Black Lugworm

Black lugworm (Arenicola defodiens) are large species of marine worms which are an extremely useful bait for anglers targeting a range of species. Despite being a widely used bait for many years they were only recognised as a separate species to blow lugworm by the scientific community in the 1990s. As they are fairly difficult to find and collect they are less common – and more expensive to buy – then blow lugworm, although they can be frozen for future use. Black lugworm have a huge range of local names, with runnydown and yellowtails two of the most common.


Black Lugworm

A picture of a black lugworm extracted from the book Atlas Colorie des Plantes et Des Animaux des Cotes de France by Maurice Langeron, published in 1906.

Black lugworm generally much larger than blow lugworm and can grow to 30cm in length. They are also thicker than blow lugworm and have a less defined tail section. As the name black lugworm suggests they are usually dark in colour, ranging from a very dark brown to black, although occasionally they can be a slightly lighter reddish or pinkish colour.

Distribution, Habitat and Life Cycle

Black lugworms are primarily found around the British Isles, with the only other reports of this species coming from a few locations in the Netherlands and Belgium. However, it may be the cast that this species is more widespread throughout Europe but is still erroneously being misidentified as blow lugworm. Black lugworm are found across the same sandy and muddy coastlines as the blow lugworm, although they can be found on expansive, open beaches which are not favoured by blow lugworm. They are generally found much closer to the low tide line than blow lug, and are mostly absent from areas further away from the sea where blow lugworm can still be present.

Black lugworm live in J-shaped burrows which can be very deep. Like the blow lugworm they feed on tiny particles suspended in sea water and also excrete a cast, although the cast of the black lugworm is much smaller and neater than the blow lugworm’s cast and there is no circular depression area, making black lugworms much harder to find.

Digging and Collecting Black Lugworm

As stated above the deeper burrow, location close to the low tide mark, and much smaller cast mean that black lugworm are significantly harder to find and dig than blow lugworm. Additionally they are almost always much more diffuse and spread out location than blow lug, so they can rarely be trenched (a large number dug out in one go), instead they must be located and dug singly. Despite all these issues black lugworm are such a good bait that many anglers find it is well worth the time to put the effort in to gather black lugworm.

Low Tide

It can be necessary to go to the low tide mark on the biggest spring tides to dig black lugworm.

Unlike digging blow lugworm (which is better with a three-pronged garden fork) digging black lugworm is better done with a spade. As worms are generally extracted singly there is no real risk of inadvertently cutting through other worms. Dig straight down the hole until the tail of the worm is located. It is then a simple case of digging the spade into the sand near to the lugworm and lifting the whole worm out on the spade. However, some anglers prefer to dig the worm out by hand to eliminate the risk of damaging the worm with the spade. There are a number of bait pumps on the market which can be used to extract black lugworm from wet sand, which saves a great deal of effort, such as this one from Shakespeare, or this cheaper one from Nerus, both of which are available from Amazon. Anglers should always be aware that they do not become stuck in soft mud or sand when digging black lugworm, or become cut off by the incoming tide.

Just like blow lugworms there should be two containers to keep black lugworm in – one for full undamaged worms and another for worms which burst or been damaged in another way. The reason for this is that the juices that come out of damaged worms have a serious effect on undamaged worms and mixing together will see all worms rapidly decline in quality as a bait. Handling worms with hands can see a yellow stain transferred onto the anglers hands and fingers. This is harmless but can prove difficult to remove and is one of the reasons these worms are nicknamed yellowtails.

Storing and Freezing Live Black Lugworm

Undamaged black lugworm can alive for a day or so wrapped in newspaper and kept in a fridge. However, if they are placed in trays which contain a few millimeters of seawater and have a cloth dampened with seawater placed over the top they will keep for up to a week, although the water must be changed with clean, refrigerated sea water every two days. However, it is important to remove and damaged, dying or burst worms and they will cause the rest of the healthy worms to decline in quality and then die themselves. Damaged or burst worms need not go to waste, as they can be frozen for future use.

Unlike blow lug it is possible to freeze black lugworms. Most anglers cut the first few millimetres of the tip of the worm off, and then squeeze out the guts. The gutted worm can then be rolled up in clingfilm in batches of five or ten and placed in the freezer. However, some anglers prefer to leave the guts in the worm in the belief that they will be an added attraction to fish. This is true but it does result in a somewhat sloppier and bait which is more difficult to use. Catches seem to be just as good with gutted black lugworms and therefore most anglers do gut worms prior to freezing. While some people claim that frozen black lugworm only keep for a few weeks this is nonsense and there is no evidence to back it up.

Frozen Black Lugworm

A packet of frozen black lugworm bought from a fishing tackle shop.

Once deep-frozen in a domestic freezer lugworm will keep in perfect condition for at least two years, and in all probability will still probably be an effective bait for a lot longer than that. The fact that black lugworm can be frozen is a bonus for winter cod anglers, as it means a supply can always be on hand during the winter when fresh baits of all types are at their most scarce.

Buying Black Lugworm

Due to the difficulty in digging black lugworm they are not easily available from fishing tackle shops in fresh, live form. Most shops will only have live black lugworm in on a sporadic basis, whereas others may require them to be ordered and even then may not be able to guarantee that they can supply them. The price of black lugworms can also be significantly higher than other types of live worm such as ragworm or blow lugworm. However,most fishing tackle shops will be able to supply black lugworm in frozen form, although the cost can vary depending on how available local supplies are, and in the winter when this bait is in demand for cod fishing anglers may find that even frozen black lugworms can be hard to come by.

Black Lugworm Bait Presentation

Black Lugworm Bait Presentation

A gutted frozen black lugworm presented on the hook.

Fresh black lugworm is a very popular winter cod bait and is usually presented in a similar manner to blow lug, with the hook point placed in it tail and the worm threaded up the hook. Because they are tougher than blow lug their presentation is generally better and due to their size only a single worm is needed to make a substantial bait. However, to bulk the bait up further and add more attraction for fish they can be made into a cocktail bait, with squid combined with black lugworm creating the classic winter cod bait. Because black lugworm is a large bait (especially when made into a cocktail) it is often presented on a pennell rig to ensure that there is a hook at either end of the bait.

Gutted frozen black lugworm takes a little more preparation. Once the lugworm has defrosted it will be apparent that – although tough – this is a somewhat limp and floppy bait which cannot therefore be threaded up the hook in the usual manner. Instead the following preparation should be done to create a bait which both stands up to casting and attracts fish:

Depending on the size a number of defrosted black lugworms can be used on a hook, and the fact that they have been wrapped in bait cotton or elastic means that they will be a tough bait which stands up well to casting, rough seas and strong tides.

Baiting Needle

Many find baiting up with black lugworm easier if a baiting needle is used.

Many anglers find that the above process is easier if a baiting needle is used. This is simply a long metal needle which has a sharply pointed end section to fit the hook in at the other end. The black lugworm can be threaded up the needle and onto the hook, making the process easier and improving bait presentation.

Two Separate Species of Lugworm … Eventually

For many years anglers were aware that there were two distinct types of lugworm – the smaller and more common blow lug, and the larger and less widespread black lugworm. However, the scientific community was slow to catch on to this and until the 1990s there was officially only one type of lugworm – the common blow lugworm (Arenicola marina). However, the evidence provided by anglers that there were two separate and distinct species became overwhelming and a 1993 academic journal article produced by the School of Biological Sciences at the University of Wales, Swansea announced that black lugworm were now officially classed as a separate species. Blow lugworm retained the scientific name Arenicola marina, while black lugworm was given the scientific name Arenicola defodiens.

Share this page: