Beadlet Anemone (Actinia equina)

Usually only seen in very shallow water. It’s easy to see their tentacles underwater when they’re wafting about but between tide marks, it retracts them and the anemone looks like a blob of jelly. It has a smooth column and you can see small blue bulges (the tubercles) which form a ring below tentacles. They’re usually deep red but can be green, brown and orange. Up to 5cm across.

Strawberry Anemone (Actinia fragacea)

Dark red with green spots on column which make it look like a strawberry; larger than beadlet anemone but similar in shape. Up to 10cm across.

Snakelocks Anemone (Anemonia viridis)

Prefers sunny tops of rocky reefs in shallow waters so you can find it in pools on the shore and on kelp fronds. Small ones can live alone on eel-grass strands. It has 200 or so long wavy tentacles, very sticky, green with purple tips which cannot be fully retracted.

Snakelock anemones like sunny sites lots of a symbiotic algae live in its tentacles. The algae is protected by the anemone and gets carbon dioxide and nutrient salts from it. In return, the anemone uses organic compounds synthesised by the algae from sunlight. The algae may also help remove wastes from the host anemone. Snakelocks anemones in deep water are dull grey probably because the algae won’t inhabit it there isn’t enough sunlight to maintain the algae at those depths.

Edible Crab (Cancer pagurus)

It looks very strong and heavily built. It has an oval shell with a ‘pie crust’ edging. The claws are large but the legs seem small. It’s pink-brown but the claws have black tips. They’re live in many different habitats at all depths. They’ll be found in crevices on rocky bottoms and they’ll dig themselves into the sediment of soft bottoms. They can dig huge pits when hunting for prey (ie clams, worms) that burrows. A softsea bed can look like a moon, full of craters made by the crabs. The abdomen of the female is wide and rounded and the male’s is narrower.

Velvet Swimming Crab (Liocarcinus puber)

It looks velvety because of the covering of short greyish-brown hairs on its body. It has bright red eyes and blue lines on its legs and claws. The velvet swimming crab has a swimming paddle in the back (made from the last pair of legs) and has a reputation for being aggressive – it doesn’t retreat, rather it stands up on its legs and spreads its claws if provoked. Found on rocky and stony seabeds; they also dig themselves into sandy bottoms. They’re carnivores but some eat lots of plant matter.

American Slipper Limpet (Crepidula fornicata)

It came from America in the 19th century and is now found all over the south of Britain. And when you turn it over, it looks like a slipper. It’s an amazing stack of as many as 12 limpets. Large stacks are usually curved, like an arch (fornicata is Latin for arch).

The animals at the bottom of the chain are female and the ones on top are male and the ones in between are a bit of each! They change from male to female as they get older and if there aren’t any females, males start to change gradually into females when they are young.

Masses of slipper limpets can be found near Weymouth and other areas and compete for space and plankton with oyster beds, which can cause problems.

Netted Dogwhelk (Hinia reticulata)

It has a characteristic conical shell with a netlike pattern. They’re frequently found on sandy bottoms, especially if there are rocks nearby. The dogwhelk breathes through clean water drawn into the body through a siphon. You can see only the siphon when the dogwhelk is buried in the sand. They are scavengers and you can see them in numbers around a carcass such as a dead fish. They can find this food through their ability to detect chemicals in the water and can travel large distances for dinner.

Common Cuttlefish (Sepia officinalis)

These are very small invertebrates. They have broad body with a long fringe of a fin on each side going from front to back. The mouth is surrounded by 10 tentacles. They can move fast when they’re spotted and sometimes leave a cloud of ink (the colour ‘sepia’ was once used by artists). But they can also hover by using their fins to control their position. You’ve heard about cuttlebones – they fill tiny chambers in the bone with liquid to sink or gas to rise.
The cuttlefish has an amazing ability to change colours according to its environment, appearing dark over rocks or almost white if going over sand. They match the seabed according to how the onlooker sees it and can completely change their colour within a few seconds. They have special cells which are like little flexible bags of pigment which expand to produce dark colours and contract for light colours.
Cuttlefish move very fast and can catch fast-moving prey and can deal with crabs and other ‘armoured animals’ with its hard beak behind the tentacles. Their numbers go up and down enormously inshore, and you can see lots of them in some years and very few in others. Can be up to 30 cm long.

Starfish – General

Starfish are in the same animal group (phylum) as brittle stars, sea urchins and sea cucumbers. The phylum name is Echinodermata which means ‘spiny-skinned,’ describing their skeleton of plates. These plates stick out and form the animals’ ‘spines’. These animals have no front or back or left or right. They have radial symmetry which means that a starfish can lead with any arm and don’t have to turn their body when changing direction.
They all have tube feet under each arm which they use to move around. The animals are able to grip hard surfaces with the tiny suckers at the end of each foot. Small encrusting animals like barnacles would like to live on starfish and sea urchins but they discourage this by killing any ‘settlers’ with tiny jaws on their exterior and sometimes eat them.
These same tube feet on starfish enable them to force their way into animals such as molluscs and other bivalves. They arch themselves over a mollusc and prise the shellfish open with a pulling force created by the tube feet. Once the shell is open by even 1/10 mm, the starfish pushes its stomach out through its mouth and slips it into the crack. It then secretes digestive juices and eats the shellfish.

Common Starfish (Asterias rubens)

They live on sandy and stony sea beds and on rocks, very common and can be seen in dense groups where food is plentiful. They can cause a lot of damage to mussel and oyster fisheries and are difficult to eradicate. Attempts to kill them but cutting them up haven’t been successful because even one arm of a starfish can regenerate itself.
Starfish are usually pale yellow/ brown, or orange. They usually have five arms, each with a row of spines down the middle.
Cushion Star (Asterina gibbosa)
Cushion stars have short arms and have a pentagonal shape. It’s small, up to 5 cm across and can be found on the shore or in very shallow water.The upper part of its body is rough and is covered in small groups of spines. The spines are normally organge but the cushion star’s general colour can vary from green or brown to cream.
Sea Urchins – General
Sea urchins have larger bony plates which form a test, or a type of shall. The body is rather spherical and doesn’t have any arms but internally they aresimilar to starfish. They also have tube feet which are longer so they can reach out beyond the spines. Each spine is attached to the test with a ball-and-socket joint which help with movement of the tube feet or can be locked into position to anchor the sea urchin onto a surface.

Green Sea Urchin

Sea Squirts – General
Sea squirts are sedentary, feeding of passing plankton and other particles of food. The adult sea squirt is a U-shaped tube surrounded by a tough ‘tunic (this is why they’re also called tunicates). The centre of the tube is the filtering system and each of the opening is a siphon, one to take water in and one to expel it. If a sea squirt is threatened it contracts and squirts water from its two siphons. Its circulatory system is unusual because it pumps blood one way for several seconds and then reverses the flow for several seconds. Many sea squirts live in colonies. Star Sea Squirt - Botryllus schlosseri Colonies of Star sea squirts live in a common dark-coloured tunic. Groups of 3 to 12 individual sea squirts form the usual star-shaped arrangements. The stars are yellow. The group shares an outflow siphon in the centre of the star but have separate feeding siphons. Colonies can be flat or bulb-like and are found clinging to rocks or seaweed; a common size is 10 cm across.