Smallfin Gulper Shark

• Maximum lengthAbout 100 cm (3.3 ft); females larger
• WeightNot published; several kilograms at full size
• LifespanNever aged; gulper sharks likely exceed 40 years
• Depth range125–823 m (410–2,700 ft)
• DietBony fishes, squid, octopus, shrimps and small sharks
• IUCN statusVulnerable (assessed 2019)

How to recognise a smallfin gulper shark

The first check is the same one that sorts out every deep-water dogfish: a stout grooved spine standing at the leading edge of each dorsal fin, and no anal fin at all. That combination places the animal in the order Squaliformes and rules out catsharks, houndsharks and everything else likely to come up in the same haul.

The eyes then narrow it to the gulper sharks. They are enormous — long, oval and taking up much of the side of the head — and in a fresh specimen they glow a distinct green, an effect of the reflective layer behind the retina that gathers what little light exists at 500 m. Add a short, thick, rounded snout and a heavy-set body and you are looking at a Centrophorus.

Getting to the species is harder, and it is worth being honest about that: the genus is one of the most confused in shark taxonomy, and specimens have been reassigned repeatedly. For this one, look for the fin proportions the name refers to — the second dorsal fin is noticeably smaller than the first, and the pectoral fins have short, angular rear tips rather than the long trailing points of some relatives. The colour is plain greyish-brown above, paler below, with dark fin margins and no spots or markings.

The skin is not smooth, whatever older descriptions say. Run a hand forward along the flank and it rasps: the body is armoured in flat, block-shaped dermal denticles set edge to edge like paving. The teeth differ between the jaws — small, upright, slightly bent teeth above, and much larger, strongly angled blade-like teeth below, which lock into a continuous cutting edge.

How big does a smallfin gulper shark get?

The largest recorded individuals measure about 100 cm (3.3 ft) in total length. That is the ceiling rather than the norm: most adults taken in trawls are smaller, with males averaging around 70 cm and females around 90 cm, so females are the larger sex by a clear margin. As gulper sharks go this is a middling species — bigger than the dwarf gulper shark, well short of the leafscale gulper shark at 1.6 m.

Weight is not published. A 90 cm gulper shark is a stocky, heavy-headed animal of several kilograms, a good deal of which is liver: in this family the liver can make up a quarter of body weight, filled with the light oil that keeps a shark without a swim bladder neutrally buoyant in deep water. That oil is also the reason the species has been fished.

The figures that matter most for its survival are the ones at the other end. Maturity is not reached until around 80 cm or more, which is four-fifths of the maximum length, and pups are born at roughly 30 cm. A female therefore spends the great majority of her life growing before she produces her first pair of pups, and a trawl that removes 90 cm animals is removing exactly the individuals the population depends on.

Where smallfin gulper sharks live

The range is wide but thin, stretching across the Indo-West Pacific. Records run from southern Africa and Mozambique, through India, to Japan as far north as Honshu, and south through the Philippines and Indonesia to New Caledonia, Vanuatu and the eastern and southern coasts of Australia. It is not a shark of the open ocean between those places; it lives where the sea floor is at the right depth, which means the outer shelf and the upper slope of continents and islands.

That depth band runs from about 125 m to 823 m, with most captures between roughly 200 and 600 m. It is a bottom-associated species: it hangs close to the sea bed, sometimes in numbers where the slope is productive, and it does not appear to range far up into midwater. Water there is cold, permanently dark and low in food compared with the shelf above.

One caveat about the map. Centrophorus has been revised repeatedly, most recently in the last few years, and gulper sharks from different oceans have been swapped between names more than once. The Australian and Japanese records are secure; some of the reports from the far west and north of the range may prove to belong to related species when material is re-examined. Anyone comparing a distribution map for this shark across two sources should expect the coastlines to disagree.

What smallfin gulper sharks eat

For a deep-slope shark this one is comparatively well documented, and the picture is of a broad, opportunistic predator. Bony fishes make up the bulk of the diet — lanternfishes, rattails and other slope species — supported by squid and octopus, shrimps and other crustaceans, and, unusually, other sharks: small dogfish and their egg cases turn up in stomach contents. Tunicates and other soft drifting animals appear as well.

The jaws explain the range. Upper and lower teeth are different tools: the small upright upper teeth hold, while the large, strongly angled lower teeth form a single continuous blade that saws through whatever the shark has gripped. A gulper shark can therefore take pieces out of prey larger than its own head, which is what allows a metre-long animal to feed on other sharks.

Finding food in permanent darkness falls to three senses working together. The huge green eyes catch the faint light of bioluminescent animals, which at 500 m is the only light there is; smell and the lateral line cover the middle distance; and the ampullae of Lorenzini take over in the final approach, detecting the electrical field of an animal even when it is buried or motionless. Sinking carrion is almost certainly part of the diet too — at these depths nothing edible goes to waste.

Behaviour on the slope

Nobody has watched this shark live. There is no submersible footage of the species, no tagging study and no aquarium record, and the honest summary of its behaviour is a short list of inferences drawn from catch data and anatomy.

The catches suggest aggregation. Gulper sharks tend to be taken in concentrated numbers on particular stretches of slope rather than evenly along it, and where a fishery has worked such a ground, it has often taken a large part of the local population in a short time. Whether these are true schools, feeding aggregations or simply the result of patchy food is unresolved, but the practical effect is the same: the species is caught in bursts.

Sex and size separation is a second likely pattern, well documented in other members of the family, where pregnant females and juveniles occupy different depths from mature males. If it holds here, a fishery working one depth band can take a disproportionate share of one part of the population.

The oil-filled liver deserves a mention as behaviour as much as anatomy. It gives the shark near-neutral buoyancy, so it can hang just above the bottom with almost no effort — an economical way to live somewhere food is scarce, and a slow, unhurried existence compared with any coastal shark. The dorsal spines are its only real defence.

Reproduction and lifespan

Smallfin gulper sharks are live-bearers of the simplest kind. The eggs hatch inside the mother and the embryos are nourished entirely by their own yolk sacs, with no placental link of any sort, until they are born at around 30 cm as fully formed miniature adults.

The litter size is the central fact about this species: two. Not two on average with occasional larger broods — two is what a female carries, one in each uterus, and the reproductive cycle is thought to run about two years. That works out at roughly one pup produced per female per year, which is close to the lowest reproductive output known in any shark, and it sits at the heart of every conservation concern about the gulper sharks.

Put that next to the size at maturity, around 80 cm, and the arithmetic is unforgiving. A female must survive to nearly her full length before breeding at all, then produce a pair of pups every second year. A population reduced by fishing cannot recover on any timescale a fishery would recognise; recovery for gulper sharks is measured in decades at best.

Age itself has never been established for this species. Nobody has sectioned its dorsal fin spines, which carry countable growth bands and are the standard tool for dogfish, so there is no growth curve and no maximum recorded age. Deep-water squaloids that have been aged routinely pass forty years, which is the best comparison available and fits everything else known here; how such figures are produced is set out under how long sharks live.

Are smallfin gulper sharks dangerous?

No. A metre-long shark living between 125 and 823 m on the continental slope has no contact with swimmers, surfers or recreational divers, and never will: the shallowest part of its range is already twice as deep as a technical dive. Nothing in the SharkSider database, and nothing in any attack file worldwide, is attributed to it.

The only risk is on deck, and it is the ordinary one for a dogfish. The grooved spine in front of each dorsal fin is sharp, the shark twists when handled, and a puncture is painful and slow to heal. Beyond that, a gulper shark's blade-like lower teeth would give a nasty cut to anyone careless with a dead animal's jaws. The species belongs among the least dangerous sharks, and the traffic in this relationship runs entirely the other way.

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 smallfin gulper shark as Vulnerable, in an assessment dated 2019, and the reason is the mismatch between what the species produces and what deep fisheries remove. It is caught in deepwater trawls, on bottom longlines and in gillnets across much of its range, partly as bycatch and partly as a target, and it is used for meat, fishmeal, fins and above all for the squalene in its oil-rich liver, which has a high value in cosmetics and other industries.

The clearest evidence comes from south-eastern Australia. When deepwater trawling expanded onto the upper slope there from the 1970s onwards, catch rates of gulper sharks fell steeply — by most estimates well over 90 per cent on the grounds that were fished, and the declines were fast enough to be visible within a single fishery's lifetime. Australia has since closed areas of slope to bottom fishing and restricted the retention of gulper sharks, which is the most substantial protection the species has anywhere.

Elsewhere there is very little. There is no CITES listing, no international management, and deepwater fishing across the Indo-Pacific is poorly monitored, so the trend outside Australian waters is essentially unknown. For a shark that produces two pups every two years and matures at four-fifths of its maximum length, a fishery does not need to be large to be unsustainable — the pattern set out under why sharks are endangered, in one of its clearest examples.

Similar species and close relatives

Its closest relatives are the other gulper sharks, and telling them apart is a specialist's job. The gulper shark itself is larger and heavier, the little gulper shark slimmer with a longer snout, and the leafscale gulper shark reaches 1.6 m with distinctive overlapping leaf-shaped denticles. The dwarf gulper shark is a smaller Indo-Pacific species that overlaps in range. All share the two spined dorsal fins, the missing anal fin, the green eyes and the enormous liver, and all have the same desperately slow reproduction.

The Australian case deserves its own mention. The dumb gulper shark, an eastern Australian endemic, was reduced so severely by the same slope fishery that it is now one of the most threatened sharks in the country — the clearest warning of what this family cannot absorb.

Slightly further out sits the birdbeak dogfish, the same family built on a long flattened snout, and beyond that the true dogfish such as the Pacific spiny dogfish, which share the spines but not the green eyes or the oil-heavy liver. How the squaliform families relate to one another is laid out in the guide to the types of sharks.

• Dwarf Gulper Sharkspecies profile
• Little Gulper Sharkspecies profile
• Gulper Sharkspecies profile
• Leafscale Gulper Sharkspecies profile
• Dumb Gulper Sharkspecies profile
• Birdbeak Dogfish 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 October 25, 2022 · Last updated September 22, 2026 · No incident attributed to this species in the SharkSider attack database, which is updated weekly.