Scuba trip to Mindoro, Nov 2010 pt 7; Mysterious Feather Stars

In all my years of snorkeling I don’t recall ever noticing a feather star. I’m sure I must have seen them—they simply didn’t register during the limited observations I must have had of them from above. That changed on my very first dive; suddenly, feather stars became the prime undersea object of my attention. It’s as if they appeared to me out of thin air; or thin water if you will.

My first time down doing scuba, there at Coral Cove, I remember seeing feather stars everywhere, covering just about everything. Only honestly, I actually assumed they were some type of tropical sea plant. They certainly resemble a plant, a very remarkable varicolored leafy one. How could anything that resembles the epitome of a plant actually be an animal? Thus, I never suspected in the slightest that they were part of the animal kingdom.

Soon however, I began to have my suspicions that my initial presumption that the feathery looking things were not actually in the plant kingdom after all. From afar, I happened to see one floating next to a large coral formation, only it wasn’t just suspended there in the water; no, it appeared to be purposefully moving it’s feathery appendages. At that point it actually resembled some kind of animal to me, albeit a weirdly monstrous one. I mean, imagine if you will suddenly seeing a marigold hopping across the yard. See what I mean? It would be a really cool thing to see, but it would also certainly freak you out.



‘Hey, plants don’t do that!’

I was too far away from it to be sure, but it sure looked that way to me, like a swimming plant. It was right side up, as if in control of its position and place in the water, its arms moving rhythmically and persistently.

In the months ahead my observations of these sometimes floating (or swimming) life forms continued over the course of further dives. It wasn’t long before I learned to avoid touching them with any part of my body. During my first series of training dives I still assumed that they were a form of plant life, a prickly sticky one. Don and I oftentimes would stop to hover in place, and during the pause we’d unavoidably brush up against them; at which point one or more would opportunistically attach themselves to our arms or legs, sometimes to both. Next thing I knew I’d feel Don attempting to brush off the unwanted hitchhikers from where they had become affixed to my dive suit material. I didn’t mind them being on me like that, although it does kind of feel creepy; but in trying to remove them they always end up in a cloud of hundreds of disattached arms and tiny pieces.

‘Stupid things!’ I would swear regrettably.

I always feel bad seeing them float away in such a cruelly dissected condition, and with me not having any choice in the matter. Surely they aren’t able to survive such a traumatic dismemberment; although I later learned that the feathery multiple-armed thing is able to regenerate lost "branches" the same way a starfish does.

After returning from my first dive trip last May I borrowed a nature book from navy diver Tom. It contains hundreds of shots of all different sorts of undersea life. Paging through the thick book I finally found a photo of the mystery creature. I learned that these odd things are called feather stars and they really aren’t plants at all, but in the same phylum as starfish.

Feather stars are crinoids, along with a closely related multi-armed sibling creature called a sea lily, which resembles a feather star, only the sea lily has a stalk that attaches them to whatever surface they choose to live on. The stalk prevents sea lilies from swimming like feather stars, but interestingly, five years ago in 2005 a stalked crinoid (sea lily) was observed actually crawling at the rate of more than 2 feet per hour (Go Speed racer Go!) So, both sea lilies and feather stars have motility.

Some interesting facts about star feathers (crinoids):

• They have a mouth on their top surface completely surrounded by its feeding arms.

• With a U-shaped gut, their anus is located also on the topside of their central dorsal cup right next to its mouth. (So, its mouth and ass are side-by-side; I wonder if they ever get them confused?)

• These creatures were so numerous in ancient times that slabs of limestone hundreds of feet thick are found to be made up of countless layers of broken crinoid pieces.

• Feather stars are free-swimming; their arms, starting out with five, the same number arms that starfish have. Only feather star arms branch again and again in multiples of two, so that as they mature, they can generate up to two hundred by the time they are done.

• They eat by collecting small particles from the sea water with their feather like arms.

• The tube feet on its multiple arms use sticky mucus to collect tiny specks of floating food; the tube feet then pass the tiny particles into its ambulacral groove located down the length of each arm, where cilia continually push the particle infused mucus stream to the mouth for digestion.

• The different species of crinoids number in the hundreds (various sites claim anywhere from 450, up to 650 species), and include every conceivable color.

• Crinoids are the state fossil of Missouri.