The lizard catshark is a slender catshark of the south-western Atlantic, reaching about 69 cm (27 in) and living on the upper continental slope off southern Brazil at roughly 120 to 435 m. It is greyish-brown with ten dark saddles along the back and tail, scattered white spots between them, a rounded snout and a long, low tail that makes up much of its length.
It feeds on small crustaceans, cephalopods and small fishes taken among deep coral and sponge, and females lay egg cases anchored to that same structure. It is listed as Vulnerable, because deep trawling works the narrow band of slope it lives on. It is harmless to people and has never been involved in an incident.
- Maximum length69 cm (27 in) females; 58 cm males
- WeightNever published; a slender shark of about 1 kg
- LifespanUnknown; no ageing study exists
- Depth rangeAbout 120–435 m (400–1,430 ft)
- DietSmall crustaceans, cephalopods and small bony fishes
- IUCN statusVulnerable (assessed 2019)
- Kingdom
- Animalia
- Phylum
- Chordata
- Class
- Chondrichthyes
- Order
- Carcharhiniformes
- Family
- Scyliorhinidae
- Genus
- Schroederichthys
- Species
- Schroederichthys saurisqualus
- Family (common)
- Catsharks
- Also known as
- Tubarão-lagartixa
On this page
How to recognise a lizard catshark
Two things stand out before anything else: the proportions and the pattern. This is an unusually elongated shark, narrow in the body and with a tail that seems to go on longer than it should, so that a 60 cm animal is no thicker through the middle than a broom handle. The colour is greyish-brown, crossed by about ten dark saddles that run from behind the head to the end of the tail, with four of them falling between the two dorsal fins. Scattered white spots sit in the spaces between the saddles, and it is that reptilian mix of blotch and fleck that gave the species its name.
The head is short and the snout rounded, with pointed nasal flaps above a wide mouth and the horizontally oval, cat-like eyes the family is named for. Both dorsal fins are set far back, the first beginning behind the pelvic fins and the second behind the origin of the anal fin, which is the standard arrangement for a true catshark and the quickest way to rule out anything from another family.
Separating it from its own relatives takes counting rather than looking. The species it most resembles is the slender catshark of the same coast, and the differences are technical: 122 vertebrae against about 110, rounded rather than pointed dermal denticles, a longer gap between the dorsal fins, and a wider space between the pelvic and anal fins. On a fresh specimen, the white spotting is the practical field mark.
How big does a lizard catshark get?
Females are the larger sex and reach about 69 cm (27 in) in total length; males stop at roughly 58 cm (23 in). For a catshark that is a respectable size — around the same length as a small-spotted catshark from European water — but the impression the animal gives is of length rather than bulk, because so much of it is tail and so little of it is body depth. No weight has ever been published for the species; a mature female is a shark of about a kilogram.
The size figures matter more than they usually would, because in this species maturity sits almost at the maximum. Males are mature at around 58 cm and females at close to 69 cm, which means that essentially every adult in the population is at or near the largest size recorded. An older account putting maturity at about 40 cm does not match the examined material and should be discarded; it would imply a very different, much faster life history than this shark actually has.
Hatchlings are reported at around 9 cm, although the sample behind that figure is small. Nobody has established a growth rate, so the number of years between a 9 cm hatchling and a 69 cm breeding female is simply unknown — and for a deep, cold-water shark it is likely to be a long time.
Where lizard catsharks live
This shark belongs to one stretch of one coast. Every confirmed record comes from the south-western Atlantic off southern Brazil, between roughly São Paulo and Rio Grande do Sul, which makes it as close to endemic as a slope species gets. It was described in 2001 from material taken there, and nothing has turned up to the north or south since.
Within that strip it occupies the upper continental slope, at depths recorded from about 120 m down to 435 m, with most captures between roughly 250 and 400 m. That band is not bare mud. The southern Brazilian slope carries deep-water reef: stony corals, gorgonian sea fans, black corals and tube sponges growing on hard bottom, with brittle stars, crabs and small fishes living among them. The lizard catshark is a resident of that structure rather than of the open sea bed beside it, sharing it with the freckled catshark and with deep-reef invertebrates.
Temperature and light are constant there in a way that shallow habitats never are: a few degrees above freezing at the deep end, permanently dark, and fed entirely by material sinking from the productive water far above. A shark adapted to that has nowhere else to go; it cannot follow its habitat into shallower water, and the coral grounds it depends on exist in patches rather than as a continuous belt.
What lizard catsharks eat
No stomach-content survey has been published for this species, which is worth stating plainly rather than dressing up. What can be said comes from its anatomy, from the company it keeps and from what other members of the genus eat: small crustaceans such as shrimps and small crabs, cephalopods including small squid and octopus, and small bony fishes, all taken on or close to the bottom.
The teeth are small, numerous and multi-cusped — a central point with a cusplet on each side, set in many rows across a fairly wide mouth. That is a design for holding slippery or lightly armoured prey and swallowing it whole, not for cutting. The largest thing a 69 cm lizard catshark can eat is therefore set by the width of its throat, which is a matter of a few centimetres.
The body plan says as much about hunting as the teeth do. A long, thin, flexible shark can work its way into the gaps between coral branches and sponge tubes, where a deeper-bodied fish cannot follow, and the deep reef is exactly where shrimps and small fishes shelter. In permanent darkness the search is done by smell, by the lateral line and at close quarters by the ampullae of Lorenzini, which register the electrical field of a hidden animal through solid coral. Feeding is probably opportunistic and unhurried; nothing at that depth can afford to waste energy chasing.
Behaviour on the deep reef
The living animal has never been filmed or studied in place. Everything below is inference from specimens, from where they were caught and from the behaviour of related catsharks, and it should be read that way.
The build points to a bottom-hugging, slow-moving life. Catsharks have small livers and no swim bladder, so they are negatively buoyant and rest on the sea bed rather than hovering; a long slim body with a low tail is built for sculling short distances between one piece of cover and the next, not for sustained swimming. Related species are nocturnal and increase their activity after dark, and while "dark" means nothing at 300 m, the daily rhythms of deep-slope animals are often still tied to the vertical migration of prey above them.
There is no evidence of migration. A species tied to patches of deep coral on one stretch of slope has no reason to travel, and none of the capture records suggest seasonal movement. Where several specimens have come up in the same haul they have tended to be of similar size, which in other catsharks reflects loose aggregation by size and sex rather than social behaviour in any meaningful sense.
Its defences are entirely passive: no spine, no venom, no speed. It relies on being thin enough to disappear into structure, and on living somewhere that few predators bother to hunt.
Reproduction and lifespan
The lizard catshark is oviparous, and its egg-laying has one detail that matters for its survival. Females produce a single capsule in each oviduct at a time — a pair of eggs, released and then replaced over a long breeding season — rather than carrying a large batch. The capsules are greyish-green, horny and drawn out at the corners into long tendrils, and those tendrils are wound around gorgonian sea fans and coral branches so that the egg sits in the current, off the mud, where it will not be smothered.
That anchoring habit ties the shark's reproduction directly to the deep coral itself. A patch of sea fans is not just habitat for the adult; it is the nursery. Damage the coral and the eggs have nowhere to go, which is the central reason this species is treated as threatened while similar-sized catsharks elsewhere are not.
The embryo develops on its own yolk inside the sealed case, with no nourishment from the mother, and hatches at around 9 cm as a fully formed miniature. How long that takes in water of a few degrees is unrecorded, but deep-water catshark eggs elsewhere take many months, and some are known to take more than a year.
Age is unstudied. No vertebrae have been sectioned, so there is no growth curve, no age at maturity in years and no maximum age; the methods that would settle it are explained under how long sharks live. Given late maturity, a small number of eggs at a time and cold water, this is a slow-breeding animal by any measure.
Are lizard catsharks dangerous?
No. A lizard catshark is a slim, soft-bodied shark under 70 cm long, with a mouth a few centimetres wide and teeth a millimetre or two high, and it lives between 120 and 435 m down on the Brazilian slope. No swimmer, surfer or recreational diver has ever been in its habitat. Neither the SharkSider database nor any shark attack file in the world records an encounter with it.
The only people who handle one are scientists and trawler crews sorting a deep haul, and the risk in that encounter runs entirely one way: the shark almost never survives it. This species sits comfortably among the least dangerous sharks. The incidents that do occur along this coast, which involve large coastal species in shallow water and nothing like this one, are recorded on the shark attacks in Brazil page.
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 lizard catshark as Vulnerable in 2019, and the reasoning is easy to follow. The species has a small known range, a narrow depth band, late maturity and a reproductive output of two eggs at a time — and that range coincides almost exactly with the grounds worked by the deep-water trawl and gillnet fleets that expanded onto the southern Brazilian slope from the late 1990s onwards, chasing monkfish, hake and deep-water shrimp.
Trawling does two kinds of damage here. The sharks themselves come up as bycatch, with no commercial value and little chance of surviving the pressure change. More seriously, the gear flattens the gorgonian and coral grounds where the egg cases are anchored. Deep corals in cold water grow at rates measured in millimetres a year and centuries of growth can be removed in a single tow, so a damaged patch does not come back on any timescale useful to a shark.
There is no CITES listing for the species and no protection written specifically for it, though Brazil has restricted some deep-water fishing effort and the Red List assessment calls for monitoring of trawl activity over the reef patches. Protecting the deep coral would protect the shark automatically, which is the rare case where one measure covers both the habitat and the animal. The wider pattern is set out under why sharks are endangered.
Similar species and close relatives
The closest relatives are the other members of Schroederichthys, a small South American genus of slim, saddled catsharks: the narrowmouth catshark of the Caribbean, the redspotted catshark of Chile and Peru, and above all the slender catshark of the same Brazilian coast, which is the species this one was confused with before 2001. The slender catshark lacks the white spotting, has fewer vertebrae and shorter gaps between its fins.
Across the family, the nearest thing in build and habit is the genus Atelomycterus on the far side of the world — the coral catshark, the Australian marbled catshark and the Bali catshark are all pipe-slim, patterned, reef-associated sharks that lay tendrilled eggs on structure. The resemblance is a case of the same problem being solved the same way, in this case on shallow tropical reef rather than deep coral.
Among sharks that simply look similar, the chain catshark of the north-western Atlantic is a comparable slope animal with a bold dark pattern, and the leopard catshark of South Africa shows how far spotting and saddling can be pushed in the family. Sharing the Brazilian slope, though not the family, is the Cuban ribbontail catshark, a much smaller deep-water species of the western Atlantic. The wider layout of the group is covered in the guide to the types of sharks.
Coral Catsharkspecies profile- Australian Marbled Catsharkspecies profile
- Bali Catsharkspecies profile
Chain Catsharkspecies profile
Leopard Catsharkspecies profile- Cuban Ribbontail Catsharkspecies profile
Frequently asked questions
How big do lizard catsharks get?
Females reach about 69 cm (27 in) in total length and males about 58 cm (23 in). Much of that length is tail, so even a full-grown female is a very slender animal weighing around a kilogram. Hatchlings are reported at roughly 9 cm, though few have been measured.
Where do lizard catsharks live?
Only off southern Brazil, in the south-western Atlantic, between about São Paulo and Rio Grande do Sul. They live on the upper continental slope at depths of roughly 120 to 435 m, usually between 250 and 400 m, among deep-water corals, gorgonian sea fans and sponges growing on hard bottom.
Why is it called the lizard catshark?
Because of its markings and its scientific name. Saurisqualus combines the Greek for lizard with the Latin for shark, a reference to the reptilian look of about ten dark saddles running along a greyish-brown body with scattered white spots between them. It has nothing to do with the shark's behaviour.
What do lizard catsharks eat?
Small crustaceans, cephalopods and small bony fishes taken on or near the bottom. No stomach-content study has been published, so the diet is inferred from relatives and from the teeth, which are small, numerous and multi-cusped. Prey is gripped and swallowed whole rather than cut, limiting it to a few centimetres.
Do lizard catsharks lay eggs?
Yes. Females are oviparous and produce one capsule per oviduct at a time, so eggs are laid in pairs over a long season rather than in a batch. The greyish-green cases carry long tendrils that are wound around gorgonians and coral branches, holding the egg in the current and off the mud.
How long do lizard catsharks live?
Nobody knows. No vertebrae from this species have been sectioned to count growth bands, so there is no age at maturity in years and no maximum recorded age. Cold water, late maturity and two eggs at a time all point to a slow-growing, long-lived animal, but that remains inference.
Are lizard catsharks dangerous to humans?
Not at all. The species is under 70 cm long, soft-bodied, with teeth a millimetre or two high, and it lives hundreds of metres down on the Brazilian slope where no swimmer or recreational diver goes. No incident involving it appears in the SharkSider database or in any attack file worldwide.
Why is the lizard catshark Vulnerable?
Because its whole known range is a narrow band of slope off southern Brazil that deep-water trawlers and gillnetters work. The sharks come up as bycatch, and the gear flattens the deep coral and gorgonian patches where the eggs are anchored. Those corals grow millimetres a year and do not recover quickly.
How is it different from the slender catshark?
By details rather than at a glance. The lizard catshark has scattered white spots between its saddles, about 122 vertebrae against roughly 110, rounded rather than pointed dermal denticles, a longer gap between the dorsal fins and a wider space between the pelvic and anal fins. The white spotting is the practical field mark.
When was the lizard catshark discovered?
It was described as a new species in 2001, from specimens taken off southern Brazil that had previously been filed under the slender catshark. It remains known from only a few dozen animals, and no one has yet photographed a living individual in its habitat or studied its behaviour in place.
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 14, 2022 · Last updated September 22, 2026 · No incident attributed to this species in the SharkSider attack database, which is updated weekly.
