1. Featherstars are also called crinoids
While featherstars are more commonly seen by scuba divers there is another form of crinoid which is attached to the ground by a stalk.
2. They can be Stars or Lilies
The ones with a large stalk are called sea lily and the other ones featherstar. Sea lilies are usually deep-sea species and the stalk can reach up to one meter in lenght. Featherstars are free-living, but can mostly bee seen attached to rocks, coral or any other substrate.
3. They are not plants
Even that they do look a bit like plants, like so many other creatures underwater, they are animals. They belong to a marine animal class Crinoidea of the echinoderms. Other echinoderms are star fish, sea urchins and sand dollars.
4. The name means “lily form”
The name comes from the Greek words for “lily” krinon and “form” eidos.
5. Crinoids are living fossiles
And they were even more common back in the days (over 600 Million years ago).
6. They can be found all over the ocean
From the very shallow waters down to 9000 meters different types of crinoids can survive.
7. They have a U-shaped gut
The mouth is located on the top surface and due to an U-shaped gut the anus is just next to the mouth.
8. and no stomach
The oesophagus connects directly to the intestines.
9. What looks like feathers are feeding arms
The arms are used to filter small particles of food from the ocean. The food gets stuck in mucus on the surface from where it is transported to the mouth
10. There are about 600 different species
That’s quite a lot, isn’t it?!
11. Crinoids are upside down
At least compared to most other echinoderms.
12. They are not very romantic
There are female and male crinoids, but the sperm and eggs are just released into the surrounding water not involving any form of mating
13. They offer shelter for many different small critters
The ocean is a dangerous place for small animals. Throughout evolution they adapted to find a safe home and many found featherstars to be a great home. Among the creatures to be found on and around crinoids are shrimp, clingfish, squat lobster, ornate ghost pipefish and juvenile fish.