There are a number of different species that live in the sea that can cause injury by biting or stinging.
Marine creatures that sting include:
- sea anemones,
- sea urchins,
- cone snails,
- stone fish,
- stingrays, and
Hydroids are plant-like animals that are closely related to jellyfish.
Marine creatures usually sting as a defence mechanism against predators. Most people who are stung by sea anemones, stingrays, or jellyfish are stung as result of touching them, either on purpose or inadvertently.
Fortunately, in the seas around the UK, there are only a few types of marine creatures that sting. These include:
- weever fish,
- sea urchins, and
This article focuses on marine creatures that sting that are found in UK waters. If you are travelling abroad, it is a good idea to familiarise yourself with animals and plants that can cause injury in the countries that you are visiting.
The weever fish is a small, sandy coloured fish that usually lies buried in the sand on the seabed, waiting for prey to swim past.
Weever fish have poisonous spines on their back and gills. Most people are stung on their feet by weever fish after accidentally stepping on them.
Stingrays are flat, circular, or diamond-shaped, fish that have a long tail with a sharp, serrated barb underneath.
Stingrays are closely related to sharks and mostly live in the sea, although there are some that are found in fresh water. They often swim in shallow water and spend most of the time near the seabed buried in the sand.
As with weever fish, most stingray stings occur to the lower legs, ankles, and feet when a person accidentally steps on one in shallow water.
Sea urchins are small, circular creatures that have a bony shell that is covered with spines. They live in seas throughout the world and are commonly found in the shallows, on rocks and in seaweed.
The spines of sea urchins are sharp and hard and can cause puncture wounds. Between the spines, small organs, called pedicellaria, contain poison which is released as a defence mechanism.
Jellyfish are 'mushroom-shaped' creatures that have many long, thin tentacles on the underside of their bodies. The tentacles are covered with small poisonous sacs called nematocysts which, if touched, produce a nasty sting.
Jellyfish live in seas throughout the world and are found at a wide range of depths, although they often float near the surface. In recent years, during the warmer months, large swarms of jellyfish have become increasingly common in the seas around Europe, such as the Mediterranean.
Experts believe that the increase in numbers of jellyfish may be the result of increasingly warmer weather conditions combined with over fishing of their natural predators.
The Portuguese man-of-war is a large, poisonous, jellyfish-like creature, but it is not actually a jellyfish. As the treatments for the two species are different, it is important not to confuse them.
The Portuguese man-of-war is sometimes found in UK waters, and has a large, gas-filled bladder that is a purple-blue colour. It floats above the surface of the water and, like a jellyfish, has long, thin tentacles that hang below the water.
The sting of Portuguese man-of-war can be very painful, but it rarely causes death. If you come across one that has been washed up on the shore, you should avoid touching it because its tentacles remain venomous and can still sting you.