WIP Reef - Brain Coral

I've been so busy lately, working on a commission and other projects I've posted, that I didn't even realize until recently that it's been almost four months since I last worked on my coral reef! So now that the commission is done, I'm going to devote some serious time to this colored pencil project.

My most recent addition is a set of four brain corals (family Faviidae), a group of corals so named because they look like brains - round with swirls of ridges and valleys. The polyps organize themselves into the ridges. The color can vary with the species, though most often they appear greyish. They are a hard, sturdy coral that helps build reefs. The polyps of brain coral feed on the algae that live within them, small organisms that come into contact with them, or even other organisms that float by using long "sweeper tentacles." They feed at night.

I used apple green, cream, yellow ochre, light umber and dark umber.

References:
http://en.wikipedia.org/wiki/Brain_coral
http://www.wisegeek.com/what-is-brain-coral.htm