top of page


It’s officially the end of the week and boy howdy it’s time for a new Weird Biology article. This week’s subject is a pointy Indiana Jones tribute with a permanently adorable expression of existential dread. I just want to pat it on the dorsal fin and tell it everything is gonna be okay, it’s the-


The Bigeye Thresher Shark is a mediumish shark that can grow up to 13 feet long, fully half of which is taken up by its ridiculous sickle-shaped tail. That’s like, almost 7 feet of tail alone. It’s like if when God was handing out tails to animalkind, the Thresher Shark kept sneaking back into line and no one noticed until it was too late. These sharks usually weigh in at about 350 pounds, putting them firmly in the “do not wrestle this animal for any reason” category. (Most modern sharks are in this category except for the Wobbegong. Go ahead, fight a Wobbegong. It probably deserves it.)

Bigeye Thresher Sharks are sleek, vaguely torpedo shaped, and bright metallic purple. It’s like a pool toy came to life and decided to try an existence that didn’t involve being gnawed on by toddlers. But seriously, Bigeye Thresher Sharks are held as some of the most beautiful of all sharks! (Though all sharks are beautiful on the inside.) While they’re alive, anyway. The second a Bigeye Thresher Shark expires, its bright colors fade to a dull lifeless grey. Like Optimus Prime in that one movie that ruined your childhood. You know the one I’m talking about. Scientists still aren’t sure why this graying-out occurs, but theories include that it’s because these sharks are a bunch of freaking divas.

(Or they just don’t want people to use them for a 101 Bigeye Threshers sharkskin coat, which is understandable.)

Bigeye Thresher Sharks are found in tropical and temperate waters around the world, even the Mediterranean Sea! They avoid shallow coastal waters and their throngs of tourists, sticking to the open ocean. This is important because Bigeye Threshers do a lot of deep diving, even for a shark. (Or maybe they just really hate tourists.) The Bigeye Thresher Sharks spend their nights close to the surface, swimming around dreaming little shark dreams. But when the sun rises, they dive over 1,500 feet down into the water column to hunt. I guess even sharks have a morning commute. (No coffee for sharks, though!)

Aside from the massive farm-equipment tail, Bigeye Thresher Sharks are noted for the gigantic anime eyeballs which gave them their name. And it’s no joke- these honkin big look-spheres can be nearly four inches across! THAT’S RIDICULOUS. The Bigeye Thresher Shark uses these big ol’ peepers to spot prey in the dark depths of the ocean. The squid think they can hide, but they cannot. Because the Bigeye Thresher Shark is an accurate and devastating hunter who can chase down fish, squid, smaller sharks, and seabirds with speed and precision.

But I’ve saved the best for last! it’s time to finally disclose what that ridiculous tail is for, and why it deserves a Grim Reaper reference. Well, it’s very simple- that super-long tail is basically a biological bullwhip. And maybe that doesn’t sound so threatening! but in this case, the Bigeye Thresher Shark cracks its tail like a whip towards a school of fish hard enough to cause an underwater shockwave which basically liquifies any small animals unlucky enough to be in the way. It completely obliterates those poor fish, who never asked for this and probably have families. (It takes “shooting fish in a barrel” to a whole new level, that’s for darn sure.)

After commiting mass fish homicide with its overpowered nuke of a tail, the Bigeye Thresher Shark is free to scoot around and vacuum up the dead and dying fish. Success! This strategy is so effective that there are even stories of Bigeye Thresher Sharks using it against birds. No word on whether this is true or not, but I mean, it sounds like it COULD be. (And they do actually eat birds! So.) It’s easy to see why the shark puts up with having a stupidly long and unwieldy tail; the AoE attack makes it MORE than worth it.

And it’s because of this attack style that Bigeye Thresher Sharks are so widespread. But unfortunately, these incredible sharks actually do have a reason for making that terrified face: they’re under threat from human activity and listed as Vulnerable. Bigeye Thresher Sharks are often caught accidentally or even on purpose by longlines, even though they pose no threat to humans. (Except looking really weird, anyway.) These thresh princes of the sea need legal protections, and they need it soon. What other sea animal are we going to make Indiana Jones jokes about? Sea cucumbers? come on.



1. Thomas Alexander, Wikimedia Commons

2. NOAA Observer Program, Wikimedia Commons

3. Jun V Lao, Wikimedia Commons

bottom of page