#pelagic

Creechur x2!

When considering the title, one might imagine the answer as “sound,” as the post-rock collective Hanry, as the album, or all three.  Defined as a “meditation on emergence,” What Came From Silence is a celebration of music and a coming-out party for the French band, who has released a series of EPs and singles leading up to this full-length debut. The core trio becomes a quintet for this release,…

Basking Shark

Cetorhinus maximus

Family: Cetorhinidae

The basking shark is a massive, slow-moving filter-feeding shark and the second-largest living fish in the world, after the whale shark. It is the sole surviving member of the family Cetorhinidae. Known for its enormous gaping mouth and habit of "basking" at the ocean's surface while feeding, this gentle giant is a harmless plankton eater found in temperate oceans worldwide.

Physical Description and Size

The basking shark has a robust, torpedo-shaped body and is one of the most recognizable shark species due to its immense size and distinctive anatomy.

Its coloration provides effective countershading camouflage: the dorsal surface ranges from greyish-brown to near-black, contrasting with a paler, often whitish underside. Its most striking feature is an enormous mouth capable of opening up to approximately 1 meter wide, complemented by five extremely long gill slits that nearly encircle the entire head — a configuration unique among sharks. It also possesses a distinctly conical, pointed snout, a large, triangular first dorsal fin reminiscent of that of a great white shark, a crescent-shaped caudal fin, and very small second dorsal and anal fins. Inside the gill slits, numerous long, brush-like gill rakers form a fine mesh that strains plankton from the passing water. Internally, an enormous liver accounting for up to 25% of total body weight stores large quantities of squalene — a low-density hydrocarbon that provides buoyancy and prevents the shark from sinking.

Size and Weight: ◦ Length: Average adult length is 6.6 to 8.8 meters, with some individuals confirmed at up to 12 meters. ◦ Weight: Maximum recorded weight exceeds 5 tonnes (approximately 5,000 kg), with the most commonly cited figure being around 4,000 kg for large adults.

Distribution and Habitat

The basking shark has a circumglobal distribution, found in temperate and cold-temperate waters around the world across the Atlantic, Pacific, and Indian Oceans, from boreal to warm-temperate regions.

◦ Atlantic: Found from Newfoundland to Florida, from Iceland and Norway to the Mediterranean Sea and South Africa. ◦ Pacific: Occurs from the Gulf of Alaska to Chile, and from Japan to Australia and New Zealand ◦ UK Waters: The basking shark is the UK's largest shark species and is protected under the Wildlife and Countryside Act

Basking sharks are highly migratory, and have been tracked traveling distances exceeding 9,000 km — for example, from the British Isles across the Atlantic to Newfoundland, Canada. They move between the northern and southern hemispheres through the tropical mesopelagic zone, appearing near the surface in boreal and warm-temperate waters during summer and descending to deeper waters in winter.

Behavior and Diet

The basking shark is a gentle, slow-moving filter feeder that poses no threat to large animals despite its imposing appearance. It occurs singly, in pairs, or in groups of three or more, occasionally aggregating in schools of up to 100 individuals in areas of high food abundance, sometimes segregated by size or sex.

Its characteristic swimming style involves cruising at the surface with the first dorsal fin and the upper caudal lobe breaking the water. Despite its unhurried pace, the basking shark is the largest shark species capable of breaching, and has been observed launching its entire body clear of the water — sometimes performing the behavior up to four consecutive times. The purpose of breaching is not fully understood, though hypotheses include parasite removal and courtship signaling.

As one of only three filter-feeding shark species — alongside the whale shark and the megamouth shark — the basking shark feeds passively by swimming with its mouth wide open, relying entirely on the forward momentum of its body to drive water through its gill rakers rather than actively pumping it. As water passes through the gill slits, the brush-like rakers trap zooplankton, fish eggs, barnacles, and other small organisms; the shark then closes its mouth to force the filtered water out and swallow the trapped prey. At a cruising speed of roughly 3.7 km/h, a basking shark can filter approximately 2,000 tonnes of water per hour.

Diet: ◦ Primary: Zooplankton, particularly copepods and krill, alongside barnacle larvae and fish eggs. ◦ Secondary: Small crustaceans and other microscopic organisms concentrated in surface waters.

Reproduction and Life Cycle

The basking shark is ovoviviparous (aplacental viviparous): eggs hatch inside the female's body and pups are born live without a placental connection, though much of the reproductive biology of this species remains poorly understood. Embryos are initially nourished by a yolk sac, and oophagy may also occur as in other lamniform sharks.

The breeding season spans late spring to early summer, followed by a gestation period estimated at 12 to 36 months — one of the longest of any shark species. Litter sizes are among the smallest relative to body size of any shark, typically yielding only 2 to 6 pups; despite these small numbers, pups are remarkably large at birth, measuring approximately 1.5 to 2.0 meters in length. Pregnant females likely give birth in coastal nursery areas, though specific pupping grounds have yet to be definitively identified.

Basking sharks are extremely slow-growing and late-maturing: males reach maturity at 4.8 to 6.0 meters at an estimated age of 12 to 16 years, while females mature at a similar size between 16 and 20 years of age. Maximum lifespan is estimated at up to 50 years in the wild.

Relationship with Humans

Basking sharks are entirely harmless and non-aggressive, posing no threat to swimmers or divers. Their immense size does, however, demand caution: they can thrash violently if harpooned or startled, and a breaching individual represents a genuine collision hazard for small vessels and sea kayaks. Because their large dorsal fins break the surface, they are sometimes mistaken for great white sharks, causing unnecessary alarm in coastal areas. Today, they serve as a popular attraction for eco-tourists and wildlife divers; responsible watching guidelines are strongly encouraged to minimize disturbance.

⚠️Conservation Status

The IUCN currently classifies the basking shark as Endangered globally, with a declining population trend.

During the 20th century, populations were severely depleted by targeted fisheries that harvested these sharks for their oil-rich livers, fins, meat, and skin; in the northeast Atlantic alone, directed harpoon and net fisheries took over 100,000 mature individuals between 1946 and 1997. A single fishery in Ireland was responsible for killing many thousands of sharks annually during this period. In modern times, the primary threats are bycatch in gillnet, longline, and trawl fisheries, as well as vessel strikes — a particularly significant risk given the species' habit of feeding directly at the surface.

Conservation Efforts: The basking shark is listed on Appendix II of CITES and included under the Convention on the Conservation of Migratory Species (CMS). In the United Kingdom, it receives strict legal protection under Section 5 of the Wildlife and Countryside Act: killing, injuring, or recklessly disturbing a basking shark carries penalties of up to six months in prison. Organizations such as The Shark Trust have developed a Code of Conduct providing clear guidance for responsible interaction during ecotourism encounters. Marine Protected Areas (MPAs) in key feeding regions offer additional refuge. Ongoing research programs using satellite tagging, photo-identification, and population genetics continue to improve understanding of the species' movements and status; public sighting networks and reporting schemes contribute valuable data to these efforts.

🦈Fascinating Facts

Despite their enormous mass and typically slow cruising speed, basking sharks are capable of spectacular breaching leaps, launching their entire bodies clear of the water. It has been calculated that breaching requires up to 32 times more energy than normal swimming — suggesting the behavior serves a meaningful biological purpose.

Historically, basking sharks were known by a variety of colorful common names, including "sunfish" (for their surface-basking habit), "elephant shark" (for their trunk-like snout), "bone shark," and "sailfish shark."

A widespread myth holds that basking sharks cannot close their mouths. In reality, they close their mouths regularly — they must do so in order to force filtered water out through the gill slits and swallow the trapped prey.

Salmon Shark

Lamna ditropis

Family: Lamnidae

The salmon shark is a large, powerful species of mackerel shark found exclusively in the northern Pacific Ocean. Named for its primary prey, salmon, it is renowned for its remarkable capacity for regional endothermy — the ability to maintain body temperature above that of the surrounding water — a trait shared with its closest relatives, the great white shark and the porbeagle.

Physical Description and Size

The salmon shark has a robust, fusiform body paired with a short, conical snout, giving it an appearance strikingly similar to a small great white shark. Its coloration consists of a medium grey to near-black dorsal surface contrasting with a white underside marked by distinctive darker blotches; juveniles share this general pattern but typically lack the spotting. The first dorsal fin is uniformly dark, without any pale coloration on the trailing tip.

Among its notable anatomical features are large, black eyes positioned well forward on the head, providing a degree of binocular vision that aids in precisely locating prey. The tail base bears a distinctive double-keel arrangement — a large central keel extending onto the caudal fin alongside a smaller secondary keel below — a structural feature shared only with the closely related porbeagle shark. The first dorsal fin is large and round-tipped, originating directly over or just behind the pectoral fin bases, while both the second dorsal and anal fins are very small.

Size and Weight: ◦ Length: Most adults measure 200 to 260 cm, with the largest confirmed individuals reaching up to 3.7 meters. ◦ Weight: Maximum recorded weight is approximately 454 kg, though most adults weigh considerably less.

Distribution and Habitat

The salmon shark has a restricted range compared to many shark species, found exclusively in the northern Pacific Ocean. Its range spans from the Sea of Japan and Korea north through the Bering Sea, and southward to southern California and Baja California, Mexico.

A notable and not fully understood difference exists between eastern and western Pacific populations: eastern Pacific aggregations (off North America) are dominated overwhelmingly by females, while western Pacific populations (off Japan and Russia) consist predominantly of males.

As a pelagic species, it inhabits both nearshore and oceanic waters, ranging from the surface to depths of at least 1,864 meters, and is most frequently encountered in cold temperate and subarctic environments where water temperatures range from approximately 2.5°C to 24°C.

Behavior and Diet

The salmon shark is a fast-swimming, opportunistic apex predator known for its voracious feeding habits and tendency to hunt cooperatively. It may be found singly, in loose schools, or in feeding aggregations of several dozen individuals — groups of 30 to 40 sharks have been observed hunting salmon together in Alaskan waters.

A key biological advantage is its regional endothermy, maintained through vascular counter-current heat exchangers known as retia mirabilia. This system allows the salmon shark to maintain an average internal body temperature of around 16 to 19°C even in waters as cold as 8°C — an adaptation that enables efficient hunting across a wide thermal range in frigid subarctic seas.

Diet: ◦ Primary: Salmon (their namesake prey), squid, sablefish, walleye pollock, and herring. ◦ Secondary: Other fish, benthic crustaceans, and seabirds.

Reproduction and Life Cycle

The salmon shark is ovoviviparous (aplacental viviparous): eggs hatch inside the female's body and pups are born live without a placental connection. Like other lamniform sharks, embryos initially nourish themselves from a yolk sac and later engage in oophagy, consuming unfertilized eggs produced by the mother once the yolk supply is depleted.

This species follows a biennial reproductive cycle, with mating occurring in late summer to early autumn and birth taking place the following spring after a gestation period of approximately 9 months. Each litter yields 2 to 5 pups, and newborns measure approximately 84 to 96 cm at birth, considerably larger than the "60 to 80 cm" cited in some secondary sources.

In the western North Pacific, males reach sexual maturity at approximately 1.77 to 1.86 meters and 5 years of age; females mature later, at 2.00 to 2.23 meters and 8 to 10 years of age. In the eastern North Pacific, female salmon sharks live up to 20 years, while males live to at least 27 years — a reversal of the typical longevity pattern seen in many other shark species.

Relationship with Humans

Salmon sharks are considered potentially dangerous to humans due to their size, but have not been associated with any confirmed injuries to people. Most encounters occur incidentally through fishing activity rather than in recreational settings.

⚠️Conservation Status

The IUCN classifies the salmon shark as Least Concern, citing a population that appeared stable at relatively high abundance levels during the 1990s and early 2000s. However, the species' low reproductive output and slow maturity mean it could be vulnerable to increased fishing pressure.

Primary threats include bycatch, climate change, and conflict with commercial fisheries — salmon sharks are frequently regarded as nuisances by fishing operations, as they can damage gear and consume portions of the commercial catch.

Conservation Efforts: Commercial fishing for salmon sharks in Alaska has been banned, and recreational fishing has been heavily regulated since 1997. In British Columbia, sport anglers are permitted to retain one salmon shark per day during the open season. The salmon shark is not currently listed under CITES. Ongoing tagging studies continue to track migration patterns and inform population assessments.

🦈Fascinating Facts

The salmon shark is the only shark besides its close relative the porbeagle to possess a double-keel arrangement at the tail base, a large primary keel extending onto the caudal fin and a smaller secondary keel below it. This structure enhances thrust efficiency during high-speed swimming.

Like the great white and the mako, the salmon shark is regionally endothermic, maintaining an internal temperature of 16 to 19°C even in waters as cold as 8°C — a thermal advantage of up to 11°C over the surrounding environment.

The common name comes directly from one of its most important prey species. Groups of 30 to 40 individuals have been documented hunting Pacific salmon cooperatively in Alaskan waters, making the salmon shark one of the few shark species known to engage in coordinated group hunting.

Tiger shark

Galeocerdo cuvier

Family: Galeocerdonidae

The tiger shark is a large, solitary macropredator and the only extant member of the genus Galeocerdo and family Galeocerdonidae. Named for the distinctive dark vertical stripes along its flanks — which resemble a tiger's markings but fade as the shark matures — it is also known for having the widest food spectrum of any shark species, earning the informal nickname "garbage can of the sea" due to its reputation for consuming almost anything, including man-made objects.

Physical Description and Size

The tiger shark has a robust, sturdy body paired with a bluntly rounded snout that is notably shorter than the width of its mouth.

For camouflage, it exhibits countershading: its bluish-green to dark grey or near-black dorsal side blends with the depths when viewed from above, while its white or light-yellow ventral side merges with the sunlit surface when seen from below. Juveniles display the prominent dark vertical stripes and spots that give the species its name, though these markings gradually fade with age.

Its wedge-shaped head allows for quick, agile turns. Additional anatomical features include a prominent interdorsal ridge and fourth and fifth gill slits positioned directly above the pectoral fins. Large, black eyes are equipped with a nictitating membrane and a reflective tapetum lucidum for enhanced vision in low-light conditions. Small pits along the snout contain electroreceptors known as the ampullae of Lorenzini, which detect weak electrical fields generated by prey.

Size and Weight: ◦ Length: Most adults measure 3.5 to 4.7 meters, with large females capable of exceeding 5 meters. ◦ Weight: Typical weight ranges from 300 to 900 kg.

Distribution and Habitat

The tiger shark has a circumglobal distribution, found in tropical and warm temperate waters around the world.

◦ Western Atlantic: From Massachusetts (USA) to Uruguay, including the Gulf of Mexico, the Bahamas, and the Caribbean Sea ◦ Eastern Atlantic: From Iceland to Angola, including the Canary Islands and the Mediterranean Sea (rare) ◦ Indo-Pacific: From the Red Sea and East Africa to Hawaii and Tahiti, north to southern Japan, south to New Zealand ◦ Eastern Pacific: From southern California (USA) to Peru, including the Revillagigedo, Cocos, and Galapagos Islands

It is primarily a coastal species, found on or adjacent to continental and insular shelves. It also inhabits coral reefs, seagrass beds, sandflats, estuaries, harbors, and lagoons, and occasionally ventures into the pelagic zone, though it is not a truly oceanic species.

Behavior and Diet

The tiger shark is a solitary, largely nocturnal apex predator renowned for its indiscriminate feeding habits.

It adheres to distinct activity patterns, primarily hunting at night and retreating to deeper waters during the day — though juveniles are commonly encountered in shallow, murky coastal environments. Its swimming style is characterized by slow undulating movements that, combined with cryptic coloration, make it exceptionally difficult for prey to detect. Despite this generally unhurried appearance, the tiger shark is fully capable of powerful bursts of speed when intercepting prey.

Adult tiger sharks face virtually no natural predators. Killer whales (orcas) represent their only documented predator, employing a highly specific strategy of driving the shark to the surface, gripping it mid-body, and holding it inverted to induce tonic immobility.

The tiger shark has the widest food spectrum of any shark.

Diet: ◦ Primary: Bony fish, rays, other sharks (including adult sandbar sharks and, on occasion, other tiger sharks), sea turtles, marine mammals (dolphins, dugongs, seals, sea lions), squid, crustaceans, seabirds, and sea snakes. ◦ Sea turtles: Have been found in up to 20.8% of studied tiger shark stomachs, suggesting a significant dietary reliance on them where the two species co-occur. ◦ Scavenging: Feeds on whale carcasses, sometimes alongside great white sharks. ◦ Terrestrial animals: Remains of horses, goats, sheep, dogs, cats, rats, and flying foxes have been recovered from stomachs of individuals caught around Hawaii. ◦ Man-made objects: Known to consume inedible items including license plates, oil cans, tires, baseballs, cans, plastic bottles, and burlap sacks.

Reproduction and Life Cycle

The tiger shark is ovoviviparous (aplacental viviparous): eggs hatch internally and pups are born live without a placental connection. Throughout a gestation period of approximately 15 to 16 months, embryos are nourished entirely by a yolk sac.

Litter sizes are highly variable, ranging from 10 to 82 pups — with 82 being the largest litter size on record for the species — though a typical average consists of around 31 to 33 pups. Newborns measure between 51 and 90 cm in length. Sexual maturity is determined primarily by size rather than age: males reach maturity at 2.3 to 3.0 meters, females at 2.5 to 3.3 meters, corresponding roughly to 5 to 7 years for males and over 7 years for females.

Once mature, lifespan estimates vary across studies, ranging from 27 to 37 years, with a maximum reported age of up to 50 years.

Relationship with Humans

The tiger shark is considered one of the most dangerous shark species to humans, ranking second only to the great white in the total number of recorded fatal unprovoked attacks. According to the ISAF, tiger sharks have been involved in 103 unprovoked attacks and are responsible for 39 fatalities — the second-highest fatality count of any species. A 30-year dataset from Hawaii shows that tiger sharks accounted for 47% of all unprovoked attacks in that region. A 2024 study published in Conservation Letters provided some of the first evidence for the existence of "problem individuals" among tiger sharks — repeat offenders that engage in agonistic behavior toward humans in probable foraging attempts.

Despite their fearsome reputation, individual risk remains exceedingly rare, and the tiger shark is officially classified by FishBase as "traumatogenic," meaning it can cause serious injury but is not an indiscriminate threat. Keeping tiger sharks in captivity is exceptionally challenging: their large size and active, wide-ranging nature make long-term maintenance in aquaria impractical, and most individuals survive only a matter of months.

⚠️Conservation Status

The International Union for Conservation of Nature (IUCN) classifies the tiger shark as Near Threatened globally, with populations in a state of global decline.

Primary threats include the fin trade, bycatch, and targeted fishing — compounded by growing demand for tiger shark products in commercial and artisanal fisheries worldwide.

Conservation Efforts: Tiger sharks are listed on Appendix II of CITES and included under the Convention on the Conservation of Migratory Species (CMS), providing some degree of international trade regulation and migratory protection. Researchers call for more comprehensive management proposals, including the establishment of protected zones for pupping and nursery grounds, minimum size restrictions, and participatory monitoring programs. Ongoing population studies focusing on exploitation dynamics and genetic diversity remain critical for informing these measures. Marine Protected Areas (MPAs) offer localized refuge, though the species' highly migratory nature limits the effectiveness of static protected zones; regional and international coordination is therefore seen as essential.

🦈Fascinating Facts

A 30-year analysis of Hawaiian shark bite data confirmed that "Sharktober" is real: approximately 20% of all recorded bites in Hawaii occur in October, two to four times more than any other month, driven primarily by a seasonal influx of large, mature female tiger sharks moving into nearshore waters to give birth. After delivering large litters, postpartum females are energetically depleted and forage more actively, further increasing the probability of human encounters.

The tiger shark's large, black eyes are equipped with a tapetum lucidum — a reflective layer behind the retina that amplifies available light — as well as a nictitating membrane that protects the eye during feeding. These two adaptations make it an exceptionally capable nocturnal predator.

The tiger shark is the sole living member of the genus Galeocerdo and the only species in the family Galeocerdonidae. Its oldest known fossils date to the Middle Miocene, approximately 13.8 million years ago.

Oceanic Whitetip Shark

Carcharhinus longimanus

Family: Carcharhinidae

The oceanic whitetip shark is a large, stocky species of requiem shark, instantly recognizable by its long, paddle-like pectoral fins and rounded first dorsal fin, both tipped with characteristic white mottling.

Physical Description and Size

The oceanic whitetip shark has a stocky, heavy-set, and robust body built for efficiency rather than speed in the open ocean. Its dorsal side ranges from dark grey to grey-bronze or olive grey, contrasting with a white underside; the undersides of the pectoral and pelvic fins are often darkly pigmented, while their tips display the species' signature white mottling.

Its most recognizable features are its long, paddle-like pectoral fins and large, rounded first dorsal fin, both displaying mottled white tips in adults — though the extent of this white pigmentation can vary and is occasionally absent altogether. It also possesses a short, rounded snout and round eyes equipped with a nictitating membrane. Its teeth are highly distinctive: the upper jaw bears broad, triangular, and strongly serrated teeth, while the lower jaw features narrower teeth with slender serrated cusps and broader bases.

Size and Weight: ◦ Length: Typical length is 1.5 to 2.5 meters, with some individuals reaching up to 3–4 meters. ◦ Weight: Typical weight is 35 to 170 kg.

Distribution and Habitat

The oceanic whitetip shark has a circumglobal distribution, found in tropical and warm temperate waters across the Atlantic, Pacific, and Indian Oceans.

◦ Western Atlantic: From Maine (USA) southward to Argentina, including the Gulf of Mexico and the Caribbean Sea. ◦ Eastern Atlantic: From Portugal south to the Gulf of Guinea . Also enters the Mediterranean Sea during winter months. ◦ Indo-Pacific: From the Red Sea and East Africa to Hawaii, Tahiti, Samoa, and the Tuamotu Islands.

It is a strictly pelagic species, inhabiting the sunlit epipelagic zone of the open ocean. It occasionally approaches the coast where deep water lies close to shore — such as around oceanic islands — and is sometimes associated with specific reef structures with high vertical relief. While typically found between the surface and approximately 200 meters depth, individuals have been recorded making deep dives down to 1,082 meters into waters as cold as 8°C.

Behavior and Diet

The oceanic whitetip is a slow-moving but bold and opportunistic predator, known for its persistent, curious behavior. It is primarily solitary, though it may aggregate in large numbers where food concentrations occur, and displays seasonal site fidelity to specific locations such as Cat Island in The Bahamas, where it is likely drawn by an abundance of large pelagic prey including billfish, tunas, and dolphinfish.

This species is most active at night, often resting at greater depths or near reef structures during daylight hours. Not built for high-speed pursuit, it relies on its large, paddle-like fins for energy-efficient gliding across vast stretches of open ocean.

Diet: ◦ Primary: Pelagic bony fishes (tunas, barracudas, marlins, swordfish, oarfish) and cephalopods (squid). ◦ Secondary: Marine mammals, other sharks, rays, crustaceans, and seabirds. ◦ Scavenging: Known to follow fishing vessels and feed on discarded catch or damage hooked fish on longlines.

Reproduction and Life Cycle

The oceanic whitetip is a viviparous species: embryos develop internally and receive nutrients directly from the mother via a yolk-sac placental connection. Gestation lasts approximately 10 to 12 months, after which females give birth to free-swimming pups measuring roughly 60 to 65 cm in length. A single litter can yield 1 to 15 pups, with a typical average of 5 to 10.

Maturity estimates vary considerably by region and source. Males generally reach maturity at 1.75 to 1.98 meters in length; females at 1.8 to 2.0 meters, with the age of maturity for both sexes ranging widely from 4 to 15 years. Lifespan also shows significant regional variation, with some sources reporting 12 years for males and 16 for females, while other estimates extend to 25 years.

Relationship with Humans

The oceanic whitetip is considered one of the most dangerous shark species to humans in open-water situations, where it displays little fear, acts persistently, and behaves in a bold, unpredictable manner when investigating divers. Encounters in a recreational context are rare, however, given that the species lives far offshore.

It is the primary species implicated in the shark attacks surrounding the 1945 sinking of the USS Indianapolis — widely regarded as the worst shark attack in recorded history. Of the approximately 900 crew members who survived the initial torpedo strike, only 316 were ultimately rescued after four days in the water, with shark attacks accounting for many of the losses. The species was also a deadly presence during World War II for survivors of other maritime disasters: when the troopship Nova Scotia was torpedoed off the coast of South Africa, close to 1,000 people were aboard, yet only 192 survived — many fatalities attributed to oceanic whitetip sharks in what eyewitnesses described as a feeding frenzy.

⚠️Conservation Status

The International Union for Conservation of Nature (IUCN) classifies the oceanic whitetip sharks as Critically Endangered globally, with population declines exceeding 80–90% in just three generations.

Primary threats include the fin trade, targeted fishing and bycatch, and the species' inherently slow life history, which limits its capacity to recover from sustained pressure.

Conservation Efforts: At CITES CoP20 in November 2025, Parties voted to uplist the oceanic whitetip shark to Appendix I — the highest level of protection under the Convention — effectively banning all international commercial trade in the species. This made the oceanic whitetip the first shark species ever to receive a full commercial trade ban under CITES. NOAA Fisheries has also developed a dedicated recovery plan outlining research and monitoring priorities, including tagging studies in The Bahamas that have identified critical aggregation sites such as Cat Island as important habitats for protection. Regional Fisheries Management Organizations (RFMOs) have additionally implemented catch limits and retention bans across several ocean basins.

🦈Fascinating Facts

The oceanic whitetip is known as the "shipwreck shark" for its historic role as the species most frequently encountered by open-ocean survivors during both World Wars. Its bold, opportunistic nature made it a lethal threat to people adrift far from shore.

The species name longimanus derives from Latin and translates as "long hands" or "long arms," a reference to the shark's characteristically elongated, paddle-like pectoral fins.

Until the 1960s, the oceanic whitetip was considered one of the most abundant pelagic sharks in the open tropical ocean. Today, populations have collapsed by over 90% in some regions — a stark reversal driven almost entirely by human activity.

Common Thresher Shark

Alopias vulpinus

Family: Alopiidae

The common thresher shark is a large, streamlined lamniform shark, instantly recognizable by its spectacularly long, scythe-like upper caudal lobe, which can equal the length of the rest of its body. It is a powerful, active swimmer found in tropical and temperate waters worldwide, and the largest of the three thresher shark species, known for its unique hunting strategy and its spectacular leaps when hooked.

Physical Description and Size

The common thresher shark has a stout, cylindrical, and streamlined body, paired with a short, pointed snout and relatively small eyes positioned near the front of the head.

For open-ocean camouflage, it exhibits countershading: the dorsal side ranges from dark green to brown, grey, blue-grey, or near-black, contrasting sharply with an abruptly white underside. A key identifying trait that separates it from other thresher species is a conspicuous white patch extending from the abdomen over the bases of its blackish pectoral fins, which are long, curved, and narrow-tipped. Its pelvic and first dorsal fins are also dark (sometimes displaying white tips) while the second dorsal and anal fins remain very small. The most remarkable feature of this shark is its scythe-like caudal fin, whose upper lobe can equal or exceed the length of the rest of the body, accounting for up to 50% of its total length, and is balanced by a shorter but well-developed lower lobe. Its teeth are relatively small for its body size, with erect, narrow cusps and no serrations, well suited for grasping small, slippery prey.

Size and Weight: ◦ Maximum confirmed length is approximately 5.73 meters for males and 5.49 meters for females, though some sources report individuals reaching 6 meters. ◦ Weight: Maximum recorded weight is approximately 348 kg, with some reports reaching up to 500 kg.

Distribution and Habitat

The common thresher has a circumglobal distribution, found in temperate and tropical seas around the world, across the Atlantic, Pacific, and Indian Oceans.

◦ Western Atlantic: From Newfoundland, Canada, to the Gulf of Mexico (rare north of New England), and from Venezuela to Argentina. ◦ Eastern Atlantic: From the North Sea and British Isles to Ghana (including Madeira, the Azores, the Mediterranean, and Black Seas), and from Angola to South Africa. ◦ Indo-Pacific: From Tanzania to India and the Maldives; from Japan, Korea, and southeastern China to Sumatra, eastern Australia, and New Zealand; also around many Pacific islands including New Caledonia, the Society Islands, and the Hawaiian Islands ◦ Eastern Pacific: From British Columbia, Canada, to Chile, including the Gulf of California.

As a coastal-pelagic species, it is found both near shore and in the open ocean, though it is most abundant close to land. Juveniles in particular frequent coastal habitats such as shallow bays.

Behavior and Diet

The common thresher is an active, powerful predator renowned for its unique use of its elongated tail in hunting. It is also an impressive aerial performer, capable of leaping a full body-length or more out of the water — and when hooked, it puts up such a determined fight that some veteran anglers have ranked it, pound for pound, a more demanding adversary than the shortfin mako.

The common thresher exhibits regional endothermy through a specialized vascular system that keeps the eyes and brain warmer than the surrounding water, particularly during deep dives or forays into colder environments — an adaptation that likely enhances neural processing speed and hunting efficiency.

This physiological edge supports its signature hunting strategy: the extraordinarily long caudal fin is used to herd schools of fish and deliver powerful, whip-like strikes to stun or kill prey. The effectiveness of this technique is illustrated by longline fishery data showing that 97% of hooked common threshers were caught by the upper lobe of the tail — evidence that they were attempting to stun already-hooked fish. There are also documented reports of individuals using their tails to strike seabirds, or to launch fish directly into their mouths.

Diet: ◦ Primary: Schooling fishes such as mackerels, bluefish, herrings, needlefish, lancetfish, lanternfish, and clupeids. ◦ Secondary: Squid, octopus, pelagic crustaceans, and rarely seabirds. ◦ Juveniles: Small schooling teleosts (bony fishes) and squids.

This species is largely solitary, though spatial and depth segregation by sex has been observed in some populations.

Reproduction and Life Cycle

The common thresher shark is ovoviviparous (aplacental viviparous): embryos develop inside the female's uterus without a placental connection. Initially nourished by a yolk sac, they later sustain themselves through oophagy — consuming unfertilized eggs continuously produced by the mother. Each litter yields 2 to 7 pups, typically 2 to 4, and newborns are remarkably large at birth, measuring between 1.1 and 1.5 meters in length.

Maturity estimates vary considerably by source and region. Males are reported to reach sexual maturity between 3 and 13 years of age, at approximately 3.2 to 4.2 meters in length; females mature later, between 5 and 14 years, at approximately 3.7 to 5.5 meters. The maximum reported lifespan for this species is 50 years.

Relationship with Humans

The common thresher is considered harmless to humans — generally docile and non-aggressive unless provoked. While a small number of boat incidents have been loosely attributed to this species, there are no confirmed unprovoked attacks on humans on record. Despite posing no real danger, the sheer size of adults commands respect; they should not be harassed, particularly since they are capable of inflicting serious damage to fishing gear when hooked.

Thresher sharks are rarely kept in captivity. Their large size, pelagic nature, need for vast open space, and specialized feeding requirements make them entirely unsuitable for most public aquariums — where they are known to injure themselves on tank walls when confined.

⚠️Conservation Status

The International Union for Conservation of Nature (IUCN) classifies the common thresher shark as Vulnerable (VU) globally.

Primary threats include targeted fishing, bycatch, and sport fishing — all compounded by the species' inherently slow reproductive rate and low capacity to recover from sustained pressure.

Conservation Efforts: All three species of thresher shark were listed on Appendix II of CITES at the 17th Conference of the Parties (CoP17) in 2016, regulating international trade in their fins and other products. Additionally, some regional fisheries management organizations (RFMOs) have implemented catch limits, size restrictions, and retention bans in certain areas. Marine Protected Areas (MPAs) may offer localized refuge, though the species' highly migratory nature limits the effectiveness of static protected zones.

🦈Fascinating Facts

The genus name Alopias derives from the Greek alopex, meaning "fox", which is why the common thresher is also known as the fox shark or sea fox.

The common thresher can be reliably distinguished from the similar-looking pelagic thresher (Alopias pelagicus) by the white patch on its belly extending in a band over the bases of its pectoral fins, a feature absent in the pelagic thresher.

Thresher sharks are known for their spectacular aerial acrobatics. At least one individual has been photographed leaping completely clear of the water by a full body-length.