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 oldest confirmed modern sharks (selachimorphs) are known from the Early Jurassic, about 200 million years ago, though records of true sharks may extend back as far as the Permian.
The tiger shark is a species of ground shark, and the only extant member of the genus Galeocerdo and family Galeocerdonidae. It is a large macropredator, with females capable of attaining a length of over 5 m. Populations are found in many tropical and temperate waters, especially around central Pacific islands. Its name derives from the dark stripes down its body, which resemble a tiger's pattern, but fade as the shark matures.
The whale shark is a slow-moving, filter-feeding carpet shark and the largest known extant fish species. The largest confirmed individual had a length of 18.8 m (61.7 ft). The whale shark holds many records for size in the animal kingdom, most notably being by far the most massive living non-mammalian animal. It is the sole member of the genus Rhincodon and the only extant member of the family Rhincodontidae, which belongs to the subclass Elasmobranchii in the class Chondrichthyes. Before 1984 it was classified as Rhiniodon into Rhinodontidae.
Pamlico Sound is a large estuarine lagoon in North Carolina. The largest lagoon along the North American East Coast, it extends 80 mi (130 km) long and 15 to 20 miles wide. It is part of a large, interconnected network of similar lagoons that includes Albemarle Sound, Currituck Sound, Croatan Sound, Roanoke Sound, Pamlico Sound, Bogue Sound, Back Sound, and Core Sound known collectively as the Albemarle-Pamlico sound system. With over 3,000 sq. mi. (7,800 km2) of open water the combined estuary is second only in size to 4,479 sq mi (11,600 km2) Chesapeake Bay in the United States.
Elasmobranchii is a subclass of Chondrichthyes or cartilaginous fish, including modern sharks, rays, skates, and sawfish. Members of this subclass are characterised by having five to seven pairs of gill clefts opening individually to the exterior, rigid dorsal fins and small placoid scales on the skin. The teeth are in several series; the upper jaw is not fused to the cranium, and the lower jaw is articulated with the upper. The details of this jaw anatomy vary between species, and help distinguish the different elasmobranch clades. The pelvic fins in males are modified to create claspers for the transfer of sperm. There is no swim bladder; instead, these fish maintain buoyancy with large livers rich in oil.
The basking shark is the second-largest living shark and fish, after the whale shark, and one of three plankton-eating shark species, along with the whale shark and megamouth shark. Typically, basking sharks reach 7.9 m (26 ft) in length. It is usually greyish-brown, with mottled skin, with the inside of the mouth being white in colour. The caudal fin has a strong lateral keel and a crescent shape. Other common names include bone shark, elephant shark, sailfish, and sunfish. In Orkney, it is called hoe-mother, meaning "the mother of the picked dogfish."
The Okinawa Churaumi Aquarium, formerly known as the Okinawa Ocean Expo Aquarium, is located within the Ocean Expo Park in Okinawa, Japan. It is a member of the Japanese Association of Zoos and Aquariums (JAZA), and was the largest aquarium in the world until it was surpassed by the Georgia Aquarium in 2005. The aquarium has the exhibit, "Encounter the Okinawan Sea", which reproduces the sea of Okinawa and most of the creatures that live in it. Churaumi was selected as the name of the aquarium by public vote amongst Japanese people: chura means "beautiful" or "graceful" in the Okinawan language, and umi means "ocean" in Japanese.
The great hammerhead is the largest species of hammerhead shark, belonging to the family Sphyrnidae, attaining an average length of 4.6 m (15 ft) and reaching a maximum length of 6.2 m (20 ft). It is found in tropical and warm temperate waters worldwide, inhabiting coastal areas and the continental shelf. The great hammerhead can be distinguished from other hammerheads by the shape of its "hammer", which is wide with an almost straight front margin, and by its tall, sickle-shaped first dorsal fin. A solitary, strong-swimming apex predator, the great hammerhead feeds on a wide variety of prey ranging from crustaceans and cephalopods, to bony fish, to smaller sharks. Observations of this species in the wild suggest that the cephalofoil functions to immobilize stingrays, a favored prey. This species has a viviparous mode of reproduction, bearing litters of up to 50 pups every two years.
Dolphin drive hunting, also called dolphin drive fishing, is a method of hunting dolphins and occasionally other small cetaceans by driving them together with boats, usually into a bay or onto a beach. Their escape is prevented by closing off the route to the open sea or ocean with boats and nets. Dolphins are hunted this way in several places around the world including the Solomon Islands, the Faroe Islands, Peru, and Japan, which is the most well-known practitioner of the method. In large numbers dolphins are mostly hunted for their meat; some end up in dolphinariums.
Shark finning is the act of removing fins from sharks and discarding the rest of the shark back into the ocean. This act is prohibited in many countries. The sharks are often still alive when discarded, but without their fins. Unable to swim effectively, they sink to the bottom of the ocean and die of suffocation or are eaten by other predators. Shark finning at sea enables fishing vessels to increase profitability and increase the number of sharks harvested, as they must only store and transport the fins, by far the most profitable part of the shark; the shark meat is bulky to transport. Many countries have banned this practice and require the whole shark to be brought back to port before removing the fins.
Shark tourism is a form of eco-tourism that allows people to dive with sharks in their natural environment. This benefits local shark populations by educating tourists and through funds raised by the shark tourism industry. Communities that previously relied on shark finning to make their livelihoods are able to make a larger profit from diving tours while protecting the local environment. People can get close to the sharks by free- or scuba diving or by entering the water in a protective cage for more aggressive species. Many of these dives are done by private companies and are often baited to ensure shark sightings, a practice which is highly controversial and under review in many areas.
Marine conservation activism is the efforts of non-governmental organizations and individuals to bring about social and political change in the area of marine conservation. Marine conservation is properly conceived as a set of management strategies for the protection and preservation of ecosystems in oceans and seas. Activists raise public awareness and support for conservation, while pushing governments and corporations to practice sound ocean management, create conservation policy, and enforce existing laws and policy through effective regulation. There are many different kinds of organizations and agencies that work toward these common goals. They all are a part of the growing movement that is ocean conservation. These organizations fight for many causes including stopping pollution, overfishing, whaling and by-catching, and supporting marine protected areas.
The undulate ray is a species of ray and cartilaginous fish found in the Mediterranean and East Atlantic from southern Ireland and England to the Gulf of Guinea. It is found in areas with mud or sand, and may occur as deep as 200 m (660 ft), though it prefers shallower depths. It is considered endangered due to overfishing.
The Shark Alliance was a global not-for-profit coalition founded in 2006 by Pew Charitable Trusts of non-governmental organizations dedicated to restoring and conserving shark populations by improving shark conservation policies.
The following outline is provided as an overview of and topical guide to sharks:
A shark sanctuary is an area that forbids commercial fishing operations from targeting and retaining caught sharks, including their fins. The first shark sanctuary was created by Palau in 2009. It was followed by Maldives, Honduras, The Bahamas and Tokelau.
The Memorandum of Understanding on the Conservation of Migratory Sharks is an international instrument for the conservation of migratory species of sharks. It was founded under the auspices of the Convention on the Conservation of Migratory Species of Wild Animals.
The giant oceanic manta ray, giant manta ray, or oceanic manta ray is a species of ray in the family Mobulidae, and the largest type of ray in the world. It is circumglobal and is typically found in tropical and subtropical waters, but can also be found in temperate waters. Until 2017, the species was classified in the genus Manta, along with the smaller reef manta ray. DNA testing revealed that both species are more closely related to rays of the genus Mobula than previously thought. As a result, the giant manta was renamed as Mobula birostris to reflect the new classification.
The Save Our Seas Foundation is a philanthropic organization committed to protecting the world's oceans. It was founded in Geneva, Switzerland, on 23 September 2003.
The blonde ray or blonde skate is a species of ray fish in the family Rajidae.
