All the sea fishes have a different diet and will be attracted to one or more types of bait. Knowing their natural preferences and offering them this will improve your catches. It is still necessary to also know where, depth and location, is best. It is known that fish take some baits that are not their normal food source so any bait could attract a bite. Cod have been known to take plastic white coffee cups presumably mistaking them for squid. Here are some other ideas for presenting the various baits after crab.

Crab

Worm

Squid

Sandeel

Mackerel

The ‘peeler’ crab can be purchased sometimes live but mainly frozen from tackle shops. A ‘Peeler’ is a crab about to shed it’s shell which happens naturally as it grows. Presentation of this bait can be provided whole or a piece dependent on which species targeted. Fixture to the hook is normally supported by using elastic thread.
Used from fresh or frozen this bait is very popular due to it’s attractiveness to fish and the low cost to buy. It can be presented in many different ways; whole live or dead, strips (slivers), as a ‘Flapper’ or just parts of body (head, tail, mid section). Sometimes used as part of a ‘cocktail’ where two or more different baits are presented on one hook e.g. lugworm and a sliver of mackerel. Use elastic thread to secure larger pieces to the hook to save slippage.
Flapper

Shrimp

Like Mackerel, Sandeel can be obtained frozen or live delivered in a tub of sea water which has to be refreshed on a regular basis. They can vary considerably in length and this will affect the hook size. Presentation on the hook depends if live or dead.
Live Dead
These are popular to use as part of a cocktail of baits or for catching the smaller species. One source of shrimp is to scrape the weed sides of pontoons with a net, these are known by some as ‘Bunters’.
Know in some circles as ‘Calamari’ and like Mackerel is a favourite amongst sea anglers for the same reasons. It can be presented again like Mackerel in strips, whole or parts. Rarely available fresh most comes deep frozen and when thawed is as good as fresh. Refreezing is not recommend but is often used again. Help hold the bait to hook by using elastic thread or a 2 hook Pennel rig.
For sea fishing lugworm are the best for some species where ragworm is king for others. When to use which is dependant on the site you are fishing. If the area holds one type over preference to the other then use that worm as the fish will be familiar with it as a natural food source. Not to say that you can still try out the alternative if the first recommendation is not possible. Worm can be expensive and in short supply so there is no guarantee that you rely on it. Often used as part of a ‘cocktail’ with mackerel of Squid care has to be taken loading onto a hook. A baiting needle is handy to help this process.
BAIT
Sandeel Sandeel Worm Worm Squid Squid Shrimp Shrimp Mackerel Mackerel