Diver And The Huge Nomura’s Jellyfish, Japan. Nomura’s Jellyfish, in all its graciousness, can tip the scales at 450 pounds. Photo by: Lucia Terui

Jellyfish are some of the most ancient and simple animals on the planet. These bizarre creatures have drifted through our oceans for over 500 million years. Photo by: Frederic Pacorel

Some jellyfish glow in the dark, which is called phosphorescence. Most jellyfish use their “lights” as a defense against predators. Photo by: Guillaume Grousset

Some jellies produce bright flashes to startle their attacker, while others such as siphonophores can either display a chain of light or release thousands of glowing particles into the water in order to confuse the predator. Photo by: unknown

Pink Jellyfish are a variety of jellyfish, stronger than their blue brethren, but weaker than green. Unlike other jellyfish, pink jellyfish only spawn in the ocean. Photo by: Alastair Pollock

The color of a moon jellyfish often changes depending on its diet. If the jelly feeds extensively on crustaceans,it turns pink or lavender. An orange tint hints that a jelly’s been feeding on brine shrimp. Photo by: Alexander Semenov

If a jellyfish is cut in two, the pieces of the jellyfish can regenerate and create two new organisms. Similarly, if a jellyfish is injured, it may clone itself and potentially produce hundreds of offspring. Photo by: Racho

Bluebottle Cnidaria jellyfish, Australia. Jellyfish don’t have brains, instead, jellyfish have nerve nets which sense changes in the environment and coordinate the animal’s responses. Photo by: Matthew Smith

Fluorescent jellyfish of dark waters. Photo by: Ali Ertürk

You may have heard that jellyfish are taking over the world’s oceans. However, there’s actually a good deal of debate about this issue among scientists. Photo by: Alexander Semenov

Sea turtle riding a jellyfish. Photo by: Super Jolly

Record numbers of the giant jellyfish, which live off plankton, have swarmed on the UK’s south-west coast this year. Photo by: Steve Trewhella