by-the-wind-sailor

This strange and beautiful species is known as a hydroid. 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.