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Dive Dry with Dr. Bill

#511: My Cup Coral Runneth Over

We've had one heck of a summer and fall with warm, toasty water that you almost didn't need a wetsuit to dive in. Despite being gone several months this year, I've already managed to notch more than 300 dives in my weight belt. Of course we all know nothing lasts forever (especially the things we want to!) and in the last week the water temperature has dropped several degrees.

I'm already dreaming of winter and the next dive trip I'll take... to WARM water! Yes, I may have to forsake the giant kelp in our temperate waters for the coral reefs of Bonaire, the Philippines and/or the Red Sea. It has been several years since I spent a good part of the winter down in Belize and Honduras diving off the Lindblad Expeditions eco-cruise ship. With the economy somewhat "stifled," especially mine, dive trips were not possible. However, I think I've perfected the printing of $100 bills and it only takes 20-25 of them to pay for each trip!

On a recent dive I decided to practice filming corals to get ready for the beautiful reefs. Yeah, right Dr. Bill... in your dreams! No actually right here in the Casino Point Dive Park. "But" you say "there are no coral here. The water is too cold." Well, you're wrong! There are no reef-building corals here. Those are the species that build the coral reefs I've dived on in Australia, Tahiti, Fiji and other tropical destinations. However, if you look very closely (or have better eyesight than I do) you will find we DO have coral right here in sunny southern California!

Coral are members of the Phylum formerly known as Coelenterata. Unlike Prince, they didn't decide to change their group's name... humans did it for them. We now know the critters with stinging cells as Cnidaria. They include the coral along with jellyfish (or sea jellies for the PC crowd), hydroids, gorgonians, sea anemones and the like. However, I've never felt any pain when dealing with our local coral. Their stinging cells (nematocysts) just don't seem to penetrate my thick skin.

Southern California is home to at least four species of what are known as cup coral. Three of them live lonely lives and are known as the solitary cup corals. These include the brown cup coral, cup coral and orange cup coral. I like to think of them as the rugged individualists of the corals. The brown cup coral is the one I see frequently in the dive park, but when I descend deep into colder water at places like Little Farnsworth I begin to see the more beautiful orange colored ones.

However, this column focuses on the colonial cup coral (Coenocyathus bowersi), a species that is gregarious like myself. A few weekends ago, I kicked out to the wreck of the Suejac in just a few minutes (shhh... don't tell anyone about the strong current that pushed this old geezer along). I was looking for those beautiful shell-less snails known as nudibranchs (and found one). However my mind strayed (as it usually does) and I ended up filming some of the colonial cup corals found on the leeward side of that hulk (not to be confused with the green Hulk you saw at your door on Halloween).

Colonial cup corals form clusters up to about six inches across and three inches high. The polyp or coral animal itself is a pinkish to orange color with small tentacles. Unlike many reef-building corals and even some of our local sea anemones, the cup corals do not appear to include tiny symbiotic algae within their tissues. When threatened, the polyp may withdraw into the protective stony cup. They feed by snagging tiny critters and organic matter out of the water column. To date I have never seen anything feeding on them, although I have seen colonies where the polyps appear to have died.

These corals are known from Monterey Bay to Baja and the Gulf of California (also known as the Sea of Cortez to those who love tales of bloody conquest). They are primarily found in caves on the sides of rocks (or wrecks). Their depth range is said to be 30 to 490 feet. I've seen them a bit shallower than that, but no way you'll get me diving down to confirm the maximum depth! Maybe James Cameron will loan me his deep diving submersible. While he's at it, maybe I can borrow Kate Winslet, too.

© 2012 Dr. Bill Bushing. Watch the "Dive Dry with Dr. Bill" underwater videos on Catalina Cable TV channel 29, 10:00 AM weekdays and on Charter Communications Cable channel 33 at 7:30 PM on Tuesdays in the Riverside/Norco area. You can also watch these episodes in iPod format on YouTube through my channel there (drbillbushing). Please help me climb out of self-imposed poverty... buy my DVD's (see this link). Yes, take Dr. Bill home with you... we'll both be glad you did!

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Reef-building coral from Belize and solitary cup coral showing stinging cells on tentacles; two colonial cup corals.

This document maintained by Dr. Bill Bushing.
Material and images © 2012 Star Thrower Educational Multimedia