It may look like a combination of a starfish, sea anemone and an octopus – but this is a feather star.
Feather stars are one of 550 living crinoid marine invertebrates in our oceans, most frequently found in the Indian Ocean. Though they could easily be mistaken for plants, these animals are known as echinoderms; part of the same family as sea urchins, starfish, and sea cucumbers. Incredibly, the first record of a feather star dates back 300 million years before dinosaurs walked the Earth.
Their arms grow in groups of 5, but some feather stars can have up to 150 arms and legs. They are able to move 5 centimeters per second, which doesn’t seem fast, but is important for their ability to survive. They use their “arm-like appendages” to collect their food, such as plankton.
Feather stars are a common food source for many other fish in the ocean, and can sometimes lose arms because of this. However, similarly to other crinoids, feather stars have the ability to regenerate limbs, as long as their central disk is left intact.
There are both male and female feather stars. The female feather stars lay eggs, and when they have been fertilized, they become swimming larvae. As they swim, they begin to develop a stalk and they attach to the ocean floor, leaving them to resemble sea lilies. However, once they have fully developed, they release from their stalk, becoming free-roaming crinoids.