We Need to Talk About Jellyfish

I cannot describe my feelings about Tim Flannery’s piece about jellyfish in the New York Review of Books without slipping into meaningless hyperbole, so please accept these quotes as textual evidence for why you’ve got to read it in full, you just really, really do. All emphases my own.

1. “Box jellyfish have bells (the disc-shaped “head”) around a foot across, behind which trail up to 550 feet of tentacles. It’s the tentacles that contain the stinging cells, and if just six yards of tentacle contact your skin, you have, on average, four minutes to live — though you might die in just two.”

2. “In November 2009 a net full of gigantic jellyfish, the largest of which weighed over 450 pounds, capsized a Japanese trawler, throwing the three-man crew into the ocean.”

3. “Salmon swimming in pens can create a vortex that sucks jellyfish in. Tens of thousands of salmon can be stung to death in minutes.”

4. “By 2002 the total weight of [the] Mnemiopsis [jellyfish] in the Black Sea had grown so prodigiously that it was estimated to be ten times greater than the weight of all fish caught throughout the entire world in a year. The Black Sea had become effectively jellified.”

5. “Off southern Africa, jellyfish have become so abundant that they have formed a sort of curtain of death, “a stingy-slimy killing field,” as Gershwin puts it, that covers over 30,000 square miles.”

6. “[Portuguese man-o-war and long stingy stringy thingies] are not, strictly speaking, organisms at all. Instead they are made up of collections of jellyfish species, the individuals of which are referred to as “persons” (as in food-catching persons, digestive persons, defensive persons, etc.) that function collectively like, and indeed appear to be, a single individual. And they can be enormous — up to 150 feet long.”

7. “Biologists characterize [Mnemniopsis] as a “self-fertilizing simultaneous hermaphrodite”…. It begins laying eggs when just thirteen days old, and is soon laying 10,000 per day.”

8. “Mnemiopsisis able to eat over ten times its own body weight in food, and to double in size, each day… Jellyfish “can eat anything, and often do,” Gershwin says. Some don’t even need to eat, in the usual sense of the word. They simply absorb dissolved organic matter through their epidermis.”

9. “The question of jellyfish death is vexing. If jellyfish fall on hard times, they can simply “de-grow.” That is, they reduce in size, but their bodies remain in proportion.”

10. “One kind of jellyfish, which might be termed the zombie jelly, is quite literally immortal.”

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