Small colonies of Elliptical Star Coral (Dichocoenia stokesi) can easily be confused with the similar Golfball Coral, although corallites of D. stokesi are usually more closely grouped, and can be more irregular in shape. This species is also a lot more common (in Anguillian waters at least) than its similarly appearing cousin, and grows to much more impressive sizes. The pictured colony, photographed in Shoal Bay East, was almost a third of a metre across and formed a perfect dome.
Looking closely at the featured image, you can see the tips of the polyp tentacles thinking about coming out to filter feed. This activity usually happens happens at night, and so by day the colonies resemble coloured rock. Extending out their tentacles (as seen in my recent post of Great Star Coral) the polyps sit in wait for passing plankton to come their way, which they then sting and consume. I have to say, plankton do get a bit of a raw deal.
Originally posted on Instagram @sea_anguilla with the text: Elliptical Star Coral just before sunset deciding if it’s time to wake up yet or not. These filter feeders spend the day tucked away in their protective calyces, only stretching out their little tentacles at night in the eternal search for food.