The arrowhead dogfish (Deania profundorum) is a slender deep-water gulper shark (family Centrophoridae) of up to about 1.1 m (3.6 ft) that lives on continental and island slopes at 275–1,785 m in the western Atlantic, off West and southern Africa, and around the Philippines. Its spade-shaped snout is longer than half its head, and it is the only Deania with a keel under the tail stalk.
It eats small bottom fishes, squid and shrimps. Females carry the embryos on a yolk sac and bear 5–7 pups of about 31 cm. The IUCN moved it to Near Threatened in 2024 because deep-water fisheries take it as bycatch across much of its range; it has never harmed anyone.
- Maximum lengthUp to about 110 cm (43 in); most adults under 80 cm
- WeightNo reliable measurement; a few kilograms at most
- LifespanUnknown; no ageing study exists
- Depth range275–1,785 m (900–5,860 ft), on the upper and middle slope
- DietSmall bottom fishes, squid, shrimps
- IUCN statusNear Threatened (assessed 2024)
- Kingdom
- Animalia
- Phylum
- Chordata
- Class
- Chondrichthyes
- Order
- Squaliformes
- Family
- Centrophoridae
- Genus
- Deania
- Species
- Deania profundorum
- Family (common)
- Gulper sharks
- Also known as
- Arrowhead shark, Deepwater arrowhead dogfish
On this page
- How to recognise an arrowhead dogfish
- How big does an arrowhead dogfish get?
- Where arrowhead dogfish live
- What arrowhead dogfish eat
- Behaviour and adaptations to the deep slope
- Reproduction and lifespan
- Is the arrowhead dogfish dangerous to people?
- Conservation status
- Similar species and close relatives
- Frequently asked questions
- References
How to recognise an arrowhead dogfish
The first thing you notice on a specimen laid out on a trawler's deck is the snout. It is extraordinarily long, flattened and spade-shaped, making up more than half the length of the head, and it gives the four Deania species their collective nickname of birdbeak or arrowhead dogfishes. Behind it sit two large green-glinting eyes set well forward, closer to the snout tip than to the gill slits, and a short mouth with two very different sets of teeth: small, narrow, upright cusps in the upper jaw and larger, blade-like lower teeth whose tips lean to one side and interlock into a single cutting edge.
The body is slim and uniformly dark grey to grey-brown, without spots, bands or pale fin margins. Both dorsal fins carry a grooved spine at the front; the second spine is the longer of the two, and the second dorsal fin is taller than the first, which is low and set behind the pectorals. There is no anal fin, as in every member of the order Squaliformes. Run a finger along the skin and it feels like coarse sandpaper, because each dermal denticle is raised on a tall stalk and ends in a crown with three prongs, a shape usually described as a pitchfork and unique to the genus.
One character separates the arrowhead from its three relatives at once: a low fleshy keel along the underside of the tail stalk, just ahead of the caudal fin. No other Deania has it. The arrowhead also matures at a smaller size than its relatives, so an adult that would be an immature birdbeak or longsnout dogfish of the same length is a fully grown arrowhead.
How big does an arrowhead dogfish get?
Bigger than the older books say. For decades the maximum was given as 76 cm (30 in), and most adults in surveys are still 45 to 80 cm; but a 2004 to 2005 deep-water survey off Madeira landed animals up to 110 cm (43 in), which is now the accepted maximum. Males are the smaller sex: they mature at 43 to 67 cm total length. Females mature from about 70 cm upward. For comparison, the birdbeak dogfish (Deania calcea) reaches around 1.2 m and the longsnout dogfish about 1.1 m, so the three are closer in size than was once thought.
Pups are born at roughly 31 cm (12 in), so a newborn is already 30 to 40 per cent of its mother's length, a typical ratio for a live-bearing deep-water shark that produces few, well-developed young.
No weights have been published for the species. A shark of this shape and length would weigh a few kilograms at most even with a full, oil-rich liver, which in gulper sharks can be a fifth of body mass. The size bar below sets the 110 cm maximum against a 1.8 m diver; the arrowhead reaches about the diver's hip.
Where arrowhead dogfish live
The arrowhead dogfish has a scattered, patchy distribution across three oceans, which is a common pattern for a slope species that is only found where deep-water trawls or longlines happen to work. In the western Atlantic it is recorded from North Carolina south past Florida into the northern Gulf of Mexico and the Caribbean, including deep water off Cuba. In the eastern Atlantic it is recorded from Madeira and along the West African slope from Western Sahara and Senegal down to Namibia, and around the Cape into the western Indian Ocean off South Africa. The type specimens came from the Philippines, collected by the US Fisheries steamer Albatross and described by Smith and Radcliffe in 1912, and the western Pacific population is still known mainly from there.
Everywhere it occurs, it is a bottom-associated shark of the upper and middle continental and island slope. Recorded depths run from 275 to 1,785 m (900 to 5,860 ft), with most catches between about 400 and 1,000 m, in water that stays at 4 to 10 °C all year and never sees daylight. The species name profundorum, Latin for "of the depths", was well chosen. There are no confirmed records from shelf waters shallower than about 250 m, so the arrowhead dogfish is never met by divers, swimmers or inshore anglers, and it does not appear on the country risk lists that SharkSider keeps for coastal species.
What arrowhead dogfish eat
Stomach contents from the few dozen specimens that have been examined show a diet of small animals that live on or just above the sea floor: lanternfish and other small bony fishes, squid and cuttlefish, and crustaceans, mainly deep-water shrimps. That is a standard menu for a small gulper shark, and it tells you how the animal hunts. The interlocking, blade-like lower teeth are built for cutting soft-bodied prey into pieces, while the small pointed upper teeth pin it in place; the arrowhead does not crush shells the way a bottom-feeding ray would.
The huge eyes and long snout are the hunting equipment. At 500 m and deeper, the only light is the faint blue glow of bioluminescent animals, and an eye with a large lens and a reflective layer behind the retina, the tapetum lucidum, gathers enough of it to spot a squid or a glowing lanternfish. The snout is packed with the jelly-filled pores of the ampullae of Lorenzini, which pick up the electric field of a shrimp buried in the mud a few centimetres away; a long, flat snout swept over the bottom works like a metal detector. The nostrils are large as well, and scent plumes carry far in slow, cold water, though the "miles away" figures often quoted for sharks are folklore (see how far sharks can really smell).
Feeding is almost certainly opportunistic: on a food-poor slope a kilogram of shark cannot afford to be choosy.
Behaviour and adaptations to the deep slope
No one has watched an arrowhead dogfish behave in the wild, so what follows is inferred from catches and from better-known relatives. Trawl hauls often bring up several individuals of the same sex or size together, which suggests the species forms loose groups sorted by sex and age, as the birdbeak dogfish and the gulper shark do. Whether these are true schools or simply animals crowded onto the same patch of productive slope is unknown. The old claim that arrowheads gather in vast schools in the open ocean is wrong: the species is demersal, not pelagic.
The dorsal spines are defensive. A predator that grabs a Deania from above meets two sharp, grooved spines, one in front of each dorsal fin, and the pitchfork-crowned denticles make the whole body abrasive. Larger sharks that share the slope, such as the kitefin and sixgill sharks, are the likely predators.
Like other gulper sharks, the arrowhead has a large liver full of squalene, a low-density oil that gives it neutral buoyancy without a swim bladder. That lets it hover just above the bottom with slow sweeps of the tail, spending very little energy, which matters in a habitat where meals are rare. Everything else about it, from growth to reproduction, runs at the unhurried pace of a cold-blooded deep-water squaliform; the basic body plan is covered on our shark anatomy page.
Reproduction and lifespan
The arrowhead dogfish is a live-bearer without a placenta, a mode usually called ovoviviparity or yolk-sac viviparity. The female retains the fertilised eggs in her uteri, each embryo feeds on the yolk it was provided with, and the pups are born fully formed. Litters are small: 5 to 7 pups, each about 31 cm (12 in) long at birth. Too few pregnant females have been examined to say when they give birth, whether there is a breeding season, or where the nurseries are. In related gulper sharks gestation lasts one to two years and a female breeds only every second or third year, and there is no reason to think the arrowhead is faster.
Males mature at 43 to 67 cm and females at about 70 to 76 cm. Nobody has aged the species: the dorsal spines of squaliform sharks carry growth bands that can be counted, but the work has not been done for Deania profundorum. Its closest relatives, and deep-water dogfishes generally, grow slowly and live for decades, and some gulper sharks appear to take more than a decade to reach maturity. A realistic guess for the arrowhead is a lifespan of 20 years or more, but treat that as a guess; see how long sharks live for what is actually measured in other species.
Is the arrowhead dogfish dangerous to people?
No. The SharkSider attack database, which draws on the Global Shark Attack File, contains no incident of any kind attributed to this species, and there is no realistic way one could occur. An arrowhead dogfish is about a metre long at most, weighs a few kilograms, and spends its entire life more than a quarter of a kilometre below the surface. The only people who ever touch one are fisheries scientists and deep-water trawler crews sorting the catch.
Even then the risk runs the other way. The two dorsal spines can give a careless hand a puncture, and the interlocking lower teeth will slice a finger if you put it in the mouth of a fresh specimen, but neither is a "shark attack" in any sense. The handful of "dogfish" injuries in the database involve larger, shallow-water species hooked by anglers. The sharks that do bite people are covered under surviving a shark encounter; this one is not among them.
The SharkSider database has no incident attributed to this species. The database draws on the International Shark Attack File, the Global Shark Attack File and verified local reports, and is updated weekly.
Conservation status
The IUCN Red List assesses the arrowhead dogfish as Near Threatened (2024), a step down from the Least Concern it carried in 2020. The species is spread across three oceans and part of its depth range, roughly below 1,000 m, lies beyond most deep-water trawl and longline fisheries, but the assessors judged bycatch in the 300 to 1,000 m band heavy enough to infer a decline approaching the threatened thresholds. It is not listed on any CITES appendix and is not covered by the Convention on Migratory Species. No country protects it by name.
The concern is inherited from its family. Gulper sharks as a family are among the most fishing-sensitive sharks known, because they mature late, bear tiny litters and cannot rebound once depleted; several Centrophorus species, including the leafscale gulper shark and the gulper shark, have collapsed under targeted fishing for their squalene-rich livers. The arrowhead is taken as bycatch in the same deep-water trawl and longline fisheries off West Africa, in the Gulf of Mexico and off the Philippines, where it is discarded or sold cheaply as fishmeal or, occasionally, for its liver oil. It has no value as a food fish.
The honest summary is that the species has been spared the worst only because it is deep and unwanted, not because anyone is looking after it. Population trends are poorly measured, and any further expansion of deep-slope fishing into the 500 to 1,000 m band, as has happened in the North Atlantic, would push it toward the position of its overfished cousins. The wider picture of why sharks are endangered applies here in miniature.
Similar species and close relatives
The arrowhead's nearest relatives are the other three Deania species, all of which share the spade snout, pitchfork denticles and paired dorsal spines: the birdbeak dogfish (D. calcea), a wide-ranging shark of the North Atlantic, Pacific and southern oceans that grows to 1.2 m; the longsnout dogfish (D. quadrispinosa) of southern Australia, New Zealand and southern Africa; and the rough longnose dogfish (D. hystricosa), a larger, rougher-skinned animal of the eastern Atlantic and Japan. Only the arrowhead has the keel under the tail stalk.
Beyond the genus, the family Centrophoridae contains the gulper sharks proper, the Centrophorus species such as the gulper shark, leafscale gulper, little gulper and dwarf gulper. They have the same two spined dorsal fins and no anal fin, but a short, ordinary snout and pectoral fins with a drawn-out, angular rear tip. Other spiny dogfishes of the slope, such as the black dogfish and the velvet dogfish, belong to different families and are darker, stockier and shorter-snouted. If a small deep-water shark has a snout longer than half its head and a keel beneath the tail, it is an arrowhead dogfish and nothing else.
Birdbeak Dogfish Sharkspecies profile- Longsnout Dogfishspecies profile
- Gulper Sharkspecies profile
- Leafscale Gulper Sharkspecies profile
- Little Gulper Sharkspecies profile
- Black Dogfishspecies profile
Frequently asked questions
How big is an arrowhead dogfish?
Up to about 110 cm (43 in), a figure from a Madeira deep-water survey that replaced the old 76 cm maximum; most adults are 45 to 80 cm. Males mature at 43 to 67 cm and females from about 70 cm. Pups are born at roughly 31 cm. Weights have not been published, but a large adult is a few kilograms at most.
Where does the arrowhead dogfish live?
On the deep slopes of the western Atlantic from North Carolina to the Gulf of Mexico and Caribbean, the eastern Atlantic from Western Sahara to Namibia and South Africa, and the western Pacific off the Philippines. It lives on or near the bottom at 275 to 1,785 m, mostly between 400 and 1,000 m, in cold dark water.
What does the arrowhead dogfish eat?
Small bottom-living bony fishes such as lanternfish, squid and cuttlefish, and crustaceans, mainly deep-water shrimps. It finds them in the dark with large light-gathering eyes, a snout full of electrical sense organs and a keen sense of smell, and cuts them up with interlocking blade-like lower teeth.
How does the arrowhead dogfish reproduce?
It is ovoviviparous: the eggs hatch inside the mother and each embryo lives on its yolk sac until birth. Litters hold 5 to 7 pups about 31 cm long. Gestation, breeding season and nursery areas are unknown, but related gulper sharks carry their young for one to two years and breed only every two or three years.
How long do arrowhead dogfish live?
Nobody knows. No ageing study has been done on the species, though the growth bands in its dorsal spines could be counted. Deep-water dogfishes generally grow slowly and live for decades, and their relatives the gulper sharks take more than ten years to mature, so a lifespan of 20 years or more is plausible.
Is the arrowhead dogfish dangerous to humans?
No. It is about a metre long at most, weighs a few kilograms and lives more than 275 m down, far below any swimmer or diver. The SharkSider database holds no incident attributed to it. The only hazard is to fishermen handling a fresh specimen, whose two dorsal spines and sharp lower teeth can cut a hand.
Is the arrowhead dogfish endangered?
Not yet, but it is close. The IUCN Red List moved it to Near Threatened in 2024, from Least Concern in 2020, because deep-water trawls and longlines take it as bycatch across much of its range. It is not on CITES or CMS. It is caught off West Africa, in the Gulf of Mexico and the Philippines, and gulper sharks as a family recover very slowly.
Why is it called the arrowhead dogfish?
Because of its snout: long, flat and pointed, shaped like an arrowhead or a bird's beak, and making up more than half the head. The scientific name Deania profundorum honours the American ichthyologist Bashford Dean, and profundorum means "of the depths" in Latin, a reference to its deep-slope habitat.
How do you tell an arrowhead dogfish from a birdbeak dogfish?
Look under the tail. The arrowhead is the only Deania with a low keel along the underside of the tail stalk in front of the caudal fin. It also matures at a smaller size, males below 70 cm, and the birdbeak dogfish grows larger, to about 1.2 m. Both share the spade snout, two dorsal spines and pitchfork-shaped denticles.
References
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 October 6, 2022 · Last updated September 22, 2026 · No incident attributed to this species in the SharkSider attack database, which is updated weekly.
