Halimeda Discoidea

I've always liked macroalgae; halimeda reminds me of a prickly pear cactus. Are the red edges part of the halimeda's coloration, or are they something else?

The red begins to develop towards the end of the plant's lifecycle. Eventually the particular segments will turn white and die, and a new plan will emerge from the holds still within the rock. Since it is calcium based, biologists say that much of the sand in and around coral reefs is made up of the remains of Halimeda species like this one.

BTW, remember to click to photo to see the enlarged full resolution image.

nice shot!

Thank you sir. It's hard to win these contests when you don't have an exotic subject matter. Maybe this umpteenth time is the charm for me.

nice picture