Blacks, blacklug and black lugworm are available from all good online bait dealers and tackle shops. They are one of the best worms to use when sea fishing.
They are very tough worms that are pitch black and ooze a tremendous scent. They can be used whole or in chunks to tip off another bait.
They are often sold in packets of 10, neatly wrapped in damp newspaper to ensure they remain fresh.
When stored in a fridge, these baits will remain fresh for up to 4 days.
Because these are a natural bait, the lengths will vary, but expect each worm to be between 6-8 inches.
Frozen black are also available. These tend to be vacuum packed for freshness, and tend to be blast frozen within hours of being collected.
The price quoted here is an average price for 10 blacks, fresh or frozen.