The blackfin gulper shark (Centrophorus isodon) is a deep-water dogfish of the north-west Pacific that reaches about 1.08 m (3.5 ft) and lives on the upper continental slope down to roughly 770 m. It is blackish-grey above and paler below, with jet-black webs to its fins, two spined dorsal fins, no anal fin and smooth, block-shaped skin denticles.
Stomach samples contain small fishes and cephalopods. Females bear live young grown on yolk alone, and the litter is just two pups, among the smallest of any shark. Maturity comes at about 97 to 100 cm, close to maximum length. Heavy deep-water fishing in the South China Sea has left the IUCN listing it as Endangered.
- Maximum length1.08 m (3.5 ft); females larger than males
- WeightNot published for the species
- LifespanUnknown; no ageing study has been attempted
- Depth rangeUpper slope, recorded to about 770 m (2,530 ft)
- DietSmall bony fishes and cephalopods
- IUCN statusEndangered (assessed 2019)
- Kingdom
- Animalia
- Phylum
- Chordata
- Class
- Chondrichthyes
- Order
- Squaliformes
- Family
- Centrophoridae
- Genus
- Centrophorus
- Species
- Centrophorus isodon
- Family (common)
- Gulper sharks
- Also known as
- Blackfin gulper dogfish
On this page
- How to recognise a blackfin gulper shark
- How big does a blackfin gulper shark get?
- Where blackfin gulper sharks live
- What blackfin gulper sharks eat
- Behaviour and deep-water adaptations
- Reproduction and lifespan
- Is the blackfin gulper shark dangerous to people?
- Conservation status
- Similar species and close relatives
- Frequently asked questions
- References
How to recognise a blackfin gulper shark
The fins give the species its name and its quickest field mark. Between the fin rays the membrane is jet black, so each fin looks as though it has been dipped in ink, standing out against a body that is otherwise blackish-grey above and only a shade lighter below. No other gulper shark in the region shows the contrast so clearly.
The rest of the anatomy is standard for the genus and worth knowing, because it is what rules out everything that is not a gulper shark. There are two dorsal fins, each with a stout grooved spine on its leading edge, and no anal fin at all. The snout is flattened and moderately long, the eyes are large and oval with the green reflective sheen typical of deep-water squaloids, and the body is stout in front and tapers sharply behind the second dorsal. Run a hand along the flank and the skin feels comparatively smooth: the denticles are block-shaped with flat crowns, set close together like paving, rather than the cusped, widely spaced scales of the long-snouted Deania dogfishes.
The teeth explain the scientific name. In most gulper sharks the lower teeth are conspicuously larger and broader than the uppers; in Centrophorus isodon the two sets are much closer in size, which is what isodon, equal-toothed, refers to. Both jaws carry blade-like cutting teeth with a single oblique cusp, arranged into a continuous edge.
How big does a blackfin gulper shark get?
The maximum recorded total length is about 108 cm (3.5 ft). Older popular accounts describe males of 2.5 to 2.8 feet and females of 2.6 to 3.1 feet, which works out at roughly 76 to 95 cm; those figures come from a small early sample and understate the species, since larger specimens have since been measured. Females run larger than males, the rule throughout the family.
Maturity is reached very late in that range, at about 97 to 100 cm, which is to say that a blackfin gulper shark is not capable of breeding until it is within a few centimetres of the largest size ever recorded for its species. Very few sharks cut it that fine. The largest embryo examined measured 32 cm, so pups are probably born at around that length, close to a third of adult size.
No weights have been published, and there is no point in guessing one; a metre-long squaloid with a soft body and an outsized liver is a light animal for its length, but a number invented here would simply be repeated elsewhere. Scale is best judged from the bar below, which compares the 1.08 m maximum with a 1.8 m diver. Everything about the dimensions of this shark, and particularly the gap between size at maturity and maximum size, matters for how it responds to fishing.
Where blackfin gulper sharks live
Honestly, hardly anyone knows. The species was described in 1981 from material collected in the northern South China Sea, and the confirmed localities are still the Xisha or Paracel Islands and the slope off the mouth of the Pearl River near Hong Kong, in southern China. That is a very small verified range for a marine fish.
Beyond it, the picture dissolves into possibility. Specimens resembling this shark have been reported from the Maldives, Sri Lanka and the Philippines, and older summaries stretch the range across the western Pacific and Indian Oceans on that basis. The genus Centrophorus has been a taxonomic swamp for a century, with species repeatedly confused, merged and split, and until those specimens are re-examined the safe position is that they may or may not belong here.
The habitat itself is clearer. This is an upper continental slope shark, not a shelf one: it has been taken between roughly 435 and 770 m, close to the bottom, in tropical water. Accounts placing it on the continental shelf are mistaken, since the shelf ends long before 400 m. That band of the slope in the northern South China Sea is among the most intensively trawled deep-water habitat anywhere on earth, which is the single most important fact about this shark's situation. For the wider pattern of how depth sorts shark species, see where sharks live.
What blackfin gulper sharks eat
The diet has never been studied properly. What exists is a short list drawn from the stomachs of specimens that happened to reach a laboratory: cephalopods, mostly squid, and bony fishes. Nothing in those samples points to specialisation, and nothing rules it out either, because the sample is far too small.
The jaws are more informative than the stomachs. Blade-like cutting teeth of similar size in both jaws, meeting edge to edge, make a scissor rather than a trap: this is a shark that slices pieces from prey or cuts a small fish in two, not one that swallows things whole or crushes shells. That matches a diet of soft-bodied squid and slope fishes and argues against any significant use of crabs or other armoured animals.
Hunting takes place in permanent darkness, several hundred metres below the last of the daylight. The relevant senses are smell, which works over long distances in still deep water, the lateral line, and the electroreceptive ampullae of Lorenzini distributed across the snout, which register the muscle activity of an animal at close range. The large green-shining eye is not useless down there: it is tuned to the blue-green flashes of bioluminescent squid and fishes, which at those depths are the only light there is.
Behaviour and deep-water adaptations
No blackfin gulper shark has ever been observed alive, so a page that describes its behaviour in detail is describing something else. What can be said comes from its anatomy and from the habits of better-studied members of the genus.
The buoyancy system is the defining adaptation. Gulper sharks carry a liver that can account for around a quarter of body weight, packed with squalene, a light hydrocarbon that offsets the weight of the animal so precisely that it can hang in mid-water without swimming. A shark that does not need to swim to stay up can afford very low muscle mass and a very low metabolic rate, which is exactly what this soft-bodied, slow-looking animal shows. It is also the reason the family is targeted at all: squalene has commercial value, and a gulper shark liver is worth more than the rest of the fish.
Other members of the genus form loose aggregations on specific slope features and segregate by size and sex, with pregnant females often occupying particular depth bands. Something similar probably happens here, but nobody has sampled enough animals to demonstrate it. There is no information on movement, none on daily rhythm, and none on social behaviour. Cataloguing what is unknown is more useful than filling the space with statements that apply to all sharks equally, and the honest summary is that the blackfin gulper shark's life has never been watched.
Reproduction and lifespan
Two pups. That is the whole litter, and it is the most important number on this page. The blackfin gulper shark is a live-bearer whose embryos develop inside the mother on the yolk supplied in the egg, with no placenta and no supplementary feeding, and the largest embryo on record measured 32 cm, so birth size is probably close to that.
A litter of two is among the smallest known for any shark, matched within this family by the dumb gulper shark, which also produces one or two pups at a time. Gestation length has not been measured for this species; in related gulper sharks pregnancy runs to two years or more, and females appear to rest between litters rather than breeding every year. Combine a two-pup litter with a multi-year cycle and maturity at 97 to 100 cm, and a single female may produce only a handful of offspring in her whole life.
Age has never been investigated. There is no vertebral study, no bomb-radiocarbon work and no growth curve for Centrophorus isodon, so any lifespan figure quoted for it is fabricated. Congeners that have been aged live a long time: leafscale gulper sharks have been estimated at around seventy years. If that applies here, a single generation of this shark spans several decades, which means a population knocked down by fishing in the 1990s would still be recovering today. The general principle is set out under how long sharks live, and it is the entire explanation for the species' Red List status.
Is the blackfin gulper shark dangerous to people?
Not in any sense. The species lives several hundred metres down on a tropical slope, reaches barely a metre, and has a mouth suited to squid. The SharkSider database records no incident attributed to it, and none is imaginable.
The only contact is commercial. Crews on deep-water trawlers and longliners in the South China Sea handle these sharks when they come up, and the practical hazards are the two dorsal spines, which are sharp enough to go through a glove, and a set of cutting teeth in a dying animal. The far more serious danger runs the other way: for the blackfin gulper shark, meeting a person has proved close to fatal as a species.
One consumer question does come up, and the answer is no. Deep-water sharks of this family accumulate mercury over a very long life, so eating slope shark meat is unwise quite apart from the conservation argument. Nor does any aquarium hold the species: animals brought up from 600 m suffer fatal decompression and temperature injuries, so a blackfin gulper shark will never be seen alive outside its own habitat.
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 Centrophorus isodon as Endangered, in the assessment carried out in 2019, and it is worth understanding how a shark almost nobody has studied earns that category. The listing rests on two things: a very restricted known range, and the intensity of fishing within it. Deep-water trawl and longline fleets have worked the South China Sea slope hard since the 1980s, and catch rates for large slope sharks across the region have fallen steeply.
When a blackfin gulper shark is caught it is kept. The meat is sold, the fins enter the trade, and the squalene-rich liver is the most valuable part of all, used in cosmetics and vaccine adjuvants. There is no size limit, no quota and no realistic prospect of release survival from a trawl hauled from 700 m. Against a two-pup litter and a generation time measured in decades, even moderate fishing mortality is more than the population can absorb.
No member of the family Centrophoridae is listed on CITES or the Convention on Migratory Species, and the species receives no specific legal protection in any country in its range. Practical conservation would mean depth limits on slope trawling, which a few nations have adopted elsewhere, and basic survey work to find out where the shark actually occurs. Both are cheap compared with the alternative. The wider economics of the deep-water shark trade are covered under shark fisheries and conservation, and the reasoning behind the listings under why sharks are endangered.
Similar species and close relatives
Telling gulper sharks apart is a specialist job, and the genus has been revised repeatedly because so many specimens were misidentified. Within the region, the gulper shark (C. granulosus) and the leafscale gulper shark (C. squamosus) are the large species, the latter reaching 1.6 m with overlapping leaf-shaped denticles quite unlike the flat paving of this one. The little gulper shark and smallfin gulper shark are closer in size and are separated on fin proportions and denticle shape rather than colour.
The dumb gulper shark of eastern Australia is the species whose story this one may be repeating: it was fished down to a fraction of its original numbers in a couple of decades on the same kind of two-pup biology, and is now Critically Endangered with closures in place. The dwarf gulper shark is the smallest member of the group.
Outside the genus but in the same family, the long-snouted birdbeak dogfish and longsnout dogfish are unmistakable once the head is seen: their snouts are longer than the rest of the skull, and their denticles are shaped like tiny pitchforks. Deeper still live the spineless squaloids, the Portuguese dogfish and the kitefin shark, which share the oily liver but carry no fin spines at all.
- Gulper Sharkspecies profile
- Smallfin Gulper Sharkspecies profile
- Little Gulper Sharkspecies profile
- Dumb Gulper Sharkspecies profile
- Leafscale Gulper Sharkspecies profile
- Dwarf Gulper Sharkspecies profile
Frequently asked questions
How big does a blackfin gulper shark get?
The maximum recorded total length is about 108 centimetres, or 3.5 feet, with females larger than males. Maturity is reached very late, at roughly 97 to 100 centimetres, so breeding adults are close to maximum size. The largest embryo examined measured 32 centimetres, which is probably close to size at birth.
Where does the blackfin gulper shark live?
Confirmed records come only from the northern South China Sea: the Xisha or Paracel Islands and the slope off the mouth of the Pearl River near Hong Kong. Similar sharks have been reported from the Maldives, Sri Lanka and the Philippines, but those specimens have not been confirmed as this species.
How deep do blackfin gulper sharks live?
They are upper continental slope sharks, recorded close to the bottom between roughly 435 and 770 metres. Descriptions placing them on the continental shelf are wrong, because the shelf gives way to the slope long before 400 metres. Their depth band is among the most heavily trawled deep-water habitat in the world.
Why is it called the blackfin gulper shark?
Because the membrane between the fin rays is jet black, so every fin looks dipped in ink against a blackish-grey body. Gulper is the English name for the genus Centrophorus, and the scientific name isodon means equal-toothed, referring to the unusually similar size of the upper and lower teeth.
What do blackfin gulper sharks eat?
The few stomachs examined contained cephalopods, mainly squid, and small bony fishes. The diet has never been studied systematically. Blade-like cutting teeth of similar size in both jaws suggest a shark that slices soft-bodied prey rather than crushing shells, which fits a squid and slope-fish diet.
How many pups does a blackfin gulper shark have?
Two. That is among the smallest litters recorded for any shark, matched within the family by the dumb gulper shark. The embryos develop inside the mother on yolk alone, without a placenta. Gestation length is unmeasured, but related gulper sharks carry their young for two years or more between rests.
Are blackfin gulper sharks dangerous to humans?
No. They live several hundred metres down, reach barely a metre, and eat squid. No incident has ever been attributed to the species and none is plausible. The only people who ever handle one are deep-water trawler crews, whose real hazards are the two sharp dorsal fin spines.
How long do blackfin gulper sharks live?
Nobody knows. There is no ageing study of any kind for this species, so any specific number would be invented. Related gulper sharks that have been aged live a long time, with leafscale gulper sharks estimated at around seventy years, which suggests a generation here spans several decades.
Why is the blackfin gulper shark endangered?
The IUCN listed it as Endangered in 2019 because of intense deep-water trawling and longlining across its small known range in the South China Sea. Caught sharks are kept for meat, fins and the valuable squalene-rich liver. With litters of two and a generation time of decades, the population cannot replace what is removed.
Is the blackfin gulper shark protected by law?
Not specifically. No member of the gulper shark family is listed on CITES or the Convention on Migratory Species, and no country in its range gives it targeted protection. Depth limits on slope trawling, of the kind used for the dumb gulper shark in Australia, would be the most practical measure available.
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 10, 2022 · Last updated September 22, 2026 · No incident attributed to this species in the SharkSider attack database, which is updated weekly.
