Other Sea Creatures

While anglers (understandably) concentrate on fish species they can catch, and other species they can use as bait, there is in fact a huge range of other species around the British Isles. Many anglers are surprised to hear that sea cucumbers, various species of coral and even sea snails are found in UK waters. Find out more about all of these species in the profiles below.

Common Sea Urchin

Common Sea Urchin (Echinus esculentus) – A species of sea urchin which has a distribution all around Europe and is found in greatest numbers in British waters in the North Sea, although it can be found elsewhere. They live on hard and rocky seabeds and can be found in water over one thousand metres deep. The common sea urchin can grow to around 10cm across. It has a thin brittle shell, covered in small spines. Like all almost all sea urchin species, is divided into five sections. They are omnivores which feed on seaweeds and algae, although they will also eat invertebrates which encrust onto surfaces such as barnacles. Unfortunately, habitat destruction and deep-sea trawling mean that the common sea urchin number have been reduced and the IUCN (International Union for the Conservation of Nature) classes the common sea urchin as Near Threatened. A further threat to sea urchin numbers is that they are collected by divers due to their attractive appearance and the collectability of their undamaged shells. The common sea urchin is edible and there is a small market for it as a source of food throughout Europe.

Sea Anemone Beadlet Anemone (Actinia equina) – The beadlet anemone is a species of sea anemone which is very common throughout the whole of the UK and is also found throughout Europe and parts of Africa. They are usually a dark red in colour and can be a maximum of 6cm across. This species is perfectly adapted to life in the intertidal zone. It attaches itself to rocks and stones and curls itself into a blob when the tide is out and it is exposed to the elements and can survive out of water for several days. However, once the tide comes in and the anemone is submerged it extends up to two hundred tentacles to catch passing prey. It will eat anything it can catch in its tentacles, but the most common source of food is isopods and small crustaceans which are common in the intertidal zone. Some of the tentacles contain a poison which paralyses the prey and allows the beadlet anemone to drawn the prey into its body and begin to digest it. There are a range of other species of anemone around the UK such as the Snakelocks Anemone (Anemonia sulcata), Elegant anemone (Sagartia elegans) and the Dahlia Anemone (Urticina felina).

Lightbulb Sea SquirtLightbulb Sea Squirt (Clavelina lepadiformis) – The lightbulb sea squirt is a species of sea squirt which has a fairly widespread distribution all around the coastlines of the UK. They grow to a maximum length of around 3cm and are often found together in groups or small colonies. Like all sea squirt species they are filter feeders and take microscopic food particles which flow past them in the tide. The name lightbulb comes from the fact that C. lepadiformis has yellow and white internal organs which are visible through its translucent body and make this species look like they glow.

Football Sea SquirtFootball Sea Squirt (Diazona violacea) – A species of small sea squirt which forms into colonies up to 30cm across. Most common in western Scotland and Ireland, although small, dispersed populations are present elsewhere in British waters. When it is in this form the colony of sea squirts does indeed look like a football, hence the name. Again this species is a filter feeder which relies on consuming microscopic matter and food particles which float past on the tide.

Gravel Sea CucumberGravel Sea Cucumber (Neopentadactyla mixta) – Sea cucumbers are marine creatures which are so called because of their resemblance to the vegetable cucumber. They have no visible sensory organs. Neopentadactyla mixta, the gravel sea cucumber, is the most common variety found in British waters, and is found along the western coast of Britain and Ireland. As the name suggests this sea cucumber lives on heavy sand, gravel or shingle seabeds, in water down to around 100m deep. It has a the typical elongated body, usually 10-15cm in length, with small feet running along the body, and a protrusion of tentacles, known as a crown, which extend from one end of the creature. The tentacles are usually 10cm long. Usually white or light grey in colour. The sea cucumber buries its body into the sediment and then leaves its tentacles exposed. It relies on living in areas where there is fairly strong tidal flow and feeds by catching organic matter in its tentacles as it flows pasts. Once the tentacle has caught enough food it is withdrawn into the body of the creature where the food is removed and digested. In some areas gravel sea cucumbers can be found in great numbers. Sea cucumbers go into some form of hibernation in winter when the whole body and tentacles are withdrawn into the gravel and they do not feed for some months. The pattern and reason for this hibernation is poorly understood.

Devonshire Cup CoralDevonshire Cup Coral (Caryophyllia smithii) – A solitary hard coral which is fund all along the coast of Ireland and Wales, and along the west coast of Scotland and south west England. Also found throughout Europe and the Mediterranean. Devonshire cup coral are found attached to rocks and stone, in waters down to around 100m. This species can be any colour, from reddish to brown, pink, yellow or green. Tentacles emerge from the coral which are translucent in colour with spherical knobs at the end. Devonshire cup coral use these tentacles to suspension feed on plankton.

Dead Man's FingersDead Man’s Fingers (Alcyonium digitatum) – A soft coral, found all around the coasts of the British Isles, as well as throughout Europe (from Scandinavia to the Mediterranean and also in American and Canadian waters). Generally grows in thick colonies and takes on a light yellow, orange or cream colour. Its shape gives it the name of ‘dead man’s fingers.’ This coral lives in shallower water (down to 50m or so) where light can penetrate and algae can grow. They suspension feed on plankton by extending tentacles into the water.

Rosy Feather StarRosy Feather Star (Antedon bifida) – A species of crinoid (related to brittlestars and sea urchins) which is fairly common around the British Isles, although it is found in its highest numbers along the western coast and is less common around the eastern side of Scotland and England. It is only the south east where it appears to be absent. It can be found in depths ranging from a few metres deep, all of the way down to several hundred metres. It consists of a small disc-like body with a number of arms protruding from the disc. They can be up to 20cm across. The colour is usually a mottled red to orange with white. These arms have small protrusions coming from them giving the rosy feather star a plant-like appearance. The underside of the disc has around fifty tendrils coming from it, which the rosy feather star uses to cling to rocks and stone, although it can use the tendrils to ‘walk’ freely and surprisingly quickly, and have a very limited ability to swim by moving their arms to propel them through the water. They are suspension feeders and hold their arms upwards to trap sediment and plankton which they then feed on. Their arms can also be folded inwards when the rosy feather star is resting.

Violet Sea SnailViolet Sea Snail (Janthina janthina) – The violet sea snail (also known as the Bubble Raft Snail) is a species of sea snail which has a truly strange life cycle. This species produces a mucus from its foot which it agitates with its foot to mix it with air fill it with bubbles. This creates a ‘bubble raft’ which keeps the sea snail floating on the surface of the sea. This species will spend its entire life here, feeding on floating jellyfish such as the by-the-wind sailor and the Portuguese man-of-war. Mating is done by the male releasing sperm which come into contact with females and fertilise the eggs inside. The young are born live and immediately create their bubble raft and spend their entire life on the surface of the sea. If, at any stage of its life the violet sea snail become detached from its bubble raft it will sink to the seabed. Once there it is unable to create another bubble raft since it can only produce the mucus and cannot blow bubbles itself. Violet sea snails which find themselves stranded on the seabed are not adapted to life there at all and will soon die. Violet sea snails are so called simply because the lightweight shell they live in is made up of various shades of purple and the flesh of the animal inside is violet. A fully grown violet sea snail is usually around 3-4cm across the shell. While they are a tropical species which is mainly at home around the equator they have been confirmed to be present around the south west coast of England, in parts of the English Channel and off the coast of Wales and the south of the Republic of Ireland.

Share this page: