Species: Scolymia lacera
Not all hard coral grow to be great big structures. And while most coral are considered to be a colony of polyps—i.e., individuals living together—there are some that are quite solitary. Some of them, like the cup corals, live a bit differently than their cousins and distant relatives.
Atlantic Mushroom coral, or Scolymia lacera, is one of a few cup corals found in the Western Atlantic Ocean. In fact, they occasionally can be found in deep-reef environments and on reef walls in the waters around Florida, the Bahamas, and the Caribbean. They prefer well-lit areas on rocky surfaces and outcroppings, somewhere nice and stable with enough light to help out their zooxanthellae friends.
S. lacera varies in color from shades of light gray to green, blue-green, and brown. The few that I have seen while diving were a mix of blues and greens, almost like an alternating stripped pattern—though this isn’t the same of all individuals.
Unlike other coral, the whole structure that is S. lacera is made up of a single polyp. That’s right; this species of coral is not a colony like its other hard coral cousins. Instead, it is a single large, fleshy, roundish polyp that looks a bit rough around the edges—texture-wise, that is. The whole structure that you see is the corallite, or the skeletal cup in which an individual polyp sits in and can retract into. For S. lacera, the center of the corallite can be either flat or curved inward; rarely is it seen with a raised center.
The Atlantic Mushroom coral can grow to between 2.5 and 6 inches and is the only type of cup coral that you can identify in person if it’s larger than 4 inches in diameter. Any specimen smaller than 4 inches has to have its corallite structure examined for identification.
During the night and in turbid, cloudy conditions, the polys will extend their tentacles in the hopes of grabbing food.
I think these guys are really cool because they break the mold, so to speak, when it comes to most hard corals. Instead of being a colony of individuals, each structure is a single large individual. They’re also pretty neat to spot on the reefs because they can be these bright colorful spots amongst drab shades. When I first saw them I didn’t think they were coral. It wasn’t until I started taking classes and we discussed them that I learned what they were.
Reef Coral Identification: Florida, Caribbean, Bahamas 3rd edition Paul Humann and Ned DeLoach
https://coralpedia.bio.warwick.ac.uk/en/corals/scolymia_lacera <–At the time of posting this article, I hadn’t gotten the rights to share any photos of the coral, but you can see pictures of this species at the link–please take a look!