People tend to notice jellyfish only when they are a bother (stinging beachgoers or showing up in massive blooms) or a beauty (tamed in an aquarium case). Surprisingly little has been known about their wild lives, as Susan Milius describes in her feature "Seeing past the jellyfish sting," largely because they are difficult to study.
Now research is revealing aspects of their lives that are seldom appreciated. Some jellies are sophisticated hunters of the open ocean. Others harbor an array of hangers-on, serving as mobile mini-ecosystems. Leatherback sea turtles fatten up on jellyfish. These and other surprises about jellyfish serve as a reminder of all that people don’t know about ocean ecosystems, and of how shortsighted notions to intervene — a la jellyfish-killing robots — may turn out to be.