Gummy Shark

• Maximum length1.75 m (5.7 ft) for females; males to about 1.57 m
• WeightUp to 30.8 kg (68 lb); most adults 5–15 kg
• LifespanAt least 16 years (oldest aged specimen)
• Depth rangeIntertidal to 403 m (1,320 ft), mostly above 80 m
• DietCrabs, rock lobsters, octopus, squid, worms, small fish
• IUCN statusLeast Concern (assessed 2015)

How to recognise a gummy shark

Pick up a gummy shark by the tail on a Victorian pier and the first thing you notice is how soft its mouth is. The teeth are low, blunt and packed edge to edge into two flat plates, more like the crushing dentition of a ray than the blades of a tiger shark. That pavement is the reason for the name: the fish looks as if it is all gums. Run a thumb along the jaw and nothing cuts.

The body is slim and slightly flattened, with a long, narrowly rounded snout, large oval eyes with a nictitating membrane, and an obvious spiracle behind each eye. The two dorsal fins are nearly the same size, which sets houndsharks apart from the school shark (Galeorhinus galeus), whose second dorsal is a small stub. The tail has a well-developed lower lobe and a notch below the tip.

Colour is the quickest field mark. A gummy shark is grey to bronze-grey above, silvery white below, and sprinkled along the back and flanks with small white spots; there are never dark spots or bands. A similar-sized whiskery shark (Furgaleus macki) has fleshy nasal barbels and a stockier build, and the school shark has a pointed snout, dark fin margins and sharp, notched teeth. If the animal has crushing teeth, twin dorsals and white freckles, it is a gummy.

How big do gummy sharks get?

Females are the big sex. The largest reliably measured female was about 1.75 m (5.7 ft) in total length, and the heaviest published weight is 30.8 kg (68 lb). Males top out near 1.5 to 1.57 m and are usually well under 10 kg. Older books and fishing sites quote a 1.85 m record; it may exist, but it has never been properly verified, so the figures above are the ones we use.

Those are extremes. In the Bass Strait gillnet fishery, where the mesh is chosen to let small and very large sharks pass, the typical landed animal is 1.0 to 1.4 m and weighs 4 to 12 kg. Pups are born at roughly 30 to 35 cm (12 to 14 in) and grow quickly for their first few years, then slow down: a 1.2 m female may already be a decade old. Sexual maturity is reached at 85 to 130 cm depending on sex and region, with a population average of about 1.2 m for females.

The size bar below sets the female maximum against a 1.8 m diver. For a fish that Australians eat by the tonne, the gummy shark is a modest animal: barely a third of the length of a great white and a fraction of its bulk.

Where gummy sharks live

The gummy shark is an Australian endemic. It occupies the continental shelf of the whole southern coast, from about Geraldton and Shark Bay in Western Australia east across the Great Australian Bight, around Tasmania and through Bass Strait, and north up the New South Wales coast to roughly Port Stephens. Its latitude band is 28°S to 44°S, and the water it lives in is cool temperate, generally 12 to 22 °C. The claim on older pages that it also swims off Japan is a mix-up with the starspotted smooth-hound, Mustelus manazo, a different species entirely.

Within that range it is a bottom-dweller of sand, mud and seagrass. It has been caught in the surf and in estuaries and, at the other extreme, at 403 m on the shelf edge, but the great majority of sharks live shallower than 80 m. Tagging by Victorian fisheries scientists shows two patterns at once: most recaptures happen within 50 km of the release point, yet a minority of sharks, nearly all of them females, cross the whole southern coast, with some moving more than 1,000 km between Bass Strait, South Australia and the Western Australian fishery.

Newborns and juveniles turn up in bays and inlets across the range, from Port Phillip and Western Port in Victoria to the gulfs of South Australia, but no single well-defined nursery has ever been mapped. Adults sort themselves into loose schools by sex and size rather than by family.

What gummy sharks eat and how they hunt

Everything about the gummy shark's head is built for crushing. Stomach samples from the Victorian and South Australian fisheries are dominated by crustaceans: swimming crabs, spider crabs, mantis shrimps and, wherever they are common, southern rock lobsters. Octopus and squid are the second staple, followed by polychaete worms and small bottom fish such as flathead, whiting and the odd young fish it can pin against the sand. It has no way to slice a large fish, so it takes what fits in its mouth whole.

Most feeding happens at night. The shark cruises slowly a few centimetres above the seabed with its snout down, reading the bottom with smell and with the electrical sense in the ampullae of Lorenzini, which can pick up a crab breathing under the sand. A gummy shark grabs prey with a short lunge and a bite that grinds rather than cuts; a crab is cracked, chewed briefly and swallowed in pieces, shell and all.

Diet shifts with size. Pups under 60 cm live largely on worms, small shrimps and juvenile crabs; adults over a metre take bigger crabs, lobsters and octopus, which is why fishers using cephalopod bait catch the largest sharks. There is nothing in the gummy's diet that overlaps with people, and no reason for one ever to approach a swimmer.

Behaviour, senses and migration

A gummy shark is a nervous, retiring fish. Divers in Port Phillip Bay rarely see one for more than a second: the shark turns and disappears into the murk at the first bubble. It spends the day resting or cruising close to the bottom and becomes active around dusk, which is why the fishery sets its nets overnight.

Its senses are the standard houndshark kit tuned for a dim, muddy world. The large eyes gather light, the nostrils are wide and grooved, and the electroreceptors on the snout do the close work. Unlike a mako or a white shark it is fully cold-blooded, and its cruising speed is low; the pavement teeth and calm temperament of the whole Mustelus group have earned them the name smooth-hounds because they can be handled without much risk.

Movement is organised by sex and season. Females travel further than males, and adults further than juveniles; the longest tag returns, over 1,000 km, are almost all mature females, some of which appear to cycle between eastern and western parts of the range over a period of years. Schools are segregated, so a net set in one place may bring up nothing but pregnant females and another nothing but males.

Predators are few. The broadnose sevengill shark takes juveniles and even adults in Victorian and Tasmanian bays, large white pointers occasionally eat them, and fur seals and sea lions rob them from nets. Countershading, grey above and white below, is the gummy shark's only real defence (see what eats sharks).

Reproduction and lifespan

The gummy shark is aplacental viviparous: the eggs hatch inside the mother and each embryo lives on its own yolk sac until birth, with no placenta and no egg-eating. Ovulation and mating take place in the southern summer, mostly November to January, and the pups are born eleven to twelve months later, in November and December of the following year, at 30 to 35 cm. Females in Bass Strait breed every year, so a mature female carries a litter almost continuously for the rest of her life.

Litter size scales with the mother. Small first-time breeders may carry a single pup or two; large females carry 20 to 30, and the maximum recorded is 38 (a few reports of 57 exist but have not been confirmed). Sons and daughters are born in equal numbers. There is no parental care; the pups scatter into the bays and inlets where they were born and fend for themselves.

Males mature at about 80 to 95 cm and four to five years; females at 85 to 130 cm and five to six years, though the average Bass Strait female is closer to 1.2 m and seven or more years old before her first litter. The oldest gummy shark aged from vertebral rings was 16 years, and because the largest females are rare in the catch and hard to age, the true maximum is probably higher. This fast life history is the main reason the species tolerates fishing that would flatten a slower breeder (compare how long sharks live and the four ways sharks reproduce).

Are gummy sharks dangerous to people?

No. A gummy shark could not hurt you if it tried: its teeth are flat plates that cannot break skin, its jaws are built to crack crabs, and its instinct on meeting a person is to leave. The SharkSider database has no incident attributed to the species. The only Australian record that even uses the word, a 1961 case in which a deckhand fell among sharks off Nambucca Heads and got scratched, was logged by the investigators as a small sharpnose shark that fishermen happened to call a "gummy", and the one British "smoothhound" case involved a different species leaping into a dinghy.

The realistic hazards run the other way. Recreational anglers catch gummy sharks in their thousands every year, and the injuries that occur are from hooks, gaffs and the rough skin of a thrashing fish, not from bites. If you are in southern Australian water and see a slim grey shark with white spots, you are watching the least dangerous shark you will ever meet. The species that actually bite people on that coast are covered on the Australia attack page, and general advice is in 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 and the flake fishery

The IUCN Red List assessed the gummy shark as Least Concern in 2015, with a stable population. It is not listed under CITES or the Convention on Migratory Species, and it needs no special protection because the fishery that depends on it has been managed with unusual care. Since the 1920s southern Australian fishers have targeted the species with bottom-set gillnets, and today the catch is taken under a quota, currently around 1,800 tonnes a year, in the Commonwealth's Southern and Eastern Scalefish and Shark Fishery run by the Australian Fisheries Management Authority.

Two rules make it work. The mesh size is fixed so that nets take mostly 1.0 to 1.4 m sharks and let pups and the largest, most fecund females through, and the fishery has been assessed against a formal harvest strategy since the 1990s; the 2023 national status report classes the stock as sustainable. The meat is sold boneless as flake, the fish in a Victorian fish-and-chip shop, and the trade name is so valuable that the main conservation problem is other species being sold under it.

The remaining concerns are bycatch and mercury. The same nets catch the far more depleted school shark, and closures have been imposed in South Australia to keep gillnets away from Australian sea lion colonies. Large gummy sharks accumulate mercury, so health authorities limit sales of fish over a certain size. Compared with the sharks on our list of why sharks are endangered, the gummy is a rare good-news story.

Similar species and close relatives

Mustelus is a genus of about thirty look-alike smooth-hounds spread around the world's temperate coasts, and telling them apart usually needs a tooth count or a tissue sample. Across the Tasman the spotted estuary smooth-hound or rig (Mustelus lenticulatus) of New Zealand is the gummy's closest relative and fills the same fish-and-chip niche there under the name lemon fish. In 2008 taxonomists split two tropical species off the northern edge of the gummy's range, the grey gummy shark (Mustelus ravidus) and the white-spotted gummy shark (Mustelus stevensi), and described the eastern spotted gummy shark (Mustelus walkeri) from Queensland; all three are smaller and rarer.

Further afield, the common smooth-hound and starry smooth-hound of Europe and the leopard shark of California are houndsharks with the same twin dorsals and crushing teeth. On its own coast the gummy is most often confused with the school shark, which shares the nets and the market, and with the whiskery shark of Western Australia. Neither has white spots.

• Spotted Estuary Smooth-Houndspecies profile
• Common Smooth-Houndspecies profile
• Starry Smooth-Hound Sharkspecies profile
• Tope Sharkspecies profile
• Whiskery Sharkspecies profile
• Leopard 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 August 16, 2022 · Last updated September 22, 2026 · No incident attributed to this species in the SharkSider attack database, which is updated weekly.