Phylum Annelida : True Worms
: Bristle worms
Worms are the most important of
bait species collected in the UK, by digging on
sediment shores. Their exploitation is also completely
unregulated, since they are not classified as seafish
and do not fall under the scope of fisheries legislation.
: Bristle worms
This Class is the largest group
of worms. All are aquatic and the great majority
is marine. A few polychaetes are commensal or parasitic,
but most are free-living and include pelagic swimmers,
crawling and actively burrowing species, and tube-dwelling
species. However, only a very small number of the
over 1,000 species which occur in UK waters are
sufficiently large, robust, common and easily obtained
to be target bait species.
Superfamily Nereidoidea, Family
Nereidae : Ragworms
Ragworms are very common errant
(free-living) polychaetes all around the British
Isles. Nineteen species have been recorded on British
coasts, in nine genera (Knight-Jones et al.,
in Hayward and Ryland 1995).
All Nereidae are semelparous (or
monotelic), breeding only once in their lifecycle
before dying. When male and female ragworms reach
maturity, hormonal changes cause their bodies to
alter. Their digestive systems break down, to enable
large numbers of eggs and sperm to be produced,
and most species develop large eyes and swimming
legs in preparation for leaving their burrows to
spawn at the water surface. A combination of a temperature
cue and lunar cycle stimulates the release of pheromones
and gametes from all the mature worms in the population.
Spawning during spring tides probably ensures the
maximum dispersion of fertilised eggs in the water
column. Some cultures collect spawning, protein-rich,
reef polychaete worms for food (e.g. Palolo palolo
worms in Samoa, South Pacific).
Some ragworms are capable of maturing
and breeding after just one years growth in
good conditions, but most important bait species
take rather longer. King ragworms Nereis virens
are two or three years old before hormonal changes
trigger breeding in UK populations. Usually, therefore,
about one third of the population will breed every
year. However a proportion of the large king ragworms
in the Menai Strait population exhibit delayed maturity,
with only about 20% spawning each year (Coates 1983,
The omnivorous nature of ragworms,
their fast growth and swift maturity, makes them
very suitable for large-scale commercial bait worm
farming. This has the capacity to alleviate some
baitdigging pressure from sensitive intertidal areas.
However, farming may also result in the accidental
release of non-native species imported for use as
bait, or for farming in the UK. Non-native species
are increasingly being imported into mainland Europe
from Korea, Taiwan and the USA to satisfy demand
for bait (Olive pers. comm.). Roch et al.
(1990) report on their purchase from a retail shop
in Italy of a Nereis sp. from the Yellow
The following species are most
commonly collected for bait on UK shores:
Hediste (Nereis) diversicolor
(O F Müller, 1776). Harbour rag. A greenish, yellowish
or orange worm with a prominent dorsal blood vessel
some 60-120 mm long. Feeds by spinning a mucous
net to catch food particles (mainly dead organic
material) suspended in the water. Found burrowing
in intertidal black (anoxic) muddy sand, often in
brackish areas, around most British coasts, and
north-west Europe as far as the Mediterranean. Neither
sex leaves their burrows when spawning and larval
young do not disperse very far. Feeding birds may
take up to 90% of the population during the year
Neanthes (Nereis) virens
(M Sars, 1835). King rag. A large dark green worm
with large leaf-like dorsal lappets giving a fringed
appearance to the body. This commonly grows to 200-300 mm
long, and much more in a few areas (notably the
Menai Strait, where maturity is delayed in a significant
proportion of large worms). The king rag occurs
in a mucus-lined burrow in black muddy sand habitat
on most British shores. It scavenges and can take
small invertebrates with its large jaws (although
these may be used mainly for defence). Male king
ragworms swim out of the burrows to spawn and fertilisation
of eggs takes place inside the females burrows.
There is a brief planktonic larval stage. Large
numbers of dead males are sometimes reported washed
up after spawning. The king rag is a highly valued
bait species, and is particularly common in the
south and west and on the Atlantic coast of Europe.
It is farmed for commercial bait production, but
some commercial bait outlets report that farmed
ragworm do not travel well and can be of poor quality.
Perinereis cultrifera (Grube,
1840). Ragworm. A bronze-green worm with bright
red dorsal vessel and parapods (legs),
reaching 100-250 mm long. Makes galleries in
mud inside rock crevices, under stones and in eel
grass. Common bait species, found all around British
coasts, in north-west Europe to the Mediterranean
(and in the Indian Ocean).
Superfamily Nephtyoidea, Family
Nephtyidae : Catworms or silver rag
Medium or large, smooth, silvery
worms which actively swim and burrow in clean sand
beaches, usually close to the low water mark. The
largest specimens are used for bait and are particularly
sought-after by some anglers, including match fishermen.
Catworms do not have permanent,
visible, burrows but wander through the sand in
search of their prey (which may include smaller
conspecifics). They are long-lived and can be aged
by counting the annual growth rings in their jaws.
An average three-inch long worm is usually four
or five years old, and the largest worms in a UK
population may be up to 12 years of age (Olive 1985b).
Caron et al. (1995) report on an enormous
individual of Nephtys caeca from Canada with
15 visible jaw rings.
Like the ragworms, the catworms
have separate sexes and all worms in the population
breed on the same day. However, catworms are iteroparous,
or polytelic, and may breed several times in their
lifetime. Breeding does not necessarily take place
every year; sometimes the worms reabsorb their gametes
before spawning can occur. Olive (1985b) recorded
only two successful spawnings in one species during
the ten year period from 1975 to 1985. Catworm larvae
have a long planktonic phase and may not settle
onto the bottom until five weeks after fertilisation.
Their slow growth, infrequent spawning and low recruitment
rates make Nephtys species very vulnerable
to bait digging (it is possible for local populations
to be dug out), and also unsuitable for bait culture.
There are about ten species in
two genera (Aglaophamus and Nephtys)
recorded in Britain (Knight-Jones et al.,
in Hayward and Ryland 1995), although Howson and
Picton (1997) record a larger number in the region.
The three most common intertidal species are listed
Nephtys caeca Fabricus.
150-250 mm long, common and widespread in the
intertidal and at low water all around Britain,
and in the Arctic and Northeast Atlantic. Caron
et al. (1995) report on an individual (>23g)
of Nephtys caeca sampled in Canada that was
over 23 g in weight and 15 years old, in a
population with a longevity of over 6 years.
Nephtys cirrosa Ehlers.
60-100 mm long, found in the intertidal and
at low water mark all around Britain and on the
Atlantic coast of Europe.
Nephtys hombergi Savigny.
100-200 mm long, common and widespread in the
intertidal and at low water all around Britain,
north-west Europe and the Mediterranean.
Family Arenicolidae : Lugworms
The lugworms are the most popular
bait worm used by anglers in the UK, and are extremely
common. They are collected extensively by anglers
for their own use, and by commercial diggers for
resale. Two species are commonly used for bait (see
below), but since one of these was only described
relatively recently, differences in their ecology
and life cycles are still not fully understood.
Lugworms live in U or J-shaped
burrows on sandy and muddy sand shores, and feed
on the remains of decaying seaweed, diatoms and
bacteria. They are also found in the sublittoral,
in muddy sands and mud, and may be particularly
common around sources of organic input (e.g. fish
farms). The location of lugworm burrows is obvious
from the spiralled faecal sand casts left on the
surface above one entrance to the burrow.
Lugworms begin to breed at an age
of two years, when they also reach a large enough
size to be considered suitable as bait. Each animal
spawns on a single day, and the entire population
of any beach completes spawning within a few days,
although populations on different beaches spawn
at different times. Most lugworms breed in winter
(October to March), with the majority spawning in
November and December. Some 20% of lugworms spawn
in summer (July to September, Shahid 1982). Some
lugworms die after spawning, and the remainder stops
feeding and producing sandcasts for the period during
which their larvae are living attached to sand grains
in the adult burrows. Adult populations are at their
lowest density, and individual worms at their smallest
size in winter after breeding. Population density
and worm size both increase quickly in spring as
growth rates rise and maturing worms migrate into
the adult lugworm beds.
Soon after fertilisation, the larvae
migrate from the adult beds to a zone just below
the low water mark, where they occur in dense populations
for the next six months until they reach a length
of about 10 mm. They then swim in a mucus tube
to the upper part of the shore, where plenty of
organic material occurs in a zone just below the
strand line (in natural conditions; beach cleaning
operations will remove much of the organic input
usually provided during the holiday season). Very
dense beds of juvenile lugworms occur in this area.
The maturing worms eventually move down to the less
densely populated adult beds at the bottom of the
shore and in the sublittoral. Adult worms are capable
of living for six years. They reach weights of 25 g
in the south and west, or 10 g in the north-east,
and may breed several times during their lifetime.
This complex life cycle makes lugworms
very resilient to bait collection pressure, provided
that bait diggers do not dig in the nursery beds
high on the shore. Populations on the lowest part
of the shore and in the shallow sublittoral are
only rarely or never exploited. Adult worms will
migrate into dug areas from these refuge populations,
as well as from the nursery beds. However, the same
complexity of life cycle and their relatively slow
growth makes lugworms difficult candidates for bait
farming, although progress is now being made with
the culture of UK species (Olive pers. comm.).
Three genera are reported by Howson
and Picton (1997) to occur in and around UK waters:
Arenicola (two species), Arenicolides
(three species), and Branchiomaldane (one
species). Bait collectors actively target the two
species of Arenicola. The two more common
Arenicolides species (A. branchialis
and A. ecaudata) are found in mixed
sediments among rocks and stones, which are less
likely to be dug over by most lugworm collectors
(although they will be encountered in this habitat
by ragworm collectors).
Other species of Arenicolidae are
apparently used for human consumption as well as
for fishing bait in East Asia. Trade statistics,
based on custom clearance statistics released by
the Japanese Ministry of Finance, record that 1,119 MT
of lugworms and sea lavenders (living), worth 710
million yen, were exported from Japan to Korea in
1997. (Data from March issue of East Asia Economic
Information, published by Tokyo-based East Asia
Trade Research Board.) Other sources record that
some of these lugworms are processed and canned
in tomato sauce, presumably for human consumption.
Arenicola marina (Linnaeus).
Blow lug (also known as lobworm and yellowtail).
This species occupies U-shaped burrows, marked by
a faecal cast and a feeding depression, on the lower
shore of clean to muddy sand beaches. Its range
extends from the Arctic to the Mediterranean in
Northwest Europe. At 150-200 mm long, this
is one of the most important UK fishing bait species,
dug by hand. The blow lug is sold commercially for
bait in many regions, but as a relatively small
worm, it is less sought-after than black lug.
Arenicola defodiens Cadman
and Nelson-Smith, 1993. Black lug (or runnydown).
A larger worm than A. marina, and therefore
particularly sought after by bait collectors (commercially
and for personal use). This species occurs in a
lower zone of the intertidal, and possibly on more
exposed beaches, in J-shaped burrows marked by a
faecal cast characterised by a hole in the centre
of the cast (Mr Sharp pers. comm.). It is therefore
mainly obtainable during low water spring tides,
and is usually collected using a bait pump. It has
only recently been distinguished from A. marina,
and full details of its geographic distribution
and life cycle are not yet available. Bait diggers
report that the species seems to prefer areas that
are relatively enriched, either by local sewage
outfalls or exposed shores in estuaries (Mr Sharp
pers. comm.). Black lug collected for resale are
usually gutted and wrapped in newspaper.
Marphysa sanguinea (Montagu).
Verm. Broad flattened body of 300 or more segments
and 300-600 mm long. Valued as angling bait in the
Channel Islands, but can bite painfully when handled.
Found in mucus-lined galleries in muddy sand under
stones and among old shells on the lower shore on
western coasts of Britain.
Other species of Marphysa
enter the international trade in bait worms (particularly
to the Mediterranean) and their introduction to
areas where they do not occur naturally could be
environmentally damaging (Peter Olive pers. comm.).
Some 16 species in four genera
are recorded in the UK, some of which can deliver
a painful bite (said to resemble a bee sting). None
of these UK species are known to be used for bait,
but this family is introduced here because of the
extensive international trade in Glycera dibrachiata,
a species from the Northwest Atlantic which is imported
to Europe (Atlantic and Mediterranean coasts) and
elsewhere (see Section 6.7 below). This species
has large jaws with a poison gland, and would be
an extremely unwelcome addition to the European