02/07/2026
#12 Moon jellyfish. A walk along our strandline on Perranporth today will reveal many stranded Moon jellyfish, driven in by the recent strong winds and wave. Unfortunately for these jellies, they are poor swimmers and passively drift with ocean currents.😞
🌙These ethereal creatures take their name from their translucent, pale, dome-shaped bell that resembles a glowing, full moon.
They are about the size of a dinner plate, and are made of 95% water! The four distinct circles in the middle are their reproductive tissues. They lack the long potent stinging tentacles of other jellyfish, so don’t worry – they will only give you a mild sting!
Moon jellyfish eat tiny sea animals like zooplankton, small fish, and tiny worms. They catch them using a layer of sticky mucus on their bodies.
They are a major food source for leatherback turtles, sunfish, seabirds, and some sharks. Floating plastic bags in the sea look like these jellyfish, and can easily be mistaken for prey by sea turtles, causing a blockage in their stomachs.
Cornwall Wildlife Trust
