Okeanos footage

National Geographic is hosting some nice footage of a submarine volcano in Indonesia.  The video was gathered as part of the Okeanos Explorer and its current collaborative research cruise between NOAA and the Indonesian Government

The footage shows some impressive fields of stalked barnacles, an abundance of shrimp and some really cool sulfide chimneys and elemental sulfur flows.

Whats in a name? Origins of the word "shark"

To a recent roundup of whale shark news, I appended a sort of human interest one-liner about how “shark” is the only word in the English language that derives from a Yucatec (Mayan) Indian word – “Xoc” (pronounced like “shock”). It was just one of those factoid tidbits picked up somewhere along the line of life, maybe while working in Mexico, I don’t remember. It tickled some interest from blogger @hectocotyli on Twitter, who posted a follow-up tweet questioning whether this was actually true, and citing a paper by Tom Jones, from the 5th Palenque Roundtable in 1983. That paper is entirely devoted to the question of the origins of the word shark. I read it and was transported, what a great story! So here it is then, a deeper look at the origins of this word "shark", with thanks to @hectocotlyi for having an inquiring mind and for finding the paper.

According to Jones, the very first mention of the word shark in association with the animal for which we use the name today was in a 1668 work by John Wilkes. One of the first mentions of the word in a diuctionary, however,  is in an anonymous work from 1689, which defines a shark as a “shifting knave”. In other words, a crook, dodgy sort or general baddie. That was surprising to me, because I had just assumed that the use of shark for a shifty character was a much more modern one derived from the noun referring to the animal wif de big nasty teef. Bailey’s Dictionary in 1724 used “scearan” as the likely origin for the word: a saxon term meaning “cut to pieces”. Webster took a different tack in his 1828 dictionary, accepting a theory that it comes from the greek word “carcharias” (sharp tooth), even though that word clearly has a typical Greek hard c sound, not the soft start of shark. These days, Oxford English Dictionary just says “of obscure origin” and to me that might be the best answer, if you insist on a European etymology.

The major alternative explanation is that the word comes from the Yucatec Indian word “xoc”. Now, explaining what the word xoc means in Mayan is not as simple as it would be for European languages; Mayan language groups are apparently among the most arcane and problematic for linguists to study, especially for the bizarre glyphic written forms. Jones goes into the issues in great detail, and its a fascinating read, but I could summarise by saying that at best the word refers specifically to sharks as we know them, and at worst to an ill-defined group of toothy aquatic animals that might also include large fish, crocodiles and toothed whales, in both fresh and salt water. There’s lots of usage examples to support the idea that it means sharks, though, including “xoc yee halal” which are arrows with sharks teeth for points, and “uayab xoc” which is a sort of demon or were-shark, part man and part shark. Its not that simple though, because xoc can also mean “to count to” or to refer to dates ahead or behind. In Mayan glyphic writing, glyphs are apparently freely substituted for other words or parts of words that are pronounced in similar fashion, even though the agreed meaning of the glyphs (or bits of ther glyph, sort of like syllables) may be radically different, which really confuses the issue and is a big part of the reason why written Mayan took so long to decode. In the glyphs from the Jones paper shown below, for example, the middle glyph is a counting glyph with the same meaning as the one on the right, but incorporates the glyph for xoc, of which the stand alone version is shown on the left. To me another obvious clue here is that the glyph for xoc is the head and mouth of a beast, even when used to mean "to count",  which seems to fit well the definition in the broad sense. The beast even has a rostrum of sorts, and triangular teeth.

If the usage roughly matches, then, how would a Mayan word make it to English?  Given that the Spanish and Portuguese were in closer contact with the New World earlier than the English, why would English not pick up the Spanish “tiburón”.  Put another way, why does the Iberian word not also resemble “xoc”? If it’s true that shark is of Mayan origin, then it must be a standalone jump – somehow going from Yucatec to English, skipping Spanish and Portuguese.  For the etymologists, it seems that this lack of intermediate steps or of words that share the same origin, which they call “cognates”, is a real problem for accepting the Yucatec origin of “xoc”.

Jones proposes a way that this could have happened, on the expeditions of John Hawkins from England to the Caribbean in the late 1560’s (incidentally, Hawkins was a pioneer of the English slave trade). Further, Jones proposes that the critical moment may have been an unanticipated battle between Hawkins and some Spanish ships forced to share moorings near Campeche in 1569.  The fight resulted in the destruction of several vessels from both sides and some pretty heavy losses, with over 200 of the English eventually consolidating onto a single ship called the Judith and heading for home.  Jones suggests that a shark frenzy feeding on the unfortunate victims of the battle – and on those who died of hunger and disease on the crowded Judith over subsequent days - might have created an indelible impression on the English (only 15 of whom made it back to Cornwall), enough to cement in their lexicon the local name for these demons of the sea.

As a complete linguistic noob, I find the proposed Mayan origins of shark to be more plausible than the Greek or Saxon suggestions. More importantly, though, it’s a way better story, and when there’s that much uncertainty, I’ll always choose the explanation that involves the greater ration of mysterious glyphic languages and dramatic ship battles on the high seas, wouldn’t you?

Whats happening all the time in 90% of the oceans, and half the time in the other 10%

To explain the title a little better - most of the oceans are in total darkness all the time, and even the sunlit zone is an inky realm every night when our star visits the other side of the planet.  Accepting that we can't easily visit the bathypelagic zone (the deepest bits) without submersibles or ROV's (remotely operated vehicles), then perhaps the best feel we can get for what's happening in the vast majority of the oceans is to don SCUBA gear and dive the surface of the open ocean, but in the dark.  In preparation for doing a bit of that later this year, I've been looking at "black water night diving" stuff on YouTube.  Honestly, the idea invokes in me a healthy amount of fear, but if these videos are anything to go on, then I hope that will soon be replaced by wonderment and fascination.

Pelagic plankton. I love the flatfish at 0:28. If you know what the spongy looking thing at 1:40 and 4:04 is, please let me know.

Humboldt squids - I especially liked the face-on attack at 2:00 and the strobing at 2:30

I guess this is the most obvious anxiety. The one at 1:20 just gives me the heebie-jeebies!

This video isn't so much pelagic as reef, but the spawning sea cucumbers and then the palolo worms about 5:40 in are just great, and I love the music, which (curiously) is from that abysmal Mel Gibson flick Passion of the Christ.

Play Bit-o-Critter Round 26

OK folks, I'll take the genus name for organism in the top half of the photo, with a bonus for the other organism in the bottom half.  If you couldn't tell that this was two organisms, then there you go, I just gave you a hint. :-)

The solution to Bit-o-Critter round 25

After some time, Sarah F. was able to get both of the Round 25 Bit-o-Critters.  Congrats, enjoy the warm inner glow of vanquishing your opponents.

25A was one of the more common salps, Salpa cylindrica.  As Sarah noted in her answer, salps are "pelagic tunicates that graze on phytoplankton. They can be found as asexual, solitary individuals or in long chains. Salps are also important in carbon cycling in the ocean."  One of the other cool things about salps is how they move; they're basically little jet engines.  The ridges you see along the body in the photo below are muscle bands that can be squeezed in sequence to push water through a central canal and jet them along through the water.  Some salps are surprisingly powerful swimmer.  Photo credit: Census of Marine Zooplankton

25B was a sea angel or Clione sp.  Even though they are about as far from snails as you can imagine, they are actually molluscs.  They're pteropods (= wing-foot), which is one of two groups of exclusively pelagic molluscs (the other being heteropods).  A photo doesn't do them justice, so instead enjoy this weird and mildly amusing Japanese video of a Clione gently swimming, and then violently attacking its lunch, to the tune of....well, just watch it and see...

If you have any idea what they are saying, I'd love to know...

PS to the WS thread...

The Whale shark that I mentioned in yesterdays thread as having been caught in Pakistan was not claimed by the Sindh Wildlife Department (citing lack of funds) but was instead butchered and sold right off the beach.  The liver was sold for 800 Pakistani rupees and will be used to waterproof the hulls of fishing boats, and the rest of the carcass was sold for 500 rupees.

How much is that in US dollars?  $9.30 and $5.83, respectively...

Whale shark news roundup

Photo: Bruce Carlson/Marj Awai

There’s a heck of a lot going on in the world of whale sharks right now, so I thought a news roundup was in order.

Blogger GrrlScientist has a nice blog post up about whale sharks right now, over at Scientist Interrupted

Sad news about a whale shark that was trapped in fishing nets in Pakistan and died. I have no idea what the scientist is talking about when he describes them as “inefficient swimmers”; as far as we know they are paragons of efficiency. I also have my suspicions about whether this animal was actually dead when it was brought back to shore. In a different story about the same event, it described the animal as being alive when the fisherman found it, tail-looped it and dragged it back to the beach, and how its illegal to fish for them, but legal to use them as you like if they die accidentally, hmmm....  Without witnesses, I guess we'll never know.

Our collaborator Bob Hueter from the Shark Research Lab at Mote Marine Laboratory is following an animal dubbed Sara in the Gulf of Mexico, who has been affixed with a real-time satellite tag. So far she is avoiding the worst affected area of the BP oil spill, which is a relief. Follow her movements here.

Unfortunately, other whale sharks don’t appear to be avoiding the pollution. NOAA scientists last week observed whale sharks among ribbons of surface oil, not 4 miles from the Deepwater Horizon wellhead. If whale sharks are unable to avoid the oil, it’s a potential disaster because the anatomy of their gills and filter-feeding apparatus are superbly susceptible to fouling, as I discussed in a recent blog post.

One of my projects is getting a bit of press this week. Georgia Aquarium has entered into a collaboration with the Core Sequencing Facility at Emory University to start sequencing the genome of the whale shark. It’s a huge job, but the lab at Emory, led by Dr. Tim Read, are up to the task! They’re using Roche 454 pyrosequencers to generate a survey sequence right now, from DNA we isolated in the lab at the aquarium. Its exciting stuff and was picked up on the AP wire. Read an example here, or just google “whale shark genome emory”

University of Southern Mississippi research Eric Hoffmayer was lucky enough to observe an aggregation of about 100 whale sharks off the coast of Louisiana last week, accompanied by legendary marine explorer and Nat Geo guru Sylvia Earle.  Eric has been working with that population for some time, but as far as I know thats the most he's ever seen in one place.  Lets hope they are animals avoiding the oil spill.

And, finally, the 3rd annual Whale Shark Festival is scheduled to get underway in Isla Mujeres, Mexico, next Friday the 16th.  I'll be there with other scientists including Bob Hueter and Rafael de la Parra, talking publically about whale sharks in the Gulf and the other amazing marine biology of the Yucatan.  There's also going to be a film festival and cultural activities highlighting Quintana Roo.  Did you know that "shark" is one of the only English words with a Yucatec Indian origin?  Its comes from the Mayan "Xoc".  Hope you can join us!

Implications of the first sighting of whale sharks in the gulf oil slick

I recently experienced a moment of genuine dread regarding the oil spill in the Gulf of Mexico, and it was neither a familiar nor comfortable feeling. What is it that invoked such a powerful feeling after a disaster that has been underway for the last 80-odd days, now? Something that struck a little close to home, of course: the first direct impact to whale sharks. You may have seen this story coming across the wires over the past two days about NOAA scientists who, while on an aerial survey of the impacted area, observed 3 whale sharks swimming among ribbons of surface oil, not 4 miles from the epicenter of the Deepwater Horizon spill. This observation has serious implications; let me explain.

Whale sharks are widely-ranging tropical migratory sharks that are unusual among their more toothy relatives in that they eat plankton. Two of the adaptations they use to pursue this lifestyle – surface filter feeding and an exquisite sense of smell – make them especially susceptible to the impacts of the oil spill. I had all but convinced myself (perhaps wishfully thinking) that whale sharks would be able to sense the altered chemistry of the affected water bodies and avoid the area. It now seems that this is not the case; the observation by the NOAA scientists suggest that either whale sharks cannot tell the difference between polluted and unpolluted water, or they can tell the difference but do not alter their behaviour in such a way as to avoid the ribbons and plumes. As USM researcher Eric Hoffmayer states in the article, this is the realization of the worst fears of whale shark scientists, and I count myself among those.

How can it be that whale sharks are unable to tell the difference if their sense of smell is so good? One simple explanation is that the olfactory abilities may be extremely selective. Scientists don’t know exactly what sort of chemicals whale sharks are homing in on when they seek out patches of food in the ocean – indeed, addressing this question is one of the goals of this year’s whale shark research program at Georgia Aquarium – but we have some good candidate molecules. If the whale shark sense of smell is highly tuned to these compounds and relatively insensitive to other families of chemicals, like hydrocarbons (oil and gas), then it’s certainly possible that whale sharks simply cannot detect the problem.

That’s when the second adaptation, surface filter feeding, becomes a liability for whale sharks trying to negotiate the deadly emulsions and surface slicks in the Gulf. To fully appreciate why this is such a problem, we need to look a little more closely at the filtration apparatus whale sharks use to feed.

Like most plankton-feeding fishes, whale sharks use filters in the mouth/gill cavity to sift food particles from the water (see the exellent illustration by Emily Damstra at right). And like most plankton-feeding fishes, these filters develop from structures associated with the gills and gill rakers (cartilaginous rods that come off the leading edge of the gills and protect the gills from fouling and shape the current of water across the breathing surface). Where whale sharks differ radically from other planktivores like, say, anchovies, is that they do not have feathery interlocking gill rakers that serve to filter the plankton but can be disengaged from each other to allow bulk water flow out through the gill opening. Rather, their filters are so derived and so heavily branched that they form a single continuous pad that occupies the space between gill arches; it looks a lot like a black scouring pad. The gill arches cannot be disengaged from each other; thus, anything that goes in the mouth must be small enough to pass through the filters (less than 2mm, or about 1/12th of an inch), or it must be swallowed, or be spat back out through the mouth (something they are surprisingly good at!). In a paper currently in the review process, comparative anatomist Phil Motta from USF is describing the full functional anatomy of these structures; he took the photo of the filter pad surface shown hereabouts based on material samples from Georgia Aquarium.

The implication here is that oil that finds its way into the mouth, if it is not to be swallowed or to foul the filters, must be continually spat back. OK, I hear you say, perhaps if the whale sharks avoid feeding, there won’t be a problem. If only it were that easy. Whale sharks do not only use their mouths for feeding, they use them for breathing. They need to be passing water continually across the filters and thence across the gills, in order to keep the body supplied with oxygen. For the whale shark swimming in oil-affected waters, therefore, the animal’s breathing needs and the susceptibility of their feeding filters to fouling are in complete opposition.

If whale sharks are swimming into oil-polluted waters and fouling their filters with oil, what does that mean? In my best estimation, it means that the oil spill represents an extremely serious threat to whale shark health. I am by no means the first person to suggest this. Nature identified whale sharks as one of the 5 species most likely to be affected by the oil spill, and other scientists like Bob Hueter from Mote Marine Laboratory have also highlighted the risks. The true toll that the spill exacts on the Gulf of Mexico whale shark population will not be known for some time, but the thought of dead or dying whale sharks sinking silently into the depths (dead sharks generally sink, not float) is yet more motivation to put an end to the spill and to undertake immediate and extensive research and conservation programs to assess the damage and plan a road to recovery for the whale sharks – and all the other affected wildlife – in the Gulf of Mexico.

Disconnect in 3... 2... 1...

Things will probably be a little quiet on here for the next week or so as I take some much needed vacation time.  In the meantime, nobody has guessed at Bit-o-Critter round 25 yet, so now's your chance to swoop in for the kill!

Two videos from our recent Mexico sojourn

Below are two short videos showing some of what we got up to on a recent lightning fast trip to Mexico, footage that our AV folks spliced together from a FLIP camera I took along.  We had heard word of whale sharks gathering at one of our research sites, so I threw together a quick trip and Jeff Reid, the Aquarium's DSO, and I went down to scope it out.  It wasn't hard science this time; mostly a reconnaissance boat survey and an aerial survey, and getting to grips with the logistics for the big trips that will happen later this summer (more about those in future posts).  But at least they give a sense of what its like down there.  Next time I will try to hold the camera a bit more steady, but in the meantime - enjoy.

Play Bit-o-Critter, round 25

OK, since yesterday's BoC went off so quickly, here's another round hot on the heels.  A double header this time.  See if you can identify the following two animals from just the bit shown.  Post your best guess in the comments section.  The winner gets bragging rights and a smug sense of self satisfaction.  First one I would like at least genus, the second one I'll accept the common or scientific name for the group.

25A

25B

The solution to that pesky Bit-o-Critter, round 23b

Commenter Will Edwards just successfully identified the BoC wrasse from Round 23 as Ophthalmolepis lineolatus, or what we Aussies like to call a Maori wrasse.  I think the common name comes from the blue lines on the face and their resemblance to the facial tattoos of several Polynesian peoples.  Its a temperate rocky shore wrasse not to be confused with the humphead maori wrasse or Napoleon wrasse Cheilinus undulatus, which is a huge beast of a thing from coral reefs.

I grew up catching O. lineolatus off the rocks in S.E. Australia with my dad, usuallly using a peeled shrimp on a No. 2 hook on a paternoster rig.  We would also catch mado sweep, which we called "footballers" (striped jersey), mono's, which we called "butter bream" and the occasional luderick, which we called "blackfish".  I looked on jealously while older guys would cast ganged pilchards with an Alvey, way out into the wash in the hopes of tailor (Americans call them bluefish) or even a kingfish (US = yellowtail) or mulloway.  I also remember my dad dressing me down one one time because I left a packet of shrimp bait in the trunk (Australia...summetime...you get the idea).  When we went to pile into the car and drive home the next day, well, lets just say I wasnt so comfortable sitting down...  Good times, good times...

Picture - Australian Museum

The solution to Bit-o-Critter round 24

Well that was quick; I guess I made it too easy.  Heather D guessed correctly that it was the beautiful Pyjama Squid, Sepioloidea lineolata.  These gorgeous little cephalopods hail from my home country of Australia, just like the wrasse in BoC 23b, which is still up for grabs.  I think technically pyjama squids are a cuttlefish because the eye is a slit not a round pupil and because the undulating fin runs the full margin of the hood.  I could be wrong, but thats what I was always taught.  Perhaps someone with more cephalopod knowledge can chime in here.

Photo credit: Mark Norman @ the cephalopod page

Play Bit-o-Critter, round 24

So here's the next round of Bit-o-Critter.  I'd like a full common name, scientific name gets bonus points.

We still don't have an answer on Round 23b, the wrasse-like fish.  Here's a hint, you have to think about where I'm from (Australia).  That and the photo is enough to get you to species.