Scientists have, to date, identified approximately 1,000 species of anemone in seas and fresh water around the world. With the advent of technology to carry us deeper into the oceans and the recent discovery of deep-water reefs, many expect to find even more as-yet-unknown species of anemones and other marine life.
Anemones are invertebrates and belong to the same Phylum (Cnidarians) as jellyfish, hydroids and corals. While fossil records of soft-bodied animals are sparse, experts believe that the first anemone probably appeared some 650 million years ago and all species now identified originate from that single, ancient animal.
The anemones‘ physical appearances are very diverse. However, they all are without a body cavity, they are all filter feeders, and all have tentacles with stinging cells known as ‘nematocysts’ that contain neurotoxins. Some are quite mild, causing only a minor irritation, while others create a violent and sometimes deadly reaction. Anemones should never be deliberately touched and caution is the key to prevent accidentally brushing against one when wading, swimming, snorkeling, or diving.
Anemones, also known as “Flowers of the Sea” due to their plant-like appearance, are actually predatory animals and yet they form symbiotic, protective relationships with other marine life that has a natural immunity to their venom. Their coloration ranges from an almost transparent white to deep blood reds and purples.
There are tube-dwelling anemones that are frequently mistaken for feather duster worms. There is the Corkscrew Anemone whose name describes perfectly the dark green anemone’s curling tentacles. Upon close inspection of
a Corkscrew Anemone, one will generally find hiding within its tentacles immature Pedersen’s Cleaner Shrimp, while the adult shrimp are often found along the outer edges of its base waiting for a fish to stop by for cleaning.
There is the Giant Caribbean Anemone whose long, thick, gelatinous white tentacles often display bulb-like tips in pink, green, or yellow as they wave gracefully in the currents. When speaking of anemones, it is the Giant
Caribbean Anemone that is most frequently brought to mind for it is the one most often depicted on film.
Anemones spend most of their lives in the same spot, anchored to rocks and reefs with their large suction-cup like bases. Some anemones are found buried in sand with short, stubby tentacles barely visible from above as they
filter the water for food. Hermit crabs place anemones on their shells as protection from predators that avoid the anemones’ stings and swim on to find a safer prey. Anemones found in tidal pools sometimes decorate themselves with bits of shell, algae, and small pebbles as camouflage and protection.
The Giant Caribbean Sea Anemone pictured here was being battered about in surf on a rocky shore in the U.S. Virgin Islands. Since free-floating anemones are rarely seen, the author shot a few quick photos and encouraged the anemone to attach itself to her camera. She then swam far offshore to an almost pristine reef not visited by divers and held it in place until it firmly reattached. Several follow-up dives have found the anemone remains in place where it is thriving, and growing.