of the camera lens in photography in order to darken skies, manage reflections, or suppress glare from the surface of lakes or the sea. Since reflections (and sky-light) tend to be at least partially linearly-polarized, a linear polarizer can be used to change the balance of the light in the photograph. The rotational orientation of the filter is adjusted for the preferred artistic effect. For modern cameras, a circular polarizer (CPL) is typically used; this comprises firstly a linear polarizer which performs the artistic function just described, followed by a quarter-wave plate which further transforms the now-linearly polarized light into circularly-polarized light before entering the camera. This additional step avoids problems with autofocus and light-metering sensors within some cameras, which otherwise may not function reliably with a simple linear polarizer. Use Light ref ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bathyscaphe
A bathyscaphe ( or ) is a free-diving self-propelled deep-sea submersible, consisting of a crew cabin similar to a bathysphere, but suspended below a float rather than from a surface cable, as in the classic bathysphere design. The float is filled with gasoline because it is readily available, buoyant, and, for all practical purposes, incompressible. The incompressibility of the gasoline means the tanks can be very lightly constructed, since the pressure inside and outside the tanks equalises, eliminating any differential. By contrast, the crew cabin must withstand a huge pressure differential and is massively built. Buoyancy at the surface can be trimmed easily by replacing gasoline with water, which is denser. Auguste Piccard, inventor of the first bathyscaphe, composed the name ''bathyscaphe'' using the Ancient Greek words βαθύς ''bathys'' ("deep") and σκάφος ''skaphos'' ("vessel"/"ship"). Mode of operation To descend, a bathyscaphe floods air tanks with se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organ (anatomy)
In biology, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ lies between tissue and an organ system. Tissues are formed from same type cells to act together in a function. Tissues of different types combine to form an organ which has a specific function. The intestinal wall for example is formed by epithelial tissue and smooth muscle tissue. Two or more organs working together in the execution of a specific body function form an organ system, also called a biological system or body system. An organ's tissues can be broadly categorized as parenchyma, the functional tissue, and stroma, the structural tissue with supportive, connective, or ancillary functions. For example, the gland's tissue that makes the hormones is the parenchyma, whereas the stroma includes the nerves that innervate the parenchyma, the blood vessels that oxygenate and nourish it and carry away its metabolic wastes, and the con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digestion
Digestion is the breakdown of large insoluble food molecules into small water-soluble food molecules so that they can be absorbed into the watery blood plasma. In certain organisms, these smaller substances are absorbed through the small intestine into the blood stream. Digestion is a form of catabolism that is often divided into two processes based on how food is broken down: mechanical and chemical digestion. The term mechanical digestion refers to the physical breakdown of large pieces of food into smaller pieces which can subsequently be accessed by digestive enzymes. Mechanical digestion takes place in the mouth through mastication and in the small intestine through segmentation contractions. In chemical digestion, enzymes break down food into the small molecules the body can use. In the human digestive system, food enters the mouth and mechanical digestion of the food starts by the action of mastication (chewing), a form of mechanical digestion, and the wetting contact o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gland
In animals, a gland is a group of cells in an animal's body that synthesizes substances (such as hormones) for release into the bloodstream (endocrine gland) or into cavities inside the body or its outer surface (exocrine gland). Structure Development Every gland is formed by an ingrowth from an epithelial surface. This ingrowth may in the beginning possess a tubular structure, but in other instances glands may start as a solid column of cells which subsequently becomes tubulated. As growth proceeds, the column of cells may split or give off offshoots, in which case a compound gland is formed. In many glands, the number of branches is limited, in others (salivary, pancreas) a very large structure is finally formed by repeated growth and sub-division. As a rule, the branches do not unite with one another, but in one instance, the liver, this does occur when a reticulated compound gland is produced. In compound glands the more typical or secretory epithelium is found forming t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalopod
A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles (muscular hydrostats) modified from the primitive molluscan foot. Fishers sometimes call cephalopods "inkfish", referring to their common ability to squirt ink. The study of cephalopods is a branch of malacology known as teuthology. Cephalopods became dominant during the Ordovician period, represented by primitive nautiloids. The class now contains two, only distantly related, extant subclasses: Coleoidea, which includes octopuses, squid, and cuttlefish; and Nautiloidea, represented by ''Nautilus'' and ''Allonautilus''. In the Coleoidea, the molluscan shell has been internalized or is absent, whereas in the Nautiloidea, the external shell remains. About 800 living species of cephalopods have been ident ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest continent, being about 40% larger than Europe, and has an area of . Most of Antarctica is covered by the Antarctic ice sheet, with an average thickness of . Antarctica is, on average, the coldest, driest, and windiest of the continents, and it has the highest average elevation. It is mainly a polar desert, with annual precipitation of over along the coast and far less inland. About 70% of the world's freshwater reserves are frozen in Antarctica, which, if melted, would raise global sea levels by almost . Antarctica holds the record for the lowest measured temperature on Earth, . The coastal regions can reach temperatures over in summer. Native species of animals include mites, nematodes, penguins, seals and tardigrades. Where vegetation o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammal
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles (including birds) from which they diverged in the Carboniferous, over 300 million years ago. Around 6,400 extant species of mammals have been described divided into 29 orders. The largest orders, in terms of number of species, are the rodents, bats, and Eulipotyphla (hedgehogs, moles, shrews, and others). The next three are the Primates (including humans, apes, monkeys, and others), the Artiodactyla ( cetaceans and even-toed ungulates), and the Carnivora (cats, dogs, seals, and others). In terms of cladistics, which reflects evolutionary history, mammals are the only living members of the Synapsida (synapsids); this clade, together with Saur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buoyancy
Buoyancy (), or upthrust, is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus the pressure at the bottom of a column of fluid is greater than at the top of the column. Similarly, the pressure at the bottom of an object submerged in a fluid is greater than at the top of the object. The pressure difference results in a net upward force on the object. The magnitude of the force is proportional to the pressure difference, and (as explained by Archimedes' principle) is equivalent to the weight of the fluid that would otherwise occupy the submerged volume of the object, i.e. the displaced fluid. For this reason, an object whose average density is greater than that of the fluid in which it is submerged tends to sink. If the object is less dense than the liquid, the force can keep the object afloat. This can occur only in a no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Cephalopod")
