Ragworm Species Identification

There can be confusion over exactly which specie of ragworm are native to the UK and which are used by anglers as bait. Much of the misunderstanding comes from the fact that different websites, books and magazine articles confuse different species of ragworm, and some of the scientific names of different species have changed over time. British Sea Fishing considers the following to be accurate:

King Ragworm (Alitta virens)

King Ragworm

The largest species of ragworm which is commonly used as bait in sea fishing. Can be up to 90cm long but is usually around 30cm. This species used to have the scientific name Nereis virens which is still commonly used, leading to confusion.

Common Ragworm (Perinereis cultrifera)

A smaller species of ragworm, growing up to round 20cm in length, which is also commonly used as bait. Also known as red ragworm. This is a separate species, although many anglers and bait collectors may confuse this species with either small king ragworm or harbour ragworm, as they all live in the same habitat.

Harbour Ragworm (Hediste diversicolor)

Harbour Ragworm

A much smaller species, usually growing to around 8-10cm. Identifiable by the red blood vessel running along its body this species is also known as mudworm, muddies, maddies, creeper rag and a range of other regional names. Confusion arises because the scientific name Nereis diversicolor has also been applied to this species, making people believe it is a separate species.

White Ragworm (Nephtys spp.)

White Ragworm

There are a number of species are classed as white ragworm by anglers, all of which are in the Nephtys genus. They include Nephtys caeca, Nephtys cirrosa, Nephtys kersivalensis and Nephtys assimili, but the most common is Nephtys hombergii. Since they are so similar (only marine biologists and other experts can tell them apart) they are considered as a single species by anglers and bait collectors. Most grow to 15cm in length, but some can be over 30cm. Colour varies from pale yellow to while, sometimes with a pinkish or reddish tinge.