What: Macro image of a Brain Coral (Diploria strigosa)
Where: I took this photo at Angelfish Reef, Grand Cayman.
Where: I took this photo at Angelfish Reef, Grand Cayman.
BNSullivan.jpg)
[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:
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.
This 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!
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.
This 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
BNSullivan.jpg)
This 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:
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.
BNSullivan.jpg)
This 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
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.
The anemone species is Heteractis magnifica.
Where: I took this photo at Sipadan Island, Malaysia.
BNSullivan.jpg)
[Click on the photo to enlarge.]
Just Passing Through
What: A school of Heller's Barracuda (Sphyraena helleri)
Where: I took this photo off the coast of Puako, Hawaii.
Where: I took this photo off the coast of Puako, Hawaii.
BNSullivan.jpg)
[Click on the photo to enlarge.]
Air Sharing Pointers for Divers
by B. N. Sullivan
BNSullivan.jpg)
Basic diver certification courses all include instruction on air sharing. (For our non-diving readers, 'air-sharing' refers to more than one diver using the same air source.) This is a very basic and essential skill, and these days it is also quite easy, in principle.
Back in the day when I first learned to dive, SCUBA regulators only had one second stage, i.e., the part of the regulator that includes the mouthpiece. In order to share air, one diver had to take the regulator out of his/her mouth and hand it to the other diver. The second diver would take a breath or two, and then pass the regulator mouthpiece back to the first diver. This alternating pattern would continue until the divers could surface. The procedure worked, of course, but it could be quite awkward. Also, since neither diver could breathe continuously, both divers could end up experiencing considerable anxiety.
These days, most divers use regulators that have two second stages, each attached to its own low-pressure port on the regulator's first stage, i.e., the part that connects to the valve of the air cylinder. Look at the photo of our friend Dan on this page. You can see that his regulator has two second stages. The hose of the primary one passes over his right shoulder, and he is breathing through the mouthpiece. The hose of the secondary one passes under his arm, with the mouthpiece attached to his vest with a quick-release clip. This is a standard sport diving configuration.
In a popular alternative configuration, the inflator hose for the diver's buoyancy compensator has a mouthpiece on it so that it can double as a breathing device.
The advantage of using regulators with two second stages should be obvious: two divers can share the same air source simultaneously and continuously, without the need to pass the mouthpiece back and forth between them. This makes air sharing much easier, and is less anxiety-producing.
Divers are taught how to signal to each other that they need to share air, and the procedure of handing off the secondary regulator to the diver in need of air is practiced during training. They are taught that as soon as air sharing begins, the divers should begin their ascent together.
I take issue with this aspect of diver training. It seems to assume that the divers are right underneath their boat, or near to their exit point if they are shore diving. In real life, things are not often so tidy.
What happens if the divers are a good ten minute (or longer) swim away from their boat or exit point? What if they are near the deepest point of a deep dive? What if it is not prudent to surface immediately because of some other hazard -- e.g., boat traffic, or a strong surface current.
Over the years we have been in a few situations when we had to share air, and we have witnessed many other divers in such situations. Rarely, if ever, have these events happened right under a boat or very near to our exit point. Divers need to understand this and prepare for it, or they may find themselves in deep trouble (pun pointedly intended).
If the diver always stays very near to the boat or exit point, and doesn't go very deep, air sharing using the procedure taught in initial training, which I described above, probably will be sufficient. Otherwise, divers need to plan for -- and practice -- sharing air during a long swim, and during an ascent that may have to include a five minute 'safety stop' at 5 meters.
In order to facilitate swimming a longer distance while sharing air, one of the regulator's second stages should have a long hose. When divers are sharing air via a regulator with a 'standard' hose length of, say, 27 inches, they necessarily have to be very close to each other. It's difficult to swim while physically close to another diver, but that is what's required when both are sharing air and both are attached to the same air cylinder by relatively short hoses. It is much better to have a much longer hose on one of the second stages -- say 40 inches or even longer.
Won't a longer hose be a nuisance when not sharing air? Not really. You can do what cave divers do: bundle it and secure the bundle with a bungee cord. Alternatively, you can feed the longer hose under your right arm and across your front, securing the mouthpiece somewhere on the left side of your gear, instead of the right side where most divers stow their secondary reg mouthpiece. (Just be sure you show your buddy where it is before you begin the dive!)
By the way, if you do need to share air from a regulator using two shorter hoses, and you have to swim any distance, we figured out that it is easier to swim with one diver positioned above and a little behind the diver with the air supply. Imagine that the diver with the air source is going to give the air-sharing diver a piggy-back ride -- except the two divers swim, one a bit above the other. The 'top' diver can hold on lightly to the other diver's shoulder to maintain position and stay in place.
Now, a final note, but a very important one: practice. Practice air sharing while swimming longer distances. Practice air sharing while hovering at a depth of five meters as you would for a safety stop. (This is much easier to do if you have a regular dive partner, but even if you don't, get someone to practice with you from time to time.)
Ever since we began diving together, we have occasionaly practiced swimming at least ten minutes while sharing air. We also have practiced sharing air while hovering in place for a safety stop. We have done this exercise three or four times a year. Then one day, while we were more than a 10 minute swim from our exit point, and at a depth of about 120 feet (37 meters), a high pressure hose on my regulator popped. Oh the bubbly froth that instantly ensued! But there was no panic. Jerry passed his secondary reg mouthpiece to me right away, and turned off the valve on my air cylinder. The two of us set off toward our exit point, swimming easily together -- side by side, but with enough space between us that it was not at all awkward or cumbersome, thanks to a longer-than-standard hose length on Jerry's secondary reg. We even did a five minute safety stop before surfacing. Our practicing had served us well.
BNSullivan.jpg)
Basic diver certification courses all include instruction on air sharing. (For our non-diving readers, 'air-sharing' refers to more than one diver using the same air source.) This is a very basic and essential skill, and these days it is also quite easy, in principle.Back in the day when I first learned to dive, SCUBA regulators only had one second stage, i.e., the part of the regulator that includes the mouthpiece. In order to share air, one diver had to take the regulator out of his/her mouth and hand it to the other diver. The second diver would take a breath or two, and then pass the regulator mouthpiece back to the first diver. This alternating pattern would continue until the divers could surface. The procedure worked, of course, but it could be quite awkward. Also, since neither diver could breathe continuously, both divers could end up experiencing considerable anxiety.
These days, most divers use regulators that have two second stages, each attached to its own low-pressure port on the regulator's first stage, i.e., the part that connects to the valve of the air cylinder. Look at the photo of our friend Dan on this page. You can see that his regulator has two second stages. The hose of the primary one passes over his right shoulder, and he is breathing through the mouthpiece. The hose of the secondary one passes under his arm, with the mouthpiece attached to his vest with a quick-release clip. This is a standard sport diving configuration.
In a popular alternative configuration, the inflator hose for the diver's buoyancy compensator has a mouthpiece on it so that it can double as a breathing device.
The advantage of using regulators with two second stages should be obvious: two divers can share the same air source simultaneously and continuously, without the need to pass the mouthpiece back and forth between them. This makes air sharing much easier, and is less anxiety-producing.
Divers are taught how to signal to each other that they need to share air, and the procedure of handing off the secondary regulator to the diver in need of air is practiced during training. They are taught that as soon as air sharing begins, the divers should begin their ascent together.
I take issue with this aspect of diver training. It seems to assume that the divers are right underneath their boat, or near to their exit point if they are shore diving. In real life, things are not often so tidy.
What happens if the divers are a good ten minute (or longer) swim away from their boat or exit point? What if they are near the deepest point of a deep dive? What if it is not prudent to surface immediately because of some other hazard -- e.g., boat traffic, or a strong surface current.
Over the years we have been in a few situations when we had to share air, and we have witnessed many other divers in such situations. Rarely, if ever, have these events happened right under a boat or very near to our exit point. Divers need to understand this and prepare for it, or they may find themselves in deep trouble (pun pointedly intended).
If the diver always stays very near to the boat or exit point, and doesn't go very deep, air sharing using the procedure taught in initial training, which I described above, probably will be sufficient. Otherwise, divers need to plan for -- and practice -- sharing air during a long swim, and during an ascent that may have to include a five minute 'safety stop' at 5 meters.
In order to facilitate swimming a longer distance while sharing air, one of the regulator's second stages should have a long hose. When divers are sharing air via a regulator with a 'standard' hose length of, say, 27 inches, they necessarily have to be very close to each other. It's difficult to swim while physically close to another diver, but that is what's required when both are sharing air and both are attached to the same air cylinder by relatively short hoses. It is much better to have a much longer hose on one of the second stages -- say 40 inches or even longer.
Won't a longer hose be a nuisance when not sharing air? Not really. You can do what cave divers do: bundle it and secure the bundle with a bungee cord. Alternatively, you can feed the longer hose under your right arm and across your front, securing the mouthpiece somewhere on the left side of your gear, instead of the right side where most divers stow their secondary reg mouthpiece. (Just be sure you show your buddy where it is before you begin the dive!)
By the way, if you do need to share air from a regulator using two shorter hoses, and you have to swim any distance, we figured out that it is easier to swim with one diver positioned above and a little behind the diver with the air supply. Imagine that the diver with the air source is going to give the air-sharing diver a piggy-back ride -- except the two divers swim, one a bit above the other. The 'top' diver can hold on lightly to the other diver's shoulder to maintain position and stay in place.
Now, a final note, but a very important one: practice. Practice air sharing while swimming longer distances. Practice air sharing while hovering at a depth of five meters as you would for a safety stop. (This is much easier to do if you have a regular dive partner, but even if you don't, get someone to practice with you from time to time.)
Ever since we began diving together, we have occasionaly practiced swimming at least ten minutes while sharing air. We also have practiced sharing air while hovering in place for a safety stop. We have done this exercise three or four times a year. Then one day, while we were more than a 10 minute swim from our exit point, and at a depth of about 120 feet (37 meters), a high pressure hose on my regulator popped. Oh the bubbly froth that instantly ensued! But there was no panic. Jerry passed his secondary reg mouthpiece to me right away, and turned off the valve on my air cylinder. The two of us set off toward our exit point, swimming easily together -- side by side, but with enough space between us that it was not at all awkward or cumbersome, thanks to a longer-than-standard hose length on Jerry's secondary reg. We even did a five minute safety stop before surfacing. Our practicing had served us well.
Yellowbar Angelfish (Pomacanthus maculosus)
What: Yellowbar Angelifish (Pomacanthus maculosus)
Legend says that the yellow patch on this fish depicts a map of Africa.
Where: I took this photo in the Red Sea near Sharm el Sheikh, Egypt.
Legend says that the yellow patch on this fish depicts a map of Africa.
Where: I took this photo in the Red Sea near Sharm el Sheikh, Egypt.
BNSullivan.jpg)
[Click on the photo to enlarge]
Close-up of a Little Lionfish with a Big Eye
What: Hawaiian Lionfish (Dendrochirus barberi), a Hawaiian endemic species.
Sometimes called the Green Lionfish -- it looks green in natural light,
but when the camera strobe flashes, we discover that it actually is red!
Where: I took this photo at Puako, Hawaii.
Sometimes called the Green Lionfish -- it looks green in natural light,
but when the camera strobe flashes, we discover that it actually is red!
Where: I took this photo at Puako, Hawaii.
BNSullivan.jpg)
[Click on the photo to enlarge.]
Sharks in The Right Blue
BNSullivan.jpg "Whitetip Reef Shark (Triaenodon obesus)")
Judging from our traffic statistics, a lot of people look on the worldwide web for information about sharks and photos of these predator fish. The word 'shark' and phrases containing that word always are among the top keywords that bring search traffic to The Right Blue, month after month.Here is a directory of articles about sharks in The Right Blue:
- Have you seen any sharks? - August 10, 2007
- Have you ever seen a pregnant shark? - January 8, 2015
- On a collision course with critters in the sea - June 9, 2008
- Tiger Sharks Don't Floss - August 8, 2008
- The Day We Met the Landlord - August 9, 2008
- In case of shark attack... [Humor] - August 12, 2008
- On Sharks, Spearfishing, and Senseless Killing - January 18, 2009
- Whale Sharks: The biggest fishes in the ocean [with video] - February 26, 2010
- Whale Shark excitement on the Kona Coast [with video] - March 4, 2010
Here is a directory of shark photos in The Right Blue:
- Tiger Shark (Galeocerdo cuvier), swimming just below the surface of the water
- Pregnant Whitetip Reef Shark (Triaenodon obesus), two sharks: one pregnant and one not! - Celebes Sea: Pulau Sipadan
- Juvenile Whitetip Reef Shark (Triaenodon obesus), hiding under coral - Red Sea: Abu Kifan Reef
- Whitetip Reef Shark (Triaenodon obesus), resting on a reef slope - Celebes Sea: Pulau Sipadan
- Whitetip Reef Shark (Triaenodon obesus), swimming - Celebes Sea: Pulau Sipadan
- Whitetip Reef Shark (Triaenodon obesus), looking for lunch - Celebes Sea: Bunaken Island
- Whitetip Reef Shark (Triaenodon obesus), sneaking up behind an underwater photographer - Celebes Sea: Pulau Sipadan
Shark videos on The Right Blue:
- Whale Sharks (Rhincodon typus), with divers at Christmas Island, Indian Ocean
- Whale Shark (Rhincodon typus), with snorkelers on the Kona Coast of Hawaii
To Friends of 'The Right Blue' -- Thank You!
From time to time, one of our readers writes about one of our articles or photos and links to The Right Blue. Some of our fellow bloggers have given awards to The Right Blue. We list all of these on our blogroll page, but we admit we're not very good about passing them along.Today we would like to acknowledge and thank those who have given us recognition in the past few months, including (in chronological order):
- Gabriel at Live from Waterloo
- Lavender Bay at Voice of the Turtle
- 2SWEETNSAXY at Eyes Mind Heart (who gave us two awards!)
- Antigoni at Antigoni's Diary
- Chris at A Free Man
- Pua and Keoki at Best Hawaii Vacation Blog
- Sheila at Go Visit Hawaii
In addition, we'd like to recognize artist Carol Cooper who wrote a thoughtful piece on her blog, Compass WebWorks, about how photographers help all of us to see things in the world that we might otherwise not see, except Through Their Eyes. To illustrate her point, Carol used a macro photo of Bubble Coral, by Bobbie.And then there is ZJ, who writes The Sreisaat Adventures in Cambodia. ZJ and Bobbie are both regular Wordless Wednesday participants and have been visiting each other's blogs for at least a year now. Imagine what a surprise it was to visit her blog this past Wednesday to see that she had posted a photo she took of a shark, and had titled that post Emulating Bobbie! What a wonderful compliment!
We thank these blogger friends for thinking of us in such a positive way and expressing it. We also would like to thank all of our subscribers and regular readers, especially those who participate interactively with us by asking questions and leaving comments. Included in that group are the many participants in the Wordless Wednesday and Watery Wednesday photo memes who stop by each week.Special thanks goes to those who have submitted various pages on The Right Blue to StumbleUpon and Digg.
You are all 'true blue' Friends of The Right Blue!
So, we decided to give all of you our own Friend of The Right Blue award. If you like, you can put a Friend of The Right Blue badge on your blog's awards page or sidebar [we've made three different sizes], but regardless, please know that we appreciate all of you very much. We enjoy your virtual companionship, and we are grateful for your friendship and support. Thank you all so much!
Juvenile Shark in the Red Sea
What: Juvenile Whitetip Reef Shark (Triaenodon obesus).
Where: I took this photo at Abu Kifan reef, near Safaga, Egypt.
Where: I took this photo at Abu Kifan reef, near Safaga, Egypt.
BNSullivan.jpg)
[Click on the photo to enlarge.]
Napoleon Wrasse: The Video
Last month we did several posts about a big fish called the Napoleon Wrasse (Cheilinus undulatus). One was a story about some encounters with the Napoleon Wrasse, and the other two were photo posts: here, and here.
I came across a video on YouTube that shows a Napoleon Wrasse in the Red Sea. According to the videographer, it was shot just a few miles away from where I photographed the Napoleons.
Notice the 'ball-turret' eyeballs that I described in our encounter post. Two other things of note: at about 55 seconds into the video, note that a Remora (a.k.a. 'shark-sucker') appears and attaches itself to the Napoleon's underbelly where it remains for the rest of the video; and beginning at about 1:53, there is a patch of fire coral visible in the left foreground the the video frame. (Long-time readers will recall that we discussed fire coral about a year ago on The Right Blue, and followed up with a photo of the most typical Red Sea fire coral, the same species seen in the video.)
Here's the video. [Tip: Turn off your sound if you don't like Frank Sinatra!]
If the video does not play or display properly above, click here to view it on YouTube.
Tip of the hat to frostcl for posting this video of the Napoleon Wrasse on YouTube for all of us to enjoy.
I came across a video on YouTube that shows a Napoleon Wrasse in the Red Sea. According to the videographer, it was shot just a few miles away from where I photographed the Napoleons.
Notice the 'ball-turret' eyeballs that I described in our encounter post. Two other things of note: at about 55 seconds into the video, note that a Remora (a.k.a. 'shark-sucker') appears and attaches itself to the Napoleon's underbelly where it remains for the rest of the video; and beginning at about 1:53, there is a patch of fire coral visible in the left foreground the the video frame. (Long-time readers will recall that we discussed fire coral about a year ago on The Right Blue, and followed up with a photo of the most typical Red Sea fire coral, the same species seen in the video.)
Here's the video. [Tip: Turn off your sound if you don't like Frank Sinatra!]
If the video does not play or display properly above, click here to view it on YouTube.
Tip of the hat to frostcl for posting this video of the Napoleon Wrasse on YouTube for all of us to enjoy.
Halloween Special: An Underwater Gravestone
What: Marker placed on a reef in honor of someone who met his death there
(or so we were told).
Where: I took this photo at Ras Mohammed, near the tip of Egypt's Sinai Peninsula.
(or so we were told).
Where: I took this photo at Ras Mohammed, near the tip of Egypt's Sinai Peninsula.
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Happy Halloween!
Dotted Sea Slug from the Mediterranean
by B. N. Sullivan
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Today we present the next example of 'Exotic Underwater Nudies' -- our series on nudibranchs (a.k.a. sea slugs) from around the world. This particular nudibranch lives primarily in the Mediterranean Sea. Its usual common name is the Dotted Sea Slug. Its scientific name is Peltodoris atromaculata -- but it used to be called Discodoris atromaculata. More on this below.
We have seen this species frequently along the coasts of both mainland Greece, in the Greek islands in the Aegean Sea, and Crete. We also have seen this species in the waters around Cyprus. It reportedly exists in many other areas of the Mediterranean region as well, including the Adriatic Sea.
Let's have a look at this nudibranch. Keep in mind that the images displayed here are macro photos. This nudibranch is actually about two inches (5 cm) long. You can click on any of the photos to enlarge them. (Note: The photos on this page all were taken near Cape Sounion, Greece).
The first two photos are of the same individual. The first shows the creature at rest. You can see how it got its common name, Dotted Sea Slug. By the way, the exact pattern and shape of the 'dots' on these nudibranchs is unique for each individual. They are similar enough to recognize that individuals belong to the same species, but they are not identical.
BNSullivan.jpg)
The second photo shows the underside of this creature. (Yes, I flipped it over on purpose so that I could photograph its underpinnings, but I then returned it to its original position before I swam away.) You can see the creature's 'foot' -- the muscular structure that it uses for locomotion -- and you can see how the mantle extends like a skirt to obscure the foot when the animal is in its normal position.
Like many nudibranchs, this species feeds on sponges. For a long time it was thought that it fed preferentially on only one sponge species, but then better and more refined methods of study revealed that it did indeed feed on at least a second sponge species, and it is possible that there may be others in its diet as well, at least occasionally.
The third photo shows the nudibranch on a sponge, Petrosia ficiformis. There is evidence that the nudie has been munching away at it for some time. These nudibranchs eat by scraping off the top layers of the sponge's tissues with their mouth parts. The scars on the sponge may eventually heal over, at least partially.
BNSullivan.jpg)
Now, about the name. Regular readers of The Right Blue know by now that we like to give the scientific names of the critters we write about or show in our photos, because common names often vary from one location to the next, and certainly from one language to the next, while the scientific name is standardized: it is the same for a given species across languages and locations. When we know and use a creature's scientific name, we can be sure that we are all talking about the same thing.
Sometimes, though, the scientific name can change, too. By this I do not mean to suggest that different scientific names are used in different locations haphazardly. Instead, creatures sometimes are re-named. That is the case with the Dotted Sea Slug.
When a new species is discovered, its anatomy is carefully examined in order to classify it. In the old days, this meant dissection in a laboratory so that its organs and other structures could be assessed for how similar or different they were to those of other, known, species. This is still done, of course, but more recently -- thanks to both the accumulation of knowledge and the development of more advanced methods and instruments -- much finer details about a creature's anatomy can be determined. In short, taxonomists (i.e., those whose job it is to categorize life forms) now can identify differences that were not visible before. One animal may 'look like' another at first glance, but when their cellular structures are examined and compared, for example, we may find significant differences that set one apart from the other in important ways.
Renaming a creature is not done on a whim. Rather, it happens when important new information about a creature becomes available some time after it was originally categorized and named. Discovery of sufficient anatomical differences may lead to re-assigning the creature to a different group or, in some cases, establishing an entirely new classification for it.
As best I can tell from what I have read, at the time this nudibranch was discovered and first described, in 1880, it was classified as a Dorid nudibranch, belonging to the genus Discodoris. It was given the scientific name Discodoris atromaculata. It kept that name for more than 100 years. Then, in the late 20th century, taxonomists using more refined methods began to notice anatomical features that seemed to distinguish this species from others in the genus Discodoris, and placed it instead in the genus Peltodoris. Slowly, the literature on this species is being amended to reflect the re-naming. Meanwhile, it is possible to search on either name and come up with information about the same critter.
Confused yet? Oh dear, I thought so. Don't worry -- there won't be a test!
BNSullivan.jpg)
Today we present the next example of 'Exotic Underwater Nudies' -- our series on nudibranchs (a.k.a. sea slugs) from around the world. This particular nudibranch lives primarily in the Mediterranean Sea. Its usual common name is the Dotted Sea Slug. Its scientific name is Peltodoris atromaculata -- but it used to be called Discodoris atromaculata. More on this below.We have seen this species frequently along the coasts of both mainland Greece, in the Greek islands in the Aegean Sea, and Crete. We also have seen this species in the waters around Cyprus. It reportedly exists in many other areas of the Mediterranean region as well, including the Adriatic Sea.
Let's have a look at this nudibranch. Keep in mind that the images displayed here are macro photos. This nudibranch is actually about two inches (5 cm) long. You can click on any of the photos to enlarge them. (Note: The photos on this page all were taken near Cape Sounion, Greece).
The first two photos are of the same individual. The first shows the creature at rest. You can see how it got its common name, Dotted Sea Slug. By the way, the exact pattern and shape of the 'dots' on these nudibranchs is unique for each individual. They are similar enough to recognize that individuals belong to the same species, but they are not identical.
BNSullivan.jpg)
The second photo shows the underside of this creature. (Yes, I flipped it over on purpose so that I could photograph its underpinnings, but I then returned it to its original position before I swam away.) You can see the creature's 'foot' -- the muscular structure that it uses for locomotion -- and you can see how the mantle extends like a skirt to obscure the foot when the animal is in its normal position.Like many nudibranchs, this species feeds on sponges. For a long time it was thought that it fed preferentially on only one sponge species, but then better and more refined methods of study revealed that it did indeed feed on at least a second sponge species, and it is possible that there may be others in its diet as well, at least occasionally.
The third photo shows the nudibranch on a sponge, Petrosia ficiformis. There is evidence that the nudie has been munching away at it for some time. These nudibranchs eat by scraping off the top layers of the sponge's tissues with their mouth parts. The scars on the sponge may eventually heal over, at least partially.
BNSullivan.jpg)
Now, about the name. Regular readers of The Right Blue know by now that we like to give the scientific names of the critters we write about or show in our photos, because common names often vary from one location to the next, and certainly from one language to the next, while the scientific name is standardized: it is the same for a given species across languages and locations. When we know and use a creature's scientific name, we can be sure that we are all talking about the same thing.Sometimes, though, the scientific name can change, too. By this I do not mean to suggest that different scientific names are used in different locations haphazardly. Instead, creatures sometimes are re-named. That is the case with the Dotted Sea Slug.
When a new species is discovered, its anatomy is carefully examined in order to classify it. In the old days, this meant dissection in a laboratory so that its organs and other structures could be assessed for how similar or different they were to those of other, known, species. This is still done, of course, but more recently -- thanks to both the accumulation of knowledge and the development of more advanced methods and instruments -- much finer details about a creature's anatomy can be determined. In short, taxonomists (i.e., those whose job it is to categorize life forms) now can identify differences that were not visible before. One animal may 'look like' another at first glance, but when their cellular structures are examined and compared, for example, we may find significant differences that set one apart from the other in important ways.
Renaming a creature is not done on a whim. Rather, it happens when important new information about a creature becomes available some time after it was originally categorized and named. Discovery of sufficient anatomical differences may lead to re-assigning the creature to a different group or, in some cases, establishing an entirely new classification for it.
As best I can tell from what I have read, at the time this nudibranch was discovered and first described, in 1880, it was classified as a Dorid nudibranch, belonging to the genus Discodoris. It was given the scientific name Discodoris atromaculata. It kept that name for more than 100 years. Then, in the late 20th century, taxonomists using more refined methods began to notice anatomical features that seemed to distinguish this species from others in the genus Discodoris, and placed it instead in the genus Peltodoris. Slowly, the literature on this species is being amended to reflect the re-naming. Meanwhile, it is possible to search on either name and come up with information about the same critter.
Confused yet? Oh dear, I thought so. Don't worry -- there won't be a test!
Smile for the Camera, Mr. Moray
What: Close-up portrait of a Yellowmargin Moray eel (Gymnothorax flavimarginatus).
Where: I took this photo off the coast of Puako, on the Big Island of Hawaii.
Where: I took this photo off the coast of Puako, on the Big Island of Hawaii.
BNSullivan.jpg)
[Click on the photo to enlarge.]
Divers, Cover Yourselves!
by B. N. Sullivan
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For the past few months, virtually all of our posts here on The Right Blue have focused on interesting species of marine life we have come to know. Feedback on those articles has been positive: our readers seem to enjoy learning about creatures that inhabit the sea. But we also have been nudged by a few readers to get back to writing about diving -- as in, "Enough with the critters, already. Get back to diving stories!"
Well, okay then. How about some tips for divers?
Over the course of a few decades of diving, we have learned a number of useful things that, for one reason or another, are not taught to divers in formal training courses. The first is a simple rule that usually does not occur to divers until after they have had a bad experience or two. Cover yourselves!
In colder water, divers must cover themselves in drysuits or heavy wetsuits in order to retain body heat. But we believe that divers should be completely covered even when diving in warm tropical locations. These days, there are plenty of lightweight dive suits designed specifically for use in warmer waters.
We see many, many divers here in Hawaii -- mostly (but not only) tourists -- who seem to think that because they are in the tropics, they should just wear a shortie suit. We see them jumping into the water with their arms and legs exposed. Worse yet, some wear no dive suit at all, donning their dive equipment right over their bikinis. Guess what happens? Sooner or later, they get wounded!
It is very easy to brush against something -- a rock, a coral head -- even when you are trying to be careful not to touch anything. Sometimes it happens because the diver is not paying attention. Other times there is a little surge, just at the wrong moment. In any case, sooner or later some part of your exposed anatomy will collide, however briefly, with something in the water, and you will get cut or scraped.
In addition to those kinds of bumps and scrapes, it happens that there are many critters in the water that can bite or sting. Some are very tiny -- stinging plankton so small that you cannot see them in the water column -- so you cannot take evasive actions. Other are big enough to spot -- jellyfish come to mind -- but even then, you run a risk of being stung. Just because you see the critters doesn't mean you can count on completely avoiding contact.
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The best way to prevent many of these inadvertent stings and scrapes is to wear a full suit that covers you from your wrists to your ankles. Wear boots or neoprene booties inside your fins. And wear gloves.
Now, we know that many dive operators discourage or even prohibit divers from wearing gloves. We also know the reason for that: they don't want to encourage divers to pick things up or handle them, and they figure if the divers are not wearing gloves, they may be less inclined to touch things.
Fair enough, but short-sighted. There are just too many situations where the protection afforded the diver by gloves outweighs the momentary protection of the reef and its critters afforded by bare-handed divers.
We think of it like this: we're grown-ups. We know we shouldn't recklessly handle things that dwell underwater. We know that touching corals (and many other things) can damage them. We promise we won't do that -- not because our hands are bare, but because we know better.
At the same time, what happens if we are shore diving and need to grab onto rocks at our exit point? We can very easily get cuts and scrapes on our hands, that's what.
If we are diving from a boat, what happens when we need to hang onto a mooring line or an anchor chain in order to remain stationary for our safety stop? Lines and chains that have been in the water for awhile are certain to be covered with algae, hydroids, and even teeny-tiny crustaceans. If you don't believe me, just have a look at the second photo on this page -- a 1:1 macro shot of an actual mooring line, totally encrusted with an entire ecosystem of its own! Hanging onto such a line is going to disrupt some of those things anyway, regardless of whether your hands are bare or gloved. But hanging on with a bare hand will really hurt. Said teeny-tiny crustaceans will cut your hand like little razors, and if you happen to grab onto a hydroid, you will know it, believe me. They sting like a son-of-a-gun -- and you will never forget the experience!
So then, even if you don't want to wear gloves for the entire dive, do carry a pair in your pocket at all times, just in case you have to hold or grab onto something for your own safety.
Dive like grown-ups. Cover yourselves completely to protect yourselves from scrapes and stings; but at the same time, do keep in mind that being covered (and thus protected) does not excuse you from responsibility for avoiding physical contact with the reef and the creatures that call it home.
BNSullivan.jpg)
For the past few months, virtually all of our posts here on The Right Blue have focused on interesting species of marine life we have come to know. Feedback on those articles has been positive: our readers seem to enjoy learning about creatures that inhabit the sea. But we also have been nudged by a few readers to get back to writing about diving -- as in, "Enough with the critters, already. Get back to diving stories!"Well, okay then. How about some tips for divers?
Over the course of a few decades of diving, we have learned a number of useful things that, for one reason or another, are not taught to divers in formal training courses. The first is a simple rule that usually does not occur to divers until after they have had a bad experience or two. Cover yourselves!
In colder water, divers must cover themselves in drysuits or heavy wetsuits in order to retain body heat. But we believe that divers should be completely covered even when diving in warm tropical locations. These days, there are plenty of lightweight dive suits designed specifically for use in warmer waters.
We see many, many divers here in Hawaii -- mostly (but not only) tourists -- who seem to think that because they are in the tropics, they should just wear a shortie suit. We see them jumping into the water with their arms and legs exposed. Worse yet, some wear no dive suit at all, donning their dive equipment right over their bikinis. Guess what happens? Sooner or later, they get wounded!
It is very easy to brush against something -- a rock, a coral head -- even when you are trying to be careful not to touch anything. Sometimes it happens because the diver is not paying attention. Other times there is a little surge, just at the wrong moment. In any case, sooner or later some part of your exposed anatomy will collide, however briefly, with something in the water, and you will get cut or scraped.
In addition to those kinds of bumps and scrapes, it happens that there are many critters in the water that can bite or sting. Some are very tiny -- stinging plankton so small that you cannot see them in the water column -- so you cannot take evasive actions. Other are big enough to spot -- jellyfish come to mind -- but even then, you run a risk of being stung. Just because you see the critters doesn't mean you can count on completely avoiding contact.
BNSullivan.jpg)
The best way to prevent many of these inadvertent stings and scrapes is to wear a full suit that covers you from your wrists to your ankles. Wear boots or neoprene booties inside your fins. And wear gloves.Now, we know that many dive operators discourage or even prohibit divers from wearing gloves. We also know the reason for that: they don't want to encourage divers to pick things up or handle them, and they figure if the divers are not wearing gloves, they may be less inclined to touch things.
Fair enough, but short-sighted. There are just too many situations where the protection afforded the diver by gloves outweighs the momentary protection of the reef and its critters afforded by bare-handed divers.
We think of it like this: we're grown-ups. We know we shouldn't recklessly handle things that dwell underwater. We know that touching corals (and many other things) can damage them. We promise we won't do that -- not because our hands are bare, but because we know better.
At the same time, what happens if we are shore diving and need to grab onto rocks at our exit point? We can very easily get cuts and scrapes on our hands, that's what.
If we are diving from a boat, what happens when we need to hang onto a mooring line or an anchor chain in order to remain stationary for our safety stop? Lines and chains that have been in the water for awhile are certain to be covered with algae, hydroids, and even teeny-tiny crustaceans. If you don't believe me, just have a look at the second photo on this page -- a 1:1 macro shot of an actual mooring line, totally encrusted with an entire ecosystem of its own! Hanging onto such a line is going to disrupt some of those things anyway, regardless of whether your hands are bare or gloved. But hanging on with a bare hand will really hurt. Said teeny-tiny crustaceans will cut your hand like little razors, and if you happen to grab onto a hydroid, you will know it, believe me. They sting like a son-of-a-gun -- and you will never forget the experience!
So then, even if you don't want to wear gloves for the entire dive, do carry a pair in your pocket at all times, just in case you have to hold or grab onto something for your own safety.
Dive like grown-ups. Cover yourselves completely to protect yourselves from scrapes and stings; but at the same time, do keep in mind that being covered (and thus protected) does not excuse you from responsibility for avoiding physical contact with the reef and the creatures that call it home.
Colony of Long Red Sea Whips - Indonesia
What: A colony of Long Red Sea Whips (Ellisella sp.), a type of soft coral.
Where: I took this photo in the Celebes Sea at Bunaken Island, Indonesia.
Where: I took this photo in the Celebes Sea at Bunaken Island, Indonesia.
BNSullivan.jpg)
The Blue Dragon, a Solar-Powered Nudibranch
by B. N. Sullivan
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This is the third article in our series on 'Exotic Underwater Nudies', i.e., nudibranchs. We began the series last month with the Spanish Dancer, exceptional for its large size and unique swimming behavior. Next we presented the lovely Gold Lace nudibranch, a species endemic to Hawaii. Today we'll take a look at a very different kind of nudibranch -- different both in form, and in how it makes its living.
Meet the Blue Dragon (Pteraeolidia ianthina). This is one of a handful of nudibranch species that is, in effect, solar powered. I know what you're thinking: A solar-powered sea slug? How is that possible?
It happens in a round-about way. The Blue Dragon is carnivorous. It eats hydroids -- stinging organisms that are related to corals. The hydroids are colonized by zooxanthellae -- microscopic plants. As plants large and small are known to do, the zooxanthellae convert energy from sunlight into sugars through the process of photosynthesis.
So, the Blue Dragon eats hydroids, which contain zooxanthellae in their tissues. The Blue Dragon is one of several nudibranch species that has evolved a method of extracting the zooxanthellae from the hydroids it eats and storing them in its own body. Once in place in the nudie's tissues, the zooxanthellae continue to produce sugars via photosynthesis, thus nourishing the creature that has now become their new host. In this way, the Blue Dragon qualifies as a solar powered nudibranch.
Zooxanthellae are found in the tissues of many marine animals, including corals. In fact, it is the presence of zooxanthellae that give corals their colors. The same is true for the Blue Dragon nudibranch. The coloration of this species varies, partly due to the concentration of zooxanthellae that a given individual carries in its tissues. Juveniles of this species are a nearly transparent white. Only as they mature and accumulate zooxanthellae in their tissues do they take on their characteristic color.
BNSullivan.jpg)
The Blue Dragon stores zooxanthellae in its cerata -- those fluffy looking bits that cover its body. In fact, one hypothesis about the Blue Dragon's form posits that the cerata may have evolved in order to provide more surface area for the zooxanthellae to inhabit. More surface area means more space for zooxanthellae, as well as a greater likelihood that they will be exposed to the light they need for photosynthesis.
Speaking of sunlight, as you might expect, the Blue Dragon nudibranch works the day shift on the reef. It needs to be exposed sunlight so that its zooxanthellae can produce nutrients. Not only is this creature seen most frequently during daylight hours, it also tends to dwell at shallower depths than some other nudibranchs. Naturally, there is more sunlight available at shallower depths than in deeper water.
About the photos on this page: In the photo at the top of the page, you can see how the cerrata are arrayed along the entire length of the Blue Dragon. Zooxanthellae are stored in the cerata. The bottom photo is a 1:1 macro of the head of a Pteraeolidia ianthina. The feathery looking bits protruding upward from its head are its rhinophores, the organs that sense 'smells' in the water. The animal uses its rhinophores to locate food, much like a mammal on land would use its nose. The striped appendages facing forward are oral tentacles, which act like 'feelers' so that the nudie can pinpoint where the food is, by touch.
Each photo shows a different individual. The photo at the top was taken at Siapadan Island, off the coast of Borneo. The bottom photo was taken near Manado, Sulawesi Island, Indonesia.
BNSullivan.jpg)
This is the third article in our series on 'Exotic Underwater Nudies', i.e., nudibranchs. We began the series last month with the Spanish Dancer, exceptional for its large size and unique swimming behavior. Next we presented the lovely Gold Lace nudibranch, a species endemic to Hawaii. Today we'll take a look at a very different kind of nudibranch -- different both in form, and in how it makes its living.Meet the Blue Dragon (Pteraeolidia ianthina). This is one of a handful of nudibranch species that is, in effect, solar powered. I know what you're thinking: A solar-powered sea slug? How is that possible?
It happens in a round-about way. The Blue Dragon is carnivorous. It eats hydroids -- stinging organisms that are related to corals. The hydroids are colonized by zooxanthellae -- microscopic plants. As plants large and small are known to do, the zooxanthellae convert energy from sunlight into sugars through the process of photosynthesis.
So, the Blue Dragon eats hydroids, which contain zooxanthellae in their tissues. The Blue Dragon is one of several nudibranch species that has evolved a method of extracting the zooxanthellae from the hydroids it eats and storing them in its own body. Once in place in the nudie's tissues, the zooxanthellae continue to produce sugars via photosynthesis, thus nourishing the creature that has now become their new host. In this way, the Blue Dragon qualifies as a solar powered nudibranch.
Zooxanthellae are found in the tissues of many marine animals, including corals. In fact, it is the presence of zooxanthellae that give corals their colors. The same is true for the Blue Dragon nudibranch. The coloration of this species varies, partly due to the concentration of zooxanthellae that a given individual carries in its tissues. Juveniles of this species are a nearly transparent white. Only as they mature and accumulate zooxanthellae in their tissues do they take on their characteristic color.
BNSullivan.jpg)
The Blue Dragon stores zooxanthellae in its cerata -- those fluffy looking bits that cover its body. In fact, one hypothesis about the Blue Dragon's form posits that the cerata may have evolved in order to provide more surface area for the zooxanthellae to inhabit. More surface area means more space for zooxanthellae, as well as a greater likelihood that they will be exposed to the light they need for photosynthesis.Speaking of sunlight, as you might expect, the Blue Dragon nudibranch works the day shift on the reef. It needs to be exposed sunlight so that its zooxanthellae can produce nutrients. Not only is this creature seen most frequently during daylight hours, it also tends to dwell at shallower depths than some other nudibranchs. Naturally, there is more sunlight available at shallower depths than in deeper water.
About the photos on this page: In the photo at the top of the page, you can see how the cerrata are arrayed along the entire length of the Blue Dragon. Zooxanthellae are stored in the cerata. The bottom photo is a 1:1 macro of the head of a Pteraeolidia ianthina. The feathery looking bits protruding upward from its head are its rhinophores, the organs that sense 'smells' in the water. The animal uses its rhinophores to locate food, much like a mammal on land would use its nose. The striped appendages facing forward are oral tentacles, which act like 'feelers' so that the nudie can pinpoint where the food is, by touch.
Each photo shows a different individual. The photo at the top was taken at Siapadan Island, off the coast of Borneo. The bottom photo was taken near Manado, Sulawesi Island, Indonesia.
Napoleon Wrasse in the Abstract
What: The first two images are abstract macro shots of the scales and a fin of a
Napoleon Wrasse (Cheilinus undulatus).
The third photo is for context, so that you can see the patterns as they appear on the fish.
Napoleon Wrasse (Cheilinus undulatus).
The third photo is for context, so that you can see the patterns as they appear on the fish.
BNSullivan.jpg)
BNSullivan.jpg)
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Fish Tales: Encounters with the Napoleon Wrasse
by B. N. Sullivan
Imagine that you are on a dive boat in the Red Sea. The boat has just tied up to a mooring at a place called Jackson Reef in the Tiran Straits. All geared up, you jump off the stern platform of the boat and begin your descent. As you drift down gently through the water column, something off in the distant blue catches your eye. At first all you can make out is a hulking shape that looks vaguely like a Volkswagen beetle, and it is moving toward you. As it lumbers along, the shape tilts this way and that, and as it gets closer you are able to make out pectoral fins, big eyeballs, and huge fat lips. You realize it's definitely not a Volkswagen; it's a great big fish - A Napoleon Wrasse.
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Earlier this week, for Wordless Wednesday, I posted a photo of a Napoleon Wrasse. Readers commented on the size of the fish, on its shape, and on its prominent eye.
These guys definitely are big: adults usually are close to four feet in length, although I read somewhere that there have been reports of older males of the species occasionally reaching a length of about six feet. Females tend to be smaller. In any case, they are said to be the largest species in the Wrasse (Labridae) family.
They are heavy-bodied, and weigh several hundred pounds. Because of their bulk, they usually lumber along, but make no mistake - they are capable of very quick speeds, too, at least over short distances.
Their eyes are large, and each can move independently. The eyes protrude and rotate in a way that might remind you of the ball turret on a World War II B-17 aircraft (without the gunner). When they are close to you, they tend to tilt to look at you with one eyeball, much as a chicken would.
The common name, Napoleon Wrasse, arises from the prominent bump that protrudes from the foreheads of fully grown adults, giving them a profile that is reminiscent of Napoleon Bonaparte with his hat. Another common name for the fish is Humphead Wrasse -- take your pick -- but in either case, the scientific designation for the species remains the same: Cheilinus undulatus.
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These fish can live for thirty years or so, and they seem to have long memories. When we first began to dive in the Red Sea a few decades ago, dive guides there sometimes would entertain their clients by hand feeding boiled eggs to the Napoleon Wrasses. After awhile, once everyone finally realized that this was not an ecologically sound thing to do, this practice was banned.
Unfortunately, no one sent a memo to these fish to tell them not to expect boiled egg handouts from divers. For years after the practice of feeding them boiled eggs had stopped, the Napoleons still converged near dive boat moorings as soon as they heard the sound of the boats' engines approaching. There they would lurk until they spotted divers descending, at which point they would approach the divers at quite close range, hoping for a free snack.
Sometimes the Napoleons would do more than wait. If a diver reached into the pocket of his vest for any reason, the Napoleon would quickly swim right up to that diver in anticipation, sometimes nudging the diver with those great big fat lips. We've heard countless of stories of divers who had to physically push a Napoleon away from them repeatedly before the fish finally got the message that they had no eggs to hand out.
In an extreme case that we actually witnessed, a friend who was diving with us lost an important piece of gear to a Napoleon, and almost lost his hand as well.
For the benefit of our non-diving readers, let me first explain that these days, scuba regulators (the device that reduces the pressure of the compressed air in the cylinder so that it can be breathed) usually have two second stages, i.e., the part that includes the mouthpiece. The primary one will be used by the diver to breathe underwater. The secondary one, though fully functional, is a back-up. As such, it is usually attached to the diver's vest by a clip or similar means, or stuffed into a pocket.
So then, on this particular dive, the clip that usually held our friend's back-up second stage had broken. Rather than let the device trail behind him, he held it at waist level, cupped in his two hands, as he swam. Now, these devices come in a wide variety of colors. Our friend's happened to be white. (Can you see what's coming?)
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Along came a Napoleon. It saw the round white shape cupped in our friend's hand and apparently mistook it for an egg. First the fish swam back and forth excitedly around our friend. Then it nudged him. Annoyed, our friend put out one hand to push the aggressive fish away. At that instant, the Napoleon lunged and snapped the white regulator out of our friend's other hand -- or tried to. The regulator was attached to a hose, of course. When the Napoleon bit, the hose partly detached and it began to froth like crazy from the rapidly escaping compressed air. That scared the fish, which went zooming past us with our friend's glove hanging from its mouth!
That was the end of that dive: time to initiate emergency procedures. A fourth diver who was with us immediately handed off his back-up second stage to our stricken friend so that he could breathe. Meanwhile, Jerry swam around behind him to turn off the valve on his cylinder, stopping the uncontrolled flow of air. Then, with the two divers sharing air, we all swam back to the boat.
Once on board, we inspected the damage. The hose had to be replaced, and although the white second stage that had been bitten probably could have been repaired, our friend announced immediately that he would replace it -- with a black one! No one ever saw the glove again, but our friend was happy enough to have relinquished it, since he still had his hand.
By the way, we have seen Napoleons elsewhere -- especially in the waters around Malaysia and Indonesia -- but only the ones in the northern Red Sea were so bold. The ones we saw in other places tended to keep their distance from divers. Apparently they had not been fed by divers. In fact a dive guide in Indonesia told us that Napoleons had been a favorite target of spear-fishermen there until quite recently; thus, they had learned to be wary of humans underwater.
About the photos on this page: Each image shows a different individual Napoleon Wrasse, and each was photographed on a different dive. I took all three photos in the Red Sea: the top photo was taken at Jackson Reef in the Tiran Straits; the other two photos were taken at Ras Mohammed, near the tip of the Sinai Peninsula. And in case you are wondering, the Napoleon in the third photo is not about to bite the leg of the diver on the left. It's an optical illusion created by the wide angle lens. The wrasse actually was positioned between the two divers.
Imagine that you are on a dive boat in the Red Sea. The boat has just tied up to a mooring at a place called Jackson Reef in the Tiran Straits. All geared up, you jump off the stern platform of the boat and begin your descent. As you drift down gently through the water column, something off in the distant blue catches your eye. At first all you can make out is a hulking shape that looks vaguely like a Volkswagen beetle, and it is moving toward you. As it lumbers along, the shape tilts this way and that, and as it gets closer you are able to make out pectoral fins, big eyeballs, and huge fat lips. You realize it's definitely not a Volkswagen; it's a great big fish - A Napoleon Wrasse.
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Earlier this week, for Wordless Wednesday, I posted a photo of a Napoleon Wrasse. Readers commented on the size of the fish, on its shape, and on its prominent eye.These guys definitely are big: adults usually are close to four feet in length, although I read somewhere that there have been reports of older males of the species occasionally reaching a length of about six feet. Females tend to be smaller. In any case, they are said to be the largest species in the Wrasse (Labridae) family.
They are heavy-bodied, and weigh several hundred pounds. Because of their bulk, they usually lumber along, but make no mistake - they are capable of very quick speeds, too, at least over short distances.
Their eyes are large, and each can move independently. The eyes protrude and rotate in a way that might remind you of the ball turret on a World War II B-17 aircraft (without the gunner). When they are close to you, they tend to tilt to look at you with one eyeball, much as a chicken would.
The common name, Napoleon Wrasse, arises from the prominent bump that protrudes from the foreheads of fully grown adults, giving them a profile that is reminiscent of Napoleon Bonaparte with his hat. Another common name for the fish is Humphead Wrasse -- take your pick -- but in either case, the scientific designation for the species remains the same: Cheilinus undulatus.
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These fish can live for thirty years or so, and they seem to have long memories. When we first began to dive in the Red Sea a few decades ago, dive guides there sometimes would entertain their clients by hand feeding boiled eggs to the Napoleon Wrasses. After awhile, once everyone finally realized that this was not an ecologically sound thing to do, this practice was banned.Unfortunately, no one sent a memo to these fish to tell them not to expect boiled egg handouts from divers. For years after the practice of feeding them boiled eggs had stopped, the Napoleons still converged near dive boat moorings as soon as they heard the sound of the boats' engines approaching. There they would lurk until they spotted divers descending, at which point they would approach the divers at quite close range, hoping for a free snack.
Sometimes the Napoleons would do more than wait. If a diver reached into the pocket of his vest for any reason, the Napoleon would quickly swim right up to that diver in anticipation, sometimes nudging the diver with those great big fat lips. We've heard countless of stories of divers who had to physically push a Napoleon away from them repeatedly before the fish finally got the message that they had no eggs to hand out.
In an extreme case that we actually witnessed, a friend who was diving with us lost an important piece of gear to a Napoleon, and almost lost his hand as well.
For the benefit of our non-diving readers, let me first explain that these days, scuba regulators (the device that reduces the pressure of the compressed air in the cylinder so that it can be breathed) usually have two second stages, i.e., the part that includes the mouthpiece. The primary one will be used by the diver to breathe underwater. The secondary one, though fully functional, is a back-up. As such, it is usually attached to the diver's vest by a clip or similar means, or stuffed into a pocket.
So then, on this particular dive, the clip that usually held our friend's back-up second stage had broken. Rather than let the device trail behind him, he held it at waist level, cupped in his two hands, as he swam. Now, these devices come in a wide variety of colors. Our friend's happened to be white. (Can you see what's coming?)
BNSullivan.jpg)
Along came a Napoleon. It saw the round white shape cupped in our friend's hand and apparently mistook it for an egg. First the fish swam back and forth excitedly around our friend. Then it nudged him. Annoyed, our friend put out one hand to push the aggressive fish away. At that instant, the Napoleon lunged and snapped the white regulator out of our friend's other hand -- or tried to. The regulator was attached to a hose, of course. When the Napoleon bit, the hose partly detached and it began to froth like crazy from the rapidly escaping compressed air. That scared the fish, which went zooming past us with our friend's glove hanging from its mouth!That was the end of that dive: time to initiate emergency procedures. A fourth diver who was with us immediately handed off his back-up second stage to our stricken friend so that he could breathe. Meanwhile, Jerry swam around behind him to turn off the valve on his cylinder, stopping the uncontrolled flow of air. Then, with the two divers sharing air, we all swam back to the boat.
Once on board, we inspected the damage. The hose had to be replaced, and although the white second stage that had been bitten probably could have been repaired, our friend announced immediately that he would replace it -- with a black one! No one ever saw the glove again, but our friend was happy enough to have relinquished it, since he still had his hand.
By the way, we have seen Napoleons elsewhere -- especially in the waters around Malaysia and Indonesia -- but only the ones in the northern Red Sea were so bold. The ones we saw in other places tended to keep their distance from divers. Apparently they had not been fed by divers. In fact a dive guide in Indonesia told us that Napoleons had been a favorite target of spear-fishermen there until quite recently; thus, they had learned to be wary of humans underwater.
About the photos on this page: Each image shows a different individual Napoleon Wrasse, and each was photographed on a different dive. I took all three photos in the Red Sea: the top photo was taken at Jackson Reef in the Tiran Straits; the other two photos were taken at Ras Mohammed, near the tip of the Sinai Peninsula. And in case you are wondering, the Napoleon in the third photo is not about to bite the leg of the diver on the left. It's an optical illusion created by the wide angle lens. The wrasse actually was positioned between the two divers.
Out of the Blue - One Big Fish!
What: Napoleon Wrasse (Cheilinus undulatus), an endangered species.
Adults are very large - about 45 inches (115 cm) long.
Where: I took this photo in the Red Sea, near Sharm el-Sheikh, Egypt.
Adults are very large - about 45 inches (115 cm) long.
Where: I took this photo in the Red Sea, near Sharm el-Sheikh, Egypt.
BNSullivan.jpg "Napolean Wrasse (Cheilinus undulatus), photographed in the Red Sea")
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