The combtooth dogfish (Centroscyllium nigrum) is a small deep-sea lanternshark of the eastern Pacific, growing to about 50 cm (20 in) and living on and just above the bottom between roughly 270 and 1,150 m. It is sooty black-brown with conspicuously white-edged fins, has two spined dorsal fins, no anal fin, and rows of many-cusped, comb-like teeth in both jaws.
It eats squid, deepwater shrimps and small midwater fish. Females carry a litter of about seven pups, which are born at roughly 11 to 13 cm after developing on yolk alone. Nothing about it is dangerous to people and no fishery targets it, which is why the IUCN lists it as Least Concern.
- Maximum lengthAbout 50 cm (20 in)
- WeightNo published maximum; under 1 kg
- LifespanUnknown; no ageing study exists
- Depth rangeAbout 270–1,150 m (900–3,800 ft)
- DietSquid, deepwater shrimps and small fish
- IUCN statusLeast Concern
- Kingdom
- Animalia
- Phylum
- Chordata
- Class
- Chondrichthyes
- Order
- Squaliformes
- Family
- Etmopteridae
- Genus
- Centroscyllium
- Species
- Centroscyllium nigrum
- Family (common)
- Lanternsharks
- Also known as
- Combtooth dogfish, Whitefin dogfish
On this page
- How to recognise a combtooth dogfish
- How big does a combtooth dogfish get?
- Where combtooth dogfish live
- What combtooth dogfish eat
- Behaviour and life in the dark
- Reproduction and lifespan
- Are combtooth dogfish dangerous?
- Conservation status
- Similar species and close relatives
- Frequently asked questions
- References
How to recognise a combtooth dogfish
Start with what is missing. Like every member of the order Squaliformes, this shark has no anal fin, and each of its two dorsal fins is armed with a grooved spine set into the leading edge. The second dorsal fin and its spine are clearly larger than the first, a detail worth insisting on because older accounts describe the two fins as equal. The body is fairly stout for a deep-sea dogfish, the snout short and bluntly pointed, and the tail fin short with a well-developed lower lobe.
The eyes are enormous, green in fresh specimens and set high on the head, the standard equipment of an animal living where the last blue daylight fades out. Colour is a uniform sooty blackish brown, relieved only by narrow white margins on the dorsal, pectoral and caudal fins, which is where the alternative name whitefin dogfish comes from. As in other lanternsharks the skin carries photophores, small light-producing organs scattered over the belly and flanks, though they do not form the sharp black flank bands seen in Etmopterus.
The teeth are the clincher and give the shark its name. In both jaws they are small, upright and carry three to seven slender cusps side by side, so a jaw looks like a row of tiny combs. No other group of sharks in the region has that arrangement: even close relatives in the lanternshark genus have cutting blades in the lower jaw and hooks above.
How big does a combtooth dogfish get?
This is a small shark even by the modest standards of the deep sea. The largest measured individuals are about 50 cm (20 in) in total length, and most specimens in museum collections fall between 35 and 45 cm. That places it comfortably among the smaller sharks of the world, though it is nowhere near the very smallest; for that comparison see our list of the smallest shark species.
Newborns measure roughly 11 to 13 cm, so a pup is about the length of a pencil. Growth rates have never been measured, but males are found to be sexually mature from around 35 cm and females from about 43 cm, meaning that both sexes breed at three-quarters of maximum length. Females run slightly larger than males, which is the usual pattern in squaliform sharks and is linked to the space a litter needs.
No maximum weight has been published. A 50 cm dogfish with a large oily liver and a lightly built skeleton weighs well under a kilogram, and specimens arrive at the surface soft and distorted by the pressure change, so weights taken on deck would not mean much in any case. Set beside the 1.8 m diver in the graphic below, 50 cm is easy to picture.
Where combtooth dogfish live
The species is an eastern Pacific animal with an outlying population in the central Pacific. Records run down the American margin from Baja California and the Gulf of California through the offshore ridges of Costa Rica and the Galapagos to Peru and northern Chile, and a separate cluster of specimens comes from the slopes of the Hawaiian Islands. Whether those two groups are one continuous population along the deep ridges between them, or two that have been separated for a long time, has never been tested genetically.
Depth is the more meaningful description of its habitat. Confirmed captures come from roughly 270 m down to about 1,150 m, with most between 400 and 900 m. The old claim that this shark occurs from one metre depth is a transcription error; nothing about its eyes, colour or body chemistry suits shallow water. Down there the temperature is a steady 4 to 8 °C, there is no daylight worth the name, and the shark lives on or just above the bottom of the continental slope, on seamount flanks and along the ridges of the tropical eastern Pacific.
Because the species is only ever caught by research trawls and occasional deepwater longlines, the distribution map below is really a map of where scientists have fished rather than the whole range. Gaps in it should be read as gaps in sampling.
What combtooth dogfish eat
Stomach contents from trawled specimens are dominated by three things: small squid, deepwater shrimps and prawns, and small bony fishes of the midwater, including lanternfishes that drift down from the layers above. Fragments of pelagic crustaceans and, occasionally, gelatinous material also turn up. In other words this is a generalist that takes soft, small, slow prey.
The comb-shaped teeth make sense in that light. A row of many-cusped teeth in both jaws works like a trap: close the jaws on a shrimp or a squid and the interlocking cusps hold it, while the shark's throat muscles do the rest. There is no cutting edge, no serration and no capacity to take a piece out of anything large. Sharks with this dentition do not tear at carcasses; they catch what they can swallow whole.
How the animal finds prey in total darkness is partly guesswork. The huge eyes are almost certainly used to detect bioluminescence, the flashes and glows produced by the shrimps and lanternfish themselves. Electroreception through the ampullae of Lorenzini works at close range whatever the light, and a well-developed lateral line registers the wake of something swimming nearby. The shark's own photophores may play a part too, as counter-illumination that erases its silhouette from below rather than as a lure.
Behaviour and life in the dark
No one has filmed a living combtooth dogfish. There is no submersible footage, no tagging study and no aquarium record, because the species cannot survive the pressure change to the surface. What follows is inference from anatomy and from trawl catches, and it should be read that way.
Trawls frequently take several individuals in a single haul, which suggests the sharks are at least loosely gathered rather than strictly solitary, and catches are sometimes dominated by one sex or one size class. Similar patterns in better-studied deep-sea dogfish point to schools sorted by size and sex, a sensible arrangement in an environment where meeting a mate at all is difficult.
The body plan describes a slow animal. The muscles are pale and poorly vascularised, the skeleton is lightly calcified and the liver is large and loaded with low-density oil that keeps the shark close to neutral buoyancy, so it can hang in the water without swimming. Food arrives rarely in the deep sea, and metabolic rates measured in related squaliform sharks are a fraction of those of a coastal species. The light organs in the skin are a genuine adaptation rather than a curiosity: they are under hormonal control in lanternsharks, and they most likely serve to break up the shark's outline and to signal to other members of its own species in water where there is nothing else to see.
Reproduction and lifespan
The combtooth dogfish is yolk-sac viviparous, the mode often called ovoviviparous. The eggs are fertilised internally and retained in the uterus, each embryo developing entirely on the yolk it started with, with no placental connection to the mother. When the yolk runs out the pups are born fully formed and ready to hunt, at roughly 11 to 13 cm long. Litters of about seven pups have been recorded, which is a typical figure for a small squaliform shark.
Males are mature by about 35 to 43 cm and females at around 43 cm. Gestation length has never been measured in this species, but deep-sea dogfish in general carry their young for a year or more, sometimes for two, because embryonic development in cold water is extremely slow. There is no evidence of a breeding season: in permanently dark, permanently cold water there is little to cue one, and mature females at different stages of pregnancy are found in the same hauls.
Lifespan is simply unknown. The vertebrae of deep-sea squaliforms are poorly calcified and hard to read, so the standard growth-band method often fails, and no ageing study has been published for this shark. Species of similar size and habitat live for decades rather than years, and the general rule described on our how long sharks live page holds here: cold, dark and slow means long-lived and slow to replace losses.
Are combtooth dogfish dangerous?
They are not, and they cannot be. A person and a combtooth dogfish have no realistic way of meeting: the shark lives hundreds of metres below the limit of recreational diving, in water too cold and too dark for anyone to swim in, and it dies on the way to the surface. Our database returns no incident attributed to the species, as the note below shows, and no shark file anywhere in the world holds one.
The only injury the species could plausibly cause is to a crew member sorting a trawl catch on deck. The dorsal spines are sharp and can puncture a hand, and the skin is covered in rough dermal denticles that will graze bare skin, so the sensible handling advice is the same as for any small dogfish: lift it by the tail with a gloved hand and keep fingers clear of the fins. The comb-like teeth are too small and too blunt to do damage even if the animal did bite. If you want to see where sharks like this sit next to the species that genuinely matter to swimmers, our list of the least dangerous sharks puts the risk in proportion.
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 combtooth dogfish as Least Concern. The reasoning is straightforward: the species is small, has no commercial value, lives across a wide stretch of the eastern and central Pacific, and much of its depth range lies below or outside the areas where deepwater fisheries currently operate.
That is not the same as saying nothing threatens it. Deepwater trawling and longlining for grenadiers, alfonsino and other slope species does take this shark as bycatch, and because it has no market value it is discarded, almost always dead. Seamounts in the tropical eastern Pacific have been fished hard in places, and a single pass of a bottom trawl removes both the sharks and the habitat structure they hunt over. The wider concern for the family is that squaliform sharks are among the least resilient fish in the ocean: a litter of seven pups every year or two, late maturity and slow growth mean that a local population, once removed, may take decades to return.
There is no fishery management measure aimed at this species anywhere in its range, and it is not listed by CITES or the Convention on Migratory Species. Its protection is entirely incidental, resting on depth limits, seamount closures and the simple fact that fishing 900 m of water is expensive. The general picture for deep-sea sharks is set out on our page on why sharks are endangered.
Similar species and close relatives
The genus Centroscyllium contains around seven species of small, dark, comb-toothed dogfish scattered through the deep water of every ocean. The best known is the black dogfish of the North Atlantic, a larger and commoner animal that is the reference point for the genus. In the southern hemisphere the granular dogfish of the south-west Atlantic and the ornate dogfish of the eastern Pacific are the nearest relatives, and separating preserved specimens of any of these from a combtooth dogfish usually needs tooth-cusp counts and fin measurements rather than a look at the colour.
Within the wider family Etmopteridae, the lanternsharks of the genus Etmopterus are the animals most often confused with it in a mixed trawl catch. The Hawaiian lanternshark overlaps with it around the Hawaiian slopes, and the green lanternshark is a similar size elsewhere, but both have dagger-like upper teeth, blade-like lower teeth and the dark flank and tail markings that Centroscyllium lacks. The oddest member of the family, the viper dogfish, is unmistakable once you see its needle teeth and protrusible jaws.
Gulper sharks of the family Centrophoridae, such as the little gulper shark, share the same depths and also carry two dorsal spines, but they are browner, larger and have blade-shaped teeth in the lower jaw.
- Black Dogfishspecies profile
- Granular Dogfish Sharkspecies profile
- Ornate Dogfishspecies profile
Viper Dogfishspecies profile- Hawaiian Lanternsharkspecies profile
- Blackbelly Lanternsharkspecies profile
Frequently asked questions
How big does a combtooth dogfish get?
About 50 cm, or 20 inches, in total length. Most specimens in collections are between 35 and 45 cm, and newborn pups measure roughly 11 to 13 cm. Males mature from around 35 cm and females from about 43 cm, so this shark breeds at three-quarters of its maximum size.
Where does the combtooth dogfish live?
On the deep slopes, ridges and seamounts of the eastern Pacific, from Baja California and the Gulf of California south past the Galapagos to Peru and northern Chile, plus a separate group of records around the Hawaiian Islands. It is a bottom-associated shark of the continental and island slopes, never found in shallow coastal water.
How deep do combtooth dogfish live?
Confirmed captures come from roughly 270 metres down to about 1,150 metres, with the majority between 400 and 900 metres. Older sources that give a depth range starting at about one metre are repeating a transcription error. The water at those depths is permanently dark and sits at around 4 to 8 degrees Celsius.
Why is it called a combtooth dogfish?
Because of its teeth. In both jaws they are small and upright and carry three to seven slender cusps side by side, so a row of them looks like the teeth of a comb. The scientific name of the genus, Centroscyllium, refers to the same feature. No other sharks in its range share that dentition.
What do combtooth dogfish eat?
Small squid, deepwater shrimps and prawns, and small midwater bony fishes such as lanternfishes. The comb-like teeth trap soft prey rather than cutting it, so everything is swallowed whole. Hunting in permanent darkness relies on large eyes tuned to bioluminescence, on electroreception and on the lateral line.
Does the combtooth dogfish glow?
Yes. Like other members of the lanternshark family it carries photophores, tiny light-producing organs, in the skin of the belly and flanks. They do not form the sharp black flank bands seen in Etmopterus lanternsharks. The most likely function is counter-illumination, erasing the shark's silhouette against the faint light from above.
How do combtooth dogfish reproduce?
They are yolk-sac viviparous. Eggs are fertilised internally and held in the uterus, each embryo living on its own yolk with no placental connection, and the pups are born fully formed at 11 to 13 cm. Litters of about seven pups have been recorded. Gestation has never been measured but is likely to exceed a year.
Are combtooth dogfish dangerous to humans?
No. They live hundreds of metres below the limit of diving and die on the way to the surface, so an encounter in the water is impossible. No incident has ever been attributed to the species. The only hazard is on deck, where the sharp dorsal spines can puncture a hand during sorting.
Is the combtooth dogfish endangered?
No. The IUCN lists it as Least Concern, because it is widespread in the eastern and central Pacific, has no commercial value and lives largely below the depths most fisheries work. It is still taken and discarded as bycatch by deepwater trawlers, and small deep-sea sharks recover from losses very slowly.
How long do combtooth dogfish live?
Nobody knows. No ageing study has been published for this species, and the poorly calcified vertebrae of deep-sea dogfish often cannot be read by the usual growth-band method. Deep-water sharks of similar size are generally long-lived, with lifespans measured in decades rather than years, so a similar figure is plausible here.
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 September 14, 2022 · Last updated September 22, 2026 · No incident attributed to this species in the SharkSider attack database, which is updated weekly.
