Fish May Lose Their Jelly Friends in a Changing Ocean

In the open ocean, it's good to have friends. Some young fish like to buddy up with stinging jellies to stay safe from predators. Hiding under the shelter of a jellyfish's bell, they can grow up unharmed (as long as they dodge its tentacles). These fish include some species that humans rely on for food. But in a warming ocean, that buddy system may fall apart. Many types of fish take advantage of hop-on jelly trolleys. Ivan Nagelkerken, a marine biologist at the University of Adelaide in Australia, and his colleagues focused their new study on the fish living with one jelly in particular: the delightfully named blue blubber jellyfish, or Catostylus mosaicus. (The jellyfish in the photo above is not a blue blubber, but you can see some C. mosaicus in all their blubbery glory at the bottom of this post.) The scientists took advantage of a jellyfish bloom ...