How this Teeny-Tiny Sea Critter hits like Mike Tyson

At less than a quarter of an inch long, the amphipod – a bark that looks a bit like a crayfish – lives its leisure life, sifting through algae up and down the east coast. Well, it is superficially to recreation, as scientists just discovered. A male amphipod wears a large claw that can be more than a third of its mass, and when it catches it in less than 10,000 seconds, it directs a fully accessible water jet to its delight. make known. Thanks to a $ 150,000 camera that shoots at 300,000 frames per second, researchers have for the first time captured male amphibians in the act, a lump so brutal that it is almost enough to do the animal exploded.

You may be wondering how to try to get away from a male amphipod – in particular, the sex Dulichiella cf. appendiculata. So let me tell you. Working in the laboratory, the researchers applied toothpaste to the animals’ backs, then attached the spines to “micromanipulators,” which allowed them to position the amphibians. All they had to do was hang single hair from a paintbrush near the amphibians, going against their personal space. And then, SNAP. “So they’re clearly using it in an aggressive context,” Duke University biologist Sheila Patek, coauthor of the paper, said.

With the ultra-fast camera rolling, Patek and her colleagues suddenly made the visibility visible. “In a way, it’s almost magical,” Patek says. Previously, you might not hear or feel an amphipod bump if you had one in a tray, not if you were picking up a ball in the country. “But then to focus on the whole thing, and beautifully lit, you suddenly see this little appendix filling the screen, loading and then sculpting,” she says. saying.

The critical part of that appendix is ​​called the dactyl, more formally known as gnathopod. In the image above, that is the long, blade-like structure at the top of the claw. It is no thicker than human hair. To snap, the amphipod contracts muscle, retrieving that dactyl and storing a lot of energy. Patek and her colleagues need to do more work to fully understand the morphology of how the snap works, but a latch seems to hold the dactyl in place. When the animal is ready to be trapped, it releases the latch, suddenly releasing the stored energy of the claw.

“And then when we look even further, we’re like, ‘Wait, yes water jet ‘Get out of there!’ Said Patek. More specifically, the force of the claw knot seems to push water at a right angle, rather than quite straight forward. “And then, oh my gosh, every once in a while, the water jet seems to cause cavitation, which is the formation of these valve bubbles, which occur when you flow at such incredible distances. “When these tiny cavitation bubbles fall, they will explosion, resolving an explosion of energy. This type of force is so powerful, in fact, that when boat propellers form their own cavitation bubbles, over time the force will chew away at the metal of the blade.