1) A group of fish is called a school. A gathering of dolphins is a pod. Several otters makes up a romp. And an assemblage of jellies is a swarm or, better yet, a smack.
2) “Swarm” and “bloom” should not be used interchangeably when talking about jellies. A swarm refers to jellies that collect in one area as a result of strong winds or currents, whereas a bloom is a dense cloud of jellies caused by an actual spike in reproduction.
3) Jellies are 95 percent water.
4) Musician Frank Zappa is the namesake of one species of jelly,Phialella zappai. (For an explanation, see Smithsonianwriter Abigail Tucker’s story, “Extreme Jellyfish.”)
5) Though jellies are soft-bodied and lack a skeleton, making fossils rare, there is evidence that jellyfish predate dinosaurs by some 400 million years.
6) A historic moment for jellyfish came in May 1991, when 2,478 moon jelly polyps and babies were launched into space aboard the shuttle Columbia. Biologist Dorothy Spangenberg of the Eastern Virginia Medical School wanted to learn about how weightlessness affected the development of juvenile jellies. She monitored calcium loss in the jellies, which by extension could further scientists’ understanding of humans’ calcium loss in space.
7) Some jellyfish, such as blubber jellies, a delicacy in parts of Asia, are edible. A former colleaguewrote about her culinary adventure tasting jellyfish in Washington D.C.’s Chinatown.
8) Most jellyfish live anywhere from a few hours to a few months. But a species of jelly calledTurritopsis nutricula may be immortal. The jelly reportedly can play its lifecycle in reverse, transforming from an adult medusa back to an immature polyp.
9) Jellies have been known to eat other jellies.
10) The creatures lack not only bones, but heads, hearts and brains.
11) Researchers from the Monterey Bay Aquarium Research Institute surmise that cross jellies (Mitrocoma cellularia), common to Monterey Bay in the spring and summer, can “smell” prey through chemicals in the water.
12) A recent study found that four of the box jellyfish Tripedalia cystophora‘s 24 eyes always point up. The jellyfish looks through the water surface for tree branches. This way, it can swim towards mangrove swamps where it feeds.
13) GFP, a green fluorescent protein found in crystal jellies, has important medical applications. Mayo Clinic scientists recently inserted a version of GFP and a gene from a rhesus macaque known to block a virus that causes feline AIDS into a cat’s unfertilized eggs. When the kittens were born, they glowed green in ultraviolet light, indicating that the gene was successfully transferred. Biologist Osamu Shimomura won a Nobel Prize in Chemistry in 2008 for discovering GFP.
14) Jellyfish can sting even when they are dead. In 2010, about 150 swimmers at Wallis Sands State Park in New Hampshire were stung by the floating, 40-pound carcass of a lion’s mane jellyfish.