By Amy Maxmen
Steve Haddock remembers every detail about his first ocean encounter with a comb jelly. The open water was a bottomless deep blue. The animal, about the size of a tennis ball, shimmered with bioluminescence. “It was just cruising along like a hover craft,” says Haddock, a marine biologist at Monterey Bay Aquarium Research Institute in Moss Landing, Calif. “Comb jellies are more alien than any aliens people imagine,” he says.
Start with their appearance: The marine animals resemble translucent balloons rigged with flashing, colored lights. Some species glow. When startled, some flash electric blue. Vertical rows, or combs, made of hundreds of iridescent, hairlike cilia run the lengths of their globular bodies (thus the name comb jellies). In some species the cilia are 2 millimeters long — 200 times the length of cilia in other animals — and they beat in coordinated waves, propelling the jellies forward, backward and diagonally in search of prey.