Contact: Science Press Package American Association for the
Advancement of Science Are you ready for this jelly? Moon
jellyfish, Gijón Aquarium. Photograph by Julio Arrontes.
[Courtesy of José Luis Acuña and Julio Arrontes, University of
Ontario] There are places in the ocean where giant jellyfish
rule. They look like dinner plate-sized water balloons, hundreds
and sometimes thousands of them floating together. When people
catch too many regular fish like sardines or anchovies, they
leave behind an empty ocean neighborhood that the jellyfish move
into in a big way. But jellyfish are sort of the couch potatoes
of the ocean world. They swim, but not very fast. They find
their meals by bumping into food, rather than darting around and
searching for stuff to eat like a sardine does. So scientists
are wondering: will jellyfish rule for long in their new homes,
or will the quick and clever regular fish soon take back their
old neighborhoods? José Luis Acuña of the Universidad de Oviedo
in Spain and his fellow scien