A is for Anemone

The ocean is home to more than a thousand species of sea anemone, showcasing an impressive variety of color. And though they inherited their name from a terrestrial flower, these colorful creatures are actually animals related to corals and jellies.

Some are barely the width of a battery and others stretch nearly 6 feet in diameter. At the base of an anemone's soft, cylindrical body is an adhesive foot. With this simple appendage, it can attach to substrates, such as rocks, coral or even the occasional crab shell—the ocean's version of a mobile home. If necessary, some can even detach and slowly move by sliding or flexing their muscular foot.

The soft-bodied sea anemone may appear delicate, but don't be fooled. It boasts unexpected predatory prowess. At the top of its tube-like body, a swirl of tentacles conceals a mouth.

Each tentacle is equipped with fierce stinging cells, called nematocysts. Triggered by touch, the nematocysts eject a spear-like filament into passing prey, injecting a debilitating neurotoxin. Once the target is rendered immobile, the anemone drags the ensnared fresh meal into its mouth.

Mussels, crabs, fish, shrimp and zooplankton all fall victim to the sea anemone's sting, but a few lucky fish have been able to avoid the toxic tentacles. Some clownfish, for example, are covered in a layer of protective mucus making them immune to the anemone's venom.