The pygmy shark (Euprotomicrus bispinatus) is a tiny oceanic kitefin shark, at most 27 cm (10.6 in) long, that lives in the open waters of the southern Atlantic, Indian and Pacific oceans and the North Pacific, far from any coast. It is blackish-brown with pale fin edges, has a bulbous snout, a minute flag-like first dorsal fin set far back, and a paddle-shaped, almost symmetrical tail.
It migrates vertically every day, hunting squid, lanternfish and crustaceans near the surface at night and sinking below 1,500 m by day. Females give birth to about 8 live pups of 6–10 cm. It has never harmed anyone and is not fished, and the IUCN rates it Least Concern.
- Maximum length27 cm (10.6 in); males to about 22 cm
- WeightNo reliable measurement; a few tens of grams
- LifespanUnknown; no ageing study exists
- Depth rangeNear surface at night to about 1,800 m (5,900 ft) by day
- DietSquid, lanternfish and other small midwater fish, crustaceans
- IUCN statusLeast Concern (assessed 2018)
- Kingdom
- Animalia
- Phylum
- Chordata
- Class
- Chondrichthyes
- Order
- Squaliformes
- Family
- Dalatiidae
- Genus
- Euprotomicrus
- Species
- Euprotomicrus bispinatus
- Family (common)
- Kitefin sharks
- Also known as
- Slime shark
On this page
- How to recognise a pygmy shark
- How big is a pygmy shark?
- Where pygmy sharks live
- What pygmy sharks eat and how they hunt
- Behaviour: the nightly climb and the glow
- Reproduction and lifespan
- Is the pygmy shark dangerous?
- Conservation status
- Similar species and close relatives
- Frequently asked questions
- References
How to recognise a pygmy shark
Picture a black cigar with fins and you are most of the way there. The body is slender and cylindrical, the snout rounded and bulbous, the eyes large, the five gill slits tiny. What settles the identification is the fins. The first dorsal fin is absurdly small, a little flag set well behind the pectoral fins, while the second dorsal is several times larger and sits above the pelvic fins. Neither fin carries a spine, which separates the pygmy shark at once from the spined pygmy shark, its closest rival for the title of smallest shark, whose first dorsal has a spine and sits further forward.
The tail is the other giveaway. Most sharks have a tail with a long upper lobe and a short lower one; the pygmy shark's is a nearly symmetrical paddle, the mark of a fish that hovers and cruises slowly rather than sprints. There is no anal fin, as in all dogfish-like sharks.
Colour is black to dark brown above and below, with the trailing edges of the fins conspicuously pale, almost white, so that in a photograph the fins look outlined. The underside carries a scattering of tiny light organs, the photophores, denser towards the belly. The teeth differ strongly between jaws: the upper teeth are small, narrow and pointed for gripping, while the lower teeth are broad, triangular blades that interlock into a single cutting edge, roughly 22 in the upper jaw and 20 to 30 in the lower.
How big is a pygmy shark?
Females top out at about 27 cm (10.6 in) in total length and males at about 22 cm (8.7 in). Those are the largest reliably measured specimens; the figures of 17 to 23 cm often quoted are typical adult sizes, not maxima. Males mature at around 17 to 19 cm and females at roughly 22 to 23 cm, so a female is adult at about the length of a ballpoint pen and a large one is barely longer than a sheet of paper.
Only the dwarf lanternshark (about 20 cm) and the spined pygmy shark (about 28 cm) compete for the title of smallest shark, and depending on which measurement you trust the pygmy shark is second or third. It appears on our list of the ten smallest sharks. No weight has ever been published for the species, and a 25 cm shark of this build weighs only a few tens of grams. Newborns are 6 to 10 cm long, about the length of a little finger, and already carry the adult colour pattern. The size bar below sets 27 cm against a 1.8 m diver, and the comparison is not flattering to the shark.
Where pygmy sharks live
The pygmy shark is an animal of the open ocean with one of the widest ranges of any small shark, and one of the strangest. It lives in a band of the southern hemisphere between roughly 20° and 45°S across all three oceans: the South Atlantic off Brazil, Uruguay and Cape Town, the southern Indian Ocean from South Africa to southern Australia, and the South Pacific from New Zealand across to Chile and Peru. Then there is a second, separate population in the subtropical North Pacific, from Japan through Hawaii to California. It is absent from the North Atlantic and from the equatorial belt, a pattern biologists call antitropical.
Its home is the water column itself, not the bottom. By day pygmy sharks are far down, probably below 1,500 m and possibly deeper than 1,800 m, in the cold, black bathypelagic zone. At night they rise, following the mass of squid and lanternfish that migrate upwards every evening, and are caught in the top few hundred metres and occasionally at the surface. The lower limit of almost 10,000 m given in some older sources is a transcription error with no specimen behind it.
Because the species never comes near a coast, country pages rarely count it. The two that do are listed under the map, and the map itself shows the true extent of the range.
2 countries list the pygmy shark in their species guide; the count is the number of incidents attributed to it there in the SharkSider database. Browse every guide on sharks around the world and sharks in the US.
What pygmy sharks eat and how they hunt
Stomach contents from Hawaiian and southern-hemisphere specimens show a diet of squid, small bony fish and crustaceans, in roughly that order of importance. The fish are chiefly lanternfish and other small midwater species; the squid are the small oceanic kinds that rise with the nightly migration; the crustaceans are shrimps, euphausiids and amphipods. The pygmy shark eats whatever is abundant in the surface layer between dusk and dawn and rides the same daily elevator as its prey.
The jaw is the key to how it feeds. The upper teeth hold; the lower teeth, fused into a saw-edged blade, cut. That is the same arrangement the cookiecutter shark uses to core plugs of flesh out of tuna and dolphins, and the pygmy shark is close kin. But the pygmy shark's mouth is smaller, its lips are not built for suction, and there is no evidence that it bites large animals; it seizes prey whole or slices it with the lower blade.
Hunting in the dark, it relies on big eyes and on the electroreceptive ampullae of Lorenzini on its snout. Its belly photophores probably help too: by matching the faint glow of moonlight or starlight from above, the shark hides its silhouette from prey below it as well as from predators, and can drift up under a school of lanternfish without being seen against the sky.
Behaviour: the nightly climb and the glow
Two things dominate a pygmy shark's life: the daily vertical migration and the light it makes on the way. The migration is enormous for an animal this size. Rising from 1,500 m or more to the surface layer and back again means a round trip of around 3 km every 24 hours, through a temperature change of 20 °C or more and a pressure change of 150 atmospheres. An oil-rich liver provides buoyancy and the paddle tail a slow, economical stroke, which is why pygmy sharks turn up in nets by night and are gone by day.
The glow comes from photophores on the underside and, in this family, from a luminous layer of tissue rather than from lens-like organs. The light is a soft blue-green, brightest on the belly and fading up the flanks, which is the pattern of bioluminescent counter-illumination: it fills in the shark's shadow so that anything looking up sees only faint sky. Its cousins the taillight shark and cookiecutter add a tail gland or a dark collar to the trick; the pygmy shark keeps it simple.
Nothing is known about social behaviour. Specimens usually come up singly, which suggests a scattered existence across enormous areas of ocean; how individuals find each other to mate is an open question. A shark that weighs less than a letter and lives in the middle of the ocean is not easy to tag.
Reproduction and lifespan
The pygmy shark is ovoviviparous, without oophagy: the eggs hatch inside the mother, the embryos live on their yolk sacs, and the pups are born alive and fully formed. The litter is small, about 8 pups, and the newborns measure 6 to 10 cm (2.4 to 3.9 in). Gestation has not been measured. Pregnant females and newborn-sized juveniles have been caught in the same regions as adults, and there is no evidence of a coastal nursery; the pups appear to be born in open water and to begin migrating at once.
Maturity comes at 17 to 19 cm for males and 22 to 23 cm for females, and in a fish that is born at 8 cm and finishes growing at 25 that represents a lifetime of very slow growth. How slow is unknown, because nobody has aged a pygmy shark; it has no dorsal spines to section and its vertebrae are tiny. By analogy with other small deep-water dogfish, which grow slowly and live 15 to 25 years or more, a lifespan of a decade or two is plausible but unproven. Our page on how long sharks live covers why cold, deep water stretches a shark's life out and why that matters for conservation.
Females are about a fifth longer than males; whether the sexes occupy different depths, as in several lanternsharks, has not been tested.
Is the pygmy shark dangerous?
No. The pygmy shark is shorter than a ruler, lives hundreds of kilometres from the nearest beach and, when it does come near the surface, does so at night in the open ocean where no one is swimming. Its mouth is too small to break human skin in any meaningful way, and it has no spines to sting with. The SharkSider database has no incident attributed to the species, and there is no plausible way for one to occur.
The only people who handle pygmy sharks are the crews of research vessels and the occasional tuna longliner sorting a night's catch, and for them the animal is a curiosity, not a hazard. If you have come here worried about the small sharks that do bite people, the pygmy shark's relative the cookiecutter shark is the one with a genuine record of biting long-distance swimmers at night; the pygmy shark has none. General advice for real encounters is on our page on how to survive a shark attack.
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 assessed the pygmy shark as Least Concern in 2018, and it is hard to see how it could be otherwise. The species has a vast range across three oceans, lives most of its life below the reach of any commercial fishing gear, and is too small to be worth catching when it does come up. It is not on CITES or CMS, is not protected by any national law, and New Zealand's threat classification lists it as Not Threatened with the note that it is secure overseas.
That does not mean it is untouched. Pygmy sharks are taken occasionally by pelagic longlines and midwater trawls, and by the fine-meshed nets of research and krill fisheries, always in tiny numbers and always discarded. The deeper risks are indirect: warming and deoxygenation of the ocean's middle layers, and the industrial harvest of lanternfish and krill that some nations are beginning to explore, both of which would hit a predator that lives on the nightly migration.
For now the pygmy shark is one of the few sharks on this site with no conservation story to tell, which is worth noting on a list dominated by declines. The context is on our page on why sharks are endangered.
Similar species and close relatives
The pygmy shark is the only member of its genus, but the kitefin family holds several look-alikes. The spined pygmy shark (Squaliolus laticaudus) is the same size and colour and also migrates vertically; it differs in having a spine on the first dorsal fin, a first dorsal placed further forward, and a range that includes the North Atlantic. The smalleye pygmy shark of the western Pacific is similar again, with smaller eyes and a shorter snout. The longnose pygmy shark (Heteroscymnoides marleyi) of the southern oceans is the rarest of the group and has a long, conical snout.
Larger relatives in the same family include the cookiecutter shark, which shares the blade-like lower teeth but grows to 50 cm and cores plugs out of whales and tuna; the taillight shark, known from a handful of specimens, with a luminous gland near its tail; and the kitefin shark, the family's giant at 1.8 m and the largest known luminous vertebrate. Among unrelated sharks, the tiny dwarf lanternshark is the only species that undercuts the pygmy shark in size, and the two are often confused in lists of the world's smallest sharks.
- Spined Pygmy Sharkspecies profile
- Smalleye Pygmy Sharkspecies profile
- Longnose Pygmy Sharkspecies profile
Cookiecutter Sharkspecies profile- Taillight Sharkspecies profile
- Kitefin Sharkspecies profile
Frequently asked questions
How big is a pygmy shark?
Females reach about 27 cm (10.6 in) and males about 22 cm (8.7 in), making the pygmy shark one of the two or three smallest sharks in the world. Males mature at 17 to 19 cm and females at 22 to 23 cm. Newborns are 6 to 10 cm long. No weight has been published; it is a matter of tens of grams.
Is the pygmy shark the smallest shark in the world?
Not quite. The dwarf lanternshark of the Caribbean, at about 20 cm, is generally considered the smallest, with the pygmy shark and the spined pygmy shark close behind at 27 and 28 cm. The three are so close that different sources rank them differently, and all three are small enough to sit in the palm of a hand.
Where do pygmy sharks live?
In the open ocean far from land, in the southern Atlantic, Indian and Pacific oceans between about 20° and 45°S, off Brazil, South Africa, southern Australia, New Zealand and Chile, and separately in the subtropical North Pacific from Japan to Hawaii and California. They are absent from the North Atlantic and the tropics.
How deep do pygmy sharks go?
Very deep by day, probably below 1,500 m and possibly beyond 1,800 m, then up to the surface layer at night to feed. That round trip of around 3 km every 24 hours is one of the longest daily migrations of any shark. Old claims of nearly 10,000 m are a transcription error with no specimen behind them.
What do pygmy sharks eat?
Squid, small midwater fish such as lanternfish, and crustaceans including shrimps and krill, all taken at night in the upper few hundred metres. Small gripping teeth in the upper jaw hold the prey while a row of broad, interlocking lower teeth slices it, the same jaw design as the related cookiecutter shark.
Do pygmy sharks glow in the dark?
Yes. The underside carries light-producing tissue that gives off a faint blue-green glow, brightest on the belly. By matching the dim light filtering down from the surface, the glow erases the shark's silhouette so predators and prey looking up from below cannot see it, a trick called counter-illumination.
How do pygmy sharks reproduce?
They are ovoviviparous: the eggs hatch inside the female and about 8 pups are born alive, each 6 to 10 cm long and nourished by its yolk sac during development. Gestation has never been measured. Pups are born in the open ocean and appear to begin the nightly vertical migration immediately.
Are pygmy sharks dangerous to humans?
No. A pygmy shark is shorter than a ruler, has a mouth too small to injure a person, has no spines, and lives in the open ocean far from any beach, rising towards the surface only at night. The SharkSider database contains no incident attributed to the species and none is realistically possible.
Are pygmy sharks endangered?
No. The IUCN lists the pygmy shark as Least Concern, based on a 2018 assessment, because it has a huge range across three oceans and lives below the reach of most fishing gear. It is caught only occasionally as bycatch and always discarded. New Zealand classifies it as Not Threatened.
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 August 19, 2022 · Last updated September 22, 2026 · No incident attributed to this species in the SharkSider attack database, which is updated weekly.
