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Echinodermata! Starfish! Sea Urchins! Sea Cucumbers! Stone Lillies! Feather Stars! Blastozoans! Sea Daisies!Marine invertebrates found throughout the world's oceans with a rich and ancient fossil legacy. Their biology and evolution includes a wide range of crazy and wonderful things. Let me share those things with YOU!

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    So, every once in awhile, I decide to go off-topic and do something weird to break up the monotony and WHAT better way to do that than to go off and dabble with cephalopods for awhile!

    I did this last year and showed some weird artsy pics from a friend who did some cool Japanese-monster inspired art! 

    I've done similar posts where I show how invertebrates have inspired pop culture. Here is the one I did for starfish awhile back..

    It seemed like THIS year, it might be fun to actually show what some of the characters from Japanese pop culture (movies, TV and toys!  actually LOOK like!  (esp. with Halloween just a few weeks away)

    GEZORA the giant cuttlefish from Yog-the Monster from Space! 
    Gezora stands 30 meters tall (98 feet) and apparently weighs 20,000 tons! Basically- a cuttlefish infected by extraterrestrial microbes! It kicks ASS! It first appeared in the 1970 classic "Space Amoeba" produced by Toho-the fine people who bring you the Godzilla movies!

    Here's a neat slide show of various posters and screen shots from the movie...

    from the people who broughtyou Godzilla!  Gezora shows up at 0:50

    This movie came out in 2004. Its about uh...well, a wrestler who becomes a giant squid!  One great part of this flick?  In the end he goes toe to toe with ANOTHER giant invertebrate! (no spoilers though!)

    Japanese Cephalopod TV Monsters!
    There's a long history of super heroes on TV in Japan-you've probably heard of characters such as Ultraman or the Power Rangers but one of the more popular, but less well-known in the US (unless you live in Hawaii) are franchises such as Masked (or Kamen) Rider. 

    Almost all of these shows were serialized and went from week to week with a monster every episode.

    What happens when you have to create a monster for your hero to fight every week?? You come up with a creative theme that's what!  Here are just a few of the ones I'm fond of!

    SQUIDFIRE! This lovely fellow is from the show Kamen Rider V3! And you guessed it he is a cyborg squid with.... A flamethrower!! 
    It uses propane and propane related products!

    AMMONITE KAIJIN (Kaijin="Monster Man') from Kamen Rider Black!

    A neat monster whose particular distinction was that the ammonite (serving as the monster's head) was kicked OFF his body early in the episode, leaving the rest of him wandering around and chasing after it!

    The disembodied ammonite, in the meantime befriended a small child and learned the meaning of kindness. I don't make this stuff up!
    The fearsome IKADEVIL (aka theDEVIL SQUID)! (from Kamen Rider)

    And this neatSQUID KAIJIN from Kamen Rider Black!
    From Ultraman 80 the gigantic octopus monster DARRON! Ya' just gotta love how they work the tentacles over the legs in all of these costumes..

    The big bad GATANAZOA from Ultraman Tiga! Kind of a hybrid between a crab and an ammonite..
    There are undoubtedly more! And one of these days..maybe I'll follow up...

    What I love about the Japanese culture is just how serious they take their collectibles and toys. Great care is given to items in a way that is seen nowhere else in the world..

    For example, here is an ammonite "candy toy"-an item that usually accompanies a piece of chocolate or some other item (kind of the way a baseball card used to accompany chewing gum).

    There is a series of these items that one collects and people sometimes hundreds of dollars to chase down a complete set of these...(the other items are mostly dinosaurs and other giant marine reptiles)

    This represents an actual species of coiled shell ammonite-but not sure off the top of my head, which one it is..

    Here is aLego ammonitethat I found how to construct here.
    And where would we be without a transforming robot?? This one is a bit of cheat since I think this might be something easily available in the US..   But its from Beast Wars: Transformers-and is called "Neo Dead End"
    It goes from this...
    To this... 
    Its great to see how cephalopods- and not just living ones-but fossils have worked their way into international pop culture!  (now let's just hope that people who see these things figure out what inspired them!)

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    Various shots of the snail Cyclonema feeding on the anal vent of the crinoid Glyptocrinus decadactylus from the excellent page of the Kentucky Paleontological Society

    So, today is National FOSSIL DAY! WOO!!  and y'know, I figure WHAT do people WANT to see on National Fossil Day???

    OBVIOUSLY the answer is PARASITES!! (and related stuff like commensals!) Everyone LOVES parasites! Especially echinoderm parasites! Its especially exotic when you can see them as fossils!

    To be fair, some of the relationships below are probably better described as "commensal" which means that one derives gain from the host without the host losing resources..

    What's often most exciting about these kinds of fossils is that we actually have DIRECT EVIDENCE of animal interaction!  Which for the fossil record is often difficult.

    We can see that fish had big bone-crushing teeth and we can even see broken snails nearby on a fossil deposit, but after 300 million years, you have to be careful about conclusions.  This is often what makes good reliable evidence of paleoecology so valuable..

    Here are 5 interesting cases of parasitism/associations/commensals on echinoderms from the fossil record! There are undoubtedly more...

    Go here to see a neat free review account by paleontologists Tom Baumiller and Forest Gahn with a list of the many different cases! 

    1. Paleozoic Platyceratid Snails on Stalked Crinoids!
    This one is probably one of the best known among fossils.  Basically there is one Paleozoic group of snails belonging to the family Platyceratidae. They often look like this:
    Platyceras  gebhardi - Hamilton group Image by Ivanvlee8 on Flickr

    Multiple genera have been observed in a specific position right on top of the calyx or "cup" in stalked crinoids.
     Here's what the animal typically looks like to give you a general bearing.
    From the TOL Crinoidea

    What the snails seem most interested in is the anal cone found on the TOP of the cup (this is the area where the mouth is found and is surrounded by the feeding arms). They are often found clamped down over the anus.

    Most interpretations suggest that platyceratid snails are  COPROPHAGES. That is a special kind of feeding which specializes on consuming POOP!

    There are literally dozens of papers on the paleoecology and biology of these animals..and so I will leave this interaction to be written up in a later blog... But platyceratids are found on MANY different crinoids AND other stalked echinoderms from the Paleozoic, such as blastoids (see this account by Tom Baumiller)!

    But that will be a story for next time...
    snail Cyclonema on Glyptocrinus from the Awesome Kentucky Paleontological Society page! 
    2. Snails that are parasites on Cretaceous (Mesozoic) to Paleocene (Cenozoic) sea urchins
    This fossil was reported by colleague Christian Neumann (see his website here) and Max Wisshak from this issue of 2009's Palaeogreography, Paleoclimatology, Palaeoecology...

    Basically Neumann discovered fossils, such as this Cretaceous urchin Echinocorys conica with this holes and marks in the body...

    Fig. 2 from Newmann & Wisshak
    and also in this specimen of the same species showing more of these discrete holes on the test...

    These holes were compared against the kinds of holes made by modern day gastropods in the family Eulimidae which are often seen as parasites on starfish such as the blue Linckia laevigata shown here... (images by Sven DeVos on Flickr)
    Thyca cristallina (SDV_5874)
    Thyca cristallina (SDV_5874)

    Snails like this basically pop their proboscis into the body wall and take advantage of the host as prey. Its thought that they occur on a relatively low number of the total population. 

    3. A Shelled amoeba (Foraminifera) parasitic on a Cretaceous Sea Urchin
    Christian Neumann and Max Wisshak have yet another paper in Ichnos (fr. 2006)!

    This time showing how a shelled amoeba (i.e. a foraminifera also informally referred to as "forams") has parasitized the Cretaceous urchin Echinocorys (same species as the one above).

    Their story here is this: Some forams will attach to an animals' shell or other hard bottom. Below is an example of one from the shell of a bivalve.

    Notice how it leaves that prominent attachment scar on the right after its been detached...
    figure 2 from Neumann and Wisshak from Ichnos
     Neumann and Wisshak observe this on 19 different locations (and thus 19 individual parasitic forams) on the test of this fossil sea urchin! Note that the big curvy worm tube isn't part of the foram traces...

    4. Symbiotic Relationship between a polychaete worm that bores into Cretaceous German Sea Urchins
    And yet another paper by the industrious Max Wisshak and Christian Neumann in Acta Palaeontologica Polonica 51: 589-597! This one can be downloaded here!

    Here Wisshak and Neumann document borings in the sea urchin's skeleton via the work of an industrious polychaete worm-a polydorid!  Such worms bore though hard substrates and are asociated with tunnels such as this:
    St Margaret's Bay: Polydora borings Image by elegaer on Flickr

    But how can you be SURE that these worms didn't just find the dead animal's skeleton and bore through that??   Why make the jump to "These holes were made in the animal when it was alive"???

    This cartoon basically shows that following the worm's "boring" through the skeleton and the deformation of the skeleton by the worm..the surface spines and other structures- pedicellarie, etc. ALL REGREW over the area that had been "bored" through!!
    Figure 5 from Wisshak and Neumann

    Here are pics of the actual borings through the sea urchin test..
    Figure 2 from Wisshak and Neumann
    5. Jurassic Worm Parasites (Myzostomes) living in crinoid arms
    Finally! This neat account was described by colleague Hans Hess in the Journal of Paleontology recently in 2010! (click here for abstract)

    Myzostomes are annelid worms (the same group of segmented worms that includes earthworms, scale worms and so forth) that live as parasites on various invertebrates, but especially crinoids!

    My colleague Greg Rouse at UC San Diego studies these! Modern day myzostome worms look like this (underside shown):

    These worms live on crinoid arms like this (the worms are the brown and yellow bits in the center). Here is Myzostoma fuscomaculatum on the arm of a South African modern crinoid.
    Image from South African Southern Underwater Research Group (SURG)
    Myzostomes can also form galls on crinoid arms and apparently have done so for a LONG time. As these fossils occur from the JURASSIC...

    Fig. from Hess 2010
    And there you have it! FIVE awesome echinoderm parasite/commensals from the FOSSIL record no less!  
    Hopefully I'll get around to elaborating on those poop-eating snails some day!

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    Benthic combjelly on Luzon seastar (Coeloplana astericola) Photo by Arne Kuilman
    This is one of those RARELY seen animals that I love sharing with people because they are SO strange.

    First lesson: Ctenophores are a group similar in appearance to jellyfish. But in a separate phylum-The Ctenophora. Here's the Wikipedia for handy-dandy quick reference. They are identified by "ctene rows" that are what they use to propel themselves. Underlight these ctene rows shimmer giving them an iridescent appearance which looks like this:

    But there's one subgrouping of comb jellies that, for some odd reason, have taken to living on the sea bottom-sometimes on other animals, such as sea stars but also on sea urchins and corals.

    Its thought that these are commensal relationships. In other words, the ctenophores live at no apparent "cost" to the host. But relationships are poorly understood-so who knows?  

    At the very least having THAT many ctenophores crawling around on your surface might clog up your papulae for respiration and so forth.

    A brief explanation was from my blog awhile back here.  I don't know how common it is to see these in the field but these are pretty rarely seen for most people (although here is a small group on Flickr devoted to them) .. so I thought it would be a good idea to put them all in one place for everyone to enjoy (especially since there's a couple of new ones!)


    The animals are those strange moving white blobs on the surface. The ones living on the sea stars are in the genus Coeloplana. I'm not sure if the ones further down that are not living on sea stars are the same genus.. but I'm guessing probably not.

    Those threads? Are the feeding tentacles that you would normally see here in the "sea gooseberry" Pleurobrachia

    But here is Some neat NEW Benthic Ctenophores on Echinaster callosus! Shot in Lembeh

    here is the FIRST video of benthic ctenophores as shot by Blenny Watcher. Host is Echinaster luzonicus

    Here are some from Bocas Del Toro, Panama without the sea star host. Shot by Rosana Rocha

    Here's are more species from Japan!!

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    From J. Mallefet's Lab Page
    Echinoderms are WEIRD animals. That's why I love them.

    Their evolution is replete with adaptations to survival that are kind of mind blowing but as with all insanely unusual things, the ideas can be a little unsettling and frankly... a little SPOOOOKKKYY................

    1. They don't seem to know when to die...
    Most biologists have noticed that echinoderms don't quite die immediately when threatened with the kind of life-threatening injuries that many would consider life-threatening. Or else..its the WRONG part of the animal that seems to go on living... [Yes, some do regenerate (and that will be a subject for a future post!) but not all.]  Some examples:

    The Story of Stumpy

    Here is a true story (although I don't remember who told me this story originally)

    Years ago, following a lab accident or perhaps a crab run amok, the disk and 4 arms from a sand starfish (Luidia clathrata) was separated from the mid to end part of its 5th arm.

    Contrary to popular myth, not all starfish can regrow a complete body from just the arm. This one certainly could not.

    This separated arm tip (which was named "Stumpy") was kept in the water table and continued to move around for weeks to months...(I honestly don't remember how long but it was  a long time).

    Stumpy was even "fed" clams, which it apparently moved via tube feet to where it thought the mouth was. These clams would move up the tube foot groove and then just...fall out when it reached the disk location. No disk! (and thus no mouth)

    It was never clear to me if Stumpy just sort of died on its own or if it creeped everyone out so much that they eventually just preserved it in the lab somewhere.

    This isn't necessarily unusual "behavior." One can often observe the arm of a brittle star sometimes continue to move long after it is separated....

    Presumably a combination of the unusual radial nervous system and the separated body part's ability to sustain itself using sea water (and nutrients) were responsible for this tenacious behavior?

    But why believe an echinoderm zombie story when you can simply watch it... 

    Here is a "Zombie" Sea Urchin..The animal is broken open with insides removed and yet....IT LIVES
    Sea Urchin Zombie from Timothy Ewing on Vimeo.

    And another...

    But on the OTHER hand.....

    2. Uh... Do Echinoderms ever die of natural causes??
    As a person who has worked in and out of museums and aquariums, one of the things you notice is how some species kept in captivity become bigger and bigger..

    Some species such as Pycnopodia helianthoides (from the North Pacific coast)
    Photo by Allison Gong
    And the enormous Pisaster brevispinus, approach three FEET in diameter (that's about a meter for those outside the US).
    Photo by Mr. J. Volz
    When kept in captivity sea stars have no predators, are fed every day, and generally don't undergo much, if any, kind of stressors. Its never been clear if any of them perish of "natural causes."

    Now, to be clear-they do die. Diseases, aquarium mishaps, introduced predators and so on.

    But under optimal conditions?? I have had people watching these cold water species live on for over 10 years (but I'll be honest I would need to verify) and more than once I've been asked "Do they EVER just die of natural causes??"

    And honestly, I don't know if they do. Some accounts from the 1960s reported that they became "reproductively senile" but this account was speculative.

    The idea of echinoderms as long-lived is not necessarily new.Here is a post I wrote back in 2009 about how ancient sea urchins can get.

    So next time you go into say hello to a large sunflower star at your local aquarium-pay it some respect. It might be much older than you are...

    3. Some of them GLOW in the Dark!
    There is a whole POST worth of stuff on bioluminesence in echinoderms! And at some point in the near future I will write up more about it..but for now accept that a LOT of echinoderms glow!
    Image from J. Mallefet's lab page
    And here is a neat video that shows the bioluminescent granular covering off a deep-sea swimming sea cucumber..

    4. They way some of them go after prey, If they were bigger, WE would be afraid of them!
    Most people seem to have a fairly benign impression of echinoderms. Harmless shapes that sit on the bottom of the sea floor that make up part of a dreamy seascape...

    Here at the Echinoblog I've done everything I can to change this image!
    Many starfish and brittle stars can capture MOVING prey and do so in a variety of surprising ways. Imagine ANY of these things as dog or even COW sized and humans would be more respectful of the humble echinoderm...

    Ophiarachna incrassata 'green serpent star'

    And just for good measure?  Here's an earlier post featuring brittle stars that capture squid or fish if they come too close, rending it apart into pieces!! click here.

    5. Dried Echinoderms are MUMMIES, NOT shells
    This is probably one of the more macabre things that I've made note of before. Undoubtedly we have all seen starfish decorations for the holidays and weddings?? 
    A sad Pisaster ochraceus
     sad Linckia laevigata
    So, let's remember/invoke some basic biology about ALL echinoderms here.  Remember that ALL echinoderms have skin covering OVER their endoskeleton.  
    When sea star (or ANY echinoderm) is prepared dried this way?  

    This isn't the same as some shell. There is/was skin on them. THESE ARE MUMMIES. 

    What you are doing above?  Is like putting funny clothes on a skeleton or a mummy like this... (which I suppose is fine if you realize what you're doing..)


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  • 11/06/12--19:47: Sea Star/Starfish Close Ups!
  • Solaster skin Image by Alexander Semenov

    Bonjour to everyone! At the moment I am continuing my research in Paris at the Museum national d'Historie naturelle! Here are a bunch of my prior posts about studying at this incredible place!

    I'll be blogging more on this shortly but in the meantime, here are some neat close ups of various starfish species!

    Solaster endeca (Pacific Northwest/N. Atlantic) click here to see what the animal looks like
    Solaster skin Image by Alexander Semenov

    Crossaster papposus (Pacific Northwest/N. Atlantic) click here to see what the animal looks like
    Crossaster skin Image by Alexander Semenov

    Culcita novaeguineae (cushion star fr. tropical N. Pacific) click here to see it!
    Maui - Starfish

    Plectaster decanus (Australia) Click here to see what the animal looks like
    Starfish close up Image by Weedy Seadragon

    Gomophia gomophia (Okinawa, Japan) click here to see what this animal looks like
    Starfish, Gomophia gomophia Image by Okinawa Nature Photography

    Nardoa sp. from the Indo-PacificWarty sea star Image by sbailliez

    Echinaster callosus from the Indo-PacificWarty seastar (Echinaster callosus)
    Warty seastar (Echinaster callosus)Images by Optical Allusion

    the sand star Astropecten aranaciacus(temperate Europe, Mediterranean) click here to see it!
    Note the star-shaped pillars are called paxillae. In theory they protect the papulae (aka the gills) from burial)
    Astropecten aranciacus mage by fabbricmare

    From  a related starfish.. Gephyreaster swifti (British Columbia) More on this species here.
    Close-Up of Gunpowder Star legs 4722

    From Mediaster aequalis (west coast of N. America) a similar bunch of structures called tabula or tabular plates.. Click here to see it!
    Starfish macro

    From an Australian relative of Mediaster called Nectria ocellata with some enlarged tabulae. It looks like this.
    Macro adventures pt 2 Image by ~aquaplane

    Close up surface texture of the Indo-Pacific Archaster typicus. Learn more about it here!
    Close up of texture of Common sea star

    More next week!

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  • 11/13/12--13:29: Paris!
  • Bonjour!
    The Echinoblog greets you from Paris France where I am currently working with my colleagues at the world famous Le Muséum national d'Histoire naturelle where I am working with my colleagues on starfish in the collections of the museum!   For my past blogs about Paris-click here!

    Much of what I do is a mixture of new cutting edge research and very classical, old-fashioned stuff. 

    Essentially, there are massive collections of starfish (and other invertebrates) in the museum which are part of biodiversity surveys, expeditions, and exploration of various exotic locales throughout the world-Antarctica, Papua New Guinea, Madagascar to name a few...

    I see a lot of this material as preserved material in buckets that look like this..
    This material may look brown and unappealing, but it is a rich treasure trove of scientific data for the modern evolutionary biologist.  Research endeavors from this kind of collection includes:
    • Describing New Taxa, including genera and species! 
    • Extracting DNA and "barcoding" populations to study relationships across different areas (ie biogeography)
    • Extracting DNA and studying evolutionary relationships among different species
    • Discovering parasites in their hosts!
    • Studying the full sizes of a species to see how they change. (e.g., think of caterpillars to butterflies to realize how this is important)
    • Ecological Modelling

    And there's probably no end to the number of potential projects. Mostly, I'm involved with the top two kinds of projects-but I've seen them all done.

    In contrast though, sometimes there's a lot that's important from a historical and scientific perspective to see some of the original material figured and illustrated from major scientific papers and books!  The MNHN is no slouch where historical persons have left their mark..Click here to see an older post about some of the labels still bearing the Lamarck's wrting! 

    Here for example is a photograph from a Plate in a famous starfish monograph from 1894 by Edmond Perrier showing Brisinga endecacnemos
    And here is the original specimen as it appears today-still largely intact and looks just like it does in the book..
    while not figured, here's a rather striking display jar for the 50-rayed Antarctic Labidiaster annulatus..
    Often times, my research trips (and those of other scientists to the museum)  fuse the old and the new. And go something like this:

    1. You find something new in the collections, 
    2. Sequence it for its DNA (or analyze its external appearance), discover it is close to an existing species...
    3. Compare the specimen to a historical voucher (often called a type) to see if it conforms to the established definition. Is it a new species?  A rarely seen species? 
    4. Publish!

    There are any number of complications.. 

    Types can be missing, analyses reveal unexpected results and of course new material is ALWAYS turning up in museums.. Sometimes new specimens can completely support a dubiously defined new species or instantly show how a recently described species is in fact just a variable individual of a known species..

    Okay! But enough about work!   Paris is a delightful city and I would be remiss if I did not share some of its charms..some not so subtle...

    For example, this ammonite is already pretty cool "as-is" 
    But then you realize WHERE it is..and it just has an awesome new twist! 

    Every good city has geology to be found in the unlikeliest of places... For example here is fossilifeous limestone used as floor stones on the Gare d'Lest train station..

    Can you see the cross-sections through various shells and other invertebrates??  Unseen by thousands of persons a day??
    Tucked away in various parts of the city are weird little fun moments like this one... (near Les Halles)

    And where would we be if we didn't show some French food porn!   Y'know what's amazing about this? The "pink" donuts in the US have famously adopted the description "pink flavor"..

    But in Paris?  not only can you get them warm-but they are RASBERRY. Tasty!

    Some Turkish Delight...
    And some very tantalizing cookingMacarons
    We'll see you next week!

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    This week, the Urchins of Paris! 

    Wait, what?  Do you mean those delightful scamps that run around making mischief in the streets ??
    Not street urchins-but oursins!  Or Sea urchins! (tests-the dried internal skeletons shown here)
    This week:  some of the rich and diverse holdings of the Museum national d'Historie naturelle!

    Sea Urchins (oursins!) or members of the Echinoidea are of course-the echinoderms that look like a big spiny ball (this includes sand dollars and sea biscuits!).  Sea urchin specimens comprise  an incredibly diverse (and important) collection in Paris with holdings from all over the world-especially from the tropical Indo and South Pacific! Undoubtedly many new species await description! 

    So for example here we have the very incredible looking Chondrocidaris gigantea

    Others from the tropics are distinctive and RED but remain sadly, unidentified. Is this a new species awaiting discovery?? 

    In addition to the above "regular" urchins, here are some cleaned tests (again-the skeleton of an urchin with all the spines removed) of some "irregular urchins" (distantly related to sand dollars).

    A test of Schizaster edwardsi from the Atlantic...
    I believe this one was called Breynia but not sure which species.                                                                        

    But why limit yourself to enjoying only the outside of these skeletons when you can go INSIDE??   No-not x-rays...but old-school careful dissection...

    Here's the Atlantic "sea biscut" Clypeaster rosaceus with the "top" completely removed..
     showing the internal struts around the mouth...
     Go ahead and take a walk around inside a sea biscuit! 
    The long history of the museum permits me to share with you some display mounts from a bygone era...

    These are the individual spines of various species mounted on one plate each. These are easily 100 years old and are possibly MUCH older... probably from the 1800s...

    Here is a vintage 1894 specimen collected by the sea urchin researcher Gustave Honoré Cotteau (he died in 1894 so this is probably just a note indicating the specimen is part of his collection).
    Here is a brief summary of who he was (in French)  A short summary translation of his bio (some edits for clarity):
    Judge, naturalist, geologist.
    Gustave Cotteau made ​​a career in the judiciary while devoting himself to paleontological studies. It was a judge in civil court Coulommiers civil court judge in Auxerre (1867), and retired in 1874.
    As a scientist, he devoted himself to the research and study of living and fossil echinoids, which he had a collection of over 500 species. With numerous articles in newsletters and journals of learned societies which he belongs, he continued the publication of the collection founded by Alcide d'Orbigny in 1840, Paleontology French. He was curator of the town of Auxerre.
    Secretary-General of the Institute of Provinces, responsible for publishing the reports of international conferences of Prehistoric Anthropology and Archaeology and the annual reports on the progress of geology and paleontology in France from 1858 to 1869...
    You can check out some of Cotteau's work at the Biodiversity Heritage Library site HERE (for free download). But Cotteau was a prolific author and wrote MANY classic texts on fossil echinoderms.

    Okay! Now time to go get some Turkish Delight! More next week!

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    Sea (not a) spider Here's looking at you!
    Image by the always awesome Arthur Anker! (Straits of Johore Biodiversity Survey, Oct 2012)
    This week, owing to "crunch time" on my trip and being up to my arm pits in Antarctic starfish- you get a nice photo essay about sea spiders (btw-not arachnids) aka pycnogonids! Not echinoderms but arthropods! 

    Mostly of these are pretty tiny, which is why most people never see them, but the details are everything! I was told once by one of my professors many years ago that you could go your whole life and never see one of these-wow! times have changed...

    From the Great Barrier Reef, Australia (probably Anoplodactylus sp.) 
    Sea spider (probably Anoplodactylus sp), GBR, Australia Image by Arthur Anker!

    Some neat south African pcynogonids in the Florida Museum of Natural History collections
    South African sea spiders (Pycnogonida) in the FLMNH collections, Gainesville, Florida Image by Arthur Anker!

    Shown this one before (from St. Martin) -but its amazing so here it is again!
    Male ovigerous sea spider (Pycnogonida)

    A neat one from Grand Cayman. Image by CourneyPlatt
    Sea Spider 5915

    This one identified as Nymphon breviostre but not sure where its from... Images by Alexander Semenov
    Sea spider posing
    Carrying eggs..
    Almost father

    This one identified as Nymphon grossipes feeding on bryozoa. Image by Alexander Semenov

    Pink and Yellow! From Australia. Image by Indr
    Sea Spider @ Jervis Bay

    Pallenopsis macneilli from Port Phillip, Australia by Peter Fuller
    Pycnogonid (Seaspider) - Pallenopsis macneilli

    Yikes. This one looks overrun by wee sea spiders! Images by Alexander Semenov

    Here's one of the deep-sea taxa, possibly Colossendeis. They get to be over 7 inches across! This one looks big.. Image courtesy of SERPENT Project
    Sea spider
    But what do Sea Spiders (Pycnogonids) actually look like alive and moving?  here's some HD macro video for ya!
    Sea Spiders from liquidguru on Vimeo.

    And thanks to NEPTUNE Canada for reminding me about this neat video of a giant deep-sea sea-spider moving!

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    Just returned from Paris and am snowed under by jet lag and catchup, so here are some stunning images of various polychate worms!  by my colleague  Arthur Anker formerly at the Universidade Federal do Ceara, Labomar but now at the National University of Singapore.

    Arthur's photography stuns me whenever I see it and if I can share it with the public than I do! Enjoy!

    and if you enjoy polychaetes go check out my link page of "bobbit worm" videos! here.

    My post on the worm-shrimp 1-2 punch vs. crown of thorns starfish here.

    Gorekia! the worm that lives INSIDE a sea urchin! here.

    The Leather star (Dermasterias) scale worm love? story! here.

     A gorgeous Trypanosyllis sp, a syllid worm from Moorea, French Polynesia.
    Wormy elegance
    A stunning Eupolymnia tube worm from the Caribbean
    Eupolymnia sp (?), a Caribbean tube worm
    Head on with Diopatra sp. (Onuphidae) from the mudflats of Singapore
    Diopatra sp ? (Onuphidae) from mudflats of Singapore
    and more Diopatra love!
    Diopatra sp (Onuphidae)

    Hermodice cf. canunculata-a fire worm from Sao Tome
    Hermodice cf carunculata - a fire worm from Sao Tome

    Eunice sp from the Caribbean coast of Panama
    Eunice sp from the Caribbean coast of Panama

    Nereis cf. riisei, rolled up into a spiral, fr. Panama
    Nereis cf riisei, rolled in a spiral
    Fireworm (Chloeia sp) from Panama Canal
    Fireworm (Chloeia sp) from Panama Canal

    Branchiomma sp. a sabellid worm from Sao Tome, Brazil
    Branchiomma sp, a sabellid worm from Sao TomeLepidonotus sp. from the Caribbean Lepidonotus (2)Pontogenia from the Great Barrier Reef, AustraliaPontogenia sp (Pontogeniidae), GBR, AustraliaA festively colored scale worm, Lepidasthenia sp. from Cozumel Island, Mexico Colourful scale worm (Lepidasthenia sp ?), Cozumel Island, Mexico

    A neat pic of a sand-tube worm, Pectinaria IN a sand-grain tube! from the Great Barrier Reef, Australia.
    Sand-tube worm (Pectinaria sp) in its sand-grain tube, GBR, Australia

    Another Pectinaria species, from Florida showing the worm and its sand-grain tube
    Pectinaria sp in its sofisticated sand tube, Seahorse Key, FL

    Finally, a maldanid polychaete worm from Australia
    Maldanid worm

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    Image courtesy of Chris Kelley, Hawaiian Undersea Research Labs
    November has been a busy month! While I was hard at work in Paris other projects were underway! I often wish that I could be in two places at once because it happens that different and exciting things happen at once! 

    Case in point-I have discussed how I have worked with the University of Hawaii and the Hawaiian Undersea Research Laboratory before. (go here to see)
    From the HUMMA Project website

    Specifically, I have been working with Dr. Margo Edwards in conjunction with the Hawai'i Undersea Military Munitions Assessment Project (or HUMMA) which is a coalition of institutions including the University of Hawai'i, NOAA, the US Army and others. 

    To put it briefly, there's a lot of unexploded bombs and munitions about 5 miles off the coast of the island of Oahu (and other locations throughout the Hawaiian Islands).

    Screen shot 2012-12-02 at 12.41.01 PM

    The HUMMA project is part of an ongoing effort to map, survey and reconcile these weapons. A Frequently Asked Questions (FAQ) about this can be found here.

    A nice video about this project is here:

    And in factthe HUMMA Project has a Youtube Channel with a bunch of interesting things documenting their work here

    So how does a humble starfish scientist like me get involved with all of this seemingly unrelated (but interesting) work?

    Brisingid starfishes!
    What are brisingids?Short answer: Sea Stars/Starfish that put their arms up into the water to capture food using a special kind of "starfish velcro".  Go here to see a full write up about these weird deep-sea starfish!

    In November the Hawaiian Undersea Research Lab (HURL) and the HUMMA Project took to the water with the submersible Pisces V (one of the only manned research submersibles still operating in the US!)
    From the Friends of HURL Facebook page
    From the Friends of HURL Facebook page!
    One of their objectives during this November dive was to look at the various animal biota in and around the ordnance (go here for a HUMMA Project update) such as these sea anemones living on a vertically oriented mine...
    From the HUMMA Project website
    Probably one of the most abundant and interesting of the animals living in and around the ordnance were brisingid asteroids. So, there was an interest in finding out more about them.

    Especially since they seemed to have large round "lesions" or swellings on the arms (note the large one on the upper center arm)..
    Image courtesy of Chris Kelley, Hawaiian Undersea Research Labs
    Unfortunately, there's only so much you can do with brisingids from video and pictures taken at a distance.  So many questions!
    What species were these brisingids?  
    How many different kinds of brisingids were present? 
    What were the swellings?  Why were there so many of them? 

    And so, collections were made by the Pisces V submersible's collector arm..

    Being able to look over the specimens at long last gave us two valuable discoveries!

    1. Possibly a new species? The brisingids we were studying belonged to a genus that had never been seen in Hawaii before! And a species that could not be reconciled with any of the known ones!  Further work remains to be done-but it seems like there is good reason to believe at least some of the brisingids studied belong to an undiscovered species!

    2. What were the swellings? An examination of the swellings revealed an even more interesting discovery!!   They were parasitic barnacles!!

    There are some VERY unusual relatives of barnaclescalled Ascothoracidansthat can enter into the body cavity of sea stars (and other echinoderms), affix themselves to the internal body structures.  

    Some  kinds of ascothoracidans have highly unusual relationships and can take over a host's reproductive system! (go here to see on case)  It is unclear what the parasites in these brisingids do however.

    The Time Lapse Project!
    Brisingids were the subject of a neat project undertaken by 3 intrepid students from Honolulu's famous Iolani High School: Kyle, Erin and Logan (shown here with model of their study organism)

    Their efforts were largely directed at some ecology and behavior of these starfish, about which VERY little is known.  Often times, we can barely identify brisingids much less describe how they live in their natural habitat!
    They participated and won awards at the 2012 International Science and Engineering Fair! Woo! Here was a pin of their crest!

    One part of the student's work involved engineering and developing their very own time-lapse camera for use in observing brisingid sea stars!!

    Here is a video from their early efforts in shallow water Extended to night time...
    And finally, here is the final product observing deep-sea brisingid starfish and some deep-sea sea anemones!  Note how the brisingids move..

    The full scientific impact and write up of all these discoveries is currently underway. 

    But I find it a hearty endorsement of these kids' abilities that they were able to develop such a clever and useful device given their constraints!  This was something they did in high school! I look forward to their efforts in college!

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    This week a departure from the weekly echinoblogging to spotlight some people behind the biodiversity of marine invertebrates! (although that is a very photogenic Protoreaster lincki on the cover!)

    A few weeks ago Ward Appeltans, who was the project manager for the massive World Registry of Marine Species database (here) collected and presented 121 contributors of various marine species, including some plants, protozoans and chromistans, fungi, some chordates and a WHOLE bunch of invertebrates!
    The link to the paper is here. I believe it is open access until January 2013.

    There are a lot of digests and news articles about this including these:
    Discovery News
    e!Science News

    But of course in a "big picture" treatment, one often lacks some detail so I thought I would spotlight a department with which I was most familiar:  Invertebrate Zoology at the National Museum of Natural History!
    Department of Invertebrate Zoology
    Eight out of the 121 contributors of the paper (that's about 6%) are residents/associates/employees of  the Invertebrate Zoology Dept. at the National Museum of Natural History!!(part of the Smithsonian Institution)
    Top:Jon Norenburg (worms), Dennis Opresko (antipatharians aka black corals), Stephen Cairns (scleractinians and gorgonians)
    Middle: Rafael Lemaitre (anomuran crabs), Kristian Fauchald (polychaetes)
    Lower: T. Chad Walter (copepods), Marilyn Schotte (isopods)
    Bottom: Me (starfish)
    6 % may not seem like a lot, but it is the largest contribution of the 95 different organizations which participated.  Only the Dept. of Marine Zoology at the Naturalis Biodiversity Center in the Netherlands had the 2nd highest number of contributors (n=7)

    A look at the number of records modified per taxonomic editor below. Several of the largest contributors are persons from the NMNH!
    This graph from the WoRMS statistics page
    Among the names and numbers!
    Chris Mah with 6,060
    Marilyn Schotte with 14, 384
    Chad Walter with 27, 508
    and Kristian Fauchald with a whopping 36, 480 records!!

    Here's which Marine Invertebrate Databases and/or taxa they oversee..

    Kristian Fauchald (lead editor: Geoff Read): World Polychaeta Database and Twitter: @WPolyDB
    Chad Walter (with Geoff Boxshall): World of Copepod Database! 
    Dennis Opresko: WoRMS-the Antipatharia (black corals)
    Chris Mah:  World Asteroidea Database (starfishes and sea stars)

    Some Neat Factoids about the NMNH Invertebrate Zoology Dept.

    • The Collection includes a representative of every recognized animal phylum, including the two most recently recognized-the Loricifera and the Cycliophora! 
    • You can always check the holdings by going to the online catalog here! 
    • The dept. has over ONE MILLION cataloged specimens in its database! 
    • IZ oversees one of, if not the largest collection of Antarctic invertebrates in North America. Here is the USARP page!
    • IZ currently hosts 10 active on-staff research zoologists whose interests range from deep-sea cucumbers, freshwater mollusks, midwater polychaete worms, to barcoding and understanding tropical biodiversity.
    • Go Check out the IZ Twitter page:  @InvertebratesDC

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    Its Christmas! I'm off to enjoy eggnog and awful movies but here's some bright colorful sea urchins for the holidays! Heterocentrotus from the Indo-Pacific (mostly Heterocentrotus mammilatus pics)
    My best to all of my readers and followers for the holiday season!

    Image by "backofthenapkin"
    Slate pencil sea urchin
    from Hawaii by weedmandan
    'Ina 'ula or slate-pencil urcin (Heterocentrotus mammillatus)
    From Hawaiian Islands. Photographed by Dwayne Meadows, NOAA-NMFS
    One from the Red Sea. Image by vanveeleen
    Pencil urchin
    Here's another one from the Red Sea (maybe H. trigonarius?). Image by furstyferret81
    Red Sea Diving - Dahab- Slate pencil sea urchin
    A nice one from Hawaii. Image by Alan Cressler
    Heterocentrotus mammillatus, Waiopae Tide Pools, Hawaii County, Hawaii 1
    One from the Sinai peninsula. Image by bluepeda
    sinai - 534
    from Hawaii. mage by mbasile
    (Red) Slate Pencil Urchin
    from Hawaii by Arian durst
    A close up by Geoff Spiby
    pencil urchin 2
    Another Hawaiian one by chinds_1133
    Pencil Urchin

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    As 2012 draws to a close here are Five (of course) cool and awesome things that the Echinoblog enjoyed this year! These are not in any particular order....

    1. MENTORSHIP!  This year I mentored 3 kids from Iolani high school in Honolulu, Hawaii who studied brisingids (deep- sea asteroids). Their research was entered into the International Science and Engineering Fair and they were rewarded for their efforts!

    Here was their group pin..
    A video that shows some of the neat biology (time lapse behavior) from their engineering feats!

    2. THIRST DC.  I gave a great and fun talk to a new social venue in Washington DC for the Smithsonian. Here's my brief outreach talk for the very gracious audience.

    I also gave some Fun talks for volunteers at the NMNH,  Invertebrate House for the National Zoo AND American University! 

    3. ANTARCTIC INVERTEBRATES  Go here! I provide a list of neat Antarctic invertebrates for all to enjoy including everyone's favorite monstrous Antarctic scale worm  Eulagisca gigantea!!

    I'm always happy when something I do takes off and gets widely circulated this one did so in a pretty big way..
    The blog was picked up by my good friends at Deep Sea News (go here) and then later on by the Austrian Newspaper Der Standard (here) (this was in no small part to Miriam Goldstein! thanks!)

    By the way the pictures from the US Antarctic Research Program (here) were WIDELY circulated and not always given proper credit. So let's remember that public research funded some of the interesting reading from here and here.

    Other popular Echinoblog posts included:
    1. Sand Dollars ARE Sea Urchins! Please make a note of it!
    2. Sea Cucumber Evisceration Defense! 
    3. Sea Cucumber: Cuverian Tubule Defense!
    4. Pedicellariae Diversity
    5. The Anal Cone Controversy!
    6. How Starfish Tube Feet work!

    To Brussels, Belgium in August for the 14th International Echinoderm Conference!  Echinoderms were studied, argued about and laughed upon! and as with the asteriid sea stars I have studied, mussels were devoured!

    and to Paris in November for research with my French colleagues at the Museum national d'Histoire naturelle! see here  and here! 

    2013 promises publications that feature new species and other new discoveries published from data collected in 2012! (yeah, I know that sounds lame but that's how it works sometimes...)

    THANK YOU TO EVERYONE who has supported the Echinoblog!! 2013 promises to be a good one but as always..I'm happy to hear what topics you'd like to read about!

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    gaebul y mongae
    Okay you invertebrate zoologists out there!! How many phyla can YOU recognize on the plate above???   By the end of this blog you WILL know! (and maybe, you will hate me for telling you)

    Everyone seems to have a "Weirdest foods" list out there-but here at Echinoblog we offer you only the STRANGEST sampling of bizarre marine invertebrates cuisine! forget insects, snails or shrimp! 

    Some of the edible (?) metazoans below are usually only noticed by marine biologists, zoologists and the well-studied biologist!

    What better application of knowing the strangest of marine invertebrate phyla can there be than to recognize it on your plate? Its scientific name disguised by colorful cultural argot  or perhaps in a different language?

    1. SEA SQUIRTS! (probably genus Pyura?). The Korean name for sea squirts as food is: meongge (although there are several more)
    Sea squirts are a kind of tunicate, which are in turn members of the phylum Chordata (the group humans and other vertebrates belong to) and when alive they look like this:
    Sea Tulips

    As it turns out, sea squirts are eaten all over the world, including Japan (called hoya and maboya) and Korea (meongge, and in a stew called agujim). They also eat sea squirts in France, Italy, Greece, and Chile .
    Images of sea squirts eaten in Korea. Image by scbrianchan
    Eating Sea Squirt
    A video showing preparation. Sea squirts are filter feeders and processing water through their body is a primary function. Thus, drainage seems to be an important feature...

    when cooked and prepared it looks like this
    sea squirt
    or this.. Image by toughkidcst
    멍게 - sea squirt
    sometimes served with oysters... Image by Food Fetishist
    Seoul 2009 - Oysters and Sea Squirts - Seoul Izakaya

    Flavor ranges from "rubbery" to something this..

    2. ECHIURAN WORMS! aka "fat inkeeper worm" aka "penis fish" aka gaebul (genus Urechis)
    Most people have never heard of this phylum of worms. Commonly known as "spoon worms"

    One of the best studied examples is Urechis caupo, occurring on the North pacific coast -living in muddy burrows which serve as homes for many other commensals, including tiny shrimps and fishes.
    fat innkeeper worm (urechis caupo)

    But in Korea, a related species, Urechis unicintus is collected and eaten!

    Apparently it is cut up into segments and served while twitching....

    In other cuisines, it is cooked and stir fired..

    the picture above? gaebul and mongae aka Echiuran and Sea squirt!!
    gaebul y mongae

    and uh yeah, there's a belief that eating these imbues men with more virility. That seems unlikely....

    Brachiopods are one of the oldest animals observed in the geological record, going as far back as 500 million years. In some cases-they appear relatively unchanged appearing very much as they do as fossils.

    and now we eat them.

    This gives you an idea of what they look like in a muddy habitat Image by Changhua Coast Conservation Action.

    亞氏海豆芽 Lingula adamsi Dall

    There are two shells that fit over the animal on the top and bottom. Bivalves and other clams are fundamentally different in that their shells are oriented on the body left-right. 

    In one group, known as the "inarticulate" brachiopods, there is a big fleshy structure called the "peduncle" which emerges from the shell

    Biologist Richard Fortey noted that they tasted like "straw' (quote is here).

    Here is an image of brachiopods as sold in a food market in Makassar. Image by Arthur Anker.
    Brachiopods (Lingula sp) sold as food on a market in Makassar

    Here is another from a Thai market. Image by Peter Roopnarine
    Lingulids, Thai market

    In Malaysia this dish is called Probolinggo TEBALAN. The blog linked here suggests that Lingula  tastes "sweet and spicy" whereas others I've seen suggest that it is served with a tasty curry.
    Huh. Brachiopod curry. NOT something I was expecting to write today!

    4. STALKED BARNACLES! Barnacles. Those well-known shelled crustaceans that live on docks and use their "legs" to filter feed out of the water like this:

    These of course are what's known as "goose" or "goose-necked" barnacles because of the long, prominent stalk attached to the body sitting on top.

    Yes. People eat them! I've seen them in Paris and Belgium.
    Percebes [Goose Neck Barnacles]
    In some places, barnacles are quite expensive...Imge by erikamussen
    Barnacle Prices 99€/kg ($65/lb)

    Other "unstalked" barnacles are also eaten! 
    barnacles have faces!
    In the Azores and Portugal, these are called cracas!  Basically, these are boiled "acorn" barnacles. Image by Bellyglad.
    Cracas bico (barnacles)

    5. SEA STARS! (family Asteriidae- species: Asterias amurensis)
    So, first let me distinguish between the "starfish for show" pictures that one sees around like this versus apparently real accounts of people who eat the gonads of starfish as seen in the video below..
    didn't know you could eat starfish Image by Robin G. Ewing.

    Honestly, eating sea stars baffles me. And I  recommend against it (as here) and here but obviously, people really eat these.  On the plus side, Asterias amurensis (the species shown below) is a problematic invasive in Australia (as I wrote here)
    so maybe there is a silver lining to this?

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    Image by Viktor Lyagushkin. Gorogonocephalus from the White Sea 
    Basket stars are a very unusual kind of brittle star (note that they are NOT proper starfish) which have long, branching arms which they extend into the water in order to feed. Basket stars occur in tropical and cold-water habitats and I have written about their feeding biology here.
    Tiny little hooks on the arms are used to capture food which eventually makes its way back to the mouth.

    Here's a nice video that shows their feeding posture in the wild

    and a nice time lapse video of feeding from the Seattle Aquarium

    There are currently 10 species of Gorgonocephalus recognized and they seem tooccur widely...(here to go to the World Ophiuroidea Database listing)

    Here are some gorgeous Gorgonocephalus sp. (which occurs mainly in cold-water settings) images to kick off 2013!! Enjoy!
    Some gorgeous shots of G. arcticus from the White Sea by Alexander Semenov

    Gorgonocephalus arcticus.jpg
    Gorgona's head
    Gorgonocephalus arcticus
    Gorgonocephalus arcticus.jpg

    G. eucnemis from echeng (the "rose star" is the solasterid sea star Crossaster papposus) in Alaska.
    Basket star (Gorgonocephalus eucnemis) and rose star, Alaska

    Gorgonocephalus from Norway, 928 meters! Arms are tucked away...Image by SERPENT Project!
    Basket star (Gorgonocephalus)
    Several more on a ridge, using their arms to feed. Also Norway, 928 meters. Image by SERPENT Project.
    Basket stars (Gorgonocephalus)

    More G. eucnemis from Alaska.. Images by jrixundewater
    basketstar branches 0027
    Close up of the arms..
    Alaskan Basket Star 0022

    An unusually pale, "bushy" individual from British Columbia. Image by Ed Bierman
    basket star

    Here's a really nice one of G. eucnemis. by "northwest diver"
    Basket star
    Gorgonocephalus fr. Newfoundland. Image by Derek Keats
    Basket star Newfoundland Image by Derek Keats
    Hmmm... y'know, it never occurred to me before but Gorgonocephalus DOES bear a striking resemblance to a certain CRYSTALLINE ENTITY from the 24th Century...

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    So, between travel, being sick, yesterday's massive Inauguration Day festivities and playing catchup, this week has been crazy!

    So here are some neat starfish time lapse videos to keep you informed and entertained!

    The awesome video of the tropical shallow-water "chocolate chip star" Protoreaster nodosus, foraging for organic particles and other food on the sea bottom.
    Stars of the Sea from Karin Brussaard on Vimeo.

    The foraging behavior of the predatory Chilean/Patagonian cold/temperate water Cosmasterias lurida (Stichasteridae)

    Some classic videos from the Shape of Life series showing behavioral complexity.Read this article frorm awhile back to see what's going on...
    Echinoderms: Sea Star Time-lapse: Eating Dead Fish from Shape of Life on Vimeo.
    Echinoderms: Sea Star Time-lapse: Don Wobber's Film from Shape of Life on Vimeo.

    Here's a nice HD time lapse of a tiny aquarium asterinid starfish. Note stomach extended and the places where the algae is absent from the glass.
    A day in the life of a starfish from Rate My Funeral on Vimeo.

    An unusual video that shows what happens when you drop a bunch of Patiriella (bat stars) and let them run free! Starfish show up at about 1:19 (its mostly set up prior to that)

    Here's a nice little vid showing Archaster typicus (different from Astropecten-you can tell between the two  by going here to see the differences) in an aquarium burying itself into gravel

    By comparison here is a species of Astropecten from Singapore doing its thing!

    The giant Pacific sunflower star (Pycnopodia helianthoides) is fast enough that you can see it moving without time-lapse. What happens when you speed it up a bit? 

    Hopefully next will be all caught up and I'll be back to posting more!

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    Tube feet
    Image by Steve Corey

    Do tube feet actually use suction as has been historically thought/taught??

    The whole "tube feet use suction" paradigm is a powerful one that has been observed since some of the earliest work on starfish in the 1840s. 

    Its a powerful and seemingly straightforward idea. Tube feet have what appears to be a suction cup on the tip of their tube feet, and so, therefore, shouldn't it work like one??

    Could this long-standing notion... BE WRONG???
    20040128_4 Podia of starfish, Asterias rubens (Sweden)
    Image by "ratexla"/Josefine Stenudo
    The suction cup idea is pervasive and can be seen in many pop culture references.

    How pervasive?  The authors of the paper I use below cite Peach the sea star from the recent movie Finding Nemo by Pixar- Peach uses the popping sounds that one associates with a rubber sucker!!
    A new, recent paper from the bioadhesion labs of Patrick Flammang in Belgium, and Romana Santos and Elise Hennebert in Portugal have demonstrated several experiments that in fact, tube feet rely on adhesion (as outlined here before) and NOT on suction. This paper is OPEN ACCESS and can be found here at the Proceedings of the 7th European Echinoderm Conference! 

    The paper is important to people who study echinoderms but is very straightforward and pretty easy to understand...  The authors work primarily on two species as test subjects:  
    The common N. Atlantic sea star Asterias rubens
    Common Starfish,Filey Brigg,North Yorkshire.
    Image by Juncea
    and the European urchin Paracentrotus lividus...
    Paracentrotus lividus
    Image by Bárbol
    Even before this recent work on adhesion in tube feet, there had been indicators, some years ago that suction was not the only force in tube feet at play. Why?

    First-A study from 1985 (Thomas & Hermans) showed that echinoderms have been observed adhering to screens, meshes and grates-so how would a suction cup work if they were being applied on a porous surface with no way to create a vaccum?

    Second.Tube feet leave footprints such as this one which leave behind residue suggesting a glue or adhesive was at play..
    In order to test whether suction played an active role in adhesion (in other words they attempted to DISPROVE the role of suction), the authors approached the problem with some very insightful observations/ experiments.

    1. Observing the tube feet directly!
    The physics of your basic suction cup model is pretty straightforward. The suction cup creates a large suction cavity between the attached foot and the substrate (i.e., the ground).  

    When you put a suction cup down, you press the top down and pull it up. This creates the suction cavity that attaches the suction cup to the ground..that's what you would expect.

    Tube feet from Asterias (the starfish) and Paracentrotus (the urchin) were sampled immediately after it was clear they were attached, and photographed with a Scanning Electron Microscope. Histological (i.e. tissue) sections were also taken...

    The top two pics (A+B) show an unattached tube foot.. But C through F? all show those attached to the bottom.
    Figure  1 from Hennebert, Santos and Flammang, 2012
    What they found? There was NO "suction cavity" between the tube foot edge and the substrate (i.e. the ground). The tube foot disc surface was actually flat and flush with the substrate surface. Thus, no physical evidence for suction could be observed.
    The authors indicate that suction may still play a secondary role, serving in conjunction with the adhesion/glue but for the most part it doesn't look like suction is a primary influence here.

    2. Measuring the Attachment Strength of the tube feet
    Next, Hennebert and her coauthors measured the attachment strength of the tube feet relative to different variables. These included

    A. Measuring the strength or tenacity (in terms of Force or Tenacity) of sea urchins as they hung from a glass plate at different angles.
    They tested the adhesion of the tube feet on glass relative to detachment force (how hard they pulled) and pulling angle (the direction). That is they tried to pull it off and at different angles on a smooth glass surface.
    fr. Fig. 3A in Hennebert et al. 2013
    If this were truly suction then the tube feet would slide (i.e., no resistance) and the amount of suction would decrease. There was no (or at least no statistical) relationship between the detachment force and the pulling angle.

    B. Measure strength and tenacity on a porous bottom
    This one was more straightforward-if tube feet are anchored by suction, then an imperfect bottom (i.e. substrate) won't really work well as a good anchoring ground. 

    The authors used a sheet of plastic with holes present in the surface.  They measured tube feet with a device that measure the force and tenacity and then recorded the footprints based on whether they completely, partially or did not cover the holes.  

    Prediction: If the tube feet use suction-the force measurements for strength and tenacity would be significantly affected. But if adhesion was at play, then the holes should make no difference.

    Basically, this experiment mirrors the early observations of watching starfish or urchins moving around on a metal grate or mesh. How important can suction be if the animal can move on a non-porous surface?

     No statistical differences were found between the different groups (i.e., the tube feet that walked over a complete, partial or covered hole). 

    CONCLUSION! And so, not only has prior work (see earlier blog post) shown the huge role of adhesion/glue in the way tube feet work but now, the original historical model..i.e., tube feet use suction has been pretty effectively undermined if not disproven outright!
    Its possible of course that there are further refinements to how all of this works in sea cucumbers and crinoids but starfish and sea urchins have always been the "model organism" for studying tube feet in echinoderms. 

    One of the oldest and most widely known perceptions about echinoderms? Not thecase.Evidence is slowly building up against it and an important lesson in science that even the most long-standing ideas can be overturned when you look at the facts with the right questions!

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    Brittle stars are everywhere. They are the most speciose of all the living echinoderms with over 2000 species (probably MUCH more than that!). 

    At this moment in time, for studying brittle stars we live in a privileged time because we have several new workers who have taken to studying the various and weird lives of brittle stars! 

    One distinctive feature of brittle stars that researchers that study morphology have always known about are the unusual jaws present on the mouth of brittle stars. These jaws vary between individual groups of  brittle stars. Its one of the fundamental ways that brittle star taxonomists tell them apart.
    These jaws are superficially similar to the ones we see in other animals in that some of them have "teeth" (called oral papillae) and other features which distinguish them.

    But other than their usefulness in telling them apart, what function do these "teeth" serve? 

    A recentopen access paper by Karin Boos, an author at the 7th European Echinoderm Conference held in 2010 (available here)addresses and discusses how the jaws might function relative to the feeding biology of two European brittle star species. 

    First off, Boos reviewed the feeding modes of two species with fairly distinct jaws and teeth.

    One of the studied organisms, Ophiothrix fragilis is covered with many needle-like and bristling spines...
    Images below by Hsacdirk
    Brittle stars. Ophiothrix fragilis.

    In life, they hold their arms up into the water and are almost always observed in this position in order to obtain food from water currents. Ophiothrix is a filter feeder. 

    They gather up food on their arms, which is then moved to the mouth via tube feet.
    Brittle stars. Ophiothrix fragilis.

    The other species studied was Ophiura albida which is more of a generalist. A sort of opportunistic feeder. Sometimes scavenging on dead animals but sometimes feeding on other smaller animals. 

    Each species has a different life mode and presumably the morphology, i.e., the teeth of each species reflects how each individual species lives.
    Ophiura albida
    Image by Danielguip
    A brittle star from a completely different group (ie. family) and with a very different set of choppers! Here is Boos' Figure 1 which shows the two "teeth" types side by side. Ophiothrix on the left vs. Ophiura on the right.
    Figure 1 from Boos 2013
    1. Predator? Or generalist? type jaw/teeth in Ophiura.
    Boos takes some pretty nice profile images (her Figure 2) of the papillae (=the "teeth") that allow her to infer some function.
    top of pic is the oral surface, bottom is top or aboral. Fig. 2d-3
    Boos argued that these teeth are in fact "predaceous (=predatory) dental equipment". Note how all of the "teeth" (=the papillae) were pointy. These, Boos argues, are used in gripping or spearing captured prey before ingestion.

    It doesn't take much to take this consideration seriously. Here is some classic video from Neptune Canada showing what looks like Ophiura sp. fighting it out with another individual over some food. 

    and don't forget this blog about "brittlestars of death" as we saw Ophiura sarsii attacking mobile prey! (vertebrates even!)

    Other related members also have jaws/teeth that sort of look like this. Maybe more of these are more predatory than we thought? 

    2. Ophiothrix-Sharp teeth! 
    Ophiothrix (and related genera of brittle stars) occur widely in temperate AND especially in tropical waters. They can be quite striking and colorful..
    Electric brittle-star (Ophiothrix sp), GBR, Australia
    Image by Arthur Anker
    Blue lined brittle star (Ophiothrix lineocaerulea)
    thanks to Wild Singapore!

    Feeding in Ophiothrix is nicely shown in this video. Food caught on the spines, is moved by tube feet along the arm to the mouth, where the food ball, called a bolus is devoured.

    Ophiothrix and indeed ALL members of the Ophiothricidae are well-known in the taxonomic literature for having these unusually striking types of teeth. 
    Here's a close up!  Usually with a very comb-like appearance... MANY papillae (ie teeth) on each "jaw"
    From imaging these teeth in profile, Boos notes that the "teeth" are arrowhead shaped and pretty sharp but also pretty wide.

    Boos states that this combination of "sharp" and "wide" serves to cut up and crush the bolus of food as it enters the mouth. Boos argues that the teeth would also be effective for devouring diatoms and/or grabbing parts of or complete  invertebrates in addition to big chunks of scavenged flesh.

    And onwards? 
    There are LOTS more brittle stars where that came from...  As I had indicated earlier, the "jaws" and "teeth" have been used heavily to classify and identify brittle stars but none were really good at understanding function...

    Boos's efforts are a start. Interpretation of these structures has been surprisingly unseen in the literature. 

    This for example, is an ophiacanthid from the Atlantic..
     Has a jaw similar to that of Ophiothrix....kinda. 
    And this euryalid ophiuroid (aka a serpent star)

    Further data from observations of actual feeding and perhaps even closer observations with x-rays and measurements of brittle star biophysics may give us more insight into how brittle stars feed!

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    Today a post about a NEW paper currently available as advance ONLINE at Marine Biology (yes, there's a paywall) authored by myself and Dave Foltz my colleague (with help from Scott Fatland) at Louisiana State University, and five multi-nationalcollaborators whose role will become clear.

    This project originally began because we were studying a relationship between two near-Arctic sea star species. One in the sub-Arctic North Pacific (called Hippasteria spinosa) which occurs widely in Alaska/the Aleutians Islands, Washington, etc.  

    Hippasteria is a cold-water animal and is important as a predator of deep-sea corals and cnidarians. Here was a blog about some prior species I've worked on...
    Spiny Red Star -  Hippasteria spinosa
    Image by Davidtodd via Flickr
    and Hippasteria phrygiana which lives in the North Atlantic near the Arctic Ocean around the United Kingdom, Norway, off the coast of Massacusetts in North America etc.
    Hippasteria phrygiana
    Image by Vidar -
    Often times, when you see two very similar looking species in far Northern parts, separated by the Arctic Ocean
    You can test the relationships between these species using genetics to determine if they are closely related.  Sometimes you can even determine if they are literally the SAME species perhaps separated by time and the history of the region.  Ice bergs and glaciers perhaps?? 

    As it turns out, we found something intriguing...

    The more we sampled these 2 species, the more we realized that scientists had assumed that Hippasteria was present from North Pacific to Arctic to North Atlantic.. it turns out no one had ever collected any from the Arctic!! (i.e., nothing in between!)
    And to add more to the mystery, there were taxonomic accounts which indicated that there were accounts of the Atlantic species, H. phrygiana in unusual places..namely.. New Zealand!! 

    We looked at the distribution of this and related turned out that H. phrygiana or species which closely resembled it were present all over the world! 

    A two-year effort on the part of myself and Dave Foltz was launched!  

    We managed to obtain samples of Hippasteria from all colleagues over the world!  Our coverage spanned 3 oceans across 2 hemispheres!

    • the North Pacific-Aleutian Islands/Alaska
    • the South Pacific-Chile, Solomon Islands and New Zealand
    • the Kerguelen Islands in the South Indian Ocean (sub Antarctic), 
    • the North Atlantic, the North Pacific-Aleutian Islands

    We gratefully acknowledge all of the the co-authors and other scientists who helped us obtain the data we used in the paper!
    What we found was pretty amazing. From all the populations around the world? 
    There was ONE species.

    We extracted tissue and DNA from multiple populations and found that the genetic differences among the many populations found around the world were minute.  SO minute that there was really no reason they should be regarded as separate species.. 

    BUT there was structure. Different populations show SOME natural differences relative to other populations. 

    The following two diagrams show what's called "haplotype networks" for the two genes that we studied. The size of the circle indicates the sample size, whereas the different colors shows the region and the lines show the connectivity between the regions sampled..
    Fig. 2 Network for COI haplotypes

    We sampled two genes but I've only shown one network so that you get the idea.  Basically, there ARE population differences between the populations in the North vs. South Pacific vs. the ones in the North Atlantic.. 

    One Species Around the World! 

    You can think of this in the same way that human beings show differences (also called heterogeneity) between populations but are all basically considered the same species. In population genetics-its often the amount of difference between isolated populations that mounts up to indicating different species.

    There's actually a LOT of animals that belong to only one species that are found all over the world (other than humans that is!)

    Usually though, its small species (such as the brittle star Ophiactis) (see here) that get carried everywhere or perhaps things that swim like jellyfish...
    Moon Jelly - Aurelia aurita

    BUT this is still kind of unusual. One species that lives on the sea bottom?? From a group of animals not known to be quick travellers or even particularly well travelled?  This species' spread is probably via the marine larvae which were carried via ocean currents...

    Widely distributed species often wreak havok with people who describe species (i.e. taxonomists). Do differences between populations mean many species? Or do they mean one species occurring widely?  

    In this case-its ONE species. This also has a pretty huge impact on taxonomy. In the old days, many species were identified as new because they were found in new places, or far away from where prior species were known. A lot of the technology to test these relationships was not yet available...

    But now that we know,  ALL those species names that fall within the range of our study will be suppressed (via international rules) by the oldest name-Hippasteria phrygiana.  So, for example, the North Pacific Hippasteria spinosa (described in the 20th Century) will now be called H. phrygiana (described in the 19th Century) because they've been shown to effectively be the same.

    Another spin- HOW FAST did they Spread Out? and from where?
    Further dynamics!
    • There was apparently NO gene flow across the Arctic and we couldn't find any records of this species currently present in the Arctic. So, in one sense they took the long way around....
    • Modelling studies of the genes showed that the three populations had been diverging with little or no connection  (i.e. gene flow) for the past 50 to 75,000 years (roughly the late Pleistocene when). 
      • That means that this species spread out over the world's oceans QUICKLY (not even a million years!) and not that long ago! That in itself is pretty surprising...
    • Could the distribution of these animals (originally spread via swimming marine larvae) be affected by glacial (i.e. ice) cover?  
    • Although evidence was not concrete-it seems likely that Hippasteria spread out from the Pacific to the Atlantic. 
    • This was not a case of spread from human transport. We know this because one of the genes we looked at had changed too much to have occurred in a human time frame.
    So there you have it!  A story about a species of starfish living in THREE Oceans! Evolved wide and Quickly!  Not invasive and not an animal that floats around the world as an adult! 

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