Re-examining the stinger of the little star anemone hits the spot.
Live animal images and 3D computer reconstructions reveal the complex structure of this tiny biological needle-like weapon. The stinger is like a harpoon studded with stingers, Rapid transition on launchBiologists Matt Gibson, Ahmet Karabulut, and colleagues report on June 17 at Nature Communications.
Scientists can now see in detail “what the device looked like before, during and after launch,” said Gibson of the Stowers Institute for Medical Research in Kansas City, Missouri.
In the wild, the little star anemone (nematodes) can live in brackish lakes or shallow estuaries where freshwater rivers flow into the sea.Its tubular body burrows into the mud, a top tentacles like medusa Reach into the water and wait for dinner to float by (SN: May 7, 2013). Each tentacle radiates heat: hundreds of stingers could mean the death of brine shrimp or free-floating plankton.
These stingers are among the fastest micro-machines in nature. Kara Blut, also from the Storrs Institute, said anemones can stab a predator or eat some lunch in about a hundredth of a second. Scientists have an idea of how the stinger works, but until now, they’ve never been so close and personal.
The researchers used fluorescent dyes to observe the stingers in action and used scanning electron microscopy to reconstruct their three-dimensional structures. This work reveals the precise, step-by-step mechanism of fast shooters.
The poison wire contained in the stinger sac is wound around the central shaft. When triggered, the shaft explodes and extends from the pressurized chamber, turning inside out like a sock. Finally, the wire is passed up the shaft, feeding its barbs into the soft tissue of the animal.
Each stinger is only good for one shot. “It’s a one-hit wonder,” Karabulut said. “once nematodes Use it, it’s gone. “