Small pink jelly fish, Pelagica noctiluca, are floating in profusion in False Bay at the moment – beautiful to look at from the safety of one’s kayak, but not very inviting if one is wishing to have a dip! Mark Gibbons of the University of the Western Cape, who identified them for me, says: “Be careful, they have a potent sting! They also give off light when disturbed at night.” He said that the jelly fish have been brought in by the winds.
The stings are painful but generally not lethal.
Browsing through Youtube I found these two delightful videos of the jellyfish “dancing”- the music is great too!
The Pelagica noctiluca are found in the Mediterranean Sea and the Atlantic Ocean although they can survive in almost any waters. They have appeared in shoals up to 45km in length. They are carnivorous, feeding on zooplankton, small fish, crustaceans, other jellyfish and eggs, catching their prey with their tentacles which have barbed filaments on them containing toxins. Although the jellyfish themselves are small – up to 10cm in diameter -their tentacles are able to extend as far as 3m.
The jelly fish may keep swimmers out of the water but it appears that they might have a positive role to play as well:
“The chemical reactions causing their luminescence are currently of great interest to researchers. Other jellyfish are used for medical and therapeutic purposes, and Pelagia noctiluca might soon be helpful for humans. One possible use of their fluorescent protein is as a genetic marker to detect protein movement or gene expression in research in developmental, environmental and medical biology. (Manning1997)” http://animaldiversity.ummz.umich.edu/accounts/Pelagia_