Sunken Secrets of the Bahr Al-Ahmar

This post was written by guest blogger Noah J. D. DesRosiers, a research colleague who accompanied the FLMNH team on the KAUST Red Sea cruise.  You can read more from him at www.naturenoah.com.

“Thousands of miles from home, hundreds of miles from our institution, and thirty miles from any solid land, I am falling slowly into darkness.  Checking my life support system, I find my breathing gas cylinder is fully charged, its valves are open, my facemask is cleared, and the needle on my depth gauge is steadily rising as the twisted crags of a monstrous limestone wall climb ever higher over my head.  I break the silence with periodic Vader-esque respiration.  At nearly a hundred feet down I push a button to halt my descent, which leaves me hanging motionless in the depths. Feeling around my shoulder, my fingers recognize and unclip a bag of sampling equipment from my rig and I kick forwards towards the wall.  I am crossing over a thousand feet of liquid blackness that falls further still beneath me, a murk laden with swirling creatures staring upwards that I’ll never know.  The light I’ve carried with me beats back shadows to reveal a gnarled jungle of swaying and crawling non-terrestrial life on the wall’s surface.  Bejeweled green, yellow, red, and silver eyes flash on and off from numerous tiny caves.  While sweeping my light across the deep reef’s surface, the apparition of a nightmarish creature stops me suddenly, and my breath catches.  With a steady gaze I reach for a jar, unscrew its lid, and cautiously move it towards the creature.  Bright red claws sway from side to side as the jar draws nearer; mysterious green eyes appear locked on mine.  Using the beam of light alone, I herd the photo-phobic creature backwards into my jar, using my last ounce of breathless concentration to carefully screw on the lid.  With the cover in place, I exhale jubilantly, relieved to respire again.  I bring the jar close to study my mysterious prize; flecked with yellow, blue, purple, and white, the almost clear body of this potential new species broods within its flimsy cage of plastic, issuing an occasional defiant CLICK!  A flash of light from a camera draws me from my reverie; Dr. Paulay is nearby.  Looking over, I see him in a similar struggle with the strange, his dive light silhouetting his head in a dim halo.  Craning my head upwards to the distant surface, the distorted outline of the moon is surrounded by the eery contours of the midnight reefscape.  I take a deep breath before returning to the search for undiscovered life, and think that surely not even astronauts feel like this.”

One such creature from the deep - a beautiful swimming crab.

The above account, of a thrilling night dive I made with FLMNH’s Dr. Gustav Paulay on a deep offshore reef wall, comes from my log of a recent expedition to the Saudi Arabian Red Sea (in Arabic, Al-Bahr Al-Ahmar).  The two week cruise, organized by the King Abdullah University of Science and Technology (KAUST), was planned as the first of five such cruises to make a rigorous survey of the region’s marine biodiversity.  Crossing nearly four degrees of latitude, our journey took us to points south in the Red Sea around the Farasan Islands (click to see our cruise map).  17 scientists (including professors, researchers, and students) from various institutions around the world participated, including various taxonomic specialists (Dr. Arthur Anker, shrimps; Dr. Sancia van der Mejj, gall crabs; Dr. Terry Gosliner, sea slugs; and Dr. Howard Choat, parrotfishes, to name just a few).  And while coral reefs are always beautiful places to survey, the Red Sea’s elevated temperature, consistently calm weather, and exceptional water clarity made our expedition particularly breathtaking.

A profile shot of a shallow Red Sea reef near Saudi Arabia's Farasan Islands.

Numerous fossilized limestone islands and aragonite cays dot the marine landscape of the Farasan Bank.

As soon as the sun was up each morning, we’d gather around the dining/lounging/data entry area of our floating home, the 85-foot liveaboard vessel Dream Master.  Over eggs, toast, and Spam we discussed the previous day’s events, laughed at each other’s morning appearances, and planned the objective for the current day’s dives.  You wouldn’t know from our appearance that we were actually a room full of professionals with years of schooling, madly pumping out written records of our sub-sea discoveries; salt, scales, and slime are the field researcher’s haute couture.  Assuming we weren’t hastily steaming south (local operators prefer not to navigate at night) we’d be suiting up and ready for our first dive by 9:00 AM.

Gearing up: cruise scientists prepare for another rigorous day on the water.

The scientists were loosely organized into two working groups – those collecting fishes, and those surveying and collecting invertebrate animals.  Some researchers, like our cruise organizer Dr. Michael Berumen, managed to assist all teams at one point or another in their collecting needs.  Your humble narrator attempted the same, only to realize when bogged down with spears, jars, vials, bags, clips, camera, forceps, bottles, brushes, and nets – that it had been too long since I’d last hunted a fish.  Avoiding the ridicule of my quarry (I swear fish laugh at you when you miss) I decided to focus on the invertebrate collecting, which offered interesting new sampling techniques of its own.

Cruise organizer Dr. Michael Berumen of the KAUST Reef Ecology Lab shows off a prize pistol shrimp.

X marks the spot?  FLMNH doctoral student Patrick Norby digging for 'burrowed' treasure.

As a prospective student, I had heard of Dr. Gustav Paulay’s legendary collecting ability.  Now, I watched it unfold before me each evening when, after two or three dives, the sun deck of our vessel was turned into a seething menagerie of abducted marine life.  Most of the other invertebrate biologists on board had worked with Dr. Paulay before, and they prepared themselves for specimen processing like dancers stretching before an arduous performance.  Certainly the work required poise; night after night workstations arose for specimen identification, labeling, relaxation (for the specimens, that is – science is too fun to take breaks), photography, DNA subsampling, and ethanol fixation.  And the star of the show each evening was Dr. Paulay; pirouetting past each plastic container, identifying every squirming specimen, and occasionally shouting with glee, “Ah, ha! Oh ho!”  The professor’s strength is his lasting excitement, carrying us all forward, as if every night were opening night in the biodiversity ballet. 

Dr. Arthur Anker acts as triage officer as the day's collection piles up on the sun deck.

While the upper deck was awash with invertebrates each evening, the dive platform at the stern was being covered with scales.  There, fish researchers measured, weighed, dissected, and at least once “subsampled” with lemon and soy sauce, their day’s catch.  A central theme of their research focused on evolutionary phylogenies; DNA from collected rare, native, or wide-spread species will be used to determine relatedness between species or populations, and thus aid in constructing part of the timeline of evolution.  With no railings around the dive platform, they could clean up with a quick dip in the sea – and enjoy the best view!

(Fish science on the dive deck!  From L to R: Dr. Luiz Rocha, asst. curator at the California Academy of Sciences, studying endemism; Richard Coleman, doctoral student at the Hawaii Institute of Marine Biology, studying cardinalfish phylogeny; Dr. Howard Choat, emeritus professor at James Cook University, studying biogeographic variation in life history traits; Mark Priest, research assistant of the KAUST Reef Ecology Lab; Dr. Joseph DiBattista, postdoctoral scholar in the KAUST Reef Ecology Lab, studying population genetics.)

Your narrator, once also a mere fish biologist, now spent his time primarily chasing sea slugs.  Dr. Terry Gosliner and I ended up collecting 88 different species!  Since their colors are so charismatic, it is actually common for a species to be known from a locality (from divers’ photographs or generic collections) before it has been given a scientific name.  Though we found plenty of known species, we also found others that have never been documented before!  The area is rich for discovery; I found four species crawling over rocks on the jetty the night before Dream Master even left port, and one of those was a new species!

Slugs collected icluded A) described species known to occur in the Red Sea (Stylocheilus striatus), B) undescribed species that are still known from the Red Sea (Siphopteron sp.), C) described species not previously known from the Red Sea (Odontoglaja guamensis), and D) species neither described nor previously known from anywhere (Eubranchus sp.).

Of course, no reef research trip would be complete without studying the corals, the ecosystem’s architects!  KAUST doctoral candidate Jessica Bouwmeester assisted Dr. Francesca Benzoni of the University of Milano-Bicocca to establish a specimen reference collection of Red Sea coral species.  After just two weeks, they believe their collection represents 80% of the Red Sea coral diversity, and can now be used by all visiting scientists for further study!  Dr. Sancia van der Mejj of the Netherlands’ Naturalis Biodiversity Center worked right alongside the pair, as her study organisms burrow into live coral (the gall crabs).  Dr. Michel Claereboudt of the Sultan Qaboos University in Oman meandered through the group, occasionally helping with local species identification, while pursuing his own questions on the marine biodiversity of the Arabian Peninsula.  The reef is an interwoven network of life; so too the efforts of those who toil to know its secrets.

Coral specimens to be added to the reference collection must dry on deck before being bleached, labeled, and carefully stored.

KAUST doctoral candidate Jessica Bouwmeester shops the reef for new species of coral.

Overall, it was a very productive trip for everyone.  Much work remains to be done studying all those new samples!  But those are stories for another time.  For now, I will end this post with an MVP award.  Without hesitation, the coveted title(s) go to Dr. Art Anker and his faithful sidekick Norby.  The pair achieved museum-quality photography of most of the identified specimens – over 3,000 individuals – after each full day’s diving, on a rocking boat in windy seas without a tripod, often until 2 in the morning.  Though nary a (serious) complaint was heard, poor Art spent more time talking to alpheid shrimps than people, and we do all so hope that his return to Singapore included “liquid re-integration therapy” lest he begin growing antennae of his own!  ♠

A welcome sight after a long day of diving; the entrance to our floating home.

(Many thanks to Tane Sinclair-Taylor, field technician at the KAUST Red Sea Research Center, whose exceptional photographs bring this story to life; our hard-working Filipino captain and crew, who navigated, cooked, cleaned, and kept us afloat; and Jean-Paul Hobbs, a fish researcher on this cruise whom, despite being a strikingly handsome young fellow from the University of Western Australia, I could not work into this narrative.  Better luck next time, mate!)

From the field: In the sea, comets become stars.

I'm currently in Papua New Guinea, with John (the Slapcinsky kind) where we are participating to the expedition "Our planet reviewed" organized by the Muséum National d'Histoire Naturelle in Paris; and the Institut pour la Recherche et le Développement. In the following weeks, I'll try to post pictures and natural history stories about the marine invertebrates we are finding.

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When it comes to plants, it is not uncommon that a small part is used to regrow a full organism. Gardeners have used this property to multiply and spread varieties of fruits and vegetables for centuries. For many species, a small branch, a leave or a root, placed in the right conditions, will give rise to a fully grown plant that will produce flowers and fruits. The plants obtained by this process are clones of their parents, they have the exact same genetic material. Many species of plants use this mode of reproduction in nature to spread. Because there is no exchange of gametes, this is referred to as asexual reproduction.

In the animal world, asexual reproduction is not very common. As I've previously mentioned, a particular group of rotifers have championed asexual reproduction. In other groups, like colonial organisms such as corals, asexual reproduction and growth are tightly linked. The colony grows by adding new individuals. If for some reason, one or a few individuals get separated from the colony, they will be able to go on with their lives and create a new colony of their own. A particular group of flatworms (planarians, class Turbellaria) have the amazing ability to regrow a full adult animal from a single adult cell (you can read more about it here). They use these regenerative abilities to reproduce asexually. They split themselves in halves, and each part regrow what is missing.

For larger and more complex animals, it is however much more uncommon to be able to regenerate the full animal from a part. Echinoderms are an exception. Some sea cucumbers can do it, but the most striking examples come from the sea stars in the genus Linckia. These sea stars can drop off an arm and from it, it will regrow a complete animal.

In the first few days of the expedition here in Papua New Guinea, divers have been bringing back many specimens of Linckia multifora. This colorful sea star comes in shapes that does not match their names. Instead of looking like stars, they often look like comets.

From the "tail" of the comet, the arm that was dropped off, 4 arms are slowly growing back to form a new complete sea star. As the process continues, the little arms grow bigger, and they will eventually end up looking like stars again.

However, the process is not always perfect, and it is often possible to say if a particular individual is the result of asexual reproduction. If you look more closely at this sea star, you can spot that it has 2 anuses (yellow arrows) and 2 madreporites (blue arrows). This is clearly the signature that this individual is the product of asexual reproduction.

Sea stars can probably undergo asexual reproduction more easily than other animals because they have most of their organs repeated in each of their arms. Also, they don't have a centralized nervous system, it would probably be a trickier thing to do if they also had to regenerate a full brain. Because of the position of their mouth, it is also one of the first thing to be regrown, so they don't have to starve for too long before they can feed again. If many species of sea stars can regrow a missing arm, only a few can, like Linckia multifora, regrow a full animal from just an arm.