Spurdog

By Alex Clayton · Updated 23 October 2026

The spurdog, also called the spiny dogfish, is a small, slim shark of UK waters with a sharp spine in front of each of its two dorsal fins. It is rated Vulnerable on the IUCN Red List, and since 27 February 2026 it has been off the UK prohibited species list under S.I. 2026/105.

That change left a lot of online advice out of date. Older guides still say every spurdog must go back, or quote a minimum size that no official source supports.

Below: how to tell it from other UK sharks, what the rules now say, why release still matters, where spiny dogfish turn up, and how to unhook one without getting spiked.

How to Identify a Spurdog: Spines, Spots and No Anal Fin

Look along the back before you touch it. A spine in front of each dorsal fin means spurdog, and it is also your warning to handle the fish with care.

Two features settle the identification on their own:

A sharp spine at the leading edge of both the first and second dorsal fins.
No anal fin on the underside, between the pelvic fins and the tail.

The back is grey or brown with scattered white spots along the flanks, over a pale belly, a pointed snout and a slim build. ICES gives a maximum length of 128cm (ICES spurdog factsheet). Don’t identify on spots alone, because the starry smoothhound carries white spots too.

Species	Dorsal spines	Quick tell
Spurdog (spiny dogfish)	Yes, both dorsals	White spots, no anal fin
Smoothhound	No	Smooth grey skin, flat crushing teeth
Tope	No	Sharp teeth, deep notch near the tail tip
Lesser spotted dogfish and bull huss	No	Rough skin covered in dark spots

For everything else, use the UK fish identification guide. If you see spines, treat the fish as a spurdog and go straight to the handling steps below.

Can You Keep a Spurdog? What the Rules Say in 2026

From 2010 to 2022 the commercial catch limit for spurdog was zero. Since 27 February 2026 the species has been off the UK prohibited list entirely.

Year	What changed
2010 to 2022	Catch limit (TAC) set at zero, with limited bycatch allowed under a scheme. Spurdog also spent years on the prohibited species list (Cefas, GOV.UK)
2022	ICES advised the stock had recovered enough for limited fishing
2023	Fishery reopened with a 100cm maximum landing size to protect big breeding females (explanatory memorandum)
27 February 2026	S.I. 2026/105 removed spurdog from the prohibited list, and the 100cm maximum went with it. Applies in England and Wales, Scotland and Northern Ireland
2026	TAC set at 10,875 tonnes. The UK and EU agreed to work on a minimum conservation reference size and on discard survivability (written record)

Expect further change, with any new commercial measures set through MMO vessel licence conditions.

For spurdog fishing with a rod, the 2026 instrument sets no recreational bag or size limit, though it raised the recreational seabass bag limit to three fish a day. Local byelaws can still differ, so before keeping any fish, check with your local IFCA (England), the Marine Directorate (Scotland), the Welsh Government (Wales) or DAERA (Northern Ireland), and see sea fish minimum sizes. The Angling Trust opposed removing the 100cm cap.

Legal to keep is not the same as worth keeping. Given the slow breeding covered next, release is the sensible default.

Why Spurdog Are Slow to Recover: Size, Breeding and Lifespan

A female spurdog carries her pups for around two years before giving birth. That one figure explains most of the species’ trouble.

Trait	Figure
Breeding	Live-bearing
Gestation	Around two years (22 to 24 months per ICES)
Female maturity	Starts at 69 to 73cm; half mature by 74 to 83cm
Male maturity	55 to 64cm
Size at birth	19 to 30cm, typically 26 to 28cm
Litters	Typically one every two years
Maximum age	40 years
Status	IUCN Vulnerable; UK Priority Species

Sources: ICES and The Wildlife Trusts.

A female needs years to reach breeding size, then produces a litter only every other year. Take the big fish out faster than they can replace themselves and numbers fall, which is why the catch limit went to zero in 2010.

Cefas notes that spurdog over 100cm are usually females producing many pups, the reason the 100cm cap was central to the 2023 reopening. The biggest spurdog you catch is the one most worth putting back.

Where and When to Catch Spurdog in UK Waters

Spurdog are travellers. Tagging suggests a single North-east Atlantic stock that moves around the British Isles (ICES).

They are most common in 10 to 200m of water and have been recorded down to 900m. That makes the spurdog mainly a boat fish, and the Angling Trust says the charter sector values it. From the shore, your best chance is where deep water runs close in.

Spurdog winter in deep water and move into warmer coastal water in summer. Pupping has been recorded off Plymouth from August to December.

They feed on herring, sprat, small gadoids such as whiting, sandeel, mackerel, crustaceans and squid. Match that with a mackerel or herring strip, squid or sandeel fished near the bottom, on the drift or at anchor. A strong trace is general practice because of their teeth and rough skin. See boat fishing.

Booking a charter for spurdog? Ask the skipper about recent catches and the depth they have been fishing.

How to Handle and Release a Spurdog Without Getting Spiked

Each dorsal spine can give a painful wound. The Wildlife Trusts note that a spurdog can curl into a bow to strike with its spines, so one that twists in your grip can bring them round into your hand.

These steps are general good practice, not official guidance:

Keep the fish in the water, or low over a wet mat or deck. Don’t lift it high.
Support the body with both hands, well clear of the dorsal spines. A wet cloth over the back helps your grip.
Remove the hook with long-nosed forceps or a disgorger.
If it is deeply hooked, cut the trace as close to the hook as you can rather than digging.
Return it quickly, head first, and let it swim off.

Cefas is researching how well recreationally caught spurdog survive after release (GOV.UK Marine Science blog), so handling counts. If you get spiked, clean the wound and seek medical advice if it swells or you feel unwell.

Have the forceps ready before the fish comes aboard.

Frequently asked questions

Can you keep spurdog in the UK?

Spurdog has been off the UK prohibited species list since 27 February 2026 under S.I. 2026/105, and no national recreational limit for it was found. Check with your local IFCA, the Marine Directorate, the Welsh Government or DAERA first, and consider releasing it.

Is a spurdog a shark?

Yes. The spurdog, or spiny dogfish, is a small shark and one of several UK sharks anglers catch. The porbeagle is a much larger UK shark.

Are spurdog dangerous?

Only when handled. A spine in front of each dorsal fin can give a painful wound if the fish curls or twists in your grip. Keep your hands clear of the spines, use long forceps, and follow the handling steps above.

How big do spurdog get?

ICES gives a maximum length of 128cm. Females start to mature at around 70cm, and the largest fish are usually breeding females, which is why they are the ones most worth returning.