Ted Kinsman is a scientific photographer that specializes in creating images for books, magazines, and television. His particular areas of interest are in x-ray radiography, high-speed photography, Scanning electron microscopy, and time-lapse cinematography. His work has appeared in numerous books and magazines ranging from Discover Magazine to Forbes. Recently his work has appeared on Gray's Anatomy and CSI New York. In addition to running 
B.N. (Bobbie) Sullivan has a strong affinity for the sea and everything in it. She first learned to dive in 1970 and has since logged thousands of dives. A wish to document the marine life she encountered prompted her to learn underwater photography more than 20 years ago. More recently, she began to write about the marine life she has photographed. A research psychologist by profession, she approaches her subject matter with the mindset of a scientist, but targets her writing to a general readership in whom she hopes to foster an appreciation for the ocean and its inhabitants.
B Jefferson Bolender is Training Coordinator of the State of Arizona's
program for disability awareness and assistive technology. Through
her travels she always has a camera at hand to photograph everything
from people to technology and nature. As a teacher of elementary
education, special education and art, her interests include a wide
array of subject matter with an emphasis on documentation with an
artist's eye.
Steve Jurvetson enjoys rocketry and photography and especially the pursuit of both in the Black Rock Desert. Some action photos and video links can be found 
Alex Wild is a postdoctoral researcher at the University of Illinois at Urbana-Champaign where he works on the molecular phylogenetics of various groups of insects. He is also a part-time photographer whose images appear in such venues as Ranger Rick, Smithsonian, BBC Wildlife, and even ScienceBlogs.
Sea fans are among the most beautiful sights seen by divers. Gorgonian sea fans are Cnidarians that build colonies in branching formations that usually are fan-shaped, thus the common name.
Like the Nephtheid soft corals I wrote about recently here on Photo Synthesis, Gorgonians are octocorals: each polyp has eight pinnate tentacles which it uses to capture nutrients suspended in the water column. They are seen most often on reef crests, or jutting out from drop-offs or steep banks in locations where natural currents will sweep plankton and other organic nutrients across the polyps' tentacles.
Some sea fan species form colonies in a single plane, while others grow their branches in somewhat of a tangle. They come in quite an array of colors, most of which actually are the result of zooxanthellae that live in the structural tissue of the Gorgonian. Beyond giving them attractive coloration, zooxanthellae also produce nutrients through photosynthesis, which benefit the Gorgonians.
By the way, not all Gorgonians form fan-shaped colonies. Some families in this order form long, slender colonies, commonly known as Sea Whips -- but we'll save those for another time. Today I'd like to show you some close-up and macro photos of some Gorgonian sea fan species from several tropical locations around the world to illustrate some of the variability in the morphology of the colonies. (A brief description follows each photo.)
Above is a sea fan from the genus Melithaea, with its polyps open for feeding. The branches of sea fans in this genus tend to intertwine. This one was photographed at Bunaken Island, Indonesia.
The next sea fan, Acabaria sp., forms a fragile looking net-like colony. There are other species in this genus that form denser structures. This one was photographed in the Red Sea, off the coast of the Sinai Peninsula.
The above macro image shows a section of Subergorgia hicksoni, a species widely distributed throughout the Red Sea. This sea fan species is not so beautifully colored, but the colonies grow to an impressive size, very often measuring more than a meter in width. The fans are relatively flat, or gently curving. This species is dominant on many deep reefs in the Red Sea, whereas Acabaria spp. seem to prefer shallower depths.
This purplish sea fan is Gorgonia ventalina, photographed in the Cayman Islands. It forms a tight mesh, and grows in a single plane. G. ventalina is very common throughout the Caribbean Sea. In fact, the sight of this purple fan is almost a hallmark of Caribbean reefs. It tends to live in on patch reefs in relatively shallow water, so it is seen very frequently by divers and snorkelers.
The final photo, below, shows an entire colony of G. ventalina, photographed at West Caicos, in the Turks and Caicos Islands.
Life Science
Comments
Gorgeous! I am really enjoying your posts this month. There's a lot of serious design fodder in this post - thanks for the inspiration.
Posted by: Virginia | August 21, 2009 10:04 AM
Wow, those are stunning.
Posted by: Alex | August 21, 2009 1:02 PM
Virginia, thanks. I'm glad to know you're enjoying these images. Not to sound corny, but I think ol' Mother Nature has the most interesting design ideas around. Unfortunately most people don't get to see very many of the ones that are under the surface of the sea.
Alex, thank you very much.
Posted by: B. N. Sullivan | August 21, 2009 1:58 PM
Lovely, extraordinary images. It's been years since I've seen such fans in person; the wonderful photography took me back in my mind to a singular adventure of many years ago...one I am now more eager than ever to recapture sometime. Thanks so much!
Posted by: Greg Peterson | August 24, 2009 1:20 PM
Thank you, Greg. If these images have inspired you to get back into the water to see some sea fans in person again, then I feel gratified for having posted them.
Posted by: B. N. Sullivan | August 25, 2009 10:23 PM
the pictures are wonderful, indeed encourages to conserve our extremly rich biodiversity
Posted by: avnish chauhan | August 27, 2009 1:54 AM
Thank you, Avnish.
Posted by: B. N. Sullivan | August 27, 2009 1:32 PM
"Gorgonia"--"gorgon" is the Greek equivalent of "mermaid"--is there a story behind this name?
Posted by: Anon | August 27, 2009 9:09 PM
@ Anon - Actually (if I remember correctly), the Gorgons in Greek mythology were female entities that had snakes for hair. Medusa was one of the Gorgons. This is only a guess, but perhaps the Gorgonian corals, which include sea whips as well as sea fans, were so named because their branches resembled 'snakes for hair'? Compared to sea fans, the gross morphology of sea whips is much more suggestive of 'snakes for hair'.
(If some coral taxonomist out there would like to chime in on the origin of the name Gorgonian, please do so.)
Posted by: B. N. Sullivan | August 27, 2009 10:26 PM
The snake-haired sweeties are not necessarily *not* mermaids--a dear friend, a Greek writer, once chastised me that "Greeks do not do Disney"; their mermaids are not cute or romantic, but monstrous. "Gorgona" in modern Greek translates to "mermaid", but the cultural difference is why I used the phrase "Greek equivalent".
Alas, my dictionary suggests a less fanciful explanation than mermaids fanning themselves. Gorgonia, it says, is from the Latin, not the Greek. Gorgon or Gorgo-, in Latin, simply refers to coral. Given Latin's penchant for borrowing from Greek, one possibility is that coral is seen as being turned to stone (which, I suppose, in a sense, it is) as were any mortals who looked at a gorgon.
A fun bit of searching, though--thank you for the beautiful and inspiring photos!
Posted by: Anon | August 28, 2009 12:20 PM
I really enjoyed that, as always.
The discussion about the etymology of "Gorgonia".
Posted by: Jasbina Misir | August 31, 2009 1:16 AM