Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachimorpha and are the sister group to the Batoidea. Some sources extend the term "shark" as an informal category including extinct members of Chondrichthyes with a shark-like morphology, such as hybodonts. Shark-like chondrichthyans such as Cladoselache and Doliodus first appeared in the Devonian Period, though some fossilized chondrichthyan-like scales are as old as the Late Ordovician. The earliest confirmed modern sharks (selachimorphs) are known from the Early Jurassic around 200 million years ago, with the oldest known member being Agaleus, though records of true sharks may extend back as far as the Permian.
The great white shark, also known as the white shark, white pointer, or simply great white, is a species of large mackerel shark which can be found in the coastal surface waters of all the major oceans. It is the only known surviving species of its genus Carcharodon. The great white shark is notable for its size, with the largest preserved female specimen measuring 5.83 m (19.1 ft) in length and around 2,000 kg (4,400 lb) in weight at maturity. However, most are smaller; males measure 3.4 to 4.0 m, and females measure 4.6 to 4.9 m on average. According to a 2014 study, the lifespan of great white sharks is estimated to be as long as 70 years or more, well above previous estimates, making it one of the longest lived cartilaginous fishes currently known. According to the same study, male great white sharks take 26 years to reach sexual maturity, while the females take 33 years to be ready to produce offspring. Great white sharks can swim at speeds of 25 km/h (16 mph) for short bursts and to depths of 1,200 m (3,900 ft).
Carcharhiniformes, the Requiem sharks, are the largest order of sharks, with over 270 species. They include a number of common types, such as catsharks, swellsharks, and requiem sharks.
The megamouth shark is a species of deepwater shark. Rarely seen by humans, it measures around 5.2 m (17 ft) long and is the smallest of the three extant filter-feeding sharks alongside the relatively larger whale shark and basking shark. According to Sharkman's World Organization a total of 286 specimens have been observed or caught since its discovery in 1976. Like the other two planktivorous sharks, it swims with its mouth wide open, filtering water for plankton and jellyfish. It is recognizable from its large head with rubbery lips. The megamouth is so unlike any other type of shark that it is usually considered to be the sole extant species in the family Megachasmidae, though some scientists have suggested it may belong in the family Cetorhinidae.
The Pacific sleeper shark is a sleeper shark of the family Somniosidae, measuring up to 4.4 m (14 ft) in length, although it could possibly reach lengths in excess of 7 m (23 ft). It is found in the Pacific Ocean, usually in the northern hemisphere, but observations in recent years show it is also present in the southern hemisphere.
The zebra shark is a species of carpet shark and the sole member of the family Stegostomatidae. It is found throughout the tropical Indo-Pacific, frequenting coral reefs and sandy flats to a depth of 62 m (203 ft). Adult zebra sharks are distinctive in appearance, with five longitudinal ridges on a cylindrical body, a low caudal fin comprising nearly half the total length, and usually a pattern of dark spots on a pale background. Young zebra sharks under 50–90 cm (20–35 in) long have a completely different pattern, consisting of light vertical stripes on a brown background, and lack the ridges. This species attains a length of 2.5 m (8.2 ft).
Malpelo is a small oceanic island in the eastern Pacific Ocean, located about 500 km (310 mi) west of the Colombian mainland with a military post manned by the Colombian Armed Forces. It consists of a sheer and barren rock with three high peaks, the highest being the 300 m (980 ft) Cerro de la Mona. The island is about 1.5 kilometres in length from northeast to southwest, and 640 metres across at its widest.
San Benedicto, formerly Isla de los Inocentes, is an uninhabited island, and third largest island of the Revillagigedo Islands, located in the Pacific Ocean.
Rebbachisaurus is a genus of sauropod dinosaur of the superfamily Diplodocoidea, that lived during the Late Cretaceous period in Africa and possibly also South America about 99-97 million years ago. Remains attributed to Rebbachisaurus have been found in Morocco, Niger, Algeria, Tunisia and possibly also Argentina, although only the Moroccan remains can be referred to the genus without doubt. The discovery of Rayososaurus, a South American sauropod nearly identical to Rebbachisaurus which may have actually have been the same animal as Rebbachisaurus, supports the theory that there was still a land connection between Africa and South America during the Early Cretaceous, long after it was commonly thought the two continents had separated.
The dusky shark is a species of requiem shark, in the family Carcharhinidae, occurring in tropical and warm-temperate continental seas worldwide. A generalist apex predator, the dusky shark can be found from the coast to the outer continental shelf and adjacent pelagic waters, and has been recorded from a depth of 400 m (1,300 ft). Populations migrate seasonally towards the poles in the summer and towards the equator in the winter, traveling hundreds to thousands of kilometers. One of the largest members of its genus, the dusky shark reaches more than 4 m (13 ft) in length and 350 kg (770 lb) in weight. It has a slender, streamlined body and can be identified by its short round snout, long sickle-shaped pectoral fins, ridge between the first and second dorsal fins, and faintly marked fins.
The longfin mako shark is a species of mackerel shark in the family Lamnidae, with a probable worldwide distribution in temperate and tropical waters. An uncommon species, it is typically lumped together under the name "mako" with its better-known relative, the shortfin mako shark. The longfin mako is a pelagic species found in moderately deep water, having been reported to a depth of 220 m (720 ft). Growing to a maximum length of 4.3 m (14 ft), the slimmer build and long, broad pectoral fins of this shark suggest that it is a slower and less active swimmer than the shortfin mako.
The gecko catshark is a species of deepwater catshark, belonging to the family Pentanchidae, native to the northwestern Pacific Ocean from southern Japan to Taiwan, and possibly also off Vietnam. It is a common, demersal species found at depths of 100–900 m (330–2,950 ft). Its body is slender, with a pattern of dark saddles and blotches. The dorsal and caudal fins are edged in white, and there is a prominent crest of enlarged dermal denticles along the dorsal edge of the caudal fin. The gecko catshark is a schooling, opportunistic predator of bony fishes, cephalopods, and crustaceans. It is oviparous, with females producing two vase-shaped egg capsules at a time. This species is captured as bycatch, but does not appear to be threatened by fishery activities at present and has been assessed as Least Concern by the International Union for Conservation of Nature (IUCN).
The northern river shark or New Guinea river shark is a species of requiem shark, in the family Carcharhinidae, found in scattered tidal rivers and associated coastal waters in northern Australia and in Papua New Guinea. This species inhabits areas with poor visibility, soft bottoms, and large tides, with immature sharks ranging into fresh and brackish water. It is similar to other river sharks in having a stocky grey body with a high back, tiny eyes, and broad fins. It measures up to 2.5 m (8.2 ft) long.
The southern sleeper shark, or Whitley's sleeper shark, is a deepwater benthopelagic sleeper shark of the family Somniosidae found in the southern and subantarctic extremes of the Atlantic, Indian and Pacific Oceans, and some northern reaches of the Antarctic oceans. It has been recorded near the southernmost areas of South America, near South Africa, southern Australia, Tasmania and New Zealand, as well as more remote locations in the south-central Indian Ocean.
Roulletia is an extinct genus of sand sharks or Haimirichiid shark. It was described by Romain Vullo, Henri Cappetta, and Didier Néraudeau in 2007, and the type species is R. bureaui, which existed during the upper Cenomanian of what is now France. The genus was named after its type locality, Roullet-Saint-Estèphe, while the species epithet honours Michel Bureau, an amateur paleontologist who gathered the material for the species. Another species, R. canadensis, was described from the Cenomanian of Canada by Charlie J. Underwood and Stephen L. Cumbaa in 2010. The species epithet refers to the country in which it was discovered. It has been suggested tentatively this genus may be related to Haimirichia, which has been placed in its own family (Haimirichiidae) based on soft-tissue preservation.
F.C. Kariobangi Sharks, commonly known as Sharks or K. Sharks, is a Kenyan professional football club. They rose over time from humble beginnings in Nairobi, to feature in Kenya's top league, the FKF Premier League, since the year 2017.
Rhinopristiformes is an order of rays, cartilaginous fishes related to sharks, containing shovelnose rays and allied groups.
The Urumaco Formation is a formation in Venezuela that includes deposits from the Late Miocene. It is the site of several "giant forms": the turtles, crocodiles, sloths and rodents of Urumaco are among the largest of their groups.
Haimirichia is an extinct genus of mackerel shark from the late Cenomanian epoch of the Cretaceous period. It currently contains a single species: H. amonensis. Teeth now assigned to this genus were originally attributed to the Odontaspis. Exquisitely preserved remains from the Akrabou Formation Lagerstätte in Agoult, Morocco allowed the species to be moved into a new genus and family. Microscopic study revealed specialized dermal denticles likely used in electroreception. Its tooth and head design suggest a lifestyle similar to the extant Whitetip reef shark, a novel one for Lamniformes. Roulletia has a similar tooth design and may be part of the same family, Haimirichiidae.
