Gallery - Stuff that floats

By the Wind Sailor

This incredibly strange and beautiful species is known as a colonial hydroid. They are similar to the Portuguese man o war as they are made up of a colony of tiny individual animals. They are not true jellyfish.

Its characteristic sail gives the animal its name, 'by-the-wind-sailor'. The sail allows the organism to catch the wind and travel on ocean currents, using its stinging tentacles to prey on young fish and other small animals while it travels. They are at the mercy of the winds and so are usually found washed up in their hundreds, or sometimes even thousands, after stormy winter weather.

Portuguese Man of War (Physalia physalis)

When on the beach it looks like a balloon, often the tentacles have come off due to damage.DO NOT TOUCH THE TENTACLES AS HAS POWERFUL STING!

Barrel Jellyfish (Rhizostoma pulmo)

Commonly known as the barrel jellyfish, but also the dustbin-lid jellyfish or the frilly-mouthed jellyfish, it is found in the northeast Atlantic, and in the Adriatic and Mediterranean Sea. It is also known from the southern Atlantic off the western South African coast and into False Bay.

It is common in the Irish Sea. It typically is up to 40 cm (16 in) in diameter, but can exceptionally reach 90 cm (35 in), making it the largest jellyfish in British waters.

It is a favourite food of the leatherback turtle.

Blue Jellyfish (Cyanea lamarckii)

A typical looking jellyfish, with a dome-shaped bell and stinging tentacles trailing underneath. The bell colour depends on maturity and can vary from pale yellow to purple. Paler (younger) individuals are easily confused with the larger lion's mane jellyfish.

Compass Jellyfish (Chrysaora hysoscella)

A translucent yellowish-white jellyfish with brown markings around the fringe and on the top of the bell. Those atop the bell resemble a compass, with V shapes radiating out from a central point. They have a bunch of frilled oral arms below the bell and long thin marginal tentacles around the fringe of the bell.

Moon Jellyfish (Aureelia aurita)

A round, dome-shaped jelly, translucent with four purple circular markings around the centre. You can usually see these jellyfish floating just below the surface of the water.

© Simon Thurgood 2025
Images on this website may not be put as any part of any collection without any prior written permission.