5 fun facts about jellyfish

We see millions of jellyfish all over the world floating around every day.

As a species, they pre-date dinosaurs.

But how do they work? How do they eat, reproduce and sting people and prey, especially since they don't have a brain or a heart?

Barbara MacDonald, external relations manager with Parks Canada on P.E.I., and Jesse Hitchcock, a biology graduate student at UPEI, have some answers to these questions and other fun facts.

1.Two types commonly found near P.E.I.

The Arctic red jellyfish is a red-purple colour and has long, stinging tentacles while the moon jellyfish is translucent white and has shorter tentacles.

Although they can contract their bell to help with motion, they mostlydrift wherethe current takes them. Swimaround or in the opposite direction of a jellyfish to avoid their stingers.

2. Rub sand on a sting

The reason jellyfish sting is that tentacles shoot a barb that contains venom.

The barbs are fragile and can be removed by rubbing sand.

The barbs can't penetrate our palms or the soles of our feet.

Stinging isbased on physical contact with the tentacles, meaningjellyfish can evensting after they are dead.

3. Jellyfish are 95% water

What is the other five per cent?The epidermis and the mesoglea ajelly-like substance.

4. No heart, no brain no problem

Jellyfish are aware of their surroundings through small sensory organs calledrhopalia. Therhopalia are aided by a co-ordinating "nerve net" on the bell.

But since jellyfish are carnivores they do have a mouth, which allows them to eat fish, plankton and even other jellyfish.

5. Mass spawning

Jellyfish are either male or female, and reproduce by releasing sperm or eggs into the water through a method called "broadcast," or mass spawning.

Their lives begin as polyps attached to the ocean floor waiting for the water to warm up.

Once that happens, they are released and begin floating around as ephyra before maturing into adults.

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