Bloodworm Tubifex sp.
INTRODUCING MARINE SEGMENTED WORMS
Segmented worms may not be the most glamorous of marine creatures, but their importance in marine ecology cannot be overstated. Burrowing, filter-feeding species help consolidate silty substrates, while almost all segmented worms are food for a wide range of predators, from crustaceans to fish and birds.
SEGMENTED WORM STRUCTURE AND CLASSIFICATION
As their common name suggests, the long, usually cylindrical bodies of members of the phylum Annelida are segmented. In many species the segments are conspicuous, while in some groups they are covered and obscured by soft plates or hairs. The mouth is near the head end and the gut runs the entire length of the body. Some annelid worm groups have bristles and outgrowths on the segments.
In the marine world, familiar representatives of the phylum Annelida are placed in three sub-groups: class Oligochaeta (whose best-known members are terrestrial earthworms) – small, easily overlooked and relatively unspecialised worms, including the Bloodworm Tubifex sp., a denizen of organic-rich silt; class Hirundinea – leeches, marine species of which suck the blood of fish and have distinct suckers at both ends; and class Polychaeta – the most diverse and well-represented class of segmented worms in the marine world. The range of polychaete worms found on the seashore is too diverse to discuss fully in a book of this size, but the following are some of the most distinctive groups:
Bloodworm Tubifex sp.
King Ragworm.
Active, predatory worms that burrow in mud and silt. The body comprises 100 or so segments and can be slightly flattened depending on the species. There are antennae, tentacles and eyes at the head end; at the front of the gut is an eversible pharynx that can be projected out of the mouth. Almost all segments have an upper and lower pair of bristles that aid locomotion, and a pair of filaments is present at the tail end.
Catworm Nephtys caeca.
Active, predatory worms, rather similar to ragworms. The body comprises 100 or so segments. The head is relatively small, and at the front end of the gut is an eversible pharynx that can be projected out of the mouth. Almost all segments have an upper and lower pair of bristles with a gill in between. There is a single filament at the tail end. Agitated animals swim in a sinuous manner.
Phyllodoce groenlandica.
Long worms comprising several hundred segments. There are tentacles and antennae at the head end, and most of the remaining segments bear a pair of flattened, paddle-like appendages. Paddleworms are active carnivores.
Alentia gelatinosa.
Unusual-looking polychaete worms whose dorsal surface is mostly or entirely covered with overlapping scales; in most species, the body is very flattened. In the case of the Sea Mouse and its relatives, the scales are covered in a dense mat of hair-like bristles that completely covers the dorsal surface.
Blow Lug in its burrow.
Sedentary worms that live in U-shaped burrows in mud and silty sand. Segments at the front end of the body are armed with bunches of bristles; segments in the middle section have feathery gills; and the tail end is narrower than the rest of the body. Lugworms feed in situ in their burrows: silt and detritus is ingested via the mouth, food particles are digested, and sand is excreted at the tail end, building up as little mounds of tubular ‘casts’.
Sand Mason removed from its tube.
Plump-bodied worms with a swollen front section and narrower, tapering tail section. At the head end are conspicuous tentacles and branched gills. Many species live in unsophisticated burrows under stones and other objects, the tentacles collecting detritus from the nearby seabed. The Sand Mason constructs a protective tube of stones and small shells, and lives part-buried in silty sand.
Peacock Worm.
Intriguing worms that have a funnel-shaped arrangement of fairly stiff tentacles at the head end. When feeding, these tentacles project beyond the mouth of the tube in which the worm lives and assist with filter-feeding. Movement or sudden changes in light intensity, detected by sensitive eye-spots, cause the tentacles to be withdrawn.
Ficopomatus enigmaticus.
Interesting worms that live inside calcified tubes, these attached along their length to a solid object; this might be a stone or shell in some species, or a broad seaweed frond in others. A fan-shaped arrangement of tentacles can be protruded outside the mouth of the tube, allowing filter-feeding. In some species the mouth of the tube can be sealed by a modified tentacle.
Neoamphitrite figulus Length to 20cm
Soft-bodied worm. Lives in burrows on muddy shores and in estuaries; sometimes found under stones. ADULT has 100 or so segments, anterior 24 swollen and with chaetae. Head has mobile brown feeding tentacles and 3 pairs of divided red gills. STATUS Widespread and locally common.
Eupolymnia nebulosa Length to 15cm
Soft-bodied worm. Lives in a slimy tube, often under stones on lower shore. ADULT has 100 segments, anterior 17 with chaetae; body is brown with white spots. Head has brownish feeding tentacles marked with narrow pale bands, and shortish red gills. STATUS Widespread and locally common.
Polycirrus caliendrum Length to 8cm
Extremely colourful and distinctive worm. Lives in a mucous tube, under stones and debris on sheltered muddy shores. ADULT is bright orange with 70–90 segments; much of head end is often obscured by tangled mass of tentacles. STATUS Local, mainly in W Britain.
Thelepus cincinnatus Length to 15cm
Tube-dwelling worm. Tube is encrusted with debris and located under stones and holdfasts on sheltered shores. ADULT has 100 or so segments, anterior 30 or more with chaetae. Head end has pale tentacles and short, branched red gills. STATUS Widespread and locally common.
Cirratulus cirratus Length to 10cm
Slender worm with fairly uniformly sized segments. Lives mostly buried in mud beneath stones or among eelgrass roots. ADULT is orange-red with 140 or so segments. Head is blunt and bears 2 groups of 2–8 tentacles; these are often all that can be seen of the worm. Slender, tentacle-like gills appear on other segments. STATUS Widespread and locally common.
Cirriformia tentaculata Length to 15cm
Colourful worm. Found under stones in muddy gravel, on lower shore. Thread-like red tentacles are sometimes visible in shallow water. ADULT has 300 or so segments and is reddish (breeding male is yellow, breeding female greenish). Head is pointed and lacks eyes; has 2 bunches of numerous red tentacles arising behind head and red tentacle-like gills along much of body. STATUS Widespread and locally common.
Sand Mason Lanice conchilega Length to 20cm
Sand Mason, tube
Sand Mason, worm
Sand Mason tube in situ
Distinctive worm, best known for the frilly-ended tube (made of sand particles) in which it lives. Found on sandy shores, even relatively exposed ones. ADULT has 150–300 segments; head end has tentacles and short, branched gills. STATUS Widespread and locally common.
Blow Lug Arenicola marina Length to 20cm
Blow Lug, head end
Black Lug, head end
Black Lug
Familiar worm that lives in a U-shaped burrow in mud and sand, often in estuaries; inhalant and exhalant holes and cast are conspicuous. ADULT is plump-bodied. First 19 segments are fatter than tail-end segments, and latter 13 of these have red gills. Chaetiger 2 and 3 separated by 3 annulations. STATUS Widespread and locally abundant. SIMILAR SPECIES Black Lug A. defodiens is similar but blackish, with chaetiger 2 and 3 separated by 2 annulations. On moderately exposed beaches, presence is revealed by exhalant hole and cast, but no inhalant hole.
Arenicolides branchialis Length to 20cm
Arenicolides ecaudata
Similar to Blow Lug but tail end is not noticeably narrower. Lives in crevices in, and gaps between, rocks lodged in muddy sand. ADULT has bristles of some sort on all segments, and gills on segments 13–40 or so. STATUS Widespread and locally common. SIMILAR SPECIES A. ecaudata has gills on segments 16–50 or so.
Scoloplos armiger Length to 12cm
Slender worm that burrows in muddy sand on lower shore. ADULT is reddish; front 20 or so segments are flattened, the remainder rounded. Head end is pointed, tail end has 2 slender appendages, and most segments except anterior 12 or so have gills. STATUS Widespread and locally common.
Glycera tridactyla Length to 10cm
Glycera tridactyla, head end
Slender worm, found in muddy sand on lower shore. Rolls into a tight corkscrew when disturbed. ADULT is pearly pink with up to 170 annulated segments. Head end is pointed with 4 minute antennae; tail end has 2 projections. STATUS Widespread and locally common.
Slender worm, found among and under rocks on lower shore. ADULT is whitish, palest towards head end, with 120 or so segments. Head end is pointed, with 4 tiny antennae arranged in star-like fashion. Parapods are armed with bristles. STATUS Local, mainly in SW and W Britain.
Estuary Ragworm Hediste diversicolor Length to 12cm
Active, flattened worm; feels ‘flabby’ when handled – if lifted midway with a pencil, body goes completely flaccid. Lives in a burrow in muddy sand, often in estuaries. ADULT is reddish or greenish, with 120 or so segments. Head has 2 small antennae, 2 palps and 4 tentacles on each side; tail end has 2 appendages. Red blood vessel runs dorsal length of body. STATUS Widespread and locally common.
Ragworm Perinereis cultrifera Length to 20cm
Familiar worm, found under stones, and in crevices and laminarian holdfasts. ADULT has 120 or so segments, slightly domed in cross section. Body is greenish brown, with red dorsal blood vessel; parapods are reddish. Head has 2 anterior antennae, 2 palps and 4 tentacles on each side; posterior pair is longest. Tail has 2 appendages. STATUS Widespread and locally common.
Nereis pelagica Length to 12cm
free-swimming, reprodutive stage (known as an epitoke) of Nereis sp.
Active worm, similar to Estuary Ragworm but favouring different habitat: lives in a mucous tube among laminarian holdfasts. ADULT is more cylindrical than flattened, with 120 or so segments. Body is reddish brown or greenish, with a metallic sheen. Head has 2 small antennae, 2 palps and 4 tentacles on each side; tail end has 2 appendages. STATUS Widespread and locally common.
King Ragworm Alitta virens Length to 25cm
Impressive worm, unmistakable when adult because of its size. Burrows in muddy sand, often in estuaries or sheltered bays. ADULT has up to 200 broadly flattened segments and is green with a metallic sheen. Head has 2 antennae, 2 palps and 4 tentacles on each side; tail end has 2 appendages. STATUS Widespread and locally common.
Catworms Nephtys sp. Length to 20cm
Nephtys caeca
Nephtys hombergii
Active worms that burrow in muddy sand on sheltered shores and in estuaries. Swim in a sinuous manner. Several species are widespread but specific identification is hard in the field. Regularly encountered species include N. caeca (in muddy gravel and sand ), N. hombergii (in muddy sand) and White Catworm N. cirrosa (in clean sand). ADULTS are flattened, with up to 200 segments, pinkish grey with a pearly iridescence. Head is tiny, with 4 tiny antennae (appears to lack antennae to naked eye). Tail has 1 tiny projecting appendage. STATUS Widespread and locally common.
Marphysa sanguinea Length to 50cm
Impressive worm. Superficially ragworm-like, but head appendages and presence of gills allows separation. Lives in a tube under stones and in mud on lower shore. ADULT is pinkish red with 250 or so segments. Head has 5 short appendages, tail end has 2 appendages, and segments on latter half of body have paired red gills. STATUS Local in S Britain.
Gallery Worm Capitella capitata Length to 8cm
Earthworm-like marine worm and one of several similar, related Capitella species. Lives buried in muddy sand on lower shore. ADULT is pinkish red and yellow, with 100 or so segments. Body is extremely contractile. Head end is conical and lacks appendages. Segments bear simple chaetae and have a ‘ribbed’ appearance. STATUS Widespread and locally common.
Lysidice ninetta Length to 5cm
Intriguing worm, sometimes found crawling over rocks in pools on lower shore. ADULT has rather rounded body. Head bears 3 small, bluntly pointed tentacles that are pale and contrast with otherwise darker, mostly reddish-purple body; segment 4 is contrastingly pale. STATUS Local, mainly in the S and SW.
Phyllodoce lamelligera Length to 50cm
Paddleworm eggs are laid inside green blobs of jelly, attached to substrate or weed.
Colourful paddleworm, found under rocks on lower shore. Secretes mucus if disturbed. ADULT has several hundred segments. Dorsal surface is bluish green, paddles are greenish or brownish. Head has 4 pairs of long tentacles. STATUS Locally common in S and SW Britain.
Phyllodoce groenlandica Length to 30cm
Impressive paddleworm, found under rocks and in crevices on lower shore. ADULT has several hundred segments. Dorsal surface is yellowish green, paddles are green with brown markings. Head has 4 pairs of long tentacles. STATUS Widespread and locally common.
Phyllodoce maculata Length to 7cm
Slender, easily overlooked paddleworm. Lives on shores with muddy sand, often around mussel beds; seen in shallow pools at low tide. ADULT has up to 250 yellowish-brown segments, each with dark central marking; yellowish paddles also have dark central mark. STATUS Widespread and locally common.
Greenleaf Worm Eulalia viridis Length to 10cm
Slender, very colourful paddleworm. Lives on rocky shores; found under stones and in laminarian holdfasts. ADULT has up to 200 green segments and leaf-like, pointed green paddles. Head has 5 antennae (2 lateral pairs and 1 on dorsal surface) plus 4 pairs of tentacles. STATUS Widespread and fairly common.
Flabelligera affinis Length to 3cm
Unusual and distinctive worm. Lives permanently inside a sheath of secreted mucus, to which particles adhere, hence easily overlooked. Found under stones on lower shore; sometimes among spines of sea urchins. ADULT has 40–50 segments, with 2 palps and fringe of delicate gills at head end. Body is rather transparent, tinged by greenish blood; red gut shows through. STATUS Widespread but generally scarce, mainly in the W and N.
Parchment Worm Chaetopterus variopedatus Length to 20cm
Parchment Worm, in situ in its tube
Bizarre and unmistakable worm. Lives in a tough U-shaped tube made of parchment-like material encrusted with sand and debris. Found on relatively sheltered shores, in muddy sand at low water and sub-littoral zone. Easily overlooked. ADULT has body in 3 sections: head end is fleshy with palps; middle region is concerned with processing food; tail end has numerous chaetae. STATUS Widespread and very locally common, except in the SE.
Owenia fusiformis Length to 9cm
Distinctive worm. Lives in a tough tube, tapering at both ends and coated with neatly ‘tiled’ flattish sand grains. Found buried in clean sand at mid-tide level on extensive beaches. ADULT is green with around 30 segments. Head end has short, frilly tentacles. STATUS Widespread and locally common, except in the SE.
Gattyana cirrosa Length to 5cm
Impressive scaleworm, always living commensally in tubes of Chaetopterus or terebellid worms. ADULT has 15 pairs of semi-opaque scales that do not cover last 4–5 segments of body. STATUS Widespread and very locally common.
Alentia gelatinosa Length to 8cm
Delicate scaleworm, found under rocks on sheltered shores. Looks gelatinous. ADULT has 18 pairs of translucent yellowish-brown scales, covering whole body. STATUS Widespread and fairly common.
Adyte assimilis Length to 20mm
Delicate worm that readily sheds scales. Found on Echinus sea urchins and in kelp holdfasts, usually where echinoderms are present. ADULT has 15 pairs of almost transparent, subtly yellowish-buff scales, covering most of body. STATUS Widespread but local and hard to detect.
Sigalion mathildae Length to 12cm
Rather atypical scaleworm with a cylindrical body. Rolls into a spiral when disturbed, recalling a miniature Slow-worm. Found in sand at low water. ADULT is creamy white with around 200 segments and 150 or so scales, covering whole body. STATUS Widespread but local, mainly in the W and NW. SIMILAR SPECIES Sthenelais boa (length to 15cm) has a slender but slightly flattened, tapering body and snake-like appearance. Head has a median antenna, 2 lateral antennae and 2 long palps. Mainly in the W, in muddy sand.
Lepidonotus clava Length to 25mm
Well-marked scaleworm, found under rocks on lower shore. ADULT is parallel-sided with 12 pairs of round scales; these do not overlap down mid-line. STATUS Widespread and locally common.
Lepidonotus squamatus Length to 5cm
Scaleworm found under rocks on lower shore. ADULT is parallel-sided with 12 pairs of round, textured scales; these are yellowish, marbled with brown, often with a dark central spot. Scales overlap down mid-line. STATUS Widespread and locally common.
Lagisca extenuata Length to 35mm
Active scaleworm, found under rocks at low tide. ADULT has 15 pairs of scales covering anterior part of body; posterior 10 or so segments are not covered. STATUS Widespread and fairly common.
Harmothoe imbricata Length to 45mm
Active scaleworm, found under rocks and in laminarian holdfasts, at low water. ADULT has 15 pairs of scales covering whole dorsal surface. Scales are coated in granules and have hair-fringed margins; often yellowish brown with a metallic sheen, sometimes dark-centred. Frontal horns and dorsal cirri are fairly long. STATUS Widespread and locally common.
Harmothoe impar Length to 25mm
Well-marked scaleworm, found under stones at low water. ADULT has 15 pairs of scales covering whole dorsal surface. Scales are textured, fringed and variably marbled brown with a yellowish central spot. Front horns and dorsal cirri are long. STATUS Widespread and locally fairly common.
Harmothoe glabra Length to 55mm
Distinctive scaleworm, found at low water, usually in association with terebellid worms and their tubes. ADULT has 15 pairs of overlapping scales. Scales are slightly translucent yellow with a chestnut margin. Front horns and dorsal cirri are long. STATUS Widespread but scarce; mainly in the W.
Harmothoe lunulata Length to 35mm
Well-marked scaleworm, sometimes found under rocks at low water but more usually in tubes of Sand Mason and other worms. ADULT has 15 pairs of overlapping scales. Scales are smooth and unfringed, pale yellowish with a dark sub-marginal crescent and central spot. Frontal horns are long, dorsal cirri are short. STATUS Widespread but local, mainly in the W and N.
Sea Mouse Aphrodita aculeata Length to 20cm
Atypical but unmistakable scaleworm; hardly recognisable as a worm. Found part-buried in sand at extreme low water; sometimes stranded. ADULT has oval body, scales hidden by a dense coat of bristly hairs; dorsal hairs are flattened, lateral ones are iridescent. STATUS Widespread; locally common but seen only occasionally.
Janua pagenstecheri Diameter to 2mm
Limpet shell coated with Janua pagenstecheri
Small worm that lives inside a calcified, sinistrally spiral tube attached to seaweed, particularly Serrated Wrack; often in small groups. ADULT has tentacles on its head that project when immersed in sea water. Tube is white; entrance can be sealed by operculum at low tide. STATUS Widespread and locally common.
Spirorbis spirorbis Diameter to 4mm
Small worm that lives inside a calcified, dextrally spiral tube, attached to a range of objects including coralline seaweeds, shells and crab carapaces. ADULT has tentacles on its head that project when immersed. Tube is grubby white and usually with 3 ridges; entrance can be sealed by operculum. STATUS Widespread and locally common.
Serpula vermicularis Tube length to 70mm
Serpula vermicularis tube
Worm that lives in a sinuous calcareous tube (round in cross section), usually with 3 longitudinal ridges; attached to rocks and bivalve mollusc shells at low water. ADULT has 60–70 tentacles. Tube is pinkish white; entrance can be plugged with funnel-shaped operculum, the end fringed with rounded teeth. STATUS Widespread and locally common.
Pomatoceros triqueter Tube length to 25mm
Pomatoceros lamarcki tube
Worm that lives inside a calcareous tube (triangular in cross section) with a single longitudinal ridge; tube is attached along its length to rock or other hard substrate. Mostly sub-littoral, sometimes found at low tide. ADULT has feathery tentacles at head end, which extend when immersed. Entrance can be plugged by cup-shaped calcareous plate. STATUS Widespread and locally common. SIMILAR SPECIES P. lamarcki is similar but tube has 3 longitudinal ridges along its length; entrance can be plugged by bulb-shaped operculum. Found on rocks on lower shore.
Hydroides norvegica Tube length to 30mm
Worm that lives in a calcareous tube (round in cross section); sometimes several entwined. ADULT has 2 groups of 8 or so tentacles. Tube is sometimes spiral at base, mostly brownish but white terminally. Entrance can be plugged with funnel-shaped, spine-tipped operculum; spine array is radiating and symmetrical. STATUS Widespread and locally common. SIMILAR SPECIES Filograna implexa (tube length to 25mm) lives in a more delicate and slender tube (round in cross section), usually in entwined masses. Has 8 tentacles and plugs tube with 2 cup-shaped opercula. Widespread and locally common.
Hydroides dianthus Tube length to 30mm
Hydroides dianthus tube
Similar to H. norvegica but separable by studying operculum. Lives in calcareous tube. ADULT has 2 groups of 8 or so tentacles. Tube is white, sometimes stained brown. Entrance can be plugged with funnel-shaped, spine-tipped operculum; spine array is asymmetrical, some spines incurved. STATUS Introduced from North America, first discovered in 1970 in the Solent. Now locally common there and may be spreading.
Ficopomatus enigmaticus Tube length to 25mm
Ficopomatus enigmaticus tube
Worm that lives in a calcareous tube (round in cross section), typically in dense masses (several tubes deep) encrusting stones and other solid objects; often in estuaries and tidal lagoons. ADULT has 12–20 feathery tentacles. Tube is often flared at mouth, mostly yellowish brown but whitish terminally; entrance can be plugged by swollen, flat-ended, spine-tipped operculum. STATUS Widespread and locally common.
Peacock Worm Sabella pavonina Tube length to 25cm
Distinctive worm that lives inside a tough, rubbery tube covered with silt particles. Lives part-buried in silty mud (5–7cm of tube protrude), often in eelgrass beds. Tentacles are visible only when worm is undisturbed and immersed. ADULT has several hundred segments. Head bears 2 arrays of up to 50 tentacles; these are banded with colour and, when spread, form a daisy-like array. STATUS Widespread and locally common. SIMILAR SPECIES Megalomma vesiculosum (tube length to 12cm) lives inside a tough tube, to which debris is attached; only 3cm or so of tube protrude. Adult has 100–200 segments and up to 50 banded tentacles; each has a terminal eye-spot, those on central 2 tentacles largest. Locally common in the S and SW.
Honeycomb Worm Sabellaria alveolata Tube length to 4cm
close up of tube entrances
close up of worm at tube entrance
colony
Worm that lives in a sandy tube. Tubes form tightly packed masses, attached basally to part-buried rocks in muddy sand, on lower shore. Overall effect of colony resembles honeycomb. ADULT has up to 30 segments, a reflexed ‘tail’ and a crown of very short tentacles at head that protrude from tube end when immersed. STATUS Very locally common, mainly in the S and SW.
Bispira volutacornis Length to 10cm
Worm that lives in a mud tube, usually mostly under rocks or in a crevice on lower shore. ADULT has up to 100 segments, head end with 2 spiral whorls of 90 or so whitish tentacles that protrude when immersed. STATUS Locally common in the S and SW.
Pseudopotamilla reniformis Length to 10cm
Worm that lives in a slightly translucent membranous tube, usually mostly protected in a rock crevice or hole. When worm withdraws, end of tube folds over, making it hard to spot. ADULT has up to 100 segments, head end with 20 or so translucent greenish tentacles, each marked with 3 dark eye-spots. STATUS Widespread and locally common.
Branchiomma bombyx Length to 45mm
Worm that lives in a membranous tube, lodged among epiphytic sea squirts and other colonists of seaweeds, holdfasts and rock undersides. Small individuals are relatively mobile and move around if dislodged. ADULT has up to 25 feathery tentacles on each side; each with several pairs of tiny eyes and paired projections (like curled tongues). Tentacles retract into tube if animal is disturbed. STATUS Widespread but local.
Polydora ciliata Length to 25mm
Slender worm, easily overlooked. Worm’s tube is in hole in limestone rock or coralline seaweeds. When undisturbed, 2 long palps protrude. ADULT has 150 or so segments, most with chaetae. Head is blunt, with 2 palps; body ends in a funnel. STATUS Widespread, except in the far N.
Euclymene lumbricoides Length to 10cm
tubes, in situ
Slender worm that lives in a particle-encrusted mucous tube in muddy sand at low water, often in eelgrass beds. ADULT is reddish with rather uniform segmentation; 19 segments bear chaetae, and the front ones are banded. Head has notched plate and tail end has fringed funnel. STATUS Widespread and locally common in the W.
Pygospio elegans Length to 15mm
Distinctive but tiny worm, easily overlooked; tubes, constructed from small sand particles, are more obvious. Lives in blackish mud, in estuaries and mudflats. ADULT has thread-like body with 55 or so segments. Head is blunt-ended with 2 long palps; rear end is fringed by leaf-like projections. STATUS Widespread and locally very common.
Malacoceros fuliginosus Length to 50mm
Tube-dwelling worm, found under stones on muddy sand, at low water. ADULT is slender, with finger-like red gills on dorsal surface of each segment. Head has 2 long palps and lobe with frontal ‘horns’. Tail end is fringed with 8 or so petal-like lobes. STATUS Widespread and locally common.
Odontosyllis gibba Length to 25mm
Active, slender worm. Found under stones and in seaweed holdfasts on lower shore; swims in surface layers of sea at night. ADULT has body comprising 40 or so segments, each marbled brown and white. Head has 4 red eyes, 3 antennae (1 median) and paired palps. STATUS Widespread but local, mainly in the S and W.
Typosyllis krohni Length to 30mm
Active worm, found in holdfasts and under stones. ADULT has slender body. Cirri alternate in length; longer ones are also thick and often curl up. Eyes are red. STATUS Local, mainly in the SW and W.
Amblyosyllis formosa Length to 15mm
Active, distinctive worm. Found among algal holdfasts on lower shore. ADULT has 15 roughly triangular segments and long cirri that often curl at tip. Eyes are red. STATUS Local, mainly in the SW and W.
Flatworms (phylum Platyhelminthes)
Small, flat carnivorous worms, unrelated to annelids; glide over substrates by means of cilia. Found under stones on lower shore. Head end has mouth; sometimes eye-spots and simple tentacles too. Most are hard to identify to specific level, but sub-littoral species Prostheceraeus vittatus has unique pattern of black stripes on a creamy-white body.
Arrow Worms Parasagitta sp. (phylum Chaetognatha) Length to 10mm
Predatory worms, unrelated to annelids. Present in plankton and rock pools. Hard to detect; easiest to observe after dark using a torch. BODY is arrow-shaped and almost transparent. Head has fringe of hairs. Fins aid movement. STATUS Widespread and common but easily overlooked.
Nemertean Worms (phylum Nemertea)
other nemerteans
Sometimes referred to as ribbon worms, nemerteans are not related to segmented annelid worms. Most species have elongate, smooth and rather flat bodies. The tail end usually tapers, and the head end is usually swollen, sometimes with visible eye-spots. Nemerteans are active predators of smaller invertebrates. Although some are well marked, most nemerteans are hard to identify to species level.
Bootlace Worm Lineus longissimus Length to 10m
Distinctive nemertean worm and a contender for Britain’s longest animal. Body is fragile. Found in coiled mass under rocks and in crevices on lower shore. ADULT has soft, slimy, dark brown body. Head end is slightly swollen and marked with longitudinal grooves. STATUS Widespread and locally common.
Golfingia elongata (phylum Sipuncula) Length to 12cm
Unusual tubular animal, unrelated to segmented annelid worms. Lives buried in muddy sand on lower shore and in sub-littoral zone. ADULT is cylindrical and creamy white, tinged pink. Main part of body has a granular surface. Rear end tapers; has retractile fringe of 20–30 tentacles at front end. STATUS Widespread but local, mainly in the W and NW; probably overlooked.