Spider Crab: A Beginner's Guide for UK Shore and Boat Anglers
By Monty · Reviewed by Andy · Published 4 October 2026
- Bottom fishing
- Shore
- Harbour or pier
- Rock marks
- Boat
- Beginner
- Spring
- Summer
The spiny spider crab is one of the UK's most eye-catching sea creatures, with a spiky shell and long legs. This guide explains how to recognise one, where and when you might meet one, whether fish baits will tempt them, and how to handle and return them safely.
- Who it suits
UK beginners and families who are curious about spider crabs. It suits anyone who has hooked one by accident while bottom fishing, or who wants to know whether fish baits can be used to find them.
- Conditions
Spider crabs are generally linked with the warmer months, when many are thought to move into shallower inshore water. They are most often met in clearer, rocky or mixed ground, especially around the south and south-west of the UK. Local timing varies, so check with local anglers and your regional authority.
What you need
A checklist to pack before you go. Tackle recommendations are editorial — we don't sell anything yet.
Essential
- Landing net or drop netHelps lift crabs safely instead of swinging them up on the line. Check local rules before using a drop net to target crabs.Alternatives: Fish over lower ledges where you can reach the water safely.
- Bucket of seawaterKeeps a crab wet and calm for a quick look before release. Keep it out of the sun.Alternatives: A shallow, safe rock pool for viewing.
- Unhooking tool or long-nosed pliersKeeps fingers away from claws and spines.Alternatives: Forceps.
- Lifejacket or buoyancy aidStrongly advised for children and anyone fishing from rocks, piers or boats.Alternatives: None. Do not fish from risky edges without one.
- Grippy footwearRocks and harbour steps can be very slippery with weed.Alternatives: Studded or non-slip boots.
Useful extras
- Bottom fishing rod and reelOnly needed if you are fishing. Spider crabs usually turn up while bottom fishing for fish.Alternatives: A simple drop line from a harbour wall, where allowed.
- Fish bait such as mackerel stripsOily fish baits on the seabed tend to attract crabs.Alternatives: Other oily fish pieces or fish heads.
- GlovesGives some protection from sharp spines.Alternatives: Careful handling from the back of the shell.
- Phone or camera in a waterproof pouchUseful for photos to help identify your crab later, and for emergencies.Alternatives: A notebook to record what you saw.
The short answer
Yes, spider crabs will often go for fish baits. Pieces of oily fish such as mackerel are a common bait for crabs in general, and anglers bottom fishing with fish baits sometimes find a spider crab clinging on when they reel in.
But there are a few important things to know first:
- A spider crab is a crustacean, not a fish, so it is usually caught by accident on a fishing line rather than hooked properly.
- Taking crabs, using pots or keeping any for the table may be covered by local rules. These can include minimum sizes, limits on pots and protection for females carrying eggs.
- Many families simply enjoy looking at one for a moment and then putting it back.
How to recognise a spider crab
The crab most UK anglers mean by "spider crab" is the spiny spider crab. Look for:
- A pear-shaped or triangular shell, wider at the back and narrower towards the front.
- Lots of spines and bumps across the shell, with two horns at the front.
- Long, thin legs that make it look spidery.
- An orange, red or brownish colour, often hidden under weed, sponges or other growths.
- Fairly small claws for its body size, compared with an edible (brown) crab.
Crabs it can be confused with
| Crab | How to tell it apart |
|---|---|
| Shore crab | Smaller, green or brown, smooth-edged shell. Very common in harbours and rock pools. |
| Edible (brown) crab | Rounded, "pie crust" edge to the shell, big black-tipped claws, short legs. |
| Smaller spider crab species | There are several smaller, long-legged crabs around the UK coast. They are much smaller and thinner than the spiny spider crab. |
If you are not sure, take a quick photo and put the crab back. You can ask a local angler or a marine life group to help identify it later.
Where and when you might find them
Where
Spiny spider crabs are mainly associated with the south and south-west of the UK. They like rocky ground, kelp, gullies and mixed sand and stone. Anglers may come across them when fishing from:
- Rock marks and deeper water off headlands
- Harbour walls and piers over rough or weedy ground
- Boats fishing near reefs and wrecks
They are less likely to turn up on clean, shallow sandy beaches.
When
Spider crabs are usually talked about as a late spring and summer visitor to shallower water. At times they are reported gathering in large groups. In colder months they are thought to move into deeper water, so shore anglers see far fewer then.
How people usually catch them
By accident while bottom fishing
This is the most common way anglers meet a spider crab. You cast a fish bait onto the seabed for fish such as wrasse, pouting or dogfish. A crab grabs the bait and holds on as you reel in. Often it is not hooked at all and lets go near the surface.
Signs a crab is on your bait:
- Slow, steady pulling rather than sharp fish-like bites
- A heavy, "dead weight" feel on the retrieve
- Baits coming back stripped or shredded
Fish baits that tend to attract crabs
- Mackerel strips or chunks
- Other oily fish pieces
- Fish heads and frames
There is no special trick. Crabs follow their noses to smelly, oily baits on the bottom.
Pots, nets and hand-gathering
Some people catch spider crabs on purpose using pots or drop nets baited with fish. Divers and snorkellers sometimes gather them by hand. These methods are often controlled by local rules, so check with your regional authority before trying them. For most beginners and families, the simplest and kindest approach is to enjoy any you catch by accident and return them.
Handling a spider crab safely
Spider crabs are slow and less snappy than some crabs, but they can still pinch and their spines are sharp.
- Lift the crab over a landing net or keep it low over the ground or water. Don't swing it up a harbour wall on the line.
- Hold it from behind, gripping the sides of the shell at the back, away from the claws.
- Gently unhook or let it release the bait. If it is gripping the bait, lower it into a bucket of seawater and it will often let go.
- Never pull on a leg or claw. Crabs can drop legs if they are stressed.
- Keep it wet and out of hot sun if you want a quick look or photo.
- Return it quickly, lowering it gently back into the water rather than dropping it from height.
Helping children handle crabs
- Let an adult do the picking up.
- Children can look closely in a bucket of fresh seawater.
- Wash hands afterwards.
Size, retention and other rules
Crabs can be covered by rules that are different from fish rules. These may include:
- Minimum sizes (measured in a set way for each species)
- Rules about females carrying eggs (often called "berried" females)
- Limits on how many you can take or how many pots you can use
- Rules about selling any catch
These rules vary around the UK and can change. Always check the current local rules with your regional authority before keeping any crab. If in doubt, put it back.
Quick tips for beginners
- If your baits keep getting stripped on rough ground, crabs may be the reason. Try a different spot or check baits often.
- Tougher baits last longer when crabs are busy.
- A spider crab on the line is a great chance to teach children about the seashore. Look, learn and let it go.
Stay safe
- Check tide times before you go and never get cut off on rocks or sandbanks.
- Wear a lifejacket or buoyancy aid near deep water, especially children.
- Keep well back from edges on rocks, piers and harbour walls, and watch for waves and swell.
- Rocks and steps covered in weed are very slippery. Wear grippy footwear.
- Spider crabs can pinch and their spines are sharp. Hold them from the back of the shell.
- Adults should handle crabs and hooks for young children.
- Hand-gathering by snorkelling or diving needs proper training and safety cover. Do not try it without experience.
- Wash hands after handling crabs and bait.
- In an emergency at the coast, call 999 or 112 and ask for the Coastguard.
Questions people ask
Can you catch spider crabs with any fish bait?
Spider crabs are attracted to fish baits on the seabed, especially oily ones such as mackerel. They are usually caught by accident while anglers bottom fish for fish. Catching them on purpose with pots or nets may be covered by local rules, so check first.
Is a spider crab a fish?
No. A spider crab is a crustacean, like other crabs and lobsters. It has a hard shell and jointed legs instead of fins.
Do spider crabs bite or pinch?
They can pinch with their claws, and their shell is covered in sharp spines. They are fairly slow, but handle them carefully from the back of the shell.
When are spider crabs most common near the shore?
They are usually linked with late spring and summer, when many move into shallower water. Local timing varies.
Can I keep a spider crab?
There may be minimum sizes and other rules for keeping crabs, and these differ around the UK. Check the current local rules before keeping any. For most families, putting it back is the best choice.
Why do my baits keep coming back empty?
Crabs, including spider crabs, are good at stripping baits on rough or weedy ground. Try tougher baits, check them more often, or move to a different spot.
Related guides
How to Catch Mackerel with Your Mum, Dad or Carer: A Family Guide
Mackerel are one of the best first sea fish for families. They often swim in shoals close to piers, harbours and rocks in the warmer months, they bite readily and they fight hard for their size. This guide explains what you need, how to fish for them together, and what to try if the fish aren't biting.