BIOLOGICAL

marlin.ac.uk
  • No tags were found...

Identification Guide for Selected Seashore Species of South Devon

THE MARINE BIOLOGICAL

ASSOCIATION

Sealife Surveys:

Identification Guide for Selected Seashore Species

of South Devon

Produced by MarLIN for the Batten Bay Breathing Places Project


Sealife Surveys:

Identification Guide for Selected Seashore Species of South Devon

Species included in this guide have been selected because they are commonly

found on the South Devon Coast or for the following reasons:

Key species influence community composition and structure. The loss or

decline of a key species would lead to the disappearance or replacement of

associated plants and animals and is very important.

Climate change species are likely to increase or decrease in abundance and

extent as seawater temperatures rise. Records of occurrence and abundance

from as many locations as possible will help to track changes in distribution.

Non-native species have been introduced from outside their native geographical

range or habitat by humans. Their impact can be substantial: for example some

may displace native species or change environmental conditions. Obtaining

records of occurrence and abundance of non-natives will help track changes in

distribution and their impact on native species.

Seashores are the most accessible part of

the marine environment and provide

opportunities to discover a range of species

in a variety of habitats. Batten Bay and

other sites in South Devon have beautiful

rocky shores, which are easy to get to and

are home to a wide diversity of life.

What you find on the shore depends

on features such as rockpools,

boulders and gullies and is strongly

influenced by levels of exposure and

height on the shore (see diagram).

When exploring the seashore, please

minimize your impact by not

removing organisms that are

attached to surfaces and by

carefully replacing any stones

or seaweed that you turn

over. Take photographs, not

specimens, if you need an

identification checked.

Dulse

Carragheen

Kelp

The species in this guide have been

selected either because they are

commonly found on the South Devon

Coast or for their significance as

Lichens

Small periwinkles

Channelled wrack

Barnacles and limpets

Winkles

Wracks (fucoid algae)

Periwinkles

Thong weed

indicators of environmental change and

biodiversity, and for their ease of recognition. If

you find any key, climate change indicator or

non-native species, it is important that you

make records and submit them to MarLIN

through the Sealife Survey (see back of guide).

Rock pool

Coralline algae

Bifurcaria bifurcata (SW shores)

Periwinkles etc.

Diagrammatic representation of the distribution of species on a

moderately exposed rocky shore.

MarLIN would like to thank all contributors for their kind permission to use their images and text in this identification guide.

}


THE MARINE BIOLOGICAL

Sealife Surveys:

Identification Guide for Selected Seashore Species of South Devon

Key:

Upper shore

Middle shore

Lower shore

Key species

Climate change

indicator species

Non-native

species

Egg wrack Ascophyllum nodosum

5 cm

PETER BARFIELD

A large brown seaweed. Long, strap-like fronds (0.5 – 2

metres in length) with egg-shaped air bladders at

regular intervals.

Often bears tufts of a small reddish-brown filamentous

algae known as Egg wrack wool (Polysiphonia lanosa).

Attached to rocks and boulders on the middle shore in a

range of habitats, from estuaries to relatively exposed

coasts.

Found on all coasts of Britain and Ireland.

Bladder wrack Fucus vesiculosus

5 cm

JAYNE EVANS

A large brown seaweed. Branching fronds may be up to

2 m long with spherical air bladders (usually paired, may

be absent in young plants and on exposed shores).

Dark olive-brown in colour.

Common around the middle shore in a wide range of

exposures.

All coasts of Britain and Ireland.

May be confused with Spiral wrack (Fucus spiralis),

whose fruiting bodies at the tips of the fronds look

similar to air bladders.

Wireweed Sargassum muticum

10 cm

KEITH HISCOCK & JACK SEWELL (inset)

A large olive-brown seaweed with fronds often over 1 m

long.

Has a characteristic ‘wirey’ stem

Has regularly alternating branches with small, flattened

oval blades and spherical air bladders.

A non-native species from the Pacific, introduced to

Britain from France and first found in the Isle of Wight in

1973.

For further information

visit www.marlin.ac.uk

A S S O C I AT I O N


THE MARINE BIOLOGICAL

Sealife Surveys:

Identification Guide for Selected Seashore Species of South Devon

Key:

Upper shore

Middle shore

Lower shore

Key species

Climate change

indicator species

Non-native

species

Toothed wrack Fucus serratus

A brown seaweed whose narrow, flat, strap-like fronds

have a midrib and serrated edges. No gas bladders

present. The whole plant grows to around 60 cm.

Olive-brown to greenish in colour.

Distinct toothed or saw-like edge.

Found on the lower shore on more sheltered areas of

the coast.

Found on all British and Irish coasts.

3 cm

Jayne Evans

Thongweed Himanthalia elongata

2 cm

STUART JENKINS

A brown seaweed which appears olive-green in colour.

The first year’s growth forms as a round button on the

shore.

The second year’s growth produces strap-like

reproductive bodies (up to 2 m long) which grow from

the centre of the button in autumn and which give this

seaweed its name.

Found on the lower shore attached to rocks.

All coasts of Britain and Ireland, except SE England.

Oarweed Laminaria digitata

1 cm

20 cm

STEVE TREWHELLA

A large kelp (up to 2 m in length) with a smooth, round

stipe (stem) extending into a broad frond which is

divided into strap-like fingers. Glossy, golden-brown in

colour with a leathery texture.

The holdfast provides a unique microhabitat for a variety

of organisms.

Found attached to bedrock on the lower shore.

Most coasts of Britain and Ireland, but scarce along the

east coast of England and absent from Liverpool Bay

and the Severn Estuary.

For further information

visit www.marlin.ac.uk

A S S O C I AT I O N


THE MARINE BIOLOGICAL

Sealife Surveys:

Identification Guide for Selected Seashore Species of South Devon

Key:

Upper shore

Middle shore

Lower shore

Key species

Climate change

indicator species

Non-native

species

Sugar kelp Saccharina latissima

A large kelp which grows rapidly in spring up to a length

of 4 m.

Slender stipe (stem), blade ribbon-like and crinkly with

obvious wavy edges.

Found on the lower shore of sheltered areas, growing in

deep rockpools.

15 cm

STEVE TREWHELLA

Sea lettuce Ulva lactuca

A broad, thin green seaweed which looks like lettuce

leaves.

Has a small holdfast with which it holds on to the rock,

but is often found unattached.

Found on all levels of the shore and can also tolerate

brackish water.

Fronds often have holes in, like swiss cheese.

1 cm

JUDITH OAKLEY

Gut weed Ulva intestinalis

1 cm

STEVE TREWHELLA

A bright, grass-green seaweed up to 75 cm long,

consisting of inflated and irregularly constricted tubular

fronds – typically unbranched and rounded at the tip –

that grow from a small disc base.

Can occur on all levels of the shore in a range of

habitats.

Tolerant of reduced salinities around freshwater inputs,

for example from streams.

Found on all British and Irish coasts.

For further information

visit www.marlin.ac.uk

A S S O C I AT I O N


THE MARINE BIOLOGICAL

Sealife Surveys:

Identification Guide for Selected Seashore Species of South Devon

Key:

Upper shore

Middle shore

Lower shore

Key species

Climate change

indicator species

Non-native

species

Coral weed Corallina officinalis

Pink / purplish calcareous seaweed with white tips that

grows up to 12 cm. Feels crusty when touched. Turns

white when dried out or dead.

Articulated, ‘feather shaped’ fronds.

Common around rock pools and under larger seaweeds

on the middle and lower shores.

1 cm

JUDITH OAKLEY

Pepper dulse Osmundea pinnatifida

A small, tough red seaweed (up to 8 cm in length), with

flattened fronds that divide alternately giving the

branches a short, stubby appearance.

Usually Brown-yellow in colour.

Forms a turf and is often found in crevices.

Produces a pungent peppery smell when dry.

Found on the middle and lower shores.

All British and Irish coasts.

3 cm

STEVE TREWHELLA

Irish moss Chondrus crispus

5 cm

JUDITH OAKLEY

A small seaweed growing up to 22 cm long. Fronds

are flat and wide with rounded tips, and

repeatedly divide into two branches. Variable in

appearance, purplish-red in colour with a

tendency to turn green in strong sunlight.

Has a blue / purple iridescence when underwater.

Abundant on rocks on the middle to lower shore

and in rockpools.

All British and Irish coasts.

May be confused with false Irish moss

(Mastocarpus stellatus) which has channelled

fronds.

For further information

visit www.marlin.ac.uk

A S S O C I AT I O N


THE MARINE BIOLOGICAL

Sealife Surveys:

Identification Guide for Selected Seashore Species of South Devon

Key:

Upper shore

Middle shore

Lower shore

Key species

Climate change

indicator species

Non-native

species

Dulse Palmaria palmata

5 cm

2 cm

JACK SEWELL KEITH HISCOCK

A tough, flat, wide red seaweed which extends

from a single holdfast.

Dark red in colour with the older parts having

small extensions from the outer edges.

Grows on the lower shore and sometimes as an

epiphyte (growing on another algae).

Generally distributed around the coast of Britain

and Ireland, but not recorded from some of the

east coast of England.

False Irish moss Mastocarpus stellatus

A small red seaweed growing up to 17 cm in

length. Has a disc-like holdfast from which a

narrow, forked frond widens and branches. Fronds

are channelled with a thickened edge and often

bear fruiting bodies as small protuberances. Dark

reddish-brown to black in colour.

Grows mainly on the lower shore and in rockpools,

particularly in exposed areas.

Occurs all around the British Isles but is abundant

mainly on the western coasts.

May be confused with Irish moss (Chondrus

crispus) whose fronds are flat and divide

repeatedly into two branches.

Orange sponge Phylum Porifera

Orange encrusting animals which feel spongy

when touched.

Common on the middle and lower shores.

Simple animals which feed by drawing water in

through an inhalant siphon (hole), filtering out the

nutrients and ejecting the water through an

exhalent siphon.

Many species are present and identification is

difficult in the field.

3 cm

JUDITH OAKLEY

For further information

visit www.marlin.ac.uk

A S S O C I AT I O N


THE MARINE BIOLOGICAL

Sealife Surveys:

Identification Guide for Selected Seashore Species of South Devon

Key:

Upper shore

Middle shore

Lower shore

Key species

Climate change

indicator species

Non-native

species

Beadlet anemone Actinia equina

2 cm

2 cm

JACK SEWELL JACK SEWELL

A medium sea anemone found from the upper to

the lower shore.

Body is red with blue beads at the base of the

tentacles.

Able to withdraw completely into its column,

reducing water loss as the tide recedes.

Feeds by stinging passing food with poison darts

(nematocysts) and passing the food into the

central mouth / anus.

Similar to the strawberry anemone (Actinia

fragacea) which has green spots on the column.

Snakelocks anemone Anemonia viridis

A common sea anemone present in two colour

morphs – green and brown, each with purple tips

on the tentacles. The colour is dependent on the

presence of algae living inside its body.

Feeds in the same way as the beadlet anemone

but also receives sugars from any symbiotic algae

present.

Reproduction may be sexual or by budding.

Abundant in middle and lower shore areas,

especially in rockpools.

Toothed top shell Osilinus lineatus

1 cm

1 cm

KEITH HISCOCK (left) MARK BRECKELS (right)

Spire is upright when held the right way up on the

hand. Has a mother-of-pearl appearance on the

inside of the lip.

There is a prominent ‘tooth’ bulge on the shell

near the operculum opening.

Common on the upper and middle shore feeding

on microscopic algae.

The operculum disc can seal the animal within the

shell, reducing water loss.

May be confused with the flat (Gibbula

umbilicalis) or grey (Gibbula cineraria) topshells,

but both are flatter and lack the ‘tooth’ bulge.

For further information

visit www.marlin.ac.uk

A S S O C I AT I O N


THE MARINE BIOLOGICAL

Sealife Surveys:

Identification Guide for Selected Seashore Species of South Devon

Key:

Upper shore

Middle shore

Lower shore

Key species

Climate change

indicator species

Non-native

species

Painted top shell Calliostoma zizyphinum

A snail with a conical, shiny shell, pink to violet in

colour, with streaks of brown, red or purple,

although white colour morphs occur.

Feed on microscopic algae and detritus.

Have no operculum disc and therefore cannot

resist desiccation effectively.

Found on the lower shore and in the subtidal

areas only, often under overhangs.

1 cm

5 cm

2 cm 1 cm

JUDITH OAKLEY (left) JAYNE EVANS (right) KEITH HISCOCK

JACK SEWELL

Limpet Patella sp.

Gastropod molluscs, conical in shape, that survive

on all levels of the shore by attaching themselves

strongly to the rock using a powerful foot.

Settle onto rock from a planktonic larval stage and

some species maintain a ‘home scar’ for the

duration of its adult life (up to 20 years).

Feeds on algal mats that form on the rocks by

scraping them off with the radula (toothed

tongue).

An important species in maintaining the balance

of seaweeds and animals on the rocky shore.

Dog whelk Nucella lapillus

Thick, conical shell up to 4 cm high with spiral

ridges and a short, pointed spire. The aperture

(shell opening) has a distinct siphonal canal.

Shell usually white but may be grey, brown or

yellow and is sometimes striped.

Found on all rocky shores from the middle shore

downwards.

Preys on barnacles, mussels and limpets using an

adaptable mouth piece to drill through the shells,

inject digestive enzymes and suck out the prey.

Their eggs are laid directly into cracks of rocks and

under seaweed in small capsules (see photo).

For further information

visit www.marlin.ac.uk

A S S O C I AT I O N


THE MARINE BIOLOGICAL

Sealife Surveys:

Identification Guide for Selected Seashore Species of South Devon

Key:

Upper shore

Middle shore

Lower shore

Key species

Climate change

indicator species

Non-native

species

1 cm

Flat periwinkle Littorina obtusata

Spire is horizontal or diagonal when held the right

way up on the hand.

Usually yellow or dark brown in colour, sometimes

orange or red.

Commonly found on the middle shore on Egg

wrack (Ascophyllum nodosum) and Bladder wrack

(Fucus vesiculosus), on which it feeds.

Different colours exist as a result of selective

feeding by birds and marine predators.

1 cm

1 cm

1 cm 1 cm

JUDITH OAKLEY JACK SEWELL

Common periwinkle Littorina littorea

Spire is horizontal or diagonal when held the right

way up on the hand. White colouration is seen

around the operculum opening.

Dark brown to black in appearance with a conical

shaped shell ending in a sharp point.

Found on the middle and lower shore, often in

large numbers in rockpools.

Feeds on algae.

Young indviduals may be confused with the rough

periwinkle (Littorina saxatilis) which is smaller

with more pronounced ridges and is found higher

up the shore.

2 cm

MARK BRECKELS

Shore crab Carcinus maenas

The most common of all intertidal crabs,

recognisable by the presence of 5 teeth (spikes)

on the carapace outside of the eyes.

Carapace colour varies between green, yellow and

reddish-brown, especially in juveniles.

Present on all shore zones.

Omnivores, feeding on detritus, mussels and

gastropod molluscs.

Individuals can be sexed by the shape of their

abdomen – the male’s is thin and triangular, the

female’s is broader with curved sides.

For further information

visit www.marlin.ac.uk

A S S O C I AT I O N


THE MARINE BIOLOGICAL

Sealife Surveys:

Identification Guide for Selected Seashore Species of South Devon

Key:

Upper shore

Middle shore

Lower shore

Key species

Climate change

indicator species

Non-native

species

Hermit crab Pagurus bernhardus

Found throughout the shore feeding on detritus in

rockpools and gullies.

Occupy empty top shell, periwinkle and dog whelk

shells using a flexible abdomen to help hold them

in inside the shell.

Carapace can grow up to 3.5 cm but these larger

specimens are usually subtidal.

1

1

cm

cm

2 cm

JACK SEWELL KEITH HISCOCK

Prawn Palaemon sp.

Several species can be found all have an elongated

body with an abdomen ending in a tailfin.

Long antennae and prominent rostrum between

the eyes.

Found in rockpools on all levels of the shore,

feeding on detritus.

Broad-clawed porcelain crab Porcellana platycheles

1 cm

STEVE TREWHELLA

A small hairy crab (up to 1.5 cm) with large, flat,

hairy claws and two long antennae.

Found under rocks and seaweed on the middle

and lower shores.

Females carry their eggs in the spring and summer

of their second year.

May be confused with the long-clawed porcelain

crab (Pisidia longicornis), which is usually smaller,

with thinner claws and lacks body hair.

For further information

visit www.marlin.ac.uk

A S S O C I AT I O N


THE MARINE BIOLOGICAL

Sealife Surveys:

Identification Guide for Selected Seashore Species of South Devon

Key:

Upper shore

Middle shore

Lower shore

Key species

Climate change

indicator species

Non-native

species

Velvet swimming crab Necora puber

2 cm

54 cm cm

FIONA CROUCH JACK SEWELL

Also known as the ‘devil crab’ because of its

distinguishing red eyes.

Has paddle-like appendages on its last legs for

swimming. The joints of its limbs are purple or red

in colour.

A fast moving crab that adopts a strong aggressive

pose when threatened. This animal has a

ferocious reputation and care should be taken

when handling.

An omnivorous species found on the lower shore.

May be confused with other swimming crab

species although the red eyes and velvety shell

are key identification features.

Edible crab Cancer pagurus

Has a characteristic pie-crust edge to the carapace

and large claws with black tips.

Is the largest of the rocky shore crabs, found

under rocks and buried in sediment on the lower

shore. The intertidal individuals are smaller while

the subtidal individuals may have a carapace

width of up to 25 cm.

A commercially important species.

Montagu’s crab Xantho incisus

2 cm

STEVE TREWHELLA

Carapace is broad and smooth, with a furrowed

surface. The front edge between the eyes is

smooth and almost straight.

Large, heavy claws with black tips.

Found under rocks and in crevices on the lower

shore.

May be confused with Risso’s crab (Xantho

pilipes), which is similar but has a fringe of hair

around its carapace and limbs.

For further information

visit www.marlin.ac.uk

A S S O C I AT I O N


THE MARINE BIOLOGICAL

Sealife Surveys:

Identification Guide for Selected Seashore Species of South Devon

Key:

Upper shore

Middle shore

Lower shore

Key species

Climate change

indicator species

Non-native

species

Squat lobster Galathea squamifera

Carapace longer than it is wide, with a distinctive

tail curled under the body (this can be used to

swim quickly and avoid predators).

Body no bigger than 3.5 cm with large claws

extending forwards.

Found under rocks on the lower shore and feeds

on suspended detritus.

1 cm

2 cm

JUDITH OAKLEY MARK BRECKELS

Barnacles Order Thoracica

Barnacles are crustaceans that have adopted a

sedentary (permanently attached) life stage.

Attach to rocks. Hard plates surrounding the

operculum open to allow the animal to feed.

Filter feeders which use their adapted legs to feed

on plankton once submerged.

Almost all species are hermaphroditic.

A number of species of barnacle exist on the

shore, showing ‘zonation’ between the lower and

upper shores and with wave exposure.

Identification is often difficult and involves the

analysis of operculum shape and the number of

plates present.

Green sea urchin Psammechinus miliaris

An almost round, slightly flattened urchin growing

up to 5 cm in diameter.

Greenish in colour with distinctive violet tips to

the spines. Spines are short, robust and closely

packed.

Often camouflaged by covering itself with pieces

of seaweed, shell and stone.

Found on the middle and lower shore under

boulders, stones and seaweeds.

1 cm

FIONA CROUCH

For further information

visit www.marlin.ac.uk

A S S O C I AT I O N


THE MARINE BIOLOGICAL

Sealife Surveys:

Identification Guide for Selected Seashore Species of South Devon

Key:

Upper shore

Middle shore

Lower shore

Key species

Climate change

indicator species

Non-native

species

Cushion star Asterina gibbosa

2 cm

1 cm

JUDITH OAKLEY HARVEY TYLER-WALTERS

Flat, broad arms growing up to 5 cm across.

Colour varies from green to brown and may be

mottled.

Feed mostly as detritivores on decaying organic

matter, but can also be carnivorous.

Found on the lower shore and lower part of the

middle shore.

Mature into males at 2 years old before changing

sex at 4 years old to become female.

Brittle star Order Ophiurida

Several species may be found on the shore.

All have the characteristic central disc with long,

thin, flexible arms.

Typically found in large numbers on the lower

shore, below rocks and in detritus on which they

feed.

The small brittle star (Amphipholis squamata) is

one of the most common intertidal species locally

(pictured left).

1 cm

STEVE TREWHELLA

Spiral worm Spirorbis sp.

worms that secrete a calcareous tube in a spiral

around their body.

Found attached to rocks, shells and the fronds of

brown seaweeds, particularly spiral wrack,

bladder wrack and thongweed.

Filter feed on particles from the passing water

current.

White in colour

Species may be confused with the Keel worm

(Pomatoceros triqueter), which grows much larger

and does not usually grow in a spiral.

For further information

visit www.marlin.ac.uk

A S S O C I AT I O N


THE MARINE BIOLOGICAL

Sealife Surveys:

Identification Guide for Selected Seashore Species of South Devon

Key:

Upper shore

Middle shore

Lower shore

Key species

Climate change

indicator species

Non-native

species

Shanny Lipophrys pholis

5 cm

2 cm

JACK SEWELL STEVE TREWHELLA

Large, blunt head and rather elongated body with

soft, slimy skin. Colour usually speckled green and

brown but can change quickly when disturbed.

Thick, light coloured lips and fairly large eyes.

The single dorsal fin extends along most of the

body, sometimes with a slight dip halfway along.

A predator which feeds on molluscs, barnacles

and soft crabs.

Common under rocks across the whole shore, to

which they often return to on each tide.

Goby Gobius sp.

Large, broad head and fairly deep body which

narrows towards the tail. Body colour varies

between species.

Thick lips and large protruding eyes, usually

towards the top of the head.

The dorsal fin is separated into two parts, the

front part short and the rear part longer.

An opportunistic carnivore which feeds near the

bottom of pools and gullies.

Found on all levels of the shore.

Worm pipefish Nerophis lumbriciformis

2 cm

HARVEY TYLER-WALTERS

A slender, smooth, worm-like body up to 15 cm

long. The snout is short and upturned (the head

appearing similar to the seahorse, to which it is

related). It has a small dorsal fin on the back

which can be seen vibrating at high speed.

The upper side is dark green or brown in colour

while the underside is paler, white to yellowish in

colour and sometimes with pale spots or bars.

Found under stones or seaweed on the lower

shore.

The female transfers eggs into a shallow groove

on the male’s belly, the male then carries and

protects the eggs until they hatch.

For further information

visit www.marlin.ac.uk

A S S O C I AT I O N


THE MARINE BIOLOGICAL

The coastline of south Devon varies from exposed rocky shores to sheltered

muddy inlets. In parts of south west England the tidal range can exceed 8

metres, producing extensive intertidal areas. These varied habitats are home

to a huge diversity of plants and animals.

Cataloguing and mapping the diversity of life around our shores is a

formidable task. Surveying the shore helps to inform us about the state of our

marine environment and about the changes that are occurring there. This

guide provides information about some of the rocky shore species, commonly

found on the shores of South Devon or that are indicators of human impacts

or biodiversity. It has been created as part of the Big Lottery funded Batten

Bay Breathing Places Project, run in Plymouth by MarLIN.

For more information on the biology and geographical distribution of species

in this guide, or to find out about other guides available in this range, visit the

MarLIN Web site at: www.marlin.ac.uk

Reference:

Help us build a

national picture of

our marine life

Join

the

Sealife

Survey

SMS or MMS

07806 938789

Hotline

01752 255026

online

www.sealifesurvey.org

The Sealife Survey helps build a

national picture of British and Irish

marine life. We accept records of

any marine species, make all

records publicly available, archive

them and pass them on to other

relevant schemes.

MarLIN (the Marine Life Information Network). 2008. Sealife Surveys. Identification Guide for

Selected Seashore Species of South Devon. Marine Biological Association of the UK, Plymouth.

ASSOCIATION

More magazines by this user
Similar magazines