HOME



picture info

Aphotic Zone
The aphotic zone (aphotic from Greek prefix + "without light") is the portion of a lake or ocean where there is little or no sunlight. It is formally defined as the depths beyond which less than 1 percent of sunlight penetrates. Above the aphotic zone is the photic zone, which consists of the euphotic zone and the disphotic zone. The euphotic zone is the layer of water in which there is enough light for net photosynthesis to occur. The disphotic zone, also known as the twilight zone, is the layer of water with enough light for predators to see but not enough for the rate of photosynthesis to be greater than the rate of respiration. The depth at which less than one percent of sunlight reaches begins the aphotic zone. While most of the ocean's biomass lives in the photic zone, the majority of the ocean's water lies in the aphotic zone. Bioluminescence is more abundant than sunlight in this zone. Most food in this zone comes from dead organisms sinking to the bottom of the lake o ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Greek Language
Greek (, ; , ) is an Indo-European languages, Indo-European language, constituting an independent Hellenic languages, Hellenic branch within the Indo-European language family. It is native to Greece, Cyprus, Italy (in Calabria and Salento), southern Albania, and other regions of the Balkans, Caucasus, the Black Sea coast, Asia Minor, and the Eastern Mediterranean. It has the list of languages by first written accounts, longest documented history of any Indo-European language, spanning at least 3,400 years of written records. Its writing system is the Greek alphabet, which has been used for approximately 2,800 years; previously, Greek was recorded in writing systems such as Linear B and the Cypriot syllabary. The Greek language holds a very important place in the history of the Western world. Beginning with the epics of Homer, ancient Greek literature includes many works of lasting importance in the European canon. Greek is also the language in which many of the foundational texts ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Phytoplankton
Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater Aquatic ecosystem, ecosystems. The name comes from the Greek language, Greek words (), meaning 'plant', and (), meaning 'wanderer' or 'drifter'. Phytoplankton obtain their energy through photosynthesis, as trees and other plants do on land. This means phytoplankton must have light from the sun, so they live in the well-lit surface layers (euphotic zone) of oceans and lakes. In comparison with terrestrial plants, phytoplankton are distributed over a larger surface area, are exposed to less seasonal variation and have markedly faster turnover rates than trees (days versus decades). As a result, phytoplankton respond rapidly on a global scale to climate variations. Phytoplankton form the base of marine and freshwater food webs and are key players in the global carbon cycle. They account for about half of global photosynthetic activity and at least half o ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  




Expl2270 - Flickr - NOAA Photo Library
C mathematical operations are a group of functions in the standard library of the C programming language implementing basic mathematical functions. Different C standards provide different, albeit backwards-compatible, sets of functions. Most of these functions are also available in the C++ standard library, though in different headers (the C headers are included as well, but only as a deprecated compatibility feature). Overview of functions Most of the mathematical functions, which use floating-point numbers, are defined in ( header in C++). The functions that operate on integers, such as abs, labs, div, and ldiv, are instead defined in the header ( header in C++). Any functions that operate on angles use radians as the unit of angle. Not all of these functions are available in the C89 version of the standard. For those that are, the functions accept only type double for the floating-point arguments, leading to expensive type conversions in code that otherwise used single- ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Lanternfish
Lanternfish (or myctophids, from the Greek language, Greek μυκτήρ ''myktḗr'', "nose" and ''ophis'', "serpent") are small mesopelagic fish of the large family (biology), family Myctophidae. One of two families in the order Myctophiformes, the Myctophidae are represented by 246 species in 33 genus, genera, and are found in oceans worldwide. Lanternfishes are aptly named after their conspicuous use of bioluminescence. Their sister family, the Neoscopelidae, are much fewer in number but superficially very similar; at least one neoscopelid shares the common name "lanternfish": the large-scaled lantern fish, ''Neoscopelus macrolepidotus''. Lanternfish are among the most widely distributed, diverse and populous vertebrates, with some estimates suggesting that they may have a total global Biomass (ecology), biomass of 1.8 to 16 gigatonnes, accounting for up to 65% of all deep-sea fish biomass. Commercial fisheries for them exist off South Africa, in the Antarctica, sub-Antarctic ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Marine Hatchetfish
Marine hatchetfishes or deep-sea hatchetfishes are small deep-sea mesopelagic ray-finned fish of the stomiiform subfamily Sternoptychinae. They should not be confused with the freshwater hatchetfishes, which are not particularly closely related Teleostei in the characiform family Gasteropelecidae. (2006): ''Fishes of the World'' (4th ed.). John Wiley & Sons, Inc. p.209 The scientific name means "''Sternoptyx''-subfamily", from '' Sternoptyx'' (the type genus) + the standard animal family suffix "-inae". It ultimately derives from Ancient Greek ''stérnon'' (στέρνον, "breast") + ''ptýx'' (πτύξ, "a fold/crease") + Latin ''forma'' ("external form"), the Greek part in reference to the thorax shape of marine hatchetfishes. Description and ecology Found in tropical, subtropical and temperate waters of the Atlantic, Pacific and Indian Oceans, marine hatchetfishes range in size from '' Polyipnus danae'' at to the c.-long giant hatchetfish (''Argyropelecus gigas''). T ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Squid
A squid (: squid) is a mollusc with an elongated soft body, large eyes, eight cephalopod limb, arms, and two tentacles in the orders Myopsida, Oegopsida, and Bathyteuthida (though many other molluscs within the broader Neocoleoidea are also called ''squid'' despite not strictly fitting these criteria). Like all other cephalopods, squid have a distinct head, Symmetry (biology)#Bilateral symmetry, bilateral symmetry, and a mantle (mollusc), mantle. They are mainly soft-bodied, like octopuses, but have a small internal skeleton in the form of a rod-like gladius (cephalopod), gladius or pen, made of chitin. Squid diverged from other cephalopods during the Jurassic and occupy a similar Ecological niche, role to teleost fish as open-water predators of similar size and behaviour. They play an important role in the open-water food web. The two long tentacles are used to grab prey and the eight arms to hold and control it. The beak then cuts the food into suitable size chunks for swal ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Copepod
Copepods (; meaning 'oar-feet') are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (living in the water column), some are benthos, benthic (living on the sediments), several species have Parasitism, parasitic phases, and some continental species may live in limnoterrestrial habitats and other wet terrestrial places, such as swamps, under leaf fall in wet forests, bogs, springs, ephemeral ponds, puddles, damp moss, or water-filled recesses of plants (phytotelmata) such as bromeliads and pitcher plants. Many live underground in marine and freshwater caves, sinkholes, or stream beds. Copepods are sometimes used as Ecological indicator, biodiversity indicators. As with other crustaceans, copepods have a larval form. For copepods, the egg hatches into a Crustacean larvae#Nauplius, nauplius form, with a head and a tail but no true thorax or abdomen. The larva molts several times until it resembles the a ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Southern Elephant Seal
The southern elephant seal (''Mirounga leonina'') is one of two species of elephant seals. It is the largest member of the clade Pinnipedia and the order Carnivora, as well as the largest extant marine mammal that is not a cetacean. It gets its name from its massive size and the large proboscis of the adult male, which is used to produce very loud roars, especially during the breeding season. A bull southern elephant seal is about 40% heavier than a male northern elephant seal (''Mirounga angustirostris''), which is nearly twice the weight of a male walrus (''Odobenus rosmarus''), or 6–7 times heavier than the largest living mostly terrestrial carnivorans, the Kodiak bear and the polar bear. Taxonomy The southern elephant seal was one of the many species originally described by Swedish zoologist Carl Linnaeus in the landmark 1758 10th edition of his ''Systema Naturae'', where it was given the binomial name of ''Phoca leonina''. John Edward Gray established the genus ''Mirou ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Sperm Whale
The sperm whale or cachalot (''Physeter macrocephalus'') is the largest of the toothed whales and the largest toothed predator. It is the only living member of the Genus (biology), genus ''Physeter'' and one of three extant species in the sperm whale superfamily Physeteroidea, along with the pygmy sperm whale and dwarf sperm whale of the genus ''Kogia''. The sperm whale is a pelagic mammal with a worldwide range, and will migrate seasonally for feeding and breeding. Females and young males live together in groups, while mature males (bulls) live solitary lives outside of the mating season. The females cooperate to protect and Lactation, nurse their young. Females give birth every four to twenty years, and care for the calves for more than a decade. A mature, healthy sperm whale has no natural predators, although calves and weakened adults are sometimes killed by Cetacea#Social relations, pods of killer whales (orcas). Mature males average in length, with the head represent ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Methane Seeps
A cold seep (sometimes called a cold vent) is an area of the ocean floor where seepage of fluids rich in hydrogen sulfide, methane, and other hydrocarbons occurs, often in the form of a brine pool. ''Cold'' does not mean that the temperature of the seepage is lower than that of the surrounding sea water; on the contrary, its temperature is often slightly higher. The "cold" is relative to the very warm (at least ) conditions of a hydrothermal vent. Cold seeps constitute a biome supporting several endemic species. Cold seeps develop unique topography over time, where reactions between methane and seawater create carbonate rock formations and reefs. These reactions may also be dependent on bacterial activity. Ikaite, a hydrous calcium carbonate, can be associated with oxidizing methane at cold seeps. Types Types of cold seeps can be distinguished according to the depth, as shallow cold seeps and deep cold seeps. Cold seeps can also be distinguished in detail, as follows: ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Vampire Squid
The vampire squid (''Vampyroteuthis infernalis'', lit. 'vampire squid from hell') is a small cephalopod found throughout temperate and tropical oceans in extreme deep sea conditions. The vampire squid uses its bioluminescent organs and its unique oxygen metabolism to thrive in the parts of the ocean with the lowest concentrations of oxygen. It has two long retractile filaments, located between the first two pairs of arms on its dorsal side, which distinguish it from both octopuses and squids, and places it in its own order, Vampyromorphida, although its closest relatives are octopods. As a phylogenetic relict, it is the only known surviving member of its order. The first specimens were collected on the Valdivia Expedition and were originally described as an octopus in 1903 by German teuthologist Carl Chun, but later assigned to a new order together with several extinct taxa. Etymology The genus name ''Vampyroteuthis'' comes from Latin ''vampyrus'', meaning vampire, and Ancien ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Anglerfish
The anglerfish are ray-finned fish in the order Lophiiformes (). Both the order's common name, common and scientific name comes from the characteristic mode of predation, in which a modified dorsal Fish fin#Ray-fins, fin ray acts as a Aggressive mimicry#Food as an attractant, lure for prey (akin to a human Angling, angler, and likened to a crest or "''wikt:Lophius, lophos''"). The modified fin ray, with the very tip being the Esca (fish anatomy), esca and the length of the structure the Illicium (fish anatomy), illicium, is adapted to attract specific prey items across the families of anglerfish by using different luring methods. Anglerfish occur worldwide. The majority are bottom-dwellers, being demersal fish, while the aberrant deep-sea anglerfish are Pelagic fish, pelagic, (mostly) living high in the water column. Some live in the Deep-sea fish, deep sea (such as the deep-sea anglerfish and sea toads), while others live in Shallow water marine environment, shallower waters, s ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]