grey spiny dogfish of the outer shelf

Size
Length: 60–90 cm, Weight: 2–5 kg
Lifespan
25–35 years
Diet
Carnivorous. Feeds on small fish, squid and crustaceans. Hunts near seafloor using electroreception. Sharp teeth grab slippery prey. Active at twilight and night.
Habitat
Shallow coastal waters, harbours and estuaries. Depth from 10 to 200 metres. Prefers sandy and muddy bottoms with moderate currents. Often in large schools near seafloor by day.
Range
Coastal waters of North and South Islands. From Northland to Otago. Common in harbours, bays and open coastlines. Also found in Australia and Southwest Pacific.
Endemism
Native
Main Threats
Bycatch in set nets, bottom trawls and rock lobster pots. Targeted by commercial fisheries for fish and chips. Slow reproduction makes populations vulnerable. Habitat loss from coastal development.
Population
Populations stable but localised declines in heavily fished areas. Taken as bycatch and targeted for flesh. Quota management sets catch limits. Better species-specific data needed for stock assessments.
Conservation Status
Not Threatened
A small shark with venomous spines guarding each dorsal fin. It is also dinner. The firm, white flesh is a staple in fish and chip shops. It is sold as lemon fish or rig. Māori names include Koinga, Oke, Okeoke and Pioke. These reflect regional variations. They hint at the shark's dogged, persistent nature. Despite its modest size, it is a skilled predator. It lives for decades in New Zealand's coastal waters. It is everywhere and nowhere. The body is slender and streamlined. The snout is pointed. The mouth is terminal. Teeth are sharp and numerous. Colour is greyish-brown on the back. It fades to white on the belly. Each dorsal fin carries a venomous spine. These spines are for defence. When threatened, the dogfish raises its fins. The spines are exposed. The venom is not lethal to humans. The wound is painful. This becomes expensive. It hunts near the seafloor. Prey includes small fish, squid and crustaceans. Electroreceptors on the snout detect prey buried in sand. Feeding is most active during twilight hours. Night hunting is common. It adapts faster than expected. Reproduction is ovoviviparous. Eggs develop inside the female. They hatch internally. The young are born alive. A litter contains up to 20 pups. The cycle continues. It is a common resident of New Zealand's coastal waters. Set nets and trawls catch it as bycatch. Commercial fisheries also target it for its flesh. The net sweeps. The dogfish is caught. Its flesh becomes lemon fish. It does not know it is being renamed. To see one is to see a small shark of the harbours. The harbour is murky. The dogfish swims near the seafloor. It is greyish-brown and sleek. Spines are raised. It just wanted to eat a crab. It is the dogfish. It is the lemon fish. It is the rig of the fish and chip shop. It is all of them. It is none of them. It just is.