Sea Anemones not as innocent as they appear

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Special thanks to Publisher of The North Island Eagle, Kathy O’Reilly
Originally printed Friday, August 31st in The North Island Eagle 

With all the smoke in the air this summer from the forest fires, our next creature feature might have been hard to spot unless you were getting your feet wet in a local tidal pool. Spongy, colourful, sticky, and deadly, the sea anemone is not as innocent as it appears.

Unlike the barnacle that we covered last time (which surprised many because it actually attaches to its host by its forehead and eats with its feet – gross!), the Actiniaria (or “Sea Anemone” as we local folk call it) is properly situated on its base by suction-cupping to a solid surface or sediment. With over 1,000 species in its family, large Sea Anemone can grow up to 2 meters in diameter and live in all oceans including tidal and sub-tidal zones.

Here on the West Coast if you are exploring local tidal pools you will most likely see green, purple, and sometimes white Anemones. If you walk up slowly, and don’t cast too much of a shadow over the little pool your standing beside, you can reach in slowly and gently touch the waving tentacles. The tentacles are comprised of thousands of tiny capsules called “stinging nematocysts”. You will notice they are slightly sticky and when you pull your finger away the mouth of the Anemone will rapidly close and suck in the tentacles you just let go (like a super sensitive trap); it’s a good thing you let go, because this is how they eat!

An Anemone is mostly carnivorous and has a digestive system that is adapted for live prey. As a marine predator, this plant like looking creature can eat a wide range of diets that include crabs, shrimp, plankton, fish, small muscles, acorn barnacles, other crustaceans, snails, chitons, and a host of other marine life.

Anemones are closely related to the jellyfish. Anemone “planula” larva can be broadcast into plankton and be carried far distances in ocean currents. Once settled and grown, Anemones are territorial and will engage in underwater combat to defend their turf against invaders that do not share their parent’s genetics. But in a weird twist, they also live in communities. When alone, with no members of the opposite sex for mating near-by, some species of Anemone can bud off a piece of their own base which then separates and grows into a new animal. This process looks like the Anemone is crawling in two different directions until it literally pulls itself apart! The result is two exact DNA copies of the parent – yes, officially a proper clone (insert super intense Star Wars music here).

So, when you are out this summer take a moment to get up close and personal with one of the ocean’s most amazing predators, the Sea Anemone. It might even give you memories of watching Little Shop of Horrors when you were a teenager. But unlike the human eating fly trap in the infamous show, I think one thing the Anemone would say if it could speak would be, “I am not a plant, I am a carnivorous predator, be afraid, very afraid!”

I’m still going to poke it though.

Bryce Casavant is a former BC Conservation Officer and Doctoral Candidate with Royal Roads University. He writes for the Eagle from his home on Vancouver Island. 

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