From the Super Mario Wiki
Electrified Anemones are life forms appearing in Donkey Kong Country: Tropical Freeze. They are grown on seafloor and other surfaces underwater, and can only be encountered in Amiss Abyss, a level from the game. They emit a soft purple glow in the dark.
Items, such as bananas and Banana Coins, are usually obscured by populations of Electrified Anemones. However, these are electrically charged and if the Kongs touch them, they lose a heart from their health meter. Electrified Anemones cannot be destroyed, but they are sensible to light and will retract immediately at its presence. The Kongs can corkscrew into a nearby school of bioluminescent fish to produce light and make the anemones retract, revealing the items they hide, if any. Electrified Anemones will grow back shortly after light disappears.