Tiger shark Temporal range: | |
---|---|
In The Bahamas | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Chondrichthyes |
Subclass: | Elasmobranchii |
Subdivision: | Selachimorpha |
Order: | Carcharhiniformes |
Family: | Galeocerdonidae |
Genus: | Galeocerdo |
Species: | G. cuvier |
Binomial name | |
Galeocerdo cuvier | |
Tiger shark range | |
Synonyms | |
The tiger shark (Galeocerdo cuvier) [3] 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 (16 ft 5 in). [4] 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. [5]
The tiger shark is a solitary, mostly nocturnal hunter. It is notable for having the widest food spectrum of all sharks, with a range of prey that includes crustaceans, fish, seals, birds, squid, turtles, sea snakes, dolphins, and even other, smaller sharks. It also has a reputation as a "garbage eater", [5] consuming a variety of inedible, man-made objects that linger in its stomach. Tiger sharks have only one recorded natural predator, the orca. [6] It is considered a near threatened species because of finning and fishing by humans. [1]
The tiger shark is second only to the great white in recorded fatal attacks on humans, but these events are still exceedingly rare. [7] [8]
The shark was first described by Peron and Lesueur in 1822, and was given the name Squalus cuvier. [4] Müller and Henle in 1837 renamed it Galeocerdo tigrinus. [7] The genus, Galeocerdo, is derived from the Greek galeos, which means shark, and kerdo, the word for fox. [7] It is often colloquially called the man-eater shark. [7]
The tiger shark is a member of the order Carcharhiniformes, the most species-rich order of sharks, with more than 270 species also including the small catsharks and hammerhead sharks. [4] Members of this order are characterized by the presence of a nictitating membrane over the eyes, two dorsal fins, an anal fin, and five gill slits. It is the largest member of the order, commonly referred to as ground sharks. It is the only extant member of Galeocerdo , the only member of the family Galeocerdonidae. [9] The oldest remains of Galeocerdo extend back to the Eocene epoch, while the oldest fossils of the modern tiger shark Galeocerdo cuvier date to the Middle Miocene, around 13.8 million years ago. [10]
The tiger shark commonly attains adult length of 3.5 to 4.7 m (11 ft 6 in – 15 ft 5 in) and weighs between 300 and 900 kg (700 and 2,000 lb). [11] [12] The International Game Fish Association's all-tackle record is 810 kg (1,790 lb). [13] It is sexually dimorphic, with females being the larger sex. Mature females are often over 3.7 m (12 ft 2 in) while mature males rarely get that large. [7] [14] [15] [16] Exceptionally large females reportedly can measure over 5 m (16 ft 5 in), and the largest males 4 m (13 ft 1 in). Weights of particularly large female tiger sharks can exceed 1,300 kg (2,900 lb). [15] [17] [18] [12] One pregnant female caught off Australia reportedly measured 5.5 m (18 ft 1 in) long and weighed 1,524 kg (3,360 lb). Even larger unconfirmed catches have been claimed. [19] Some papers have accepted a record of an exceptional 7.4-metre (24 ft 3 in), 3,110-kilogram (6,860 lb) tiger shark, but since this is far larger than any scientifically observed specimen, verification would be needed. [20] [21] [22] A 2019 study suggested that Pliocene tiger sharks could have reached 8 m (26 ft) in maximum length. [23] There is variation in the speed of growth rates of juvenile tiger sharks depending on the region they inhabit, with some growing close to twice as fast as others. [24]
Among the largest extant sharks, the tiger shark ranks in average size only behind the whale shark (Rhincodon typus), the basking shark (Cetorhinus maximus), and the great white shark (Carcharodon carcharias). This makes it the second-largest predatory shark, after the great white. [25] Some other species such as megamouth sharks (Megachasma pelagios), Pacific sleeper sharks (Somniosus pacificus), Greenland sharks (Somniosus microcephalus), and bluntnose sixgill sharks (Hexanchus griseus) broadly overlap in size with the tiger shark, but as these species are comparatively poorly studied, whether their typical mature size matches that of the tiger shark is unclear. [7] [19] The great hammerhead (Sphyrna mokarran), a member of the same taxonomic order as the tiger shark, has a similar or even greater average body length, but is lighter and less bulky, with a maximum known weight coming from a heavily pregnant 4.4 m (14 ft) long individual at 580 kg (1,280 lb). [26]
Tiger shark teeth are unique with very sharp, pronounced serrations and an unmistakable sideways-pointing tip. Such dentition has developed to slice through flesh, bone, and other tough substances such as turtle shells. Like most sharks, its teeth are continually replaced by rows of new teeth throughout the shark's life. Relative to the shark's size, tiger shark teeth are considerably shorter than those of a great white shark, but they are nearly as broad as the root as the great white's teeth and are arguably better suited to slicing through hard-surfaced prey. [27] [28]
A tiger shark generally has long fins to provide lift as the shark maneuvers through water, while the long upper tail provides bursts of speed. The tiger shark normally swims using small body movements. [29]
The skin of a tiger shark can typically range from blue to light green with a white or light-yellow underbelly. The advantage of this is that when it is hunting for its prey, when prey looks at the shark from above, the shark will be camouflaged, since the water below is darker. When prey is below the shark and looks up the light underbelly will also camouflage the shark with the sunlight. This is known as countershading. Dark spots and stripes are most visible in young sharks and fade as the shark matures. Its head is somewhat wedge-shaped, which makes it easy to turn quickly to one side. [5] [30] They have small pits on the snout which hold electroreceptors called the ampullae of Lorenzini, which enable them to detect electric fields, including the weak electrical impulses generated by prey, which helps them to hunt. [27] Tiger sharks also have a sensory organ called a lateral line which extends on their flanks down most of the length of their sides. The primary role of this structure is to detect minute vibrations in the water. These adaptations allow the tiger shark to hunt in darkness and detect hidden prey. [31]
Sharks do not have moveable upper or lower eyelids, but the tiger shark—among other sharks—has a nictitating membrane, a clear eyelid that can cover the eye. [32] A reflective layer behind the tiger shark's retina, called the tapetum lucidum, allows light-sensing cells a second chance to capture photons of visible light. This enhances vision in low-light conditions. [33]
The tiger shark is often found close to the coast, mainly in tropical and subtropical waters throughout the world. [7] Its behavior is primarily nomadic, but is guided by warmer currents, and it stays closer to the equator throughout the colder months. It tends to stay in deep waters that line reefs, but it does move into channels to pursue prey in shallower waters. In the western Pacific Ocean, the shark has been found as far north as Japan and as far south as New Zealand. [4] It has also been recorded in the Mediterranean Sea, but rarely, off Malaga (Spain), Sicily (Italy) and Libya. [34]
Tiger sharks can be seen in the Gulf of Mexico, North American beaches, and parts of South America. It is also commonly observed in the Caribbean Sea. Other locations where tiger sharks are seen include off Africa, China, India, Australia, and Indonesia. [5] Certain tiger sharks have been recorded at depths just shy of 900 m (3,000 ft). [7]
The tiger shark is an apex predator [35] and has a reputation for eating almost anything. [7] These predators swim close inland to eat at night, and during the day swim out into deeper waters. [36] Young tiger sharks are found to feed largely on small fish, as well as various small jellyfish, and mollusks including cephalopods. Around the time they attain 2.3 m (7.5 ft), or near sexual maturity, their selection expands considerably, and much larger animals become regular prey. [37] Numerous fish, crustaceans, sea birds, sea snakes, [38] marine mammals (e.g. bottlenose dolphins (Tursiops), common dolphins (Delphinus), [39] spotted dolphins (Stenella), [40] dugongs (Dugong dugon), seals and sea lions, and sea turtles (including the three largest species: the leatherback (Dermochelys coriacea), [41] the loggerhead (Caretta caretta) [42] and the green sea turtles (Chelonia mydas) [37] ), are regularly eaten by adult tiger sharks. In fact, adult sea turtles have been found in up to 20.8% of studied tiger shark stomachs, indicating somewhat of a dietary preference for sea turtles where they are commonly encountered. [43] They also eat other sharks (including adult sandbar sharks (Carcharhinus plumbeus)), as well as rays, and sometimes even other tiger sharks. [5] [37]
Due to high risk of predation, dolphins often avoid regions inhabited by tiger sharks. [44] [45] Injured or ailing whales may also be attacked and eaten. A group was documented killing an ailing humpback whale (Megaptera novaeangliae) in 2006 near Hawaii. [46] A scavenger, the tiger shark will feed on dead whales, and has been documented doing so alongside great white sharks. [47]
Evidence of dugong predation was identified in one study that found dugong tissue in 15 of 85 tiger sharks caught off the Australian coast. [48] Additionally, examination of adult dugongs has shown scars from failed shark attacks. [49] To minimize attacks, dugong microhabitats shift similarly to those of known tiger shark prey when the sharks are abundant. [50]
The broad, heavily calcified jaws and nearly terminal mouth, combined with robust, serrated teeth, enable the tiger shark to take on these large prey. [44] In addition, excellent eyesight and acute sense of smell enable it to react to faint traces of blood and follow them to the source. The ability to pick up low-frequency pressure waves enables the shark to advance towards an animal with confidence, even in murky water. [29] The shark circles its prey and studies it by prodding it with its snout. [29] When attacking, the shark often eats its prey whole, although larger prey are often eaten in gradual large bites and finished over time. [29]
Notably, terrestrial mammals, including horses (Equus ferus caballus), goats (Capra aegagrus hircus), sheep (Ovis aries), dogs (Canis lupus familiaris), cats (Felis catus), and brown rats (Rattus norvegicus), are fairly common in the stomach contents of tiger sharks around the coasts of Hawaii. [37] In one case, remains of two flying foxes were found in the stomach of this shark. [51] Because of its aggressive and indiscriminate feeding style, it often mistakenly eats inedible objects, such as automobile license plates, oil cans, tires, and baseballs. [5] Due to their habits of eating essentially anything, Tiger sharks are often referred to as the "garbage can of the sea".
Tiger sharks are preyed on by orcas. Orcas have been recorded hunting and killing tiger sharks by holding them upside down to induce tonic immobility in order to drown the shark. The orcas bite off the shark's fins before disemboweling and devouring it. [6]
All tiger sharks generally swim slowly, which, combined with cryptic coloration, may make them difficult for prey to detect in some habitats. They are especially well camouflaged against dark backgrounds. [44] Despite their sluggish appearance, tiger sharks are one of the strongest swimmers of the carcharhinid sharks. Once the shark has come close, a speed burst allows it to reach the intended prey before it can escape. [44]
Males reach sexual maturity at 2.3 to 2.9 m (7.5 to 9.5 ft) and females at 2.5 to 3.5 m (8.2 to 11.5 ft). [27] Typical weight of relatively young sexually mature specimens, which often locally comprise the majority of tiger sharks encountered per game-fishing and scientific studies, is around 80 to 130 kg (180 to 290 lb). [28] [52] Females mate once every three years. [5] They breed by internal fertilization. The male inserts one of his claspers into the female's genital opening (cloaca), acting as a guide for the sperm. The male uses his teeth to hold the female still during the procedure, often causing the female considerable discomfort. Mating in the Northern Hemisphere generally takes place between March and May, with birth between April and June the following year. In the Southern Hemisphere, mating takes place in November, December, or early January. The tiger shark is the only species in its family that is ovoviviparous; its eggs hatch internally and the young are born live when fully developed. [7] Tiger Sharks are unique among all sharks in the fact that they employ embrytrophy to nourish their young inside the womb. The young gestate in sacks which are filled with a fluid that nourishes them. This allows for the young to dramatically increase in size, even though they have no placental connection to the mother. [53]
The young develop inside the mother's body up to 16 months. Litters range from 10 to 80 pups. [7] A newborn is generally 51 to 76 cm (20 to 30 in) long. [7] How long tiger sharks live is unknown, but they can live longer than 12 years. [5]
Tiger shark ontogeny has been little studied until recently, but studies by Hammerschlag et al., indicated that as they grow, their tails become more symmetrical with age. Additionally, while the heads on juvenile tiger sharks are more conical and similar to other requiem sharks, adult tiger sharks have a head which is relatively broader. The reason for the larger caudal fin on juvenile tiger sharks is theorized to be an adaptation to escape predation by larger predators and to catch quicker-moving prey. As tiger sharks mature, their head also becomes much wider and their tails no longer become as large in proportion to their body size as when they are juveniles because they do not face elevated levels of predation risk upon maturity. The results of this study were interpreted as reflecting two ecological transitions: as tiger sharks mature they become more migratory and having a symmetrical tail is more advantageous in long-distance traveling, and that tiger sharks consume more diverse prey items with age, which requires a greater bite force and broader head. [54]
The tiger shark is captured and killed for its fins, flesh, and liver. It is caught regularly in target and nontarget fisheries. Several populations have declined where they have been heavily fished. Continued demand for fins may result in further declines. They are considered a near threatened species due to excessive finning and fishing by humans according to International Union for Conservation of Nature. [1] In June 2018, the New Zealand Department of Conservation classified the tiger shark as "Migrant" with the qualifier "Secure Overseas" under the New Zealand Threat Classification System. [55]
While shark fin has very few nutrients, shark liver has a high concentration of vitamin A, which is used in the production of vitamin oils. In addition, the tiger shark is captured and killed for its distinct skin, as well as by big-game fishers. [7]
In 2010, Greenpeace International added the tiger shark to its seafood red list, which is a list of commonly sold fish likely to come from unsustainable fisheries. [56]
Although sharks rarely bite humans, the tiger shark is reported to be responsible for a large share of fatal shark-bite incidents, and is regarded as one of the most dangerous shark species. [57] [58] They often visit shallow reefs, harbors, and canals, creating the potential for encounter with humans. [5] The tiger shark also dwells in river mouths and other runoff-rich water. [7] [27] While it ranks second on the list of number of recorded shark attacks on humans, behind only the great white shark, such attacks are few and very seldom fatal. [7] [57] Typically, three to four shark bites occur per year in Hawaii; one notable survivor of such an attack is surfing champion Bethany Hamilton, who lost her left arm at age 13 to a tiger shark in 2003. This bite rate is very low, considering that thousands of people swim, surf, and dive in Hawaiian waters every day. [59] Human interactions with tiger sharks in Hawaiian waters have been shown to increase between September and November, when tiger shark females are believed to migrate to the islands to give birth. [60]
On 8 June 2023, a tiger shark attacked and killed a 23-year-old Russian man in the Red Sea off the coast of the Egyptian city of Hurghada. The attack was filmed by onlookers and the recording went viral. The shark was later captured by fishermen and killed. This was the third fatal tiger shark attack in the area since 2022. [61]
Between 1959 and 2000, 4,668 tiger sharks were culled in an effort to protect the tourism industry.[ where? ] Despite damaging the shark population, these efforts were shown to be ineffective in decreasing the number of interactions between humans and tiger sharks. Feeding sharks in Hawaii (except for traditional Hawaiian cultural or religious practices) is illegal, [62] [63] and interaction with them, such as cage diving, is discouraged. South African shark behaviorist and shark diver Mark Addison demonstrated divers could interact and dive with them outside of a shark cage in a 2007 Discovery Channel special, [64] and underwater photographer Fiona Ayerst swam with them in the Bahamas. [64] [65] At "Tiger Beach" off Grand Bahama, uncaged diving with – and even the handling of – female tiger sharks has become a routine occurrence. [66]
Warming Atlantic Ocean currents have caused tiger shark migration paths to move further north, according to a University of Miami study. [67]
Tiger sharks are considered to be sacred 'aumākua (ancestor spirits) by some native Hawaiians. [68] The Tiger shark, possess a unique significance as 'aumakua, revered as family guardians in Hawaiian culture. The Tiger shark, regarded as an intelligent and highly perceptive spiritual entity, assumes the role of a messenger bridging the gap between humans and the divine. In the Hawaiian belief system, 'aumakua take on various forms, either animals or objects, representing ancestral connections and manifestations of departed family members. This perspective underscores the intricate web of interdependence among plants, animals, elements, and humans, underscoring the imperative to honor and coexist harmoniously with nature. [69]
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 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 (4,410 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).
The blue shark, also known as the great blue shark, is a species of requiem shark, in the family Carcharhinidae, which inhabits deep waters in the world's temperate and tropical oceans. Averaging around 3.1 m (10 ft) and preferring cooler waters, the blue shark migrates long distances, such as from New England to South America. It is listed as Near Threatened by the IUCN.
Risso's dolphin is a dolphin, the only species of the genus Grampus. Some of the closest related species to these dolphins include: pilot whales, pygmy killer whales, melon-headed whales, and false killer whales.
The Cuvier's beaked whale, goose-beaked whale, or ziphius is the most widely distributed of all beaked whales in the family Ziphiidae. It is smaller in size than most baleen whales—and indeed the larger toothed cetaceans —yet it is large among the beaked whales and smaller cetaceans, appearing somewhat like a bigger and stockier bottlenose dolphin. Cuvier's beaked whale is pelagic, generally inhabiting waters deeper than 300 m (1,000 ft), though it has been observed closer to shore on occasion. In these offshore waters, Cuvier's beaked whale executes some of the deepest, longest recorded dives among whales, and extant mammals, at 2,992 m (9,816 ft), for 222 minutes. While likely diving to forage and hunt prey, such as cephalopods, and potentially evade predators, the frequency and exact reason for these extraordinary dives is unclear. Despite its deepwater habitat, it is one of the most frequently-spotted beaked whales when surfacing.
The blacktip reef shark is a species of requiem shark, in the family Carcharhinidae, which can be easily identified by the prominent black tips on its fins. Among the most abundant sharks inhabiting the tropical coral reefs of the Indian and Pacific Oceans, this species prefers shallow, inshore waters. Its exposed first dorsal fin is a common sight in the region. The blacktip reef shark is usually found over reef ledges and sandy flats, though it has also been known to enter brackish and freshwater environments. It typically attains a length of 1.6 m (5.2 ft). Like other sharks, the females are larger than the males.
The cookiecutter shark, also called the cigar shark, is a species of small squaliform shark in the family Dalatiidae. This shark occurs in warm, oceanic waters worldwide, particularly near islands, and has been recorded as deep as 3.7 km (2.3 mi). It migrates vertically up to 3 km (1.9 mi) every day, approaching the surface at dusk and descending with the dawn. Reaching only 42–56 cm (16.5–22 in) in length, the cookiecutter shark has a long, cylindrical body with a short, blunt snout, large eyes, two tiny spineless dorsal fins, and a large caudal fin. It is dark brown, with light-emitting photophores covering its underside except for a dark "collar" around its throat and gill slits.
The sand tiger shark, gray nurse shark, spotted ragged-tooth shark or blue-nurse sand tiger, is a species of shark that inhabits subtropical and temperate waters worldwide. It inhabits the continental shelf, from sandy shorelines and submerged reefs to a depth of around 191 m (627 ft). They dwell in the waters of Japan, Australia, South Africa, and the east coasts of North and South America. The sand tiger shark also inhabited the Mediterranean, however it was last seen there in 2003 and is presumed extinct in the region. Despite its common names, it is not closely related to either the tiger shark or the nurse shark.
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.
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 blacktip shark is a species of requiem shark, and part of the family Carcharhinidae. It is common to coastal tropical and subtropical waters around the world, including brackish habitats. Genetic analyses have revealed substantial variation within this species, with populations from the western Atlantic Ocean isolated and distinct from those in the rest of its range. The blacktip shark has a stout, fusiform body with a pointed snout, long gill slits, and no ridge between the dorsal fins. Most individuals have black tips or edges on the pectoral, dorsal, pelvic, and caudal fins. It usually attains a length of 1.5 m (4.9 ft).
The Caribbean reef shark is a species of requiem shark, belonging to the family Carcharhinidae. It is found in the tropical waters of the western Atlantic Ocean from Florida to Brazil, and is the most commonly encountered reef shark in the Caribbean Sea. With a robust, streamlined body typical of the requiem sharks, this species is difficult to tell apart from other large members of its family such as the dusky shark and the silky shark. Distinguishing characteristics include dusky-colored fins without prominent markings, a short free rear tip on the second dorsal fin, and tooth shape and number.
The smalltooth sand tiger or bumpytail ragged-tooth is a species of mackerel shark in the family Odontaspididae, with a patchy but worldwide distribution in tropical and warm temperate waters. They usually inhabit deepwater rocky habitats, though they are occasionally encountered in shallow water, and have been known to return to the same location year after year. This rare species is often mistaken for the much more common grey nurse shark, from which it can be distinguished by its first dorsal fin, which is larger than the second and placed further forward. It grows to at least 4.1 m (13.5 ft) in length. They have also been recently sighted in Irish and English waters.
The spinner shark is a type of requiem shark, in the family Carcharhinidae, named for the spinning leaps it makes as a part of its feeding strategy. This species occurs in tropical and warm temperate waters worldwide, except for in the eastern Pacific Ocean. It is found from coastal to offshore habitats to a depth of 100 m (330 ft), though it prefers shallow water. The spinner shark resembles a larger version of the blacktip shark, with a slender body, long snout, and black-marked fins. This species can be distinguished from the blacktip shark by the first dorsal fin, which has a different shape and is placed further back, and by the black tip on the anal fin. It attains a maximum length of 3 m (9.8 ft).
The tiger catshark is a species of catshark, belonging to the family Scyliorhinidae. It is found over sandy areas and near reef peripheries off South Africa and perhaps Mozambique, from close to shore to usually no deeper than 100 m (330 ft). Reaching a length of 50 cm (20 in), this small, slim shark has a broad, flattened head with an upturned snout tip. It can additionally be identified by its dorsal colour pattern of ten dark brown saddles on a yellowish brown background.
Rhina ancylostoma, also known as the bowmouth guitarfish, shark ray or mud skate, is a species of ray and a member of the family Rhinidae. Its evolutionary affinities are not fully resolved, though it may be related to true guitarfishes and skates. This rare species occurs widely in the tropical coastal waters of the western Indo-Pacific, at depths of up to 90 m (300 ft). Highly distinctive in appearance, Rhina ancylostoma has a wide and thick body with a rounded snout and large shark-like dorsal and tail fins. Its mouth forms a W-shaped undulating line, and there are multiple thorny ridges over its head and back. It has a dorsal color pattern of many white spots over a bluish gray to brown background, with a pair of prominent black markings over the pectoral fins. This large species can reach a length of 2.7 m (8.9 ft) and weight of 135 kg (298 lb).
The lined butterflyfish is a species of marine ray-finned fish. a butterflyfish belonging to the family Chaetodontidae, one of the largest species in the genus Chaetodon. It has a wide range from the Red Sea to South Africa and as far east as southern Japan and Hawaii.
A bait ball, or baitball, occurs when small fish swarm in a tightly packed spherical formation about a common centre. It is a last-ditch defensive measure adopted by small schooling fish when they are threatened by predators. Small schooling fish are eaten by many types of predators, and for this reason they are called bait fish or forage fish.
Intraguild predation, or IGP, is the killing and sometimes eating of a potential competitor of a different species. This interaction represents a combination of predation and competition, because both species rely on the same prey resources and also benefit from preying upon one another. Intraguild predation is common in nature and can be asymmetrical, in which one species feeds upon the other, or symmetrical, in which both species prey upon each other. Because the dominant intraguild predator gains the dual benefits of feeding and eliminating a potential competitor, IGP interactions can have considerable effects on the structure of ecological communities.
Galeocerdo alabamensis is an extinct relative of the modern tiger shark. Nomenclature of this shark has been debated, and recent literature identified it more closely with the Physogaleus genus of prehistoric shark, rather than Galeocerdo. The classification of Physogaleus is known as tiger-like sharks while Galeocerdo refers to tiger sharks. In 2003, P. alabamensis was classified as Galeocerdo. However, in 2019, they were proclaimed to be more morphologically similar to the genus Physogaleus. This definition was based primarily on tooth shape, as the majority of information on P. alabamensis is a result of studying tooth fossils. Distinctions between Physogaleus and Galeocerdo are difficult with extinct sharks from the Oilgocene/Miocene as there is little paleobiological information allowing for hard conclusions.
{{cite journal}}
: CS1 maint: multiple names: authors list (link){{cite news}}
: CS1 maint: unfit URL (link){{cite journal}}
: CS1 maint: DOI inactive as of March 2024 (link){{cite web}}
: CS1 maint: bot: original URL status unknown (link)