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The 2011 Philippine Biodiversity Expedition 

May 27, 2011

Taal Tails – May 12, 2011

The initial timing was unfortunate, a storm kept the Hearst Expedition divers out of the sea for two days, but as the storm abated and the nearshore water became clearer, several of us made a trip to Lake Taal, an hour and a half north of Club Ocellaris, the base of operations for the expedition’s shallow water marine component. Compensation for not diving those two additional days was a glimpse at a truly unique place.


For the purpose at hand, the timing couldn’t have been better. A stage 2 alert had virtually shut down the local tourist industry, which exists to take people to and from the island in the Lake and show them around on horseback. What is this alert? You see, the island in Lake Taal is an active volcano, with the most recent eruption having ended in 1977. The alert was issued and remains in effect because monitors recorded several seismic events early on, a rise in magma level, and an increase of noxious emissions.

Why visit an active volcano? Well, the surrounding lake has a very interesting history. Lake Taal is the third largest lake in the Philippines in terms of surface area and possibly the deepest (approaching 200 meters). The surface of Lake Taal lies at an elevation of less than 30 meters which means that a significant part of the lake water lies below sea level. Lake Taal used to be broadly open to the ocean, but volcanic activity approximately 250 years ago closed it off, and over time, runoff from the surrounding mountains has lowered the salinity to a point where it is essentially freshwater. Many of the Lake’s native fishes are derived from marine species that have adapted to freshwater, including the Lake’s most famous inhabitant, the world’s only freshwater sardine, the Tawilis (Sardinellla tawilis), an endemic species found nowhere else.

The logistics for our half-day excursion proved more challenging due to the presence of an ABS-CBN news team doing a documentary on the Hearst Philippine Expedition tentatively due to air in September. Upon arriving at the Talisay Yacht Club, we began unloading our gear and obtained gasoline for the electroshocker. Representatives from the Bureau of Fisheries and Aquatic Resources (BFAR) and PUSOD (a non-profit Philippine environmental organization) were present along with the TV crew. While we discussed our plan, the Invertebrate Zoology team made a small shore collection. With our gear finally loaded on two bangkas, we set off for Volcano Island.


Lake Taal is home to extensive aquaculture operations with thousands of floating cages for raising tiapia and milkfish. The heaviest concentration of cages lies in the northern and western parts of the lake. It was in this region we made our first stop, at a particular place where Philippine scientists reported netting two or three kinds of gobies new to science. These are species not yet named in the scientific literature. En route to this first stop, the bangka carrying our invertebrate zoologists experienced engine trouble and put to shore. In a wonderful turn of events, there were two pipefishes in the water next to the boat that they were able to collect. This was one of our targets for this trip. The operable bangka went to pick-up the Invertebrate Zoology team and bring them to the first site. The second boat joined us later, after repairs were made. It was time to begin our search in earnest.


Our primary tool for this hunt was an electroshocker. This is a device primarily used by fisheries biologists to capture fishes for tagging and/or data gathering. It is essentially a sophisticated power supply using two electrodes to create an electric field in the water, stunning fish that can then be netted. Our unit consists of a small gasoline generator to power the electronics box both of which are mounted on a pack frame. Everything checked out fine, but each time we started to fish, the unit registered an overload. Our backup plan called for dipnets and a small seine. While executing this “plan B,” we noticed areas of hot water in excess of 50 deg. C. that had seeped up through the sand plus plenty of sulphurous odors. It then occurred to me that this might provide an explanation for why the electroshocker failed to work. Volcanic activity increased the amount of dissolved minerals in the lake water near Volcano Island increasing the conductivity to a point where the unit could only register an overload. Subsequent inquiry not only confirmed this but also revealed that the entire lake has high conductivity.


Regarding the specimens we did manage to collect, no conclusions could ever be drawn from a sample that small, but there are some highlights. We did collect seven gobies, of which three are common and the remaining four, very small. We will probably seek the help of specialists to determine what they are or if they might be new to science. The three freshwater pipefishes are of particular interest to Dr. Healy Hamilton and the researchers in her lab at the California Academy of Sciences who are working on a molecular phylogeny of the seahorse / pipefish family Syngnathidae. Probably the most significant aspect of our visit to Lake Taal concerns the jaguar fish, an aggressive, fish-eating, Central American Cichlid, introduced a little over 15 years ago. Since then, this invasive species has increased to the point where it is now ranks fourth in number of individuals caught per year. We were able to provide limited anecdotal evidence of just how pervasive the jaguar fish has become. We also observed first hand, it’s tolerance for poor water quality, a definite competitive advantage. Finally, for our mini-expedition to Volcano Island, a delicious lunch was provided by Ipat Luna of PUSOD, and even though we weren’t able to collect the famous freshwater sardine, the Tawilis, we were able to taste it.

We presented our findings during a meeting at the town hall in Talisay. In attendance were representatives from PUSOD and BFAR as well as mayors from several municipalities around the lake. The good news is that the Philippine government approved a comprehensive management plan for Lake Taal that has strong local support. Implementation and enforcement of the plan’s provisions are the next critical steps.


-Dave Catania

Filed under: Academy,Catania,Philippines,Shallow Water,Terrestrial — admin @ 2:50 pm

Like…totally tubular!

Most of the critters I’m working with during this expedition are so tiny that you need a microscope to examine them…sometimes even just to locate them!   There are lots of exceptions, however, and one of them involves a very cool critter called a chaetopterid worm that I encountered the other day. Since it was fairly big and impressive (colleagues actually stopped by to gawk at it in awe) and because these are such creepy-cool worms, I thought I’d share.
While working in a sandy seagrass area the other day, I dug up a large parchment (which is sand stuck together with mucus) tube about an inch in diameter that was sticking up out of the sandy sea bottom.
Typically this type of tube houses a fanworm (a sabellid) with delicate fan-shaped radioles stretched into a sort of funnel-shaped plume like this:
In sabellid fanworms each radiole has tiny hair-like structures called cirri used to filter small particles of food from the water to be carried to the mouth.   So considering the tube’s appearance, I was expecting a nice fat fanworm to emerge as I eagerly cut into my tube back at the lab, kind of like I was unwrapping some sort of creepy worm shaped gift.  This tube, however, was shaped more like a “U” buried under the sand and so I suspected that it might house something a bit different. And it did…a very large chaetopterid worm!
Chaetopterids are very specialized polychaetes (marine bristleworms) that live their lives confined in tubes. These worms have 3 distinct body regions: the head/anterior region is large and equipped with bristles and a set of palps used for sensory.  The middle of the body is made up of the darkened gut and highly modified lobes that pump back and forth like big flaps to provide a steady water current used in feeding.
The tail/posterior region is more “normal-worm-looking”, meaning long with foot appendages called parapodia carrying bristles on either side of the body.


These worms feed using mucus nets which they string across the inside of their tubes to trap food particles by pumping water through their tubes to filter food onto the net.   Once it’s full of food they eat the whole deal and then proceed to make a new net. Other critters, such as smaller worms and crabs, often live alongside chaetopterids in their tubes as commensal animals which score free food scraps and shelter while living there.

Another cool thing about these worms is that even though they live rather clandestine lives hidden in tubes, they produce bioluminescence (they emit light!). What in the world they are doing with this light-producing capability?  Well, we don’t know for certain.  Studies have shown that when a chaetopterid is disturbed, it shoots a wave of glowing particles from its tube.  One idea is that this light surge alerts prospective predators that “I don’t taste particularly good”, or maybe the light bursts are used to freak out and evict some of the free-loading critters out their tubes if it starts getting too crowded in there.

Many polychaetes and other invertebrates emit light when disturbed, either for warning/predator avoidance or for communication with potential mates.   The yellow bands shown here on a nereid “pileworm” may be bioluminescent areas of the body used for signaling.
Polychaete worm behavior and physiology is as extremely diverse as their morphology.  For such “sleeper” creatures that are unfamiliar to most regular folks, polychaete worms actually have alot going on!

Filed under: Academy,Diving,Philippines,Piotrowski,Shallow Water,Uncategorized — cpiotrowski @ 4:39 am

May 21, 2011

When it comes to echinoderm collagen, there is always a catch

I was taught a lesson in self control the other day, while snorkeling in an area that had lots of rocks. In between the rocks were lots of crevices, and in those crevices we found some of the most magnificent of all the sea urchins. The self-control of the sea urchins (which I will talk about in a moment) inspired self-control in me with respect to scientific collecting as well.

The aforementioned magnificent urchin goes by the mellifluous name of Heterocentrotus mamillatus, and here is the creature, securely jammed into its urchin home:


That is the correct spelling of the species name. Some of my colleagues might be tempted to put an extra “m” in there to make it “mammillatus“, but that is not what the original author of the name, none other than Carl von Linné (a.k.a. Carolus Linnaeus) himself, had in mind back in 1758. The reference is to more or less the same mammalian attribute in either spelling, but there are nuances of the usage that have to be respected, and Linnaeus knew that. He was nothing if not a smart guy who knew his human anatomy. He wanted the mammalian reference in the name because when cleaned of its spines, Heterocentrotus mamillatus displays the most beautiful of smoothly domed, glassy spine tubercles that reminded him of… well, a certain mammalian attribute. Maybe he had spent too much time in the field. The big, heavy spines of Heterocentrotus sit neatly on end, one spine over each of these tubercles.  Think of balancing a baseball bat on a half-buried baseball. In the base of the spine is a neatly polished little hollow, or socket, making a finely honed ball and socket joint that any car mechanic would greatly appreciate. To think that this piece of urchin machinery, with its very fine engineering tolerances, is made basically of limestone is simply to wonder at it all the more.

At this point I feel it necessary to mention that you might have encountered these spines, minus the urchin, in various tropical places where a certain type of wind chime might be offered for sale. Turns out that when a Heterocentrotus spine is gently tapped with a hard object, such as another spine, it sounds with a gentle ring that some find pleasing to the ear.

Frankly, I am not a fan of wind chimes of any kind. The only place I have these big spines installed in my lab in San Francisco is in the form of my “Acme Echino Quake Detector”, which is a strange composite “decoration” that hangs from the ceiling with my hope that it will jangle in time to warn of the next “big one”. Otherwise, I don’t think the natural and soothing sound of any breeze that would activate a set of wind chimes needs any enhancement whatsoever, as the breeze has its own kind of auditory beauty. Humans can be strange animals sometimes.

Before people get upset, I should also chime in that Heterocentrotus spines for the “wind music” industry are not usually harvested from the living animals.  When the urchin dies, hopefully after a long and happily productive life (however that is measured by urchin standards), the spines remain so durable that they wash up in large numbers on certain beaches, where they can be picked up and employed in the noble noisy cause described above.

The genus name, Heterocentrotus, is in reference to these incredible spines, which come in two basic varieties: big and strong, and small and stubby. You can see these in the close-up below:


“Hetero” means “different”, so this urchin is named for the fact that is has two very distinct types of spines. As I’ve said before, I love it when scientific nomenclature makes sense. But if you really insist on a common name for this creature, you could call it the “slate pencil urchin”. Does that feel better? In my opinion, it shouldn’t.  There is a reason that biologists coin scientific names. How many of you out there have ever encountered a “slate pencil” in this day and age of electronic gadgetry? Would you even recognize one if it flew up your nose and did the lambada? Heck, even pencils come in mechanical form now, and not to write on slates either. And just to make matters worse, sea urchins in a completely different order, the Cidaroida, are also called “slate pencil urchins”. So much for common names.  Heterocentrotus it is. It’s really not that hard after all. If a 5-year-old can remember “Triceratops“, an adult can surely come to grips with “Heterocentrotus“.

Speaking of grips, Heterocentrotus is nearly impossible to remove from its stony home. Actually, make that fully impossible, at least without dynamite, a crowbar, or otherwise hurting the poor thing. The primary reason for this is in the spines, which are, appropriately enough, called primary spines. As I mentioned, primary spines sit on a ball and socket joint. They are held down to the urchin’s skeletal test by a ring of muscle that can be differentially contracted around the ring to point the spine in different directions. This is a handy attribute to have if you are nearly spherical, and want to point your spines at an incoming enemy, or to wedge yourself into a crevice in the rock. However, muscles are metabolically expensive to run, and sea urchins are not what you would call physiological dynamos. So there must be something else going on to keep these animals in place 24/7, safe from dislodging by waves, predators, or marauding echinodermologists.

Turns out that inside the ring of muscle is a second ring of connective tissue, which is not muscular, but composed of a connective tissue made of collagen. This tissue is ubiquitous in animals, and is usually used to connect muscles to bone, or bone to bone, amongst other uses. In the case of the sea urchins, the collagen is found in a ring just inside the muscular ring.  I’ve shown this in the diagram below (which I have modified from a couple of images in Clarke and Rowe, 1971).  In this diagram, all the spines have been removed except one primary spine, so that you can see the connection to the surface of the body, or test:


The collagen in this inner ring is rather special — it’s so-called “catch collagen”. It’s stiffness is under voluntary control by the sea urchin, probably through nerve action. When the urchin wants to move the spine, the collagen ring becomes soft and pliable, allowing the muscles to place the spine… just so… perhaps to brace against the rocky wall of a cozy reef nook or cranny. Then the urchin stiffens the collagen in the inner ring, effectively locking the spine into position. The muscles can now relax, and ta-da! A powerful brace is in place in the space with energy of zero trace. With a bunch of these spines employed in this way, the urchin simply canNOT be dislodged without breaking something — usually the spines. But in the case of Heterocentrotus, the spines are so big and so powerfully built, any prying force strong enough to make the spines move away from the rock wall usually ends up breaking the urchin’s test. And that is truly a shame, given just how beautiful this animal is.

A few other last words about catch collagen. This substance is part of a group of such tissues in echinoderms known generally as “mutable collagenous tissues”. These have been found in all the major echinoderm groups. In fact, alongside the special stereom version of calcium carbonate used to make echinoderm skeletal elements and basic 5-part symmetry in adults, I would list mutable collagenous tissue as a unifying characteristic of the phylum. In the body wall of a starfish, for example, mutable collagenous tissues can be softened to allow the animal to glide neatly over uneven surfaces, then stiffened to lock the animal into place in an infinite number of what look like the most awkward poses that would be the envy of any acrobat. Such staying power, with no energy output! In sea cucumbers, we have arguably the most extreme usage of mutable collagenous tissues. The entire body can soften to allow movements into the tiniest of holes and cracks, yet stiffen again in an instant to hold the front end of the animal up to filter feed with elevated tentacles around the mouth, or wedge the animal into a small crack.

Okay, I lied. There is one more thing I wanted to add. Turns out that there is at least one other place where similar mutable collagen can be found. This is between the pelvic bones of human females (and perhaps other mammals). One of the many hormonal changes that happen in women during child-bearing is the softening of this connective tissue to loosen the bones in the pelvic girdle, allowing them to move a bit relative to one another. With a 10-pounder in the womb, many women have been the perhaps unknowing, yet ever-so-slightly happier beneficiary of collagenous tissue softening. With all that yelling going on, most women aren’t thinking about that during the joyous occasion of childbirth, and who could blame them?

(Almost) all of this ran through my head as I looked at Heterocentrotus locked into its home, and after a few attempts to brute-force them out of there, I gave up. It felt like picking the rarest and most beautiful of flowers in the woods with a weed-whacker.


Filed under: Mooi,Philippines,Shallow Water — rmooi @ 3:24 am

May 18, 2011

Urchins are really into rock

I’m thinking that maybe there is a career in sea urchin dentistry.

While working at Sepok Point today, I came to realize that most of the biomass in sea urchins in the Verde Island Passage is arguably in the form of Echinometra mathaei, also known as the rock boring urchin.  The concept of a boring urchin is not new to my colleagues here, who are very gracious in tolerating my windy stories about what I think are remarkable animals.  However, Echinometra really does bore — right into rock.  It does this in part by abrasion from its formidable spines, but mostly by using its teeth.  Urchins actually have five teeth, mounted in a 5-part, radial jaw that can open and close like the chuck of a drill.  This jaw apparatus is known as Aristotle’s lantern, for reasons that are obscure and part of a strange history of urchin nomenclature.  But we’ll let that go for now or this blog entry will end up being a treatise, not a nature nugget.  Suffice it to say that the mouth of the urchin is situated on the bottom surface of the globose body, and large enough to allow protrusion of the Aristotle’s lantern so that it can chew on, um… the rock.

The 5 teeth of an urchin are sharp and chisel-shaped at the tip. Although they are largely made of limestone, the teeth are hardened by “doping” this limestone with magnesium, a process known as dolomitization.  The term, incidentally, derives from an Italian mountain chain known as the Dolomites.  The mountains are very hard limestone with… high magnesium content.  Who would have thought there was a connection between sea urchin dentition and mountains in Tyrol?

Anyway… these hard little teeth can do a lot of damage to rock, especially over the lifespan of a sea urchin.  Here is the culprit, removed from his (or her — it’s hard to tell from the outside) boring life in the rock:


In spite of the hardened teeth and fierce-looking spines, these little fellows are gardeners.  Sort of.  They don’t chew straight down into the rock, but make a channel, or a groove in the stone.  This channel is enlarged as the animal grows, and as it harvests its food.  This consists of algae growing in the channel.  Bare surfaces don’t stay that way for very long in the sea.  Algae is a very quick colonizer of newly exposed surfaces, including those chewed to nakedness by busy little urchin teeth.  As the urchin chews, it removes a bit of the rock along with the algal food, thereby doing two jobs — making a protective channel in which to live, and getting nutrition from the algae growing inside this home.  Soon, the rock can look a bit like Swiss cheese:


When the algae at one end of the channel are all eaten, the urchin moves along to the other, allowing regrowth of the plant cover.  By the time the urchin gets to the end of the channel, there is enough regrowth to make it worthwhile to move slowly back to the other end again, munching the newer algae as urchin inches along.  The rock is hard, but hey, the urchin has all day.  There is some evidence to suggest that individual urchins can keep this up for decades.  In light of that supposition, it’s no wonder that a perfectly good coastline can start to look like this for much of its length:


Which brings us to the question of urchin dentistry.  Now that I think of it, maybe the idea of being an echinoid dental practitioner needs some rethinking.  Besides being very hard, sea urchin teeth are advanced along the inside of the jaw as they wear out, providing fresh tooth tip as the old tip erodes away.  Urchin teeth are very cleverly designed as long shafts of tightly packed, minute plates such that as these flake off the worn end, they leave a fresh, sharp edge.  No need for night guards or other hideous plastic dental aides to prevent wear from gnashing or grinding.

One could say that the teeth are boring, but never dull.

Along some parts of the Mabini coast, I have noticed that young Echinometra start out in less boring accommodations.  They crawl into a dead barnacle, which has become a shell of its former self:


Presumably as they outgrow this living situation, the urchins crawl out of the barnacle and start a new channel, or get into an old groove left behind by an urchin who has gone on to that great cheeserock in the sky.

I should mention that there is an urchin that does burrow straight down into the rock, making a cylindrical shaft in which it can live like Timmy stuck in a shallow well.  This urchin, Echinostrephus aciculatus, has no need for rescue from Lassie, though, as it is perfectly shaped to fit into its tiny well, with the spines sticking out ever so much:


How Echinostrephus manages to make this amazing vertical shaft, which is several times as deep as the urchin is high, is not fully understood.  Presumably they use their Aristotle’s lantern as well.  The shaft of the boring is long enough that when disturbed, for example by an urchin-hunting echinoderm biologist, the urchin quickly skootches (to use the highly scientific term) down into the hole.  The animals are nicely designed for this.  The body is slightly conical, with a narrow end pointing downwards.  This end is furnished with lots of strong tube feet that pull the urchin downward.  The spines on the bottom of the body are very short, as opposed to the ones on the more exposed top, as can be seen in this laboriously extracted captive, flipped upside down (i.e. mouth upwards):


How this stationary urchin makes it’s living is not understood either.  Some claim that it snags bits of drifting food with the long, exposed spines.  One has to question whether that is enough.  They can’t farm like the Echinometra does, because it’s too dark down there in the recesses of the bore hole.

As usual, nature leaves me with no recourse but a fascinated shrug.

Filed under: Mooi,Philippines,Shallow Water — rmooi @ 8:57 am

May 13, 2011

Photosynthetic Slugs

This is by far one of my favorite animals collected on the expedition, I did not even knew these existed!

Marionia rubra

Marionia rubra

This slug’s sequesters/hosts single celled, algae as symbionts in its cerata (the fuzzy bits on its back).  The symbiosis is a mutualism: dinoflagellates from the genus Symbiodinium get raw materials required for photosynthesis and a safe place to live with full access to sunlight inside the slug’s body.  In return the dinos donate some portion of the sugars they generate from photosynthesis to the slug, meaning that most of the slug’s food is generated inside its body!

(Explanation courtesy of Dr. Michele Weber)

Elliott Jessup
Diving Safety Officer
California Academy of Sciences

Filed under: Academy,Diving,Jessup,Philippines,Shallow Water — ejessup @ 4:15 am

May 12, 2011

Shallow Water Team update

The Aquarium team has joined the shallow water expedition early this morning and have already made two dives. In spite of enduring a 13 hour flight that departed SFO at 11PM and arrived in Manila at 3 AM and a 2 hour drive south to the CAS field station, the aquarium team of Bart ShepherdMatt Wandell and Richard Ross were suited up and ready for their first dive in Balayan Bay only hours after arriving.

CAS Dive Safety Officer, Elliot Jessup debriefing new arrivals for their first dive
CAS Dive Safety Officer, Elliott Jessup debriefing new arrivals for their first dive.




Loading the boats


CAS videographer David McGuire preparing video equipment


Dr VanSyoc ready to go


Dito, Healy, Elliott, Terry and Beth motoring to dive sites.


Chrissy Piotrowski sampling something from the sand, probably some kind of worm


Sea Pen


Beth Moore searching for seahorses and pipefish


snowflake moray eel (Echidna nebulosa)


Very cute puffer fish


A little and big tunicate (a.k.a. urochordates or sea squirts)


this big puffy sea star (Choriaster granulatus) is about the size of a dinner plate


Dr Rich Mooi sharing one of his finds with Beth and Elliott


Dave Catania of CAS and Joseph of the Philippines National Museum processing samples from today’s dives


Terry Gosliner processing todays specimens.


The expedition is proceeding well with many new species being discovered every week,

Filed under: Philippines,Shallow Water,Simison — Brian Simison @ 3:51 am

May 10, 2011

New species up the wazoo

Very few biodiversity specialists can look at their plant or animal in the field and immediately be fairly certain that they have found a new species or not. Working on nudibranchs provides a luxury in that regard. When we find something we can be pretty sure that whatever we find is something recognizable or something we have not seen before. That provides us with a huge advantage when undertaking surveys like the 2011 Philippine Biodiversity Expedition. Things started off slowly, and we did not find any new species on the first eleven dives we made. I was starting to get a little concerned that maybe the trips here over the last 19 years had finally reached saturation; that we had finally found everything that was here. Boy, was I wrong. The next night dive, we found 8 new species on one dive. It was a shallow dive of only 17 feet, but it was slug city. Most were fairly smallish (about 0.5-10 mm) and several were fairly cryptic, but they were clearly new.

a new species of Favorinus that feeds on the eggs of other nudibranchs

A new species of Favorinus that feeds on the eggs of other nudibranchs

A new species of Philinopsis with a tail like a spaniel.

A new species of Philinopsis with a tail like a spaniel.

Cerberilla sp., a new species of sand-dwelling aeolid nudibranch

Cerberilla sp., a new species of sand-dwelling aeolid nudibranch

It is almost as exciting to find a known species that has not been found previously in the Philippines. We have come across several of these old friends from different places. One species, Trapania darvelli is striking and had been previously known only from Hong Kong, Malaysia, Vanuatu and the Solomon Islands. Our always sharp-eyed dive guide, Peri Paleracio, turned up a gorgeous specimen in 60 feet of water on a morning dive.

The first Trapania darvelli from the Philiippines

The first Trapania darvelli from the Philiippines

Last year my former postdoctoral collaborator, Shireen Fahey, and I named a new species based on only one specimen collected from Okinawa. It is always a bit dangerous to name a new species from one specimen, but we were convinced that it was so different from all known species that we felt confident enough to name it Dermatobranchus dendronephthyphagus. And while that sounds like a mouthful, it was given this name because it was found on the soft coral Dendronephthya. One of the other season dive guides at Club Ocellaris, Alexis Principe, spotted three more Dermatobranchus dendronephthyphagus on a night dive at a dive site called Basketball, the first records for the Philippines.

The first specimen of Dermatobranchus dendronephthyphagus

The first specimen of Dermatobranchus dendronephthyphagus

Again logic prevails in the naming of dive sites. The site is located off a basketball court near the southern tip of the Calumpan Peninsula.
The hunt for new species is back on a normal pace. We are now up to 27 new species and have another four known species never recorded previously from the Philippines. We are back to the pace we have been on for the last several years of finding an average of one new species per dive.

Filed under: Diving,Gosliner,Philippines,Shallow Water — tgosliner @ 8:37 am

May 8, 2011

Rubble with a Cause

While other Shallow Water researchers are busily gathering sea urchins, sieving sediment for sand dollars, spotting vibrant and cryptic miniature sea slugs, stalking elusive reef fish, and gardening the reef to harvest symbiotic barnacles, I….as odd as this is going to sound….am collecting rocks.

A tub of.....rocks???

A tub of.....rocks???

Not just any rocks, mind you….. specifically coral rubble rocks. Coral rubble consists of fragments of hermatypic (reef-forming) coral which, over time and during storms, have broken from the reef and rest on the seafloor, providing habitat and surface area for the settlement of new recruits.  I collect these coral rubble fragments in search of polychaete worms.

When diving on a coral reef, several fairly obvious species of polychaetes can be observed. Polychaetes are a highly diverse (about 10,000 known species) group of segmented marine “bristle worms” distantly related to earthworms and which occur in all habitats of all marine ecosystems.  Polychaete worms vary in size from a couple of millimeters up to 2 meters in length.  These organisms serve as an important food source for birds, fish and other invertebrates, function in symbiotic relationships with various other reef organisms, and may even bio-engineer reef environments.

Examples of polychaetes you may have encountered in photos or on reefs include the “Christmas tree worms” and “feather duster worms”. These two types of sedentary polychaetes can be easily observed living in tubes deeply buried within large sections of live coral.  Many other polychaetes are free-living and do not form permanent tubes.

Spirobranchus gaymardi, "christmas tree worms", on coral
Spirobranchus gigantea complex cf. gaymardi, “christmas tree worms”, on live coral
Sabellastarte indica "feather-duster worm"

Sabellastarte indica, "feather-duster worm"

We are strongly against destructive sampling activities that would adversely affect the reef, so I don’t collect these worms burrowed in live coral. Many of these are common species, anyhow, and are quite well-studied (although others may benefit from taxonomic revision or DNA comparisons with other populations).

However…let me tell you….the really interesting stuff is in the rocks! As I dive, I typically head for the “dead” looking section of the reef.  You know, the area you might pass over accidentally on your way to the cool-looking colorful stuff but would certainly not intentionally photograph because it’s all basically one greyish color and has little interesting macro-fauna living associated with it.
This is my hunting grounds.

Searching for worms under coral rubble

Searching for worms under coral rubble

I carefully turn over all the most interesting-looking rocks and coral rubble in the immediate area. Sometimes I get lucky and there might be an obvious larger animal sheltering under the rubble, using it for cover from daylight as it waits to forage at night. Other times, there may be a nice fat worm tube stuck to the underside of the rubble…that one’s a keeper.

Most of the time, though, I just select a few rocks that I think look particularly promising, bag them up in whirlpacks and add them to my collecting bag. My rock collection helps keep me stay neutrally buoyant as my tank grows lighter at the end of the dive, but if I go overboard on collecting heavy stuff our Dive Safety Officer, Elliot Jessup, is often around with a lift bag (similar to an orange partly-deflated balloon) to help me slowly transport my rubble to the surface.

Using a lift bag makes carrying rubble easy

Using a lift bag makes carrying rubble easy

Collecting rubble may seem like sort of a weird activity, and perhaps folks don’t get quite as worked up about admiring my catch of rocks at the end of a dive as they might, say, a cool new fish. However, after the rubble sits in the tub next to my microscope for a few hours, it becomes apparent that these chunks of rubble abound with tiny yet fascinating cryptic organisms. In most cases, animals that live within rubble remain hidden for part or all of their lives, and thus are less likely to have been studied yet by humans. We can learn a great deal about the true biodiversity of a coral reef from closely examining its rubble communities.

Each batch of rubble and all animals from it is labeled with data

Each batch of rubble and all animals from it is labeled with data

Small organisms use the crevices and spaces within rubble rocks for a hard surface to attach to or for a refuge that is safely hidden from large predators. Miniature food webs occur within a chunk of rubble.  Algae is fed upon by grazers, who may in turn be fed upon by small predators.  Many organisms live within rubble crevices for much of their reproductive lives, releasing gametes or buds into the water column from these safe confines during their reproductive periods (more about this in a future posting).

Syllidae, a small but striking worm from the rubble

Syllidae, a small but striking worm from the rubble

Eunice, another resident of rubble

Eunice, another resident of rubble

Communities of organisms inhabiting coral rubble have been used in scientific studies for measuring diversity, productivity, and general reef health. Some organisms living in these communities assist in the breakdown of the rubble itself, permitting the release of calcium carbonate into the water for use in building new reef structure.

Dorvilleidae, another worm from rubble

Dorvilleidae, another worm from rubble

For me, examining coral rubble is an excellent way to sample for the small and cryptic “sleeper” critters  (such as polychaete worms) which live hidden lives buried deep within the reef ecosystem, quietly providing critical services to the community.

Once I have my samples, I can return the rubble back to the seafloor to be colonized again.

Filed under: Academy,Diving,Philippines,Piotrowski,Shallow Water — cpiotrowski @ 4:16 pm

May 6, 2011

There’s just some sting about you…

This may surprise some of you out there, but I hear a lot of talk about sea urchins.  Especially from divers and snorkelers who’ve had the good/bad luck of encountering these gorgeous beasts.  The good luck is in observing some of the strangest of all the Earth’s marine animals.  The bad luck is in getting a bit too close to certain kinds.  I would like to highlight the latter concept a little bit, and perhaps clear up some of the misinformation out there.  Or simply add some information that isn’t all that easy to come by, even though urchins are among the most common and conspicuous animals you can see on a dive or in a tidepool.  Doing this during the Expedition is easy because, well, the diversity of the urchins here is pretty amazing, and they’re right out there off the place where we are staying in the case of most species, especially the ones who can cause some damage.

To recap, sea urchins (Echinoidea) are in the phylum Echinodermata (“echino” = spiny; “derm” = skin).  The urchins are related to things like starfish, brittlestars, sea cucumbers, and sea lilies.  The most familiar of the sea urchins are globose things, adorned with spines distributed over the body.  The shape of the urchin is maintained by a skeleton of tightly sutured columns of plates made of a type of limestone (a.k.a. calcium carbonate) secreted as a biological form of calcium carbonate called “stereom”, making a structure not unlike your skull in that it is covered with skin.  In urchins, this skin, or epithelium, even forms a thin layer over all the external appendages, including the spines.  The columns of plates are arranged in a radiating pattern based on five.  Why five is a subject for another day, perhaps.  Nevertheless, this is a powerfully unique way to identify an echinoderm.  Look for that 5-part radiating symmetry.  The mouth of a sea urchin is on the bottom, and the anus is on the top.  Because the skeleton is technically internal to the epithelium (and not external like the shell of a snail or clam), it gets a special name, the “test”.  There are lots of puns I could make here, but I’ll largely refrain and instead only indicate that terminology tests us all at times.  But new terms add precision, and that’s what science is all about.  So test it is.

Back to stinging.  It always startles and pleases me to learn just how many divers have learned the genus name of a sea urchin:  Diadema.  Necessity is the mother of learning, I guess, because the memory of the name is almost always linked to a negative encounter with this black-spined urchin that decorates so much of the world’s coral reefs.  I actually really like this animal, but this is not a unanimously held reaction.  However, with a little caution and awareness of where your body parts are while drifting over a mass of Diadema, you can enjoy the encounter quite unscathed.  I’ve been collecting and observing these guys for many years, and I’ve only been hit once in a way that really mattered.  It served to instill respect that I hold close to this very day.  Most of the black urchins with the really long spines belong to the genus Diadema.  There are two common species of Diadema in the Philippines’ reefs.  Here they are:


The one on the left, D. setosum, is arguably the most common species ’round these parts, and is easily distinguished from the one on the right when seen alive and under natural light by the amazingly bright red ring in the little raised area on the top of the body (called the anal sac).  In both species, there are beautiful patterns of iridescence on the top of the test, and this makes urchin-watching just that much more special.

When hidey-holes under coral rubble are available, D. setosum tends to be solitary and able to defend against attacks (usually by triggerfish if anecdotal reports hold) by directing spines outwards.  However, out in the open they become more gregarious, gathering in small gangs of nervous pincushions, with the spines just touching to maintain their own respectful distances, spines constantly waving a little, particularly towards changes in light and pressure waves from passing animals such as fish or divers.  The effect can be dramatic, with just the right hint of menace.


Look, but don’t touch.  The long spines are very, very sharp, and come to a point so fine that it’s hard to see precisely where they end in a watery medium where distances can be deceptive to start with.  The spines can penetrate flesh so easily and quickly that once you feel it, it’s way too late.  You’ve been perforated.  More than likely, the spine (or spines, if you are really unfortunate) will break off in the skin.  You can try to pull them out, but the delicate and easily broken structure of the spine (which is hollow) makes that difficult.  Most people know about the barbs, but what they don’t realize is that the barbs don’t point backwards toward the animal, but towards the tip of the spine.  So the damage is done going in.  The other common misconception is that these spines are poisonous.  It only feels that way.  Most of the post-encounter discomfort comes when tissues inside the hollow spine start to decompose and attract bacteria.

And remember that epithelium I mentioned?  It also can break down and cause infection in the wound. Best way to deal with that is to immerse the afflicted body part in vinegar.  This does three things.  It makes the urchin tissues inert to bacterial feasting, kills the bacteria themselves, and dissolves the spine skeleton, which is also made of the calcium carbonate stereom described above for the plates in the test.  Being limestony, this material fizzes and dissolves readily in any acid such as vinegar.  Vinegar adds to the hurtin’ at first, but trust me, it helps and greatly reduces future damage that can be caused by leaving the spine in there whole.  If you don’t have vinegar, you can also roll the skin around the spine or tweeze the spine in the wound until it crushes up into smaller pieces for your natural immune system defenses to deal with.

Although the long spines of Diadema are not venomous, there are toxin-bearing spines on all members of the family Diadematidae, to which Diadema belongs.  In Diadema, these are relatively short, very sharp (yes, even sharper than the long spines), and almost never reached by an errant hand or foot or whatever, because you hit those long “guard spines” first.  That generally keeps you from reaching the stinging spine layer, unless you are really unfortunate and set up for a trip to the hospital because you put all your weight down on a Diadema.  Each of these shorter spines has a slight swelling at the tip where gland cells in the epithelium make and accumulate a toxin that causes a real, honest-to-goodness sting.

Although these gland-bearing spines are hard to reach (or even see) in Diadema, they are really prominent in another diadematid genus, Echinothrix:


Again, we have two species common in the Philippines.  E. calamaris has lighter spines, with beige or brown on the test, a nicely speckled anal cone (not a phrase you will see everyday), and very obvious and exposed, light brown spines tipped with poison glands, as in the close-up below (red arrow).


Note that the long spines of this close relative of Diadema are not sharp.  In fact, they are hollow with thin walls, like a straw with the end closed off.  In the juveniles, these spines are so large relative to the test that the urchin looks like it’s carrying little, narrow vases sticking out from its test.  Weird.

The other Echinothrix, which is very black with very nice, blue iridescent patches on the test, also has these shorter, poison-bearing spines.  You can see this iridescence and the poison glands (red arrow again) well when you get close up.


Then there is the fire urchin, Asthenosoma varium.  This is an urchin whose characteristics are so unusual I just have to tell you about it.  It’s also common in coral reefs just about everywhere.  Nature has found a special way to tell us “do not touch this animal”.  The bright colors might be inviting, but when you see that in nature, it usually hints at something dangerous.   This lovely photo is courtesy of Terry Gosliner, who has the same respect for this relatively large and powerful stinger as I do:


The test of this urchin, which can exceed 20 cm across, is flexible because the plates that make it up are separated by connective tissues that allow the plates to hinge against each other.  The urchin keeps its shape by gently inflating itself with sea water, but if you poke it (use something other than a body part, please), it yields a bit like a crunchy balloon.  The fire urchin uses this feature to get into crevices, and possibly also to economize on the metabolically expensive calcium carbonate that other urchins use to make up their stiffer tests.  This isn’t so much a factor in coral reefs, where dissolved calcium carbonate is relatively abundant.  But this urchin species has as its closest relatives a bunch of equally bizarre forms that live in the deepest parts of the ocean.  Evolutionary studies show that the ancestors of the fire urchin live in the abyss where calcium carbonate is harder to come by and to shape into urchin skeletal parts, selecting for species with thin, flexible tests in which calcium carbonate is used sparingly.  And guess what?  Those deep-sea relatives of A. varium compensate for the relative lack of an armored test by having the worst stinging capability of any urchin that I know.  I got hit by one in my left middle finger while doing deep-sea work in the Bahamas — just a tiny pinprick of one spine — and my left arm was useless for several hours.

Here is a close up of the spines on a fire urchin.  Most of that blobby, balloon-like tissue on the spines is filled with toxin.  Never pick up a fire urchin.  There is some evidence to suggest that you could go into shock if enough spines zap you at the same time.


Finally, I would like to mention one more stinging urchin with a difference.  This one hurts a lot, but not because of the spines.  The so-called “flower urchin”, Toxopneustes pileolus, is another one very pretty to look at, but deserving of respect:


The flowers are not spines, but a special structure unique to urchins called pedicellariae (for you sticklers — pun intended — out there, the pedicellariae on starfish are an independent evolutionary invention and only superficially similar to urchin pedicellariae). Pedicellariae (singular: pedicellaria — not “pedicellarium”) are ice-tong-like pincers mounted on the ends of stalks interspersed all over the test among the spines.  All urchins have pedicellariae, but they are usually small and inconspicuous, and too small to do any damage unless you are a tiny barnacle larva trying to find a nice home to stick to on the top of a sea urchin.  This is the usual type of thing that pedicellariae are used to defend against.  In Toxopneustes, the spines are very short and not very sharp.  This urchin protects itself from larger animals with the grossly enlarged pedicellariae instead.  Although they look like flowers, inside the pink fleshy bit that makes the “bloom” are three tongs that meet together at their points when the “flower” closes, tearing a hole in the transgressor’s flesh and injecting a toxin into the wound:


You can tell when the animal is all worked up and in the urchin equivalent of “DEFCON 1″ when the whitish spines lie down to expose the open jaws of the pedicellariae.  Put your hand on that and you’ll get a powerful dose of toxins from several pedicellariae at once.  A complicating factor is that this urchin, like many other species, likes to cover itself with bits of coral rubble, sometimes making it hard to see in the shadows.  Still, a beautiful animal and always interesting to see in its native habitat. It’s a real favorite of underwater photographers with an interest in abstract art.

So that’s my primer on stinging urchins.  I wanted to call this blog, “Oh test, where is thy sting?”, but I wasn’t sure if that might have been a bit unforgivable — or even obscure.  Heck, I don’t know my Shakespearean sonnets or Corinthians either.


Filed under: Mooi,Philippines,Shallow Water — rmooi @ 10:41 pm

May 4, 2011

The Underwater Gardener

As the Collection Manager of invertebrates (except for insects and arachnids) at the Academy, I have at least a passing interest in most animals without backbones.  The variation in body forms and lifestyles among these animals never ceases to fascinate and often boggles the mind.

My research is focused primarily on barnacles, the shrimp-like animals that make a hard shell to protect themselves from the rest of the world.

Boaters are familiar with barnacles as those pests that attach themselves to boat hulls.  Barnacle guys like me, however, often look for them living attached to other animals.  Barnacles of various sorts have evolved special adaptations that allow them to live on or in whales, sea turtles, sea snakes, crabs, lobsters, corals, and sponges.

With the Academy’s Dr. Gary Williams and Dana Carrison, I’ve been studying barnacles in the genus Conopea. This group of barnacles lives only on certain types of seafan or seawhip corals.


Seafan with barnacle gall in center of image

Seafan with barnacle gall in center of image

Photo: Bob Van Syoc

IMG_3571Photo: Bob Van Syoc

In the summer of 2009, Gary and I advised Liezl Madrona in the Summer Systematics Institute program at the Academy.


Liezl studied the Academy’s current collection of Philippines Conopea and discovered 3 new species among the unidentified specimens on our shelves.  Certainly, the collections resulting from the Philippines Biodiversity Expedition will add greatly to that number.

Collecting Conopea galls requires a sharp eye, something that I have now only with the aid of magnifying lens in the lower part of my mask, and a sharp pair of sturdy shears.

IMG_2780Photo: Elliott Jessup

I’ve become an “underwater gardener” of sorts.  Looking for little bumps on seafans and seawhips, then pulling my shears out of my mesh bag and trimming them off the coral “bush”.  This method of collecting allows the coral colony to live and continue to grow and provide habitat for more of my little Conopea friends.

IMG_2747Photo: Elliott Jessup

It’s difficult to know exactly how many species of Conopea barnacles we’ve collected on our Expedition to date.  We’ll only know that after we’ve carefully dissecting them in our lab at the Academy and compared them to the known species.  However, based on our previous work with Liezl and Dana, I think we have several new species to work up and describe.

There will certainly be more.  The underwater coral gardens of the Philippines extend out for many miles in all directions.  My shears will be busy trimming away small branches.


Filed under: Academy,Diving,Philippines,Shallow Water,Van Syoc — bvansyoc @ 2:23 am
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