Porbeagle Shark Facts

• Maximum lengthAbout 3.5 m (11.5 ft); most adults 1.5–2.5 m
• WeightUp to 230 kg (507 lb); typical adult 80–135 kg
• LifespanAt least 26 years validated; models suggest 45–65
• Depth rangeSurface to 1,360 m (4,460 ft), mostly above 200 m
• DietMackerel, herring, sand lance, cod, squid
• IUCN statusVulnerable (assessed 2018)

How to recognise a porbeagle

A porbeagle looks like a great white that has been compressed: the body is deep and barrel-shaped, the snout is a short cone, the eyes are large and black, and the tail is a crescent with a keel on each side of the tail stalk. Two features settle the identification. On the free rear tip of the first dorsal fin there is a sharp white patch, unique among the mackerel sharks, and below the main keel on the tail there is a second, much smaller keel running onto the lower lobe, a feature shared only with the salmon shark of the North Pacific.

Colour is dark grey to blue-grey above and white below, with no spots or blotches. The pectoral fins are long, the first dorsal fin is tall and begins just behind the pectoral base, and the second dorsal and anal fins are tiny. The gill slits are long but stop short of the top of the head.

The teeth are the third clue and the one that separates a porbeagle from a mako on a fish market slab: each is a narrow, smooth-edged blade with a tiny cusplet at either side of the base, roughly 28 to 30 in each jaw, where a mako's teeth are longer, hooked and without cusplets.

How big do porbeagles get?

Older sources, ours among them, undersold the porbeagle at 2.5 m and 135 kg. The species is bigger. Reliable measurements reach about 3.5 m (11.5 ft), with unconfirmed reports of 3.7 m, and the heaviest verified individual, the rod-and-line record from the Pentland Firth off northern Scotland in 1993, weighed 230 kg (507 lb). A 3 m porbeagle is a very large one; most adults in the catch are 1.5 to 2.5 m and weigh 80 to 135 kg.

Pups are born at 60 to 75 cm (24 to 30 in) and about 5 kg, with a liver that is a tenth of their weight, the fuel reserve that carries them through their first weeks. Males mature at 165 to 180 cm and females at 200 to 220 cm; in the north-west Atlantic that means about 8 years for a male and 13 for a female, and later in the Southern Hemisphere, where growth is slower. Females are the larger sex and account for nearly all the animals over 3 m.

For scale, the size bar below puts the biggest porbeagle on record beside a 1.8 m diver.

Where porbeagles live

The porbeagle has an odd, split distribution. One population fills the North Atlantic from the Grand Banks, the Gulf of St Lawrence and the Bay of Fundy in Canada, south to New Jersey and occasionally South Carolina, and from Iceland, Norway and the Barents Sea down the coasts of Ireland, Britain and France to Morocco, with a thin presence in the Mediterranean. The Gulf of Maine, from Maine to Massachusetts, is the species' stronghold in the western Atlantic. A second population rings the Southern Hemisphere between about 30° and 60° S: southern Chile and Argentina, South Africa, southern Australia, New Zealand and the sub-Antarctic. There is no porbeagle in the North Pacific; its place there is taken by the salmon shark.

Within that range it is a shark of the continental shelf and the shelf edge, most often in the top 200 m over banks and fishing grounds where its prey shoals. Water temperature is the limit: porbeagles are recorded from 1 to 23 °C but spend most of their time in 5 to 15 °C, and they move inshore and north in summer and offshore and south in winter to stay in that band.

Satellite tags have corrected two older ideas. Porbeagles are not deep-water sharks that "prefer 1,350 m": tagged animals spend most days above 200 m, and 1,360 m is the deepest dive on record, made during winter off Nova Scotia. They also migrate far: tagged sharks from Ireland have reached the Bay of Biscay and Canadian animals the Sargasso Sea.

What porbeagles eat and how they hunt

The porbeagle's English name in fishing ports is "mackerel shark", and that is a fair summary of its diet. In the North Atlantic the stomachs examined are dominated by pelagic schooling fish, mackerel, herring, sand lance and pilchard, and by the groundfish of the banks, cod, haddock, hake, whiting and flatfish, with squid in every season and spiny dogfish now and then. Southern Hemisphere porbeagles eat more squid and lanternfish.

Hunting is by pursuit, not ambush. A porbeagle drives into a shoal at speed, seizes a fish crosswise in its narrow teeth and swallows it whole or in two bites; the little cusplets at the base of each tooth help hold slippery prey. The warm muscle described below is what makes this possible in water of 5 °C, where a cold-blooded predator would be too sluggish to catch a mackerel.

Feeding follows the fish. Porbeagles work the surface in summer over the banks and drop deeper in winter, and they concentrate where shoals gather: the mouth of the Bay of Fundy, the Celtic Sea, the Norwegian banks and the Lofoten cod grounds. Commercial fishermen once regarded them as a pest for stealing hooked fish and ripping nets.

Warm blood, senses and behaviour

The porbeagle is one of the few fish that make their own heat. A counter-current network of blood vessels, the rete mirabile, holds the warmth generated by the red swimming muscle inside the body instead of losing it at the gills, and porbeagles have been measured with muscle temperatures 7 to 10 °C above the sea around them. It is why the species can live year-round in water that would immobilise most sharks, and why it must eat a great deal: a warm body burns fuel whether or not there is anything to catch.

The senses are standard mackerel shark equipment: big eyes adapted to dim water, a good sense of smell, a lateral line for the pressure waves of a shoal and the ampullae of Lorenzini for the electrical field of a fish in the last few centimetres.

Porbeagles are usually seen alone or in small groups and there is no evidence of a social structure, but they do gather where food is dense, and they segregate by sex and size: the Bay of Fundy fishery, for example, was dominated by mature females in autumn. Reports of porbeagles "playing" with floating objects and kelp are old and unverified, and the animals filmed circling divers near oil platforms were, on the evidence, simply curious.

Reproduction and lifespan

Mating in the north-west Atlantic takes place from September to November, on the banks off Newfoundland and in the Gulf of Maine, and later into January in some areas; males bite the female's flanks, gill region and pectoral fins to hold on, and the scars are common on mature females. The porbeagle is ovoviviparous with oophagy: the eggs hatch inside the mother, and each embryo then feeds on unfertilised eggs she keeps releasing. A litter is 1 to 5, typically 4, usually two in each uterus, born in spring after a gestation of 8 to 9 months. Females appear to breed every year.

Pups of 60 to 75 cm arrive in April to June in the Gulf of Maine and on the Scotian Shelf, and juveniles stay on the shelf in shallower, warmer water than the adults for their first years. Age has been studied more carefully in the porbeagle than in most sharks. Growth bands in the vertebrae, validated by bomb radiocarbon, show males maturing at about 8 years and females at about 13 in the north-west Atlantic, and 18 or more in New Zealand waters, where everything is slower.

The oldest validated porbeagle was about 26 years, and the growth models built on those data suggest a lifespan of 45 to 65 years for the species as a whole (compare other species on how long sharks live). A female that starts breeding at 13 and bears four pups a year cannot replace a population removed by the thousand.

How dangerous are porbeagles to people?

Not very, and the record says so plainly. The SharkSider database attributes nine incidents to the porbeagle, seven of them since 1900, none fatal; four have occurred since 2000. Of the six most recent, five caused no injury at all: a diver collecting sea urchins in the Bay of Fundy in 2000, a scuba diver in Maine in 2010 whose video camera was bitten, a shark fisherman off Islay in 2012 whose shoe was bitten by the porbeagle he had just landed, a Devon diver in 1971 who drove a shark off with a lobster hook, and a 1956 case near Malta that involved a boat and a shark that may have been a great white. The only genuine injury in the recent record is a bodysurfer with cuts to the foot from a 1.5 m porbeagle at Gran Canaria in 2017.

Diving and spearfishing account for three of the nine incidents, fishing and boats for two, with one each for surfing and swimming and two unrecorded, and the cases are spread across Canada, the United States, Britain, Spain, Malta and Italy. That distribution is a map of where people fish for porbeagles, not of any aggression: nearly every incident involved a hooked or landed shark, or a diver who approached one.

The reason porbeagles and swimmers so rarely meet is temperature. The species keeps to water below about 18 °C and to offshore banks, while people swim in warm shallows. The advice on what to do in a shark encounter is unlikely to be needed for this species.

Porbeagle Shark incidents in the SharkSider database

• Records attributed9 (7 since 1900)
• Fatal0 (0%)
• Years covered1812–2017
• Since 20004 incidents, 0 fatal
• Most common activityDiving & spearfishing
• Most recordsEngland (2)

The six most recent records attributed to the porbeagle shark

• 16 September 2017 · Gran Canaria, Canary Islands, SpainBody surfing — Lacerations to right footRecorded as: Porbeagle, 1.5 m · not fatal
• 31 August 2012 · Off the Isle of Islay, Inner Hebrides, ScotlandShark fishing — No injury, shoe bitten by hooked and landed shark provoked incidentRecorded as: Porbeagle shark, 7' · not fatal
• 23 October 2010 · Burnt Cove near Eastport, Washington County, Maine, USAScuba diving — No injury to diver, shark bit his video cameraRecorded as: Porbeagle shark, 8' · not fatal
• 5 December 2000 · Bay of Fundy, New Brunswick, CanadaDiving for sea urchins — No injuryRecorded as: Porbeagle shark, 3 m [10']rk · not fatal
• 1 June 1971 · Beesands, South Devon, British IslesScuba diving — No injury, said to have been attacked by shark but drove it away with a lobster hookRecorded as: 3.6 m porbeagle shark · not fatal
• August 1956 · Between Filfla Island and Wied iz-Zurrieq, Congreve Channel, MaltaFishing — No injury to occupants, but emmanuel "later died of shock in hospital"Recorded as: Porbeagle or white shark · not fatal

Records are matched on the shark named in each report (“porbeagle”), so they include incidents where the species was reported rather than confirmed. Full records by country on the shark attacks pages.

Conservation status

The porbeagle is Vulnerable on the IUCN Red List, assessed in 2018 with a decreasing global trend, and the regional picture is worse: the north-east Atlantic population is assessed as Critically Endangered and the north-west Atlantic as Endangered, and the Mediterranean stock is close to gone. The species has been on CITES Appendix II since 2013 (in force from September 2014), requiring export permits for its meat and fins, and on Appendix II of the Convention on Migratory Species since 2008.

The decline was caused by two fisheries. Norwegian longliners began targeting porbeagles in the north-east Atlantic in the 1930s; landings peaked after the Second World War and collapsed in the 1960s. The Norwegian and Faroese fleets then moved to the north-west Atlantic, took about 9,000 tonnes in 1964 and fished that stock down within six years. A Canadian fishery in the 1990s repeated the pattern on the recovering stock, and by 2002 quotas had been cut to a fraction.

Management has caught up. The European Union set a zero quota in 2010 and now bans EU vessels from landing porbeagles; Norway prohibited directed fishing in 2007; Canada closed its directed fishery in 2013 and allows only a small bycatch; the United States keeps a small quota under its Atlantic shark plan and lists the species as a species of concern. Recovery is expected to take decades because of the late maturity and small litters described above, and bycatch on longlines and in trawls continues everywhere the shark meets a net.

Similar species and close relatives

The porbeagle's twin is the salmon shark, the only other member of Lamna, which replaces it in the North Pacific: the salmon shark is chunkier, lacks the white dorsal patch and has dark blotches on its belly, but shares the double tail keel and the same warm-blooded physiology. The other mackerel sharks are the great white, which is far larger with serrated triangular teeth, and the two makos, the shortfin and the longfin, both slimmer, with a single keel, no white dorsal patch and hooked teeth without cusplets. The whole family shares the crescent tail, the conical snout and the heat-exchanging rete described above; for how they relate, see the evolution of sharks.

Outside the family, small porbeagles in British and Irish waters are regularly reported as great whites, and larger ones as makos. The blue shark, the other common offshore shark in the same seas, is slender, long-snouted and blue with no keel, and the basking shark, occasionally mistaken for a huge porbeagle at the surface, has gill slits that almost meet under the throat and a cavernous mouth.

• Salmon Sharkspecies profile
• Shortfin Mako Sharkspecies profile
• Longfin Mako Sharkspecies profile
• Great White Sharkspecies profile
• Blue Sharkspecies profile
• Basking Sharkspecies profile

Written and reviewed by

SharkSider Editorial Team

A small team focused on researching sharks and making marine biology easy to understand. Every page is reviewed against current species records and the SharkSider attack database, and updated when new incidents or research appear.

Published December 1, 2014 · Last updated September 22, 2026 · 9 incidents attributed to the porbeagle shark in the SharkSider attack database (0 fatal), updated weekly.