A small yellow fan that I picked up off the beach. The sea has been rough lately, and this little guy broke off from his footing and washed ashore. I'm guessing this fan to be four to six years old. There are some that are taller than I am, in deeper water, thirty feet and more, sometimes to 100 feet deep. ten to thirty meters, roughly. I have no idea how old they must be! Maybe even over a hundred years.
I love the patterns of the branches.
This is another fan that's lost the chalky covering on it's skeleton. Fans are made up of polyps just like stony coral. The polyps live embedded in this chalky layer that they grow, their bones! When the polyps are out feeding, the fan looks brownish, from the tentacles. I'll have to try to get a detailed photo on my next dive, tho' my camera isn't very good at extreme close-ups. These polyps are teenie tiny! They start out as eggs floating around, hatch, and in several weeks settle to the bottom hopefully finding a good place to stick and grow from. Each fan started out as one teeny tiny little critter that multiplied and gradually got bigger. The polyps do not separate, but form one living growing creature. Nothing on land to compare.
Another yellow fan, and the only purple one I found that day, it's kind of beat up from tossing in the surf. Before I had a good book that taught me that there are only two colors of fans, yellow and purple, I thought they came in lots of different colors. The purple is called 'Common' but sometimes is yellow, and the yellow is called 'Venus' but is sometimes purple!
It's fascinating how the fans grow around the edges, and as they keep going, the inside parts fuse together. Beautiful patterns! I've never seen an accurate drawing of these patterns, a project for me!
They grow flat, sideways to the waves coming into the shore, so they wave back and forth beautifully. The growth habit makes the seawater flow through the fan, so the polyps can catch the most food particles passing through.