Sunday, 11 July 2010


Why are jellyfish different colours? I'm assuming that it's not some sort of display put on for the benefit of other jellyfish. Jellyfish don't have eyes, although some have a few light-sensitive cells that can distinguish light from dark. Come to think of it, they haven't got anything you could call a brain.

I don't think the different colours are camouflage, either. Jellyfish can be transparent, which is about as good a disguise as you can get, so I can't imagine that any additional colouration helps in this respect.

Maybe the colours are signals to warn off predators, like the yellow and black stripes of a wasp, but I really don't have a clue.

Answer to follow when I find it...

Picture courtesy of Malene Thyssen.