Happy Holidays from 'The Right Blue'

Wordless Wednesday
Watery Wednesday

On this not quite so Wordless, Watery Wednesday, we would like to say Happy Holidays to all of our readers. We are taking a short break, spending the holidays with family and friends away from home. We will resume sharing our underwater photos and telling our diving stories in the New Year. Meanwhile, we hope all of our readers are enjoying the holiday season, and we wish you all a very happy, healthy, and prosperous New Year.

About the Photo: We chose this image for our holiday post because we thought it looked festive. The photo, which was taken on a night dive in the Cayman Islands, shows a stand of Pillar Coral (Dendrogyra cylindrus) with its polyps extended for feeding. Nestled cozily in the coral is a kind of Polychaete worm called the Christmas Tree worm (Spirobranchus giganteus). The worm burrows into coral, and secretes a calcareous tube in which it lives. Only its pair of feathery 'Christmas Tree' shaped crowns are visible outside its tube. The feathery tentacles on the crowns trap tiny tidbits of food, and also are used for respiration.

The Christmas Tree worm can retract its crowns into its tube for protection. When the crowns retract, a structure called the operculum closes snugly over the tube like a lid or a little trap door. Christmas Tree worms come in lots of colors: red, orange, yellow, blue, and white. We also have seen a version that is striped!

It's Not a Maze, It's a Brain Coral

Wordless Wednesday
Watery Wednesday

What: Macro image of a Brain Coral (Diploria strigosa)

Where: I took this photo at Angelfish Reef, Grand Cayman.

Diploria strigosa
[Click on the photo to enlarge.]

Perceived Risk, and Point of View

by B. N. Sullivan

Our blogger friend Sheila Beal posted an adventure story (with pictures and a short video) on her Go Visit Hawaii blog earlier today. In the story she told about a thrill ride she and her husband tried during a recent visit to Kauai. It's called a zip line.

Here's Sheila:
When we approached the first zip line, a 170-foot “bunny” line, I got butterflies in my stomach and that internal chicken was obnoxiously loud. Our guides did a great job of giving us safety pointers and telling us what to expect. So, with excited reluctance, I climbed to the platform, allowed John to hook my harness to the line. I watched him pull on the harnesses and double check the connection for safety. I asked again what I needed to do and John kindly explained it all to me again. I said a prayer, took a deep breath, and ran off the platform. It was fun and I survived.
Sheila's husband took his video camera along on his zip line ride, filming a blur of foliage during the short, fast trip -- accompanied by a clearly audible yell that is part Tarzan, and part terror.

I left a comment on the blog, saying you could never get me to do that! Sheila replied that she thinks we are the brave ones, because we dive. Well, I suppose it's all a matter of perspective.

Hang glider at Waimanalo, HawaiiThis exchange reminded Jerry and me of an experience we had years ago, when we were still living on Oahu. One day we gathered up our dive gear and went to an area near the eastern tip of the island to dive. We entered the water from an area near Makapu'u Beach, right across the road from Sea Life Park.

As we were preparing to enter the water, we saw several hang gliders wheeling around in the sky directly overhead. This is not an uncommon sight in that area, since one of the favored launch sites for hang gliders is Kamehame Ridge, directly behind Sea Life Park. We could see the edge of the launch platform at the top of the very steep, very high cliff, and it always made us shudder to see someone launch, hanging onto what looked like a very flimsy kite. We'd always look at each other, shake our heads, and say how crazy those hang glider pilots were.

Well, on this particular day, we saw one of the hang gliders come in for a landing on a grassy patch, just steps from where we were wading ashore at the end of our dive. We had never seen a hang glider up close, so we took off our heaviest gear, and -- still wearing our wetsuits -- walked over to have a look.

The hang glider pilot was just beginning to disassemble his rig as we approached. He looked our way and said hello. We struck up a conversation, asking him lots of questions about the glider, about what the ride felt like, and so on. He raved about the experience of hang gliding, and was barely short of rapturous about the views he saw, and the sheer joy he felt while soaring. He said, "If you are interested, why don't you come on up to the ridge some time and try it. Several of our club members can give tandem rides."

As I recall, we literally backed away a bit as we shook our heads and told the guy that we couldn't imagine jumping off a cliff on a hang glider. Too scary! This prompted him to tell us, at some length, all the reasons why the sport was not nearly so risky as most people believed. Again we demurred, but said we might hike up to the launch site one day to watch from that vantage point -- we just didn't want to "make the leap", as it were.

The hang glider pilot threw his head back and laughed. He said, "I saw the two of you swimming in toward shore while I was descending. Scuba diving -- now THAT's a risky sport!"

Of course, that prompted us to go on at some length about how scuba diving really was not all that risky, as long as you were properly trained, followed your training, kept your equipment well-maintained, and so on. The hang glider pilot kept interrupting us with questions like, what if you run out of air; what if you get bad air in your tank; what if you see a big shark; what if a boat runs you down just as you are surfacing? It seemed that no matter what we said, there was no way we could convince the hang glider pilot that scuba diving was a safe sport.

A clear case of 'never the twain shall meet'? Or maybe a version of 'one man's meat is another man's poison'? Pick your metaphor, but the point is the same. Perceived risk depends on your point of view, and that in turn probably depends on what you have learned, either formally through training, or from experience.

We both are good swimmers, and we always have felt comfortable in and under the water, even in conditions that are not optimal. But we still wouldn't jump off a cliff on a hang glider -- and we will leave the zip line adventures to Sheila and Andy!

About the photo: Taken by Jodi Cobb for National Geographic, it is titled "Hang Glider, Waimanalo, Hawaii, 2000." Given the location, and the recognizable islet in the photo, the hang glider likely launched from Kamehame Ridge. The photo is available as a computer wallpaper. Click on the photo above to visit the page where you can download it for free.

For more photos of hang gliders launching from Kamehame Ridge, visit this page at Tim's great photography website, Pa'iki'i Imagery.

UPDATE Feb. 3, 2009: This article is featured in the February 2009 Carnival of Aloha, a blog carnival with a Hawaii theme, hosted by Evelyn at Homespun Honolulu. Go and have a look!

Commerson's Frogfish (Antennarius commerson)

by B. N. Sullivan

Antennarius commersonThis funny looking little guy is a frogfish. More precisely, this species is Commerson's Frogfish (Antennarius commerson). Although there are a number of frogfish species in Hawaiian waters, this is the one seen most often -- possibly because it is easier to see than the others! Most of the other frogfish species are so well camouflaged that they're almost impossible to spot.

Even though this individual is bright yellow, it can still go unnoticed on the reef. Since the shape of the fish resembles a lumpy blob, and it tends to remain still much of the time, it is easy to mistake it for a small sponge.

This species comes in a wide variety of colors: red, orange, yellow, gray, black and mottled. Over its life span, a frogfish can change color several times. According to ichthyologist Jack Randall of Hawaii's Bishop Museum:
The color of frogfishes is extremely variable; they generally match their surroundings very well. If the background color is changed, they may in a few weeks dramatically change color, as from red or yellow to black.*
Pretty good trick!

One of the interesting things about this fish is that its pectoral fins have evolved into limb-like appendages that have an "elbow" joint. The pectoral fins also are prehensile, that is, the fish can grab onto things with them. The frogfish uses its prehensile pectoral fins to hold onto the surface where it is perched.

Frogfish eat little crustaceans and other fish. They have really big mouths for their size, and they can engulf a fish longer than themselves. The frogfish family (Antennariidae) are among the fishes known as "anglerfish," because their first dorsal spine is adapted into a little lure that they can extend and wiggle above their mouths to attract prey.

Frogfish tend to have a very small range, since they don't swim around much. This means that once a diver has located a fish of this species, it's usually easy to find it again and again.

A Commerson's Frogfish can grow to about a foot (30 cm) in length, but the individual pictured on this page was quite small -- maybe two or three inches (5 to 7 cm). I photographed it at Puako, Hawaii.

* Quoted from John E. Randall's Shore Fishes of Hawaii (Vida, OR: Natural World Press), p. 43.

Nemo, Clowning Around

Wordless Wednesday
Watery Wednesday

What: Clownfish (Amphiprion ocellaris) -- the model for the cartoon character 'Nemo'
The anemone species is Heteractis magnifica.

Where: I took this photo at Sipadan Island, Malaysia.

Amphiprion ocellaris
[Click on the photo to enlarge.]

You can't touch this...

by B. N. Sullivan

...and you definitely can't swallow it!

That is the message that fishes in the Spiny Puffer family attempt to transmit to potential predators. While other creatures defend themselves from predators by fleeing, or hiding, or camouflage, members of this family (Diodontidae) inflate themselves. In addition, evolution has armed these guys with another feature: rigid spines all over their bodies that are erected when the fish inflates.

Ain't nobody gonna swallow these babies!

When Spiny Puffers are molested or feel threatened, they open their mouths and draw sea water into their stomachs, which are capable of expanding greatly -- so greatly that the stomach and its watery contents can virtually fill the whole fish, squishing the rest of its organs up against its backbone. Its skin is stretchy, which also helps it to expand like a balloon.

The Spiny Puffer's spines actually are like specialized scales. When the puffer is not inflated, most of the spines lie more or less flat against the skin, but when the skin stretches during inflation, the spines go upright.

Diodon hystrixBoth of the Spiny Puffers on this page are Caribbean species. I photographed them on two separate night dives in the Cayman Islands. Both photos are 1:2 macro shots. To give you an idea of their size, each of these fish was approximately 12-14 inches (30-35 cm) in length. [Click on either photo for a larger view.]

The common name of the fish in the top photo is 'Balloonfish' (Diodon holocanthus). This species has fairly long spines compared to the species in the second photo at left. The fish in the second photo is called the 'Porcupinefish' (Diodon hystrix). Its spines are really short and stubby compared to its cousin above.

Both fish pictured are partially inflated. Each was pottering along in a shallow reef area when we spotted them. In each case, Jerry shined his light on the fish so that I could approach closely and aim the camera. These are touchy critters, and that was enough to induce them to begin to inflate, so in each instance I snapped two frames and retreated before they freaked out.

Puffers are not very streamlined, even when they are not inflated, so they are not fast swimmers. Once they inflate they really are ungainly. Their little pectoral fins will flutter, but they don't attain much in the way of forward motion. To survive, they rely entirely on making themselves look unappealing as prey.

Some divers intentionally harass or even try to grab puffers, just to see them inflate. This is quite a mean thing to do. Remember, inflation is a defense. If the fish begins to inflate, that means it is alarmed. If it puffs out to its maximum, it is really scared! This behavior may be amusing to divers, but it really stresses the poor fish.

If you see a puffer and it begins to inflate, move away from it to let it know you are not a threat. Don't terrorize the puffers!