The Atlantic Ocean is the second-largest of the world's oceans, with an area of about 106,460,000 km2 (41,100,000 sq mi). It covers approximately 20 percent of Earth's surface and about 29 percent of its water surface area. It is known to separate the "Old World" from the "New World" in the European perception of the World.
The Mid-Atlantic Ridge is a mid-ocean ridge located along the floor of the Atlantic Ocean, and part of the longest mountain range in the world. In the North Atlantic, the ridge separates the North American from the Eurasian Plate and the African Plate, north and south of the Azores Triple Junction respectively. In the South Atlantic, it separates the African and South American plates. The ridge extends from a junction with the Gakkel Ridge northeast of Greenland southward to the Bouvet Triple Junction in the South Atlantic. Although the Mid-Atlantic Ridge is mostly an underwater feature, portions of it have enough elevation to extend above sea level, for example in Iceland. The ridge has an average spreading rate of about 2.5 centimetres (1 in) per year.
Halosaurs are eel-shaped fishes found only at great ocean depths. As the family Halosauridae, halosaurs are one of two families within the order Notacanthiformes; the other being the deep-sea spiny eels, Notacanthidae. Halosaurs are thought to have a worldwide distribution, with some 17 species in three genera represented. Only a handful of specimens have been observed alive, all in chance encounters with Remotely operated underwater vehicles.
The dusky smooth-hound, also called the smooth dogfish or the dog shark, is a species of houndshark in the family Triakidae. This shark is an olive grey or brown in color, and may have shades of yellow or grayish white. Females live to 16 years and males have a lifespan of 10 years. M. canis was the first shark recognised to have viral infections.
An abyssal plain is an underwater plain on the deep ocean floor, usually found at depths between 3,000 metres (9,800 ft) and 6,000 metres (20,000 ft). Lying generally between the foot of a continental rise and a mid-ocean ridge, abyssal plains cover more than 50% of the Earth's surface. They are among the flattest, smoothest, and least explored regions on Earth. Abyssal plains are key geologic elements of oceanic basins.
In hydrology, an oceanic basin may be anywhere on Earth that is covered by seawater, but geologically, ocean basins are large geologic basins that are below sea level. Geologically, there are other undersea geomorphological features such as the continental shelves, the deep ocean trenches, and the undersea mountain ranges which are not considered to be part of the ocean basins; while hydrologically, oceanic basins include the flanking continental shelves and the shallow epeiric seas.
The bigeye sand tiger is an extremely rare species of mackerel shark in the family Odontaspididae, with a possible worldwide distribution. A large, bulky species reaching at least 3.6 m (12 ft) in length, the bigeye sand tiger has a long bulbous snout, large orange eyes without nictitating membranes, and a capacious mouth with the narrow teeth prominently exposed. It can be distinguished from the similar smalltooth sand tiger by its teeth, which have only one lateral cusplet on each side, and by its uniformly dark brown color.
The Atlantic sharpnose shark is a requiem shark in the family Carcharhinidae, found in the subtropical waters of the northwestern Atlantic Ocean, between latitudes 43°N and 18°N.
The Portuguese dogfish or Portuguese shark, is a species of sleeper shark of the family Somniosidae. This globally distributed species has been reported down to a depth of 3,675 m (12,057 ft), making it the deepest-living shark known. It inhabits lower continental slopes and abyssal plains, usually staying near the bottom. Stocky and dark brown in color, the Portuguese dogfish can be distinguished from similar-looking species by the small spines in front of its dorsal fins. Its dermal denticles are also unusual, resembling the scales of a bony fish. This species typically reaches 0.9–1 m (3.0–3.3 ft) in length; sharks in the Mediterranean Sea are much smaller and have distinct depth and food preferences.
The sailfin roughshark is a species of dogfish shark in the family Oxynotidae, found in the eastern North Atlantic from Scotland to Senegal between latitudes 61°N and 11°N, at depths of between 265 and 720 m. Its length is up to 1.2 m (3.9 ft).
The King threadfin, also known as the blind salmon, blink tassel-fish, burnett salmon, gold threadfin, king salmon, kingfish, Sheridan threadfin, triped tassel fish, or threadfin salmon, is a species of marine ray-finned fish, a threadfin from the family Polynemidae which is found in southern New Guinea and northern Australia.
Jensen's skate, also known as the shortail skate, is a poorly known species of fish discovered in 2004 during a study of bottom ichthyofauna aboard the Norwegian RV G.O. Sars, where four species were identified, including A. jensieni.
Halosaurus is a genus of fish in the family Halosauridae. This genus currently contains the following recognized species:
Halosaurus johnsonianus, also called the Sahara halosaur, is a deep-sea fish in the family Halosauridae. It is found in the eastern Atlantic Ocean from southern Spain and Portugal to Mauritania, including the Azores and Canary Islands. It is a benthopelagic species living on the continental slope in depths from 800 to 2,200 m. It grows to 50 cm (20 in) total length.
Halosaurus radiatus, also known as the Albatross halosaur, is a fish in the family Halosauridae.
Halosaurus ovenii, also called the Oven's halosaur, is a deep-sea fish in the family Halosauridae. It is found in the eastern Atlantic where it is widely distributed in tropical and subtropical waters along both coasts. In the Mediterranean, H. ovenii is considered rare. It can reach up to 60 cm in length.
Imants (Monty) George Priede is a British-Latvian zoologist, author and academic. He is Professor Emeritus in the University of Aberdeen, Scotland known for his work on fish and life in the deep sea.
