Marine Life Info Pictures

The waters around Ireland are home to some very talented and beautiful animals. From shape shifting octopus to flattened out fish they are a talented bunch. Have a look below to see a selection of the most commonly encountered animals.

All pictures were taken by Séamus Heffernan.

Branching sponge


These are the most simple of all marine animals and they are fixed to the sea bed or rocks. The scientific name for the group is Porifera which means “pore bearer”.  They are covered in tiny holes which they draw water in through to get their oxygen and food. They then expel the water back out through larger holes which are often at the end of extremities so that the filtered water is not accidentally drawn in again. Most sponges are hermaphrodites but the eggs and sperm mature at different times so they do not fertilise themselves.


Boring sponge – Cliona celata
Branching sponge
Elephant hide sponge – Pachymatisma johnstonia
Sea orange – Suberites ficus




The main feature these animals have is that they have stinging cells. The cells have capsules in them called cnidae, which is were the group gets its name. The cells are used for both offense to capture prey and for defense. They occur in two forms either as a polyp which lives anchored to the seabed or as a medusa free swimming in the sea. Anemone and corals are examples of polyps. Jellyfish and hydroids start out as polyps and mature into free swimming medusa.


Beadlet anemone – Actinia equina
Burrowing anemone – Cerianthus lloydii
Dahlia anemone – Urticina felina
Dead men’s fingers – Alcyonium digitatum
Elegant anemone – Sagartia elegans
Lion’s mane – Cyanea capillata
Moon jellyfish – Aurelia aurita
Plumose anemone – Metridium senile
Slender sea pen – Virgularia mirabilis
Snakelocks anemone – Anemonia viridis
White-cross jellyfish – Staurophora mertensii




A collection of animals that includes crabs, lobsters, shrimp and even barnacles. The hard shell they are covered by allows them to grow strong muscles and cutting devices like claws. This is a great advantage but is balanced out by having to be moulted once they have out grown the shell. When they moult it is also a great time to regenerate a damaged or lost limb, this is why we see so many crabs with one unusually small claw, it will catch up in size through future moults. 


Edible crab – Cancer pagarus
Common hermit crab – Pagurus bernhardus
Common lobster – Hamarus gammarus
Common prawn – Palaemon serratus
Olive squat lobster – Galathea squamifera
Shore crab – Carcinus maenas
Spiny spider crab – Maja squinado
Velvet swimming crab – Necora puber



Double spiralWorms

This is an animal that gets about as much attention as earth worms.  There are three groups: Flat worms which are usually very small or flattened. Ribbon worms are much longer and thinner. The segmented worms are the most complex as they have advanced internal organs. 


Candy stripe flatworm
 – Prostheceraeus vittatus
Double spiral – Bispira volutacornis
Lug worm – Arenicola marina



Painted topshellMolluscs

This group comes in all shapes and sizes. From the obvious snail like creatures with hard shells to unexpected variations like the slugs octopus and squid. The name for the group comes from the Latin word for soft. They have an usual feeding mechanism called a radula which is only found in molluscs. It is a tongue like piece of tissue that has replaceable teeth and it is used by scrapping back and forth on its food.


Auger shell – Turritlla communis
Blue-rayed limpet – Helcion pellucidum
Cuttlebone – Common Cuttlefish
Dog-whelk – Nucella lapillus
Edible periwinkle – Littorina littorea
Lesser octopus – Eledone cirrhosa
Lined polycera – Polycera quadrillineata
Sea lemon – Archidoris pseudoargus
White mud slug – Philine aperta
Painted topshell – Calliostoma zizyphinum
Yellow edged polycera – Polycera faeroensis



 Spiral bryozoanBryozoans

This group look like plants and it takes a sharp eye to spot them. The name Bryozoa means “moss animal” and if you take a look at the mesh like structure of the Sea-mat you will see why. The individual animal is called a zooid which are tiny and are found in colonies. They have a a circle of tentacles around its mouth similar to anemone. Instead of stinging its prey like an anemone the zooids have small hairs called cilia. These hairs move rapidly to create water movement towards their mouths to bring in microscopic bacteria or algae to feed on.

 – Membranipora membranacea
Spiral bryozoan – Bugula plumosa



Seven armed starfishEchinoderms

The name means spiny skinned which is fairly obvious when you look up closely to one. There body is made up of bony plates and shows radial symmetry and has no front or back end. So the very agile (for this group) starfish will happily walk in any direction. Starfish can move around by using hydraulic set of tube feet.  Sea urchins are part of this group but unlike the softer more mobile starfish its bony plates are rigid and form a solid body called a test. They still use the same system of tube feet as starfish but they are longer. Sea cucumbers which do not look like they should belong in this group should be thought of as a stretched out starfish with out the arms.  Feather stars might be the hardest to identify as belonging to this group as they appear more plant like than animal.

Bloody henry – Henricia sp.
Common sea urchin – Echinus esculentus
Common starfish – Asterias rubens
Cotton-spinner – Holothuria forskali
Cushion star – Asterina gibbosa
Seven armed starfish – Luidia ciliaris
Spiny starfish – Marthasterias glacialis




Our coastal waters are home to a beautiful and diverse range of fish. From bottom dwelling flat fish to the free swimming pollack. They also come in a wide variety of shapes and sizes, from tiny two-spot goby to big chunky Ballan wrasse. The character of some fish can make them endearing to divers and snorkellers, like the jolly looking Tompot blenny. Some have wonderful colour mimicry talents to let them blend in and escape predators or to lay in ambush for unlucky prey.


Ballan wrasse – Labrus bergylta
Butterfish – Pholis gunnellus
Common dragonet – Callionymus lyra
Cuckoo wrasse – Labrus mixtus (male)
Cuckoo wrasse – Labrus mixtus (female)
Fifteen-spined stickleback – Spinachia spinachia
Greater pipefish – Syngnathus acus
Goldsinny – Ctenolabrus rupestris
Long-spined sea scorpion – Taurulus bubalis
Plaice – Pleuronectes platessa
Pollack – Pollachius pollachius
Tompot blenny – Parablennius gattorugine

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