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The most voracious predator in West Coast waters, from Alaska to California, is not the octopus, the killer whale or even the shark. It’s the sunflower star (Pycnopodia helianthoides), which will eat almost anything in its path, whether it’s a clam, sea urchin or a dead duck!

Nicole Cann, manager of interpretive delivery, chose the sunflower star to highlight for October’s Staff Pick of the Month because it’s an animal she got to know when she first started as a volunteer seven years ago. As part of her volunteer duties, Nicole regularly put on a Critter Corner program called “Predator Versus Prey,” which required her to demonstrate how the sunflower star eats.

Nicole Cann, manager of the Vancouver Aquarium’s interpretive delivery department, started as a volunteer seven years ago.

She says, “They look so cool and yet have deceptively simple bodies that are so different from our own. They’re also incredibly successful predators. It’s amazing!”

The sunflower star is the largest sea star in the world – growing up to one metre wide – and is the heaviest at five kilograms (about the weight of a bag of potatoes). It’s also the fastest animal on the ocean bottom, crawling almost two metres a minute, which may not seem that fast to us but is speedy if you’re a clam just chillin’ on the sand.

And because this sea star is best described with superlatives, you’ll be interested to know that it can have up to 26 arms (unlike the measly five of other sea stars) and 15,000 tube feet under them. No wonder it’s so speedy.

The sunflower star also uses those tube feet to pry a live clam (its favourite food) apart before pushing its stomach out of its mouth and inside the clam, digesting the hapless clam in its own shell (the sunflower star digests its food outside of its body).

Nicole says, “I think people are attracted to these alien-looking creatures but I don’t know if they truly understand how incredible these sunflower stars are!”

Well, now you do know just how incredible these unassuming spineless animals (invertebrates) are.

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5 Responses

  1. Skye Bartz

    Hi Nicole, I’m 10 and learning about invertibrae. I watched the sunflower video and want to learn more about the stomach eating the food. I would like to know if the stomach has acid like we do? Does the sunflower star have many predators?

    Thank you 🙂 Skye Bartz

    Reply
    • Vancouver Aquarium

      Hi Nicole, thanks for your note. To answer your question, when the sunflower sea star extends its stomach to eat its prey, it does use digestive enzymes to consume its food, which allows it to eat animals larger than even its own body size. Also, as with many other animals, the sunflower sea star does have predators (such as the King Crab), but as you can see, is a predator itself. Fascinating animal!

      Reply
  2. Suzie

    Is this the same sea star that they told us about on the news last night? They said It is destroying the Australian coral reef?

    Reply
    • Vancouver Aquarium

      Thanks for your question, Suzie. I believe you are referring to the crown-of-thorns starfish, which is what has been reported in Australia’s Great Barrier Reef.

      Reply

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