Black Lugworm

Black lugworm (Arenicola defodiens) is a large species of marine worm 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 – than blow lugworm, although unlike blow lugworm they can be frozen for future use. Black lugworm are known under different names in different parts of the UK, 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 and appear to be rare around the rest of Europe, although this may be due to black lugworms being erroneously being misidentified as blow lugworm. Black lugworm are found across the same sandy and muddy coastlines as the blow lugworm but they can be found on expansive, open beaches with little shelter which are not favoured by blow lugworm. They are generally found much closer to the low tide line than blow lugworms, 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 seawater 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 harder to find.

Digging and Collecting Black Lugworm

As black lugworm are found much closer to the low tide mark and have a much smaller cast they are significantly harder to find and dig than blow lugworm. Additionally, they are almost always much more diffuse and spread out location than blow lugworms, so they can rarely be trenched (a large number dug out in one go), and instead they must be located and dug individually. Despite the difficulty in gathering black lugworm they are such an effective bait that many anglers find that it is well worth the time to put the effort in to dig 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 more effective 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. 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, such as these bait pumps which are available from Amazon. A further issue with digging black lugworm is that as they are found close to the low tide mark the amount of time available to gather lugworm before the tide starts to come back in is limited. For this reason it is often best to dig for black lugworm on the largest spring tides. Anglers should always be aware of safety issues when digging for black lugworm (such as getting cut off by the tide) and ensure that bait digging is permitted.

Just like blow lugworms, there should be two containers to keep black lugworm in – one for full undamaged worms and another for worms which have 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 the two together will see all worms rapidly decline in quality. 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. If they are placed in trays which contain a few millimetres 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 seawater every two days or so. 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. Damaged or burst worms need not go to waste, as they can be frozen for future use.

Black lugworms can be frozen. 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. 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 less firm bait which is more difficult to present on the hook. Catches seem to be just as good with gutted black lugworms and therefore most anglers do gut worms prior to freezing.

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

While some anglers claim that frozen black lugworm only keep for a few weeks this is nonsense and there is no evidence to back it up and plenty of anglers catch fish on black lugworms which have been frozen for well over a year. 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. Most fishing tackle shops will be able to supply frozen black lugworm, 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 lugworm, with the hook point placed in the tail and the worm threaded up the hook. Because they are tougher than blow lugworm their presentation is generally better and due to their size only a single worm is needed to make a substantial bait. To bulk the bait up further and add more attraction for fish they can be made into a cocktail bait, with squid and black lugworm creating a 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.

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 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 where the hook is placed at one end and baits are threaded up the needle and on to the hook. With black lugworm this makes the baiting process easier and improves bait presentation. Baiting needles designed for sea fishing can be bought from Sea Angling Shop by clicking here or from Amazon by clicking here.

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 lugworm, 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). Over time the evidence provided by anglers that there were two 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.