Small-spotted Catshark, a typical elasmobranch.
Fish are the most diverse group of vertebrates in inshore waters, and it is usually possible to discover a dozen or more species on almost any stretch of coast. Each species is adapted to a particularly niche, thus minimising competition for food. Consequently, many of our seashore fish look strikingly different from one another.
FISH CLASSIFICATION
Small-spotted Catshark, a typical elasmobranch.
Pollack, a typical bony fish.
Marine fish belong to a subdivision of the phylum Chordata (vertebrates) called Pisces. Within this class are two basic forms: elasmobranchs (sharks, rays and relatives), which have a cartilaginous skeleton; and teleosts, or bony fish, whose skeletons are calcified. In general terms though, the basic layout is broadly similar, given the variability in fish form generally.
FISH STRUCTURE
Many seashore fish species, such as this Tompot Blenny, are not free-swimming and their shape reflects their habits: some rest on rocks or sand, and a few species (clingfish being good examples) have suckers that allow them to grip onto substrates. In terms of general form, if not appearance, the arrangement of fins in these species is similar to that of their open-water cousins.
Flatfish, such as this Plaice, are an exception to the rule in terms of fish structure. In their early stages they resemble conventional species. But during their development the head shape distorts so that, although they lie and swim on their sides, both eyes are on top.
Most open-water coastal fish species are streamlined. Typically, their body is torpedo-shaped, deeper in profile than it is wide, and the thin fins can be raised or lowered to suit the animal’s requirements. Seen side on, a fish’s caudal (tail) fin is striking and is the main means of propulsion. The remaining fins aid directional control and stability: on the dorsal surface is the dorsal fin (or fins in some species); on the ventral surface are pelvic fins at the front and an anal fin at the back; and on the side, just behind the gill opening, are pectoral fins. Most bony fish have an internal swim bladder that aids buoyancy.
SKIN AND SCALES
Ray’s Bream scales.
The body of a fish is covered with a tough skin, and in most species small plates (called scales) are embedded in this to form an additional protective layer. Because the scales are not connected to one another, the body’s flexibility is not compromised; in many bony fish the scales are large and overlap. Fish scales get bigger as the animal grows, new scale material being laid down in layers by the fish’s skin.
STAYING ALIVE
Like air-breathing animals, fish need oxygen in order to survive. Dissolved oxygen is extracted from the water in which they live using gills; these are sited in chambers that connect with the back of the mouth and exit via openings on the side of the body. The comb-like structures that comprise the gills are covered in blood-filled tissues that absorb oxygen.
SHOALING AND REPRODUCTION
Egg case of Small-spotted Catshark with embryo inside.
Although some fish species lead essentially solitary lives, many live in single-species shoals, particularly when young; each shoal usually contains fish of a similar size. This behaviour benefits individuals on the principle of safety in numbers – there are more eyes on the lookout for potential danger, and if a predator attacks a shoal the chances of an individual becoming its meal are reduced.
Most open-water marine fish form shoals when breeding, producing vast numbers of eggs to allow for heavy predation. Inshore species often attach their eggs to rocks or weeds, and some make a nest. Many cartilaginous fish (catsharks and skates) protect their eggs and developing young within a tough, horny case attached to seaweed, called a ‘mermaid’s purse’. Although the eggs of these species are laid in deep water, mermaid’s purses are often found washed up on the shoreline; sometimes they still contain a live embryo.
Basking Shark Cetorhinus maximus Length to 12m
Our largest fish, and 2nd largest on the planet. Filter-feeds surface plankton in summer. ADULT has typical shark shape but disproportionately large mouth. Above water, nose, dorsal fin and top of tail fin are often visible. STATUS Most records are from SW England, N Irish Sea and NW Scotland, Jun–Sep. Scarce in some years if plankton is poor.
Blue Shark Prionace glauca Length to 2m
Large predatory shark. Feeds mainly on squid and fish. Tagging records indicate most British individuals are immature females that migrate long distances. ADULT is blue-grey above and whitish below. STATUS Scarce seasonal visitor, mainly to the SW.
Small-spotted Catshark or Dogfish Scyliorhinus canicula Length to 75cm
Small-spotted Catshark, juvenile in daytime
Small-spotted Catshark, juvenile after dark
Small-spotted Catshark, embyro inside egg case
Familiar inshore fish. Found in inshore waters, on mixed substrates. ADULT is slender and buffish yellow above with darker spots. Skin is rough – like sandpaper. Eye has slit-like pupil. Lays eggs, protected in a tough case, a so-called mermaid’s purse. STATUS Widespread and locally common, except along the E coast.
Starry Smooth Hound Mustelus asterias Length to 1.2m
Elegant shark relative, found in inshore waters over sand and gravel; feeds mainly on crabs. ADULT is slender and streamlined. Buffish grey above with numerous white spots; underside is pale. Eye has round pupil. Gives birth to live young. STATUS Widespread and locally common in the S and W only; mainly in summer. SIMILAR SPECIES Smooth Hound M. mustelus (length to 1.5m) is less frequently caught in inshore waters. Dorsal surface is uniformly grey-brown and lacks white spots. Widespread but generally scarce, in the S and SW only.
Thornback Ray Raja clavata Length to 90cm
Thornback Ray, juvenile underside
Thornback Ray, newly hatched juvenile
The most familiar inshore ray. ADULT has flat, roughly diamond-shaped body with short snout. Dorsal surface of long tail has thorny spines with swollen bases; these continue in a line along dorsal surface of body. Upper body surface is grey-brown with dark stripes or pale and dark spots; lower surface is pale. Tail looks banded. Lays eggs, protected in a tough case. STATUS Widespread and locally common in the S and W only. SIMILAR SPECIES Common Skate Dipturus batis (length to 2m) is larger, with a more elongate snout and spines only on tail; upper surface is uniformly dark grey-brown. Generally rare due to overfishing.
Spotted Ray Raja montagui Length to 75cm
Similar to Thornback Ray but separable using pattern and structure. Fairly common in shallow inshore waters over sand. ADULT has roughly diamond-shaped body and short, pointed snout. Upper surface is grey-brown with dark spots that do not extend to wing margins. Tail is long and does not look banded. Has spines along dorsal surface of tail and along centre of body; these lack swollen bases. Lays eggs, protected in a tough case. STATUS Widespread and locally common in the S and W only. SIMILAR SPECIES Blonde Ray R. brachyura (length to 1m) has dark spots on upper surface that extend to wing margins. Widespread but rather scarce, in the S and W only.
Small-eyed Ray Raja microocellata Length to 75cm
Small-eyed Ray, juvenile underside
Small-eyed Ray, newly hatched juvenile
Undulate Ray
Well-marked ray. Found in mouths of estuaries and sandy bays. ADULT has typical ray shape with rather short snout. Upper surface is grey-brown with pale lines and spots. Lays eggs, protected in a tough case. STATUS Widespread and locally common in the S and W only. SIMILAR SPECIES Undulate Ray R. undulata (length to 1m) is grey-brown above, with dark lines bordered by white dots. Scarce, mainly in the S.
Common Stingray Dasyatis pastinaca Length to 1.2m
Fairly distinctive ray, renowned for its ability to inflict a painful wound. Favours estuary mouths and shores with muddy sand. ADULT has shield-shaped body outline with long, tapering tail, armed dorsally with single ‘stinging’ spine. Upper surface of body is uniformly yellowish grey. Gives birth to live young. STATUS Generally scarce, mainly in the S.
Marbled Electric Ray Torpedo marmorata Length to 1.5m
Unusual ray, capable of delivering a powerful shock (up to 220V) from organs in pectoral fins. ADULT has unmistakable rounded outline; tail is relatively short with rounded dorsal fins. Body upper surface is mottled and marbled grey-brown. STATUS Scarce, mainly in the W and SW.
Sea Lamprey Petromyzon marinus Length to 1.2m
Parasitic eel-like fish with a cartilaginous backbone. Lacks jaws; toothed sucker is used to latch onto live fish. Sometimes found on rocky coasts; migrates to fresh water to spawn. ADULT has a slender body, reduced fins for swimming and line of round gill openings behind eye. STATUS Widespread but generally scarce.
Conger Eel Conger conger Length to 1.8m
Impressive eel. Large individuals favour wrecks and rocky crevices, and are sometimes seen when snorkelling. Smaller animals are found under rocks at low water. ADULT has slender body, blue-grey above, paler below. Eyes are relatively large, upper jaw protrudes and dorsal fin starts just behind pectoral fins. STATUS Widespread and generally common, least so on E coasts.
Common Eel Anguilla anguilla Length to 1m
Common Eel, migrating across coastal mudflat.
Similar to Conger Eel but with subtle structural differences. Found in fresh water for much of life but also on rocky shores and in estuaries. ADULT is yellowish for much of life, but turns silvery blue as adult before migration. Compared to Conger, note relatively smaller eyes, protruding lower jaw and dorsal fin that starts way down body. STATUS Widespread but rather scarce, numbers much reduced in recent years.
Herring Clupea harengus Length to 40cm
Shoal-forming, economically important fish. Favours open seas but sometimes found inshore. ADULT is streamlined, blue-grey above and silvery on sides. Dorsal fin starts in front of pelvic fin. STATUS Widespread but rather scarce, numbers much reduced in recent years due to overfishing.
Sprat Sprattus sprattus Length to 16cm
Shoal-forming relative of Herring. Found in open seas but comes inshore in summer in particular. ADULT is streamlined, blue-grey above and on sides, silvery white below. Dorsal fin lies above pelvic fins. Belly has rough, saw-scaled outline. STATUS Widespread and fairly common.
Pilchard Sardina pilchardus Length to 25cm
Shoal-forming fish. Found in open seas, often inshore in summer. ADULT is streamlined, bluish above and silvery on sides and below. Scales are relatively large. Dorsal fin starts in front of pelvic fins. STATUS Widespread but rather scarce, mainly in the SW; numbers much reduced in recent years due to overfishing.
Atlantic Salmon Salmo salar Length to 1.5m
Distinctive large fish. Found in open seas for much of life, but migrates into fresh water to spawn. ADULT has streamlined, powerfully muscular body. At sea, silvery grey above and silvery white below, with dark spots on back and flanks; spawning individuals become duller and more yellow. STATUS Widespread and locally, and seasonally, fairly common, least so in the E and SE.
Sea Trout Salmo trutta ssp. trutta Length to 1.3m
Migratory subspecies of Brown Trout; found in opens seas for much of life but spawns in fresh water. Similar to Atlantic Salmon but separable with care. ADULT is silvery blue above and pale below at sea, but acquires reddish-yellow hues in fresh water. All individuals have dark spots on back and flanks; these are proportionately larger and more intense than on Atlantic Salmon. STATUS Widespread and locally, and seasonally, fairly common, least so in the E and SE.
Angler Fish Lophius piscatorius Length to 2m
Large, flattened and unmistakable fish. Favours sandy substrates; sometimes seen in shallows, but also in deeper water. ADULT has a proportionately large head and tapering tail end. Lies in wait for prey, attracted by slender fishing ‘lure’; these are engulfed by huge mouth, armed with sharp teeth. Marbled brown and buff colours provide good camouflage on seabed. STATUS Widespread and fairly common only in the W and SW.
Shore Clingfish Lepadogaster lepadogaster Length to 8cm
Shore Clingfish, underside
Distinctive intertidal fish, found under rocks and in pools on lower shore. ADULT is overall tadpole-shaped and broadly flattened, with a pointed snout. Colour is variable, but typically yellow or orange with a pattern of pale lines and dark spots, and 2 blue eye-spots behind real eyes. Note also feathery tentacles in front of eyes. Pelvic fins are modified to form sucker, used for clinging to rocks. STATUS Widespread but local, commonest in the SW from Dorset to N Wales.
Connemara Clingfish Lepadogaster candollii Length to 7cm
Connemara Clingfish, underside
Similar to Shore Clingfish but separable with care. Found under rocks and in pools on lower shore. ADULT has a flattened body and large head. Typically green with reddish marbling. Lacks eye-spots but note 2 red spots present at base of dorsal fin. Eyes are relatively large, with radial bands of colour. Dorsal and anal fins are not connected to tail fin (they are in Shore Clingfish); this feature is hard to discern. STATUS Local and rather scarce, mainly in the SW and NW.
Small-headed Clingfish Apletodon dentatus Length to 4cm
Small clingfish. Found in pools and sub-littoral zone on rocky shores; sometimes inside bulbous Saccorhiza holdfasts. Easily overlooked: well camouflaged and often remains motionless when exposed. ADULT has slender, rather flattened but angular body with pointed snout. Colour is variable: usually marbled greenish (sometimes reddish), with pale patches on back. Has dark patch at base of dorsal and anal fins. Anal fin lies below dorsal. STATUS Widespread but local in the W and SW. SIMILAR SPECIES Two-spotted Clingfish Diplecogaster bimaculata (length to 4cm) is usually reddish. Position of anal fin is slightly staggered behind dorsal fin. Male has 2 dark spots on flanks behind pectoral fins. Widespread but local in the W.
Whiting Merlangius merlangus Length to 70cm
Streamlined pelagic fish. Young in particular often occur in shallow inshore waters. ADULT is brown (can appear bluish) above, silvery below. Note dark spot at base of pectoral fin. Has 3 dorsal fins and 2 anal fins. Lower jaw is slightly shorter the upper; tiny barbel on lower jaw is sometimes present but usually absent. STATUS Widespread, commonest in the S and W.
Pollack Pollachius pollachius Length to 1.25m
Classic fish of rocky coasts. ADULT is beautifully patterned: tinged golden overall, marbled with silvery-grey spots. Lower jaw protrudes; barbel is absent. Has 3 dorsal fins and 2 anal fins. STATUS Widespread and generally common, least so on E coasts.
Saithe Pollachius virens Length to 75cm
Northern cousin to Pollack, found on rocky coasts. ADULT is dark greenish black above, paler on sides and below. Lower jaw is only slightly longer than upper; barbel is absent. Has 3 dorsal fins and 2 anal fins. STATUS Widespread and generally common in the N; scarce in the SW, absent from the SE.
Bib or Pout Trisopterus luscus Length to 40cm
Attractive, rather deep-bodied fish with relatively tall fins. ADULT is golden brown above, silvery blue below. Fins are yellowish, dorsal and tail fins with dark margins. Has 3 dorsal fins and 2 anal fins. Lower jaw is slightly shorter than upper, with long barbel. Note dark spot at base of pectoral fin. STATUS Widespread and generally common in S and W Britain; absent from much of the NE.
Poor-cod Trisopterus minutus Length to 25cm
Streamlined but rather deep-bodied pelagic fish with proportionately very large eyes. Young in particular venture into inshore waters. ADULT is brown above, silvery below. Has 3 dorsal fins and 2 anal fins. Lower jaw is roughly same length as upper, with delicate barbel. STATUS Widespread and locally common although absent from much of the NE.
Atlantic Cod Gadus morhua Length to 120cm
Distinctive fish with a proportionately large head. Young in particular venture into inshore waters, especially in winter. ADULT is brown above and silvery below, marbled with golden spots and a yellowish hue on flanks. Has 3 dorsal fins and 2 anal fins. Lower jaw is shorter than upper, with long barbel. STATUS Widespread and fairly common, least so where fished commercially.
Three-bearded Rockling Gaidropsarus vulgaris Length to 50cm
Attractive, well-marked fish. Mostly sub-littoral but sometimes found in pools on lower shore. ADULT is pinkish orange, marbled with darker patches; overall, darker above than below. Head has 3 barbels. STATUS Widespread and locally common in the SW and W only.
Shore Rockling Gaidropsarus mediterraneus Length to 45cm
Shore Rockling, juvenile (so-called ‘Mackerel Midge’) amongst floating seaweed.
Found on lower shore, under rocks and in pools. ADULT is dark brown overall, paler below than above. Head has 3 barbels. First dorsal fin has long ray at front; 2nd dorsal fin continues almost to tail. STATUS Local, in the SW only. NOTE Young of this species, and other rocklings, are known as ‘mackerel midges’ and are greenish above, silvery below; they are found among drifting seaweed rafts, and tangled hiding places on the seabed.
Five-bearded Rockling Ciliata mustela Length to 30cm
Elongate, rather cylindrical fish. Similar to Shore Rockling but with 5 barbels. Found in pools and under rocks on lower shore; adept at slithering into crevices to escape capture. ADULT is overall brown above, paler below. Head has 5 barbels. Fin arrangement is similar to that of Shore Rockling. STATUS Widespread and fairly common, except in the N.
Horse Mackerel or Scad Trachurus trachurus Length to 70cm
Pelagic open-water fish. Ventures into inshore waters in summer; young fish associate with floating seaweed rafts. ADULT often looks pale and silvery overall; close view reveals green tinge to upperparts. Note also striking curve in lateral line. Eyes are proportionately large. STATUS Fairly common in the S and SW only.
Black Sea-bream Spondyliosoma cantharus Length to 55cm
Gilthead
Deep-bodied fish with a steep head profile. Ventures into inshore waters in summer. ADULT is bluish grey overall, darker above than below, and tinged reddish on head and underparts. Dorsal fin has spiny rays; pectoral fins are relatively long. STATUS Widespread and fairly common in the S and W; commonest from Dorset to Sussex. SIMILAR SPECIES Gilthead Sparus aurata (length to 70cm) has diagnostic yellow band across steep forehead and dark patch at anterior end of lateral line. Small numbers move into shallow waters and estuary mouths on S coast in summer.
Blackspot Sea-bream or Red Sea-bream Pagellus bogaraveo Length to 60cm
Young in particular venture into inshore waters in summer months. ADULT is deep-bodied with a blunt head. Typically reddish overall with a black spot above base of pectoral fin. Dorsal fin has spiny rays. STATUS Occasional in the S.
Ray’s Bream Brama brama Length to 80cm
Fast-swimming predator. Typically favours deep waters off W coasts, but regularly beached (sometimes alive) on the E coast, notably in N Norfolk in winter. ADULT is laterally flattened, oval in side profile; tall dorsal and anal fins, long pectoral fins and forked tail. Forehead is steep and mouth has numerous fine teeth. Overall, appears silvery; has rainbow colours on dorsal surface in life. STATUS Recorded annually, seemingly in increasing numbers.
Striped Red Mullet Mullus surmuletus Length to 40cm
Striking, colourful fish. Sometimes found inshore, on sandy and muddy substrates. ADULT has a powerful, thickset body. Head is relatively large and blunt, with 2 barbels. Overall colour is red, with darker and yellow longitudinal stripes on sides. First dorsal fin is striped. STATUS Fairly common in the S and SW.
Three-spined Stickleback Gasterosteus aculeatus Length to 10cm
non-breeding adult
Three-spined Stickleback, breeding male
Three-spined Stickleback, non-breeding adult
Familiar freshwater ‘tiddler’ that also occurs in estuaries and brackish lagoons. ADULT has slender body, elongate tailstock, and 3 spines (2 long, 1 short) in front of dorsal fin. Mostly yellowish green above, silvery below; breeding male has red belly and blue eyes. STATUS Widespread and locally common. SIMILAR SPECIES Nine-spined Stickleback Pungitius pungitius (length to 10cm) has 9–10 dorsal spines; yellowish green above, silvery below. Locally common, except in the SW.
Fifteen-spined Stickleback Spinachia spinachia Length to 15cm
Truly marine stickleback, found in sheltered seas among seaweeds and eelgrass. ADULT has a slender body, elongate tailstock and 14–16 dorsal spines. Greenish above, silvery below. STATUS Widespread and locally common except in the SE.
Greater Pipefish Syngnathus acus Length to 50cm
Relatively large and robust by pipefish standards. Found among seaweeds and eelgrass. ADULT has long, slender body, with pectoral fins and small tail and dorsal fins. Head is angular-looking with ‘hump’ behind eye; snout is long with concave profile. Typically brown above, paler below, often with dark bands down back. STATUS Widespread and locally common in the S and W only. SIMILAR SPECIES Deep-snouted Pipefish S. typhle (length to 35cm) has head and long snout that form continuous straight profile. Typically marbled yellowish green. Local, mainly in the SW. Nilsson’s Pipefish S. rostellatus (length to 15cm) has shorter snout (roughly same length as rest of head) and lacks ‘hump’ behind eye. Favours sandy estuaries and bays.
Snake Pipefish Entelurus aequoreus Length to 40cm
Nilsson’s Pipefish
Deep-snouted Pipefish
Straight-nosed Pipefish
Similar to Greater Pipefish but separable by studying markings and head profile. Found among seaweeds and eelgrass. ADULT has slender body, with small dorsal fin and tiny caudal fin; pectoral fins absent. Usually yellowish brown with vertical dark-bordered pale lines along body, and dark line through eye. Head is not angular; snout is long with straight, or very gently concave, profile. STATUS Widespread but local; absent from much of the E.
Worm Pipefish Nerophis lumbriciformis Length to 15cm
At first glance, hard to recognise as a living creature, let alone a fish. Found among seaweeds and under rocks at low water, but easily overlooked. ADULT has very slender, stiff body with small dorsal fin; pectoral and tail fins absent. Snout is short and upcurved, creating a ‘pug-nosed’ look. Usually dark yellowish brown. STATUS Widespread and locally common in the SW and W; mostly absent from E England. SIMILAR SPECIES Straight-nosed Pipefish N. ophidion (length t 25cm) has straighter, longer snout (roughly same length as rest of head). Found among seaweeds and eelgrass, but mainly sub-littoral.
Short-snouted Seahorse Hippocampus hippocampus Length to 15cm
Enigmatic, unmistakable fish. Extremely hard to observe and protected by law. ADULT has classic seahorse shape; profile is angular and body lacks slender projections. STATUS Local, mainly along S coast of England. SIMILAR SPECIES Long-snouted Seahorse H. guttulatus (length to 14cm) has body adorned with spiny projections. Local, mainly in the S and W.
Sand Smelt Atherina presbyter Length to 15cm
juvenile
Slender, silvery-looking fish. Swims in shoals, often in inshore waters in summer. ADULT is yellowish green above, pale below with silver scales along flanks. Has 2 dorsal fins, sited above pelvic and anal fins, respectively. STATUS Local and seasonal, mainly in the S and SW.
Garfish Belone belone Length to 90cm
Unmistakable pelagic fish. Ventures into inshore waters in summer, along with Mackerel. ADULT has a very slender body, and long, pointed jaws armed with sharp teeth. Dorsal, anal and tail fins are set far back on body. Green above, silvery on sides and white below. STATUS Locally, and seasonally, common, mainly in the S and W.
Grey Gurnard Eutrigla gurnardus Length to 45cm
Distinctive fish. Favours sandy and mixed substrates; found in inshore waters in summer. ADULT has large head and eyes, and sloping forehead. Pectoral fin does not reach vent; lowest 3 rays lack webbing and are tactile. First dorsal fin often has dark spot. Lateral line is spiny. Overall usually grey-brown with swirly pattern of pale lines and spots on lower flanks. STATUS Locally common in the S and W; scarce or absent from the E.
Red Gurnard Aspitrigla cuculus Length to 30cm
Stunning fish. Favours sandy and mixed substrates; found in inshore waters in summer. ADULT has large head and eyes; sloping forehead has more concave profile than that of Grey Gurnard. Pectoral fins extend beyond vent; lowest 3 rays lack webbing and are tactile. Lateral line is not spiny. Overall red, grading to pinkish white on belly. STATUS Locally common in the S and W; scarce or absent from E coasts.
Tub Gurnard Chelidonichthys lucerna Length to 55cm
juvenile
Attractive fish. Favours sandy and mixed substrates; found in inshore waters in summer. ADULT has large head and eyes; forehead slopes abruptly. Pectoral fins extend beyond vent; lowest 3 rays lack webbing and are tactile. Lateral line is not spiny. Overall orange-brown; pectoral fins are often yellow with a blue margin. STATUS Locally common in the S and W; scarce or absent from E coasts.
Sea Scorpion Taurulus bubalis Length to 20cm
Bull Rout
Any rockpool fish with a large spiny head is likely to be this species. ADULT has an angular, almost lizard-like head; operculum is armed with 4 spines. Lateral line is spiny. Has white barbels at corners of mouth. Colour and patterning are variable and match background; often marbled reddish brown, with dark banding. STATUS Widespread and locally common, least so in the SE. SIMILAR SPECIES Bull Rout Myoxocephalus scorpius (length to 25cm) has 2 (not 4) obvious spines on operculum, and lacks white barbels at corners of mouth. Lateral line is not spiny. Range is similar to that of Sea Scorpion; seldom intertidal except in the far N. Pogge Agonus cataphractus (length to 15cm) is elongate, with an ‘armoured’ look about it; broad, flattened head is armed with spines and barbels. Inshore waters, commonest in the W.
Montagu’s Sea Snail Liparis montagui Length to 5cm
Montagu’s Sea Snail, underside, showing sucker
Montagu’s Sea Snail, swimming
Montagu’s Sea Snail, clinging to stone
Unusual species, recalling a plump tadpole. At first glance, hard to recognise as a fish at all. Found in pools and under stones on lower shore. ADULT is slimy and scaleless, with skin that wrinkles. Head is bulbous. Dorsal and anal fins do not overlap tail fin. Colour variable, often yellowish but sometimes dark reddish brown. STATUS Widespread but local; mainly in the S and W. SIMILAR SPECIES Common Sea Snail L. liparis (length to 10cm) is widespread but occurs mainly offshore and is seldom observed. Dorsal and anal fins overlap tail fin.
Lumpsucker Cyclopterus lumpus Length to 55cm
Lumpsucker, juveniles among floating seaweeds
Lumpsucker, male
Unmistakable fish. Usually offshore, but males, guarding eggs, sometimes found in rocky shallows. Young sometimes occur in pools on lower shore, and among floating rafts of seaweed. ADULT is size and shape of a rugby ball. Skin is lumpy and sometimes covered in parasites. Typically bluish black above, marbled reddish below. Young are often uniformly red or yellow. STATUS Widespread but local; commonest in the N.
European Sea Bass Dicentrarchus labrax Length to 1m
Fast-swimming, streamlined predator and a popular sportfish. Often occurs close inshore. ADULT is silvery grey overall, darkest on dorsal surface, almost white on belly. Has 2 dorsal fins; 1st is spiny. STATUS Widespread but locally common only in S Britain.
Thick-lipped Grey Mullet Chelon labrosus Length to 60cm
The commonest of our grey mullet species. Ventures into estuaries and bays in summer. ADULT is cigar-shaped overall, with a thick tailstock and narrowly tapering head. At its broadest, upper lip width equals or exceeds eye diameter. Overall colour is silvery grey, darker above than below. STATUS Widespread and locally common in S Britain; scarce or absent elsewhere. SIMILAR SPECIES Thin-lipped Grey Mullet Liza ramada (length to 50cm) is silvery grey with a dark spot at base of pectoral fins. At its broadest, upper lip width is less ½ diameter of eye. Golden Grey Mullet Liza aurata (length to 40cm) is silvery grey with a golden patch on gill cover. At its broadest, upper lip width is roughly diameter of eye.
Ocean Sunfish Mola mola Length to 1.5m or more
Massive, unmistakable fish. Sometimes seen at surface inshore, usually from W coast headlands or ferries, in late summer and autumn. ADULT is flattened laterally and roughly circular in side profile. Has tall, narrow dorsal and anal fins, and frilled fringe at tail end. STATUS Occasional; mainly in W Britain.
Grey Trigger-fish Balistes capriscus Length to 60cm
Bizarre fish with the look of a tropical species about it. Found on rocky coasts, sometimes around harbour walls. ADULT is oval in outline with relatively small eyes and mouth set far apart. Overall buffish brown; dorsal, anal and tail fins are marbled with blue. STATUS Locally common in the S and SW, occasional elsewhere.
Ballan Wrasse Labrus bergylta Length to 50cm
Ballan Wrasse, juvenile
Our most familiar and colourful wrasse. Found inshore on rocky coasts. ADULT has a thickset body and long dorsal fin characteristic of all wrasse. Colour is variable but often marbled reddish brown or green. STATUS Widespread and locally common except off the coast of E England.
Cuckoo Wrasse Labrus mixtus Length to 30cm
Cuckoo Wrasse, male
Cuckoo Wrasse, female
Colourful, distinctive wrasse. Found on rocky coasts, venturing inshore in summer months. ADULT has a rather slender body. Male is mostly blue on head, flanks and tail, and pinkish orange elsewhere. Female is orange with black spots at base of dorsal fin. STATUS Widespread and locally common in the S and W; almost absent from the coast of E England.
Rock Cook Centrolabrus exoletus Length to 15cm
Colourful wrasse with a relatively small mouth. Found on rocky coasts and around pier pilings. ADULT is variably colourful, often with reddish-brown, blue and yellowish reticulations. Note diagnostic dark band across base of tail. STATUS Widespread and locally common in the S and W; almost absent from the coast of E England.
Corkwing Wrasse Symphodus melops Length to 15cm
Another colourful wrasse. Found on rocky shores with abundant seaweeds. ADULT has variable colouring, but often yellowish or reddish with blue and red banding, especially on head. Dark spot at base of tail is diagnostic. STATUS Widespread and locally common in the S and W.
Goldsinny Ctenolabrus rupestris Length to 17cm
Distinctive wrasse. Found on rocky coasts with plenty of seaweed cover; usually in shallow sub-littoral zone. ADULT is rather slim-bodied; mostly pinkish buff, with a diagnostic dark spot at front of dorsal fin and another at top of tail base. STATUS Widespread and locally common only on S and W coasts.
Dragonet Callionymus lyra Length to 20cm
Dragonet, female
Distinctive fish, broad and flattened at head end, slender and tapering behind. Favours shallow inshore seas; sometimes found in pools on lower shore. ADULT has rather long, tapering snout. Breeding male is distinctive: marbled reddish brown with blue spots; 1st dorsal fin is very tall, 2nd marked with blue and yellow. Immatures and females are marbled yellow-brown; 1st dorsal fin is much shorter. STATUS Widespread, but commonest on S and W coasts. SIMILAR SPECIES Spotted Dragonet C. maculatus (length to 12cm) has a steep, short snout and rather short, almost colourless 1st dorsal fin; this and pectoral fins sometimes have small white spots. SW England and Wales, and Irish Sea coasts. Reticulated Dragonet C. reticulatus (length to 10cm) also has a steep snout. First dorsal fin is also short but often blackish. Breeding male is patterned with red patches and blue spots. S and W coasts, as far N as Orkney.
Lesser Weever Echiichthys vipera Length to 15cm
Notorious fish, capable of inflicting a painful sting to a bather’s foot. Found on sandy beaches, mostly buried in substrate during daytime with just eyes visible. ADULT has elongate, laterally flattened body with upturned mouth and eyes on top of head. First dorsal fin (with venomous spines) has black membrane; fin is raised in defence. Body is marbled reddish and yellow-grey above, paler below. STATUS Widespread and locally common, mainly in S half of Britain.
Greater Weever Trachinus draco Length to 40cm
Appreciably larger and more colourful than its Lesser cousin. Found on sandy substrates but usually sub-littoral. ADULT has elongate, laterally flattened shape with upturned mouth and eyes on top of head. Upperparts marbled with yellow, brown and blue; underparts pale. STATUS Widespread but local, mainly in S half of Britain.
Mackerel Scomber scombrus Length to 55cm
Fast-swimming predatory fish, popular with anglers. Shoals frequent inshore waters in summer. ADULT has streamlined body, pointed head and rather small dorsal fins. Small ‘finlets’ extend along top and bottom of narrowly tapering tailstock. Body is greenish with black bands above, silver on sides and whitish below; green colour fades to blue after death. STATUS Widespread; locally and seasonally common, especially in the S and W.
Boar Fish Capros aper Length to 25cm
Bizarre and unmistakable fish. Typically lives near seabed in deep water, but occasionally occurs inshore (or beached, dead), especially in winter, possibly after surviving trawling by-catch. ADULT is laterally flattened, rhomboid in side-on profile, with a tall, spiny 1st dorsal fin and very large eyes. STATUS Scarce in inshore waters, in the SW only.
John Dory Zeus faber Length to 80cm
Another bizarre and unmistakable fish. Regular inshore; usually in fairly deep water but sometimes near surface. ADULT is incredibly laterally flattened and angular-oval in side-on profile. Dorsal fin is tall and spiny; other fins are also relatively large. Overall colour is silvery yellow with diagnostic central black spot. STATUS Widespread, mainly in the S and W.
Wolf Fish Anarhichas lupus Length to 90cm
Unmistakable, superficially eel-like fish. Mostly sub-littoral, usually hiding in crevices in daytime. But sometimes found in deep pools on lower shore. ADULT is elongate with large, bulbous head and visible, peg-like teeth. Skin is typically blue-grey but young animals are marbled and banded brown. STATUS Locally common in E and NE Scotland only.
Butterfish Pholis gunnellus Length to 25cm
Distinctive and unmistakable fish. Found under rocks and seaweed on lower shore. ADULT is superficially eel-like but laterally compressed, yellow body with 15 pale-margined dark spots down dorsal surface. Scales are tiny and embedded in skin; fish is very slippery. STATUS Widespread and locally common; least so in E England.
Greater Sand Eel
Extremely slender fish. Easily recognised as sand eels but specific identification is challenging. Two species are widespread and generally common, more so in the S than N. Both swim in shoals (sometimes both species together), and can burrow into sand and disappear almost instantly if alarmed. Both appear silvery in water; out of water, upper half is greyish yellow and lower half silvery white. In Lesser Sand Eel Ammodytes tobianus (length to 20cm), dorsal fin starts above pectoral fin; in Greater Sand Eel Hyperoplus lanceolatus (length to 35cm), dorsal fin starts behind pectoral fin.
Shanny Lipophrys pholis Length to 13cm
The commonest blenny on British shores. Found in pools and under rocks on lower shore. Moves around in short bursts, seldom swimming far. Typically props itself up on pectoral fins. ADULT is elongate, smooth and scaleless, with proportionately large head. Has single long dorsal fin with dip in middle. No tentacles on head. Usually mottled and marbled brown and buff. STATUS Widespread and locally common, except in the SE.
Tompot Blenny Parablennius gattorugine Length to 25cm
Impressive and colourful blenny. Found on rocky coasts, on lower shore and in sub-littoral zone. ADULT has similar shape overall to Shanny, but with stouter body and striking dorsal fin that starts further forward and lacks obvious dip in middle. Head bears pair of frilly tentacles. Colour is variable, but usually marbled reddish brown and buff with dark bands. STATUS Locally common, in the SW only.
Montagu’s Blenny Coryphoblennius galerita Length to 8cm
Colourful and distinctive blenny. Found in pools on rocky coasts, usually on mid-shore. ADULT has similar shape overall to Shanny but with more obvious dip in middle of dorsal fin and diagnostic tall, frilly tentacle on centre of forehead, with smaller ones behind. Colour is variable but often marbled black, reddish and blue with pale spots. STATUS Locally common but mainly in the S and W.
Sand Goby
Sand Goby
Common Goby
Common Goby
Three confusingly similar gobies are recognised by experts. These are notoriously difficult to identify and you could be forgiven for doubting the validity of calling them separate species. Colours and markings are variable and change according to background, and immature animals often lack characters needed for accurate identification. Their 2 dorsal fins are clearly separate (distinguishing them from small Rock and Black gobies). But beware confusion with Two-spotted Goby, whose spots can ‘fade’ if fish is kept in a pale container. The following descriptions apply to well-marked animals only. Sand Goby Pomatoschistus minutus (length to 65mm) is the most likely small goby you will come across on the shore. Favours sandy coasts and estuaries, and is usually buff, marbled and mottled darker; adult male has a blue-ringed black spot on 1st dorsal fin and scales are present dorsally in front of 1st dorsal fin. Eyes are relatively large and body tapers evenly. Common Goby P. microps (length to 70mm) is patchily distributed and absent from much of the NE; it favours estuaries and brackish water. Scales are absent dorsally in front of 1st dorsal fin; body has slightly ‘hunchback’ appearance, and snub nose makes head look almost frog-like. Adult male has dark spot at bases of 1st dorsal and pectoral fins. Painted Goby P. pictus (length to 55mm) (not illustrated) is usually sub-littoral on gravelly substrates; there are 4–5 dark patches on flanks and back is subtly banded; 1st dorsal fin has 2 rows of dark spots and dorsal fins have red, blue and yellow hues.
Two-spotted Goby Gobiusculus flavescens Length to 6cm
Well-marked fish that spends more time swimming in water column than most other gobies. Found among seaweeds and eelgrass beds in shallow water. ADULT has rather streamlined body; marbled brown and buff, with blue spots and pale dorsal patches. Typically, there is a dark spot at base of tail; male has 2nd dark spot behind pectoral fin. STATUS Locally common except along the E coast.
Rock Goby Gobius paganellus Length to 12cm
Rock Goby, adult
Rock Goby, mature adult, dark form
Robust goby. Found in pools and under rocks on lower shore. ADULT has relatively large head and tail; head is rounded in profile and lacks visible lines of papillae seen in Black Goby. Typically, body is marbled brown, buff and grey. Some individuals are very dark, leading to confusion with Black Goby. First dorsal fin is short in relative terms (cf. Black Goby); pale yellowish-orange outer margin is diagnostic. Dorsal fins abut one another. Head lacks lines of sensory papillae. STATUS Locally common in the S and W.
Black Goby Gobius niger Length to 16cm
Black Goby, adult
Black Goby, mature adult, dark form
Similar proportions to Rock Goby, and often with similar coloration. Favours estuaries and sheltered coasts with muddy substrates; often in eelgrass beds. ADULT has more angular head than Rock Goby, with steeper forehead. Some individuals are uniformly black, but typical colour is marbled brown and grey-buff, sometimes with 4 or 5 dark spots on flanks. First dorsal fin is typically tall and pointed (middle rays are tallest), and lacks a pale margin. Both dorsal fins usually show a dark spot at front; the fins abut one another. Head has lines of sensory papillae. STATUS Locally common, in the S and W.
Lemon Sole Microstomus kitt Length to 60cm
Well-marked flatfish, found on sand and gravel; sub-littoral. ADULT lives with right side, and eyes, facing uppermost. Outline is oval and head is rather small and rounded. Dorsal and anal fins almost reach tail, which is relatively long. Upper surface is marbled grey and yellowish brown. STATUS Widespread and locally common, except in the N and NE.
Dab Limanda limanda Length to 25cm
Robust flatfish, found on sandy coasts. ADULT lives with right side, and eyes (which are relatively large), facing uppermost. Lateral line on upper surface makes a curving detour above pectoral fin. Upper surface is rough, marbled orange-brown and grey. STATUS Widespread and locally common except in the N and NE; declining everywhere.
Flounder Platichthys flesus Length to 50cm
One of our most widespread and familiar flatfish. Found on sandy substrates, young animals often inshore. Ventures into freshwater mouths of estuaries. ADULT lives with right side, and eyes, facing uppermost. Outline is elongate-oval, and head, tail and tailstock are proportionately large. Mottled patterning resembles sand and gravel. STATUS Widespread and locally common.
Plaice Pleuronectes platessa Length to 50cm
Plaice, swimming
Well-marked flatfish. ADULT lives with right side, and eyes, facing uppermost. Outline is oval-rhomboid with a pointed head and slender tail. Marbled patterning on upper surface is a good match for sand; note the dark-centred red spots. STATUS Widespread and locally common.
Sole Solea solea Length to 50cm
displaying pectoral fin
Distinctive flatfish whose outline recalls the sole of a shoe. Found on sandy substrates on coasts and in estuaries. ADULT lives with right side, and eyes, facing uppermost. Mouth is not terminal, upper pectoral fin has a black spot. Skin is rough and patterned to look like sand and gravel. Anal fin has 61–74 rays. STATUS Widespread and locally common in S half of Britain; scarce further N. NOTE Black spot on upper pectoral fin is ‘flashed’ as fin is erected in alarm. This looks very similar to ‘warning’ issued by Lesser Weever, whose fin spines are venomous.
Solenette Buglossidium luteum Length to 12cm
Small flatfish, similar to Sole but separable with care. Typically sub-littoral, on sand and gravel, but sometimes in shallows. ADULT is narrowly oval, living with right side, and eyes, facing uppermost. Upper pectoral fin lacks a black spot and blind-side pectoral fin is vestigial (fully formed in Sole). Has black line marks every 5th or 6th ray of dorsal and anal fins (those that fringe body). Anal fin has 49–63 rays. Moves in a distinctive, seemingly shuffling manner: ripples the dorsal and anal fins, the black rays looking like slender feet. STATUS Locally common, in S Britain only.
Brill Scophthalmus rhombus Length to 55cm
Beautifully patterned flatfish. Superbly camouflaged against the sandy substrates it favours. ADULT lives with left side, and eyes, facing uppermost. Outline is broadly oval. Anal and dorsal fins are broadest towards tail, and anterior rays of dorsal fin are separated into filaments. STATUS Locally common only in the S and SW, N to the Irish Sea.
Topknot Zeugopterus punctatus Length to 20cm
Distinctive fish. Unusually for a flatfish, it favours rocky coasts and happily clings onto vertical sides of rock faces. ADULT lives with left side, and eyes, facing uppermost. Outline is rounded-oval. Anal and dorsal fins almost meet at head end, and are continuous with tail. Upper surface is typically marbled reddish brown. STATUS Widespread and locally common, except on the E coast.
Turbot Psetta maxima Length to 70cm
Large flatfish, only juveniles of which are found inshore. Favours sandy substrates. ADULT lives with left side, and eyes, facing uppermost. Outline is rhomboid-diamond-shaped with a pointed head and long tail. Upper surface is typical mottled grey with pale and black spots. STATUS Locally common in the S and SW.