- RSS Channel Showcase 6883038
- RSS Channel Showcase 5288085
- RSS Channel Showcase 8276878
- RSS Channel Showcase 6085266
Articles on this Page
- 10/29/13--01:22: _5 Worms that will g...
- 11/05/13--16:00: _Treasures of Paris ...
- 11/12/13--23:58: _Because Brachiopods...
- 05/28/13--22:49: _New "Tam O Shanter"...
- 06/04/13--19:47: _FIRE Urchins! Brill...
- 11/19/13--11:50: _Synaptid Sea Cucumb...
- 11/26/13--21:33: _BRITTLE STARS! COLO...
- 12/04/13--06:38: _Where do those star...
- 12/10/13--19:15: _SAND ANGELS! Astrop...
- 12/17/13--19:53: _The Ocean's Holiday...
- 12/24/13--08:13: _Tis the season for ...
- 01/07/14--22:56: _Classic Echinoderm ...
- 01/15/14--00:34: _Stunning Photos of ...
- 01/22/14--21:08: _Worms & Snails that...
- 01/28/14--22:24: _Brittle Star Divers...
- 02/04/14--19:58: _What we know about ...
- 02/11/14--21:09: _Reflections on Scot...
- 02/17/14--18:16: _For the next five w...
- 02/25/14--14:27: _EchinoTravelog! Vis...
- 03/04/14--05:41: _EchinoTravelog: Pt....
- 10/29/13--01:22: 5 Worms that will give you the creeps! Happy Halloween!
- 11/05/13--16:00: Treasures of Paris 2013: Brittle Stars @Le_Museum!
- 11/12/13--23:58: Because Brachiopods-that's why! 5 Things to know about Brachiopods!
- Mostly deep-sea urchins found all over the world (many in greater than 1500 m depths-in NZ they range from 100 to 5000 m!), but with some shallow water relatives (aka the Fire urchins, I'll save these for another day)
- They often have very sharp and poisonous spines. And yes, the deep-sea ones too...
- They "walk" around on the sea bottom with special spines that have hoof like tips
- They were described FIRST as fossils and the living animals were found AFTER...
- 11/26/13--21:33: BRITTLE STARS! COLOR EXPLOSION!
- 12/10/13--19:15: SAND ANGELS! Astropecten The starfish that dig it!
- 12/24/13--08:13: Tis the season for diatom arrangements! Happy Holidays!
- 01/15/14--00:34: Stunning Photos of Marine Invertebrates from Australia
- 01/22/14--21:08: Worms & Snails that Live On/In Sea Cucumbers!
- 01/28/14--22:24: Brittle Star Diversity! How many are there and where do they live?
- 02/17/14--18:16: For the next five weeks! The Echinoblog Goes to Tokyo, Japan!
WHY DO WORMS GIVE US THE CREEPS??
|Image by Divaholic|
Curiously, there's something ABOUT animals with this body shape that seems to freak people out.
Is it the body shape? Something left over from our "metazoan" brain from a LONG time ago?
|Image by Mely-o|
Its Halloween week! Here's FIVE disturbing predatory worms!
Imagining ANY of these as human sized or above would be cause for alarm!
1. Bobbit Worm-Raptorial Predator!
|image by Eunjae|
Short version: Tropical, shallow-water predators. Up to 6 or more FEET long. They lie in wait and pounce on prey with their spring-loaded jaws. They feed on fish and other vertebrates!
|Image by MerMate|
Wanna see WORSE than the Bobbit worm?? Let's GO!
2. Ribbon Worms-Long distance Death!
Basically the proboscis is an extended feeding structure used for a FAST grab which in some cases, extends easily 100% of the worms body LENGTH!
Ribbon worms really need to be seen to be appreciated. So here's some video!
But not all nemerteans are small, cryptic beasts. Some species, such as the Antarctic Parborlasia are HUGE. I wrote about them in this post about Weird Antarctic Invertebrates. They are upwards of THREE FEET LONG. And are about as wide around as a garden hose!
|Image by Icy_Sea_Slugs|
Ribbon worms are CRAZY abundant and are almost certainly important to the ecosystems they inhabit but they're often difficult to find...
3. Marine Flatworms! Eating from the inside out
|Image from this website on introduced Netherlands invertebrates|
In this video, Euplana attacks a shrimp-like amphipod by wrapping around its back and completely immobilizing it. Sticking its tube-like pharynx through a segment of the amphipod, the flatworm then consumes and digests its internals--a process that takes about half an hour. Once finished, it abandons the empty carcass and goes into a resting period until its next meal. On the outside, an amphipod that's been eaten doesn't look that different from a normal amphipod...except for the fact that it's, well, dead.Videographer: Dean Janiak (Smithsonian Environmental Research Center Benthic Ecologist)
4. LAND Flatworms! Eat em' while they're alive!
|image by pbertner|
|Image by mistifarang|
|Image by Amuderick|
|Image by Cornell Fungi|
As summarized nicely in the video. No earthworms? No aeration of the soil. No crops.
Flatworms: An Invasive Flatworm Hunts Earthworms from Shape of Life on Vimeo.
|Image by uezane|
While many leeches do the blood sucking thing- others are purely predatory, feeding on earthworms and other comparably sized animals. Here is a pretty amazing pic of a leech eating a tiny toad!
Here's some marine leeches! One from Lembeh, Indonesia.
|Image by Christian Loader|
|Image by Ria Tan and Wild Singapore!|
When I say "whale worms" No, I don't mean, yet another post about Osedax, I mean worms that live IN the INTESTINES OF WHALES! (and other cetaceans)
|thanks to Miriam for letting me borrow her pic to the Tokyo Tapeworm Museum & fr providing scale|
But that's for another day....
PARIS! I'm here continuing my research at the world famous and awesome Museum national d'Histoire naturelle! (Twitter: @Le_museum) in Paris, France!
Many of my new species were found in these collections. I enjoy my visits to Paris, one of the most delightful cities in the world, and of course, the opportunity to collaborate with my echinoderm colleagues (whom I've profiled in prior posts!)
Why? Because this was one of the original specimens prepared by the great French naturalist Jean-Baptiste Lamarck!
|Image by Open Up!|
Brachiopods are actually a PHYLUM of animals. That's right a whole GROUP of animals that most folks have probably never heard of!
|image by Herman Giethoom|
Brachiopods are one of the few groups of marine animals which live ONLY in the Ocean! (Echinoderms being one of the others...)
Some places you learn about some new mammal, but HERE at the Echinoblog? you learn about a whole PHYLUM of animals in five easy steps!
1. What does the name mean?
Brachiopoda, when you break it down: "brachio"= arm and "poda"= foot. Wha? The Arm foot?
The name refers to a structure known as the pedicle. That's the purple stalk bit that is anchoring the animal down to the substrate. This is how the pedicle looks
in the group informally known as the "articulate" brachiopods. Arm refers to the muscular arm-like aspect and "foot" to its use (or disuse) in attatching to the bottoms.
The pedicle manifests in two different ways relative to which of the two major groups of brachiopods you are looking at!
One group has been referred to as the "Articulate" brachiopods. And yes; they are very well spoken thank you. ha ha.you have now caught up with the jokes:
The "articulate" part refers to how the two shells have teeth that articulate with one another.. Here are some hinges on various brachiopod valves.. (images below by Open Up! fr. this awesome photoset fr. the University of Tartu-go take a look at some AWESOME photos! )
In the "inarticulate" brachiopods the pedicle is this much more developed tail-like feature. the animal is almost kind of a worm. These live in burrows. People eat these! (see below)
|Lingula adamsi Dall by Changhua Coast Conservation Action|
Relative to the animal inside, brachiopod shells are oriented top-bottom vs. those in bivalves, which are oriented left-right
|This image from Kristie Bradford's Historical Geology web page!|
image by mpjones_007|
|Image by Royston Vasey|
3. What/How do they eat?
Brachiopods have a feathery feeding structure called a lophophore! Brachiopods are basicaly suspension feeders. Water flows in and over the lophophore and tiny finger-like bits called cilia pick the food up!
Here's some reality from the very talented Arthur Anker showing the lophophore with the animal's valves open!
A further GREAT pic of the lophophore can be found here..
And here is the diagrammatic approach that gives you a general idea of what you're looking at.... The animal below has been turned upside down to show parallel orientation with the pic above...
4. In the Paleozoic (roughly 250-500 million years ago), brachiopods were once THE happening invertebrate!
|image by David Cartier|
According to the World Brachiopod Database only about 385 species occur today from the ~30,000 described (mostly fossil) ones!!
Many of these species live in out of the way and isolated places...
Here is a gorgeous pic of Coptothyris adamsia from the Sea of Japan
|Image by Alexander Semenov|
and more from Alexander Semenov: Hemithyris psittacea (Rhynchonella psittacea)
5. Geology! Fossil Brachiopod Shells are sometimes replaced by Pyrite! (aka Fool's Gold)
In the fossil record, the "shells" (called valves) of brachiopods sometimes undergo a process in which they are replaced with pyrite aka fool's gold!
This makes them golden and sparkly!
|Image by jsj1771|
|Image by E. Sese|
|Image by JS1771|
5a! More Geology Fun! Brachiopod valves are often found in cross sections of rock!
Geologists know the value of a good cross section! Brachiopods are VERY abundant in Paleozoic rock. And if you cut through the shells of one you get some pretty distinctive impressions in the rock..
|Image by Maitri|
Sometimes there are minerals such as agate!
|Image by Captain Tenneal|
Brachiopod shells can be pretty dense and sometimes you see a lot of them!
Sometimes you see some neat rare stuff.. like this soft-part preservation of a lophophore!
|Image by Dietmar Down Under|
FUN FACT! People EAT brachiopods!
I wrote about this earlier... but yes, apparently some curry and/or garlic is appropriate....
|Image by Peter Roopnarine|
The original NIWA press release is here. These urchins have been getting all sorts of keen press, includinghere in the N.Z. Herald and here in The Sun. And of here on New Zealand's Maori news..
and I thought.. EVERYONE needs to know more about these exciting urchins! and so today is a bit of a "refresher" on echinothurioid sea urchins!
I wrote a short summary about these for Deep Sea News several years ago...(here) and wrote a short bit about the commensal relationships between these urchins and fish here.
The quick summary version is:
|An Atlantic species by Hankplank|
|Image by Neptune Canada|
|Also by Neptune Canada|
Here's the spine close up showing the "walking tip"
|Image from the NIWA Benthic Inverts Facebook page|
|Image from SERPENT project here|
|From the NIWA page on this story|
For those who are not as keen on Scottish headwear, a "Tam o Shanter" is a cap, sort of like a beret (wikipedia here) and you can sort of see the resemblance.
|Image by DrHaggis|
|Image by H2omom.2006|
|Image by Neptune Canada!|
These were all discovered and described by looking at a variety of different characteristics. Some as straightforward as body color as well as spine shape and location. But some characteristics are more subtle. These are the individual pieces of pedicellariae-little claw like structures that are present on all sea urchins..which were studied using a Scanning Electron Microscope to yield distinct shapes...
|Fig. 28 from Anderson 2013|
|Figure 28 from Anderson 2013|
|Image by Aboireoujtulchien|
"Spiny" urchins are distinguished by the presence of an Anal Cone. See that white bulb on top? THAT is where the poop comes out! You don't see that in "proper" fire urchins as we'll be seeing.. Note also that the spines are much longer.
These urchins all belong to the genus Asthenosoma which includes six species spread throughout the Indo-Pacific region. Here's a neat video that gives you an idea of what they look like..
Yes, the colors are a huge shift in appearance, but similar to their deep-sea cousins, Asthenosoma also has the distinctive "walking" spines...
On this image of Asthenosoma varium the walking spines form a fringe around the lower oral side composed of distinctly yellow spines. My understanding is that most of these prefer soft, muddy bottoms.
|Image by Ben Naden|
|Image by NEPTUNE Canada|
But they remain venomous...
|Image by JianXu|
And if its not clear by now, YES. They're pretty damn venomous. My understanding is that its very painful.. but typically not lethal.
and they certainly do seem like they do, don't they??
|Image by Bruce Magun|
|Image by Daniel Stassen|
Close ups! showing some of the brillaint colors, spine patterns and etc.. I suspect most of these are Asthenosoma varium
|Image by MerMate|
|Image by Daphna130|
|Image by lupopeye|
|Image by maractwin|
|Image by Nick Hobgood|
|Image by B. Maither|
|Image by Russell Taylor|
From the Red Sea, Asthenosoma marisrubi with a more mellow look...
|Image by Key of Life|
|Image by Le Congre|
|Image by S1mon Mar5h|
|Image by Clark Chang|
|Image by Jesse Claggett|
|Image by Richard Barnett|
Urchin Riders from liquidguru on Vimeo.
Some of the little buggers actually "hollow" out a space, clearing out spines where they can live! You can see the bare patch on this one...
|Image by Klaus Stiefel|
|Image by Mark Atwell|
|Image by Jay Dryden|
As the video shows, synaptids move along the bottom in a snake-like-fashion using their tentacles to move food into their mouth as they move as this species (Synapta maculata) from Lembeh Strait in Indonesia is doing..
|Image by Bernard DuPont|
This shows how long these get.. Some reach 6 FEET long...
|Image by shamsulazar|
Some are decoratively patterned!
|Image by ania115|
In Synaptula spp., you'll often see hundreds of them on a single sponge! What I like to think of as a veritable city of sea cucumbers!
See all those wormy white things on the sponge? THOSE ARE SEA CUCUMBERS! (the genus Synaptula sp.).
|image by Enice Khoo (mermate)|
|image by Bernard DuPont|
|image by Tom Puchner|
|image by Alfonsator|
|Image by Wild Singapore|
|image by Wild Singapore|
|image by Rob Jeff|
|Image by Richard Ling|
|A big heads up thanks to Wild Singapore who took these lovely images!|
|Ophiothrix from Arthur Anker!|
Ophiothrix spp. below Fantastic images below by Michael Zeigler via Flickr...
|Image by Mark Rosenstein|
Various shots of Ophiothela danae, a small brittle star that lives wrapped around gorgonian branches..
An outstanding ophiothricid in pink and blue...
|Image by Budak|
Ophiothricid on a sponge..
|Image by Steve Williams|
|Image by Mike Toy|
|Wonderful Image by Krystle D|
|Image by Werner Wittersheim|
|Image by Ria Tan (Wild Singapore)|
|Image by Pau Estrada|
|Image by TVN|
|Image by RJAdams55|
|Image from Iamheretokelp|
3. Archaster typicus
This treats the two specimens at the top of the "wreath".. these are another species which is widely occuring the tropical Pacific.
4. Sand Dollars: Mellita spp.
Mellita spp. are from the tropical Atlantic coast, the Gulf of Mexico, Florida, etc. in shallow water.
Sand dollars are sea urchins! And here's more on that. Those holes in the body (ie. the skeleton also known as the test) are called lunules and they are pretty nifty.
Another commonly encountered species in holiday decorations. Sand dollars, especially these species have the most "benefit of the doubt" because its not unusual to encounter their dead skeletons as beach wash.
Although one has to wonder how much collecting one needs to have enough to create a regularly marketable wreath such as the ones I've been seeing marketed on the Internet...
I'm pretty damn amazed at just how WIDESPREAD these get via the tourist industry. I've literally seen these sand dollar shipped across the country and across the WORLD for sale at tourist shops.
Here is what they look like with all the original spination and such...
5. Echinometrid? "Sea urchin tree"?
Maybe Echinometra from Australia? Not sure. Like sea urchins, the tests can be gotten as beachwash.. but not regularly. So, I'm thinking these were likely harvested...
|Image from NOAA photo library|
So to recap:
1. Starfish decorations are mummified remains of living animals, which had to be killed in order to get you a holiday wreath. I wouldn't lick them.
2. Many of the species used in these industries from the tropical Pacific are probably not sustainable fisheries.
3. Personally, I just think decorating starfishes like Santa Claus is tacky. So, please. just stop. Use sea shells or give people candy. People like candy.
4. Sand dollars are okay. Still possible to kill them for use as decorations. But also possible that they were collected beachwash.
5. Good grief. Who pays 150 dollars for holiday decorations made from beachwash??? or mummified starfish remains??? You know what's good for 150 dollars? chocolate.Send to the Echinoblog. Or charity. charity is good.
|Image by Alan Cressler|
I am referring to the widely known "sand star" called Astropecten, which includes over 100 species present all over the world, in tropical to temperate waters. Go here to see some awesome pics of Japanese Astropecten and related spp. Most occur in shallows but some live in deeper-waters.
|Image by Kevin Bryant|
Here's a nice image of Astropecten indicus from Singapore, illustrating the animal next to the star-shaped impression it makes in the sand.
|Image by Kok Sheng|
|Image by Hamed Saber|
Image below of an Astropecten from Singapore.
|Image by Wildsingapore.|
Which famous Simpsons gif meme does Astropecten remind you of?
|image by Bill & Mark Bell|
As I mentioned, Astropecten occurs widely around the world. And is quite diverse. Here is Astropecten articulatus from Georgia (south coast of the US)
|Image by Alan Cressler|
|Image by Wild Singapore|
|Image by Yoichi Kogure!|
|Image by comunerimini|
|Image by Archipelagos Institute of Marine Conservation|
|Image by sarsifa|
|Image by Dimitrious Poursanidis|
|Image by Dimitrious Poursanidis|
|Radiolarians! A colored SEM image. Photo by John Cravens|
First some phytoplankton from the Southern Ocean (Antarctica and thereabouts) from Robert Johnson! Actual size of most of these is probably VERY small on the order of mm or less..
I believe these are diatoms called Chaetoceros
More on its biology here.
Image: Ian McMillan, Cardiff University.
|Another foraminifera: Halkyardia minima. Image by Ian McMillan, Cardiff University.|
|Image by Sea Surface OA cruises. |
Scanning electron microscope of Emiliania huxleyi: coccospheres and loose coccoliths from a bloom in the South Atlantic.
|Image by Jessica Matheson|
Happy Holidays!Echinoblog is off next week !
(thanks to Chris Taylor and Rhi L. for corrections!)
yeah, I said I was off this week..but I couldn't resist these.. Go check out the arranged diatom photo set at the California Academy of Sciences Flickr. here.
I love libraries.
But for some reason, people NEVER know enough about them. Case in point-one of the most amazing but, I think, underutilized resources available for people studying taxonomy and biodiversity: The Biodiversity Heritage Library! (and note the button for donations!)
What are they? You can certainly go and read all about them at their Wiki here. But simply put, they are a massive digital, online archive of OPEN ACCESS (that's the academic word for "free") taxonomic, naturalist and other literature which pre-dates copyright, or is by definition freely available to everyone (such as federal government materials) and has been made available via the Internet to ANYONE who wants it.
This helps a LOT of people who are looking for VERY old and RARE taxonomic monographs which might ONLY be available from either a handful of Natural History Museum libraries OR a very expensive used book dealer.
For example, let's take the work of starfish taxonomist, Walter K. Fisher former director of Stanford University's Hopkins Marine Station "back in the day" during Ed Ricketts time (circa 1930s)....
Prior to the BHL, these books were vintage. 1906. 1911. 1919. It took me many, an hour scrubbing tanks and hauling boxes to get the 200 bucks it cost me to buy my first copy of Fisher's "Asteroidea of the North Pacific". Now, thanks to the BHL, you can get it as a freely available download!
But what's the catch? Well, the thing is they kind of did too good a job! There is SO much material available that actually finding the stuff that is useful for certain people requires a bit of navigation and experience. Some monographs are part of other series that weren't distinguished. So herein, I make it easy for the interested starfish taxonomy student.... Here's a bunch of his big monograph/books (click to go):
The North Pacific Asteroidea Monographs
Fisher 1911-Asteroidea of the North Pacific. Pt. 1. Phanerozonia and Spinulosa
Fisher 1928-Asteroidea of the North Pacific. Pt. 2. Forcipulata
Fisher 1930-Asteroidea of the North Pacific. Pt. 3. Forcipulata (concluded)
The Starfishes of the Hawaiian Islands. 1906. (I cheated on this one-its from NOAA)
Starfishes of the Philippines. 1919.
The HMS Discovery Antarctic monograph. 1940.
Here are a BUNCH more Starfish Taxonomy Monographs as pdf for everyone via the BHL...
1. Here are the starfish collected by the HMS Challenger!
The Text pt. 1
and the PLATES
5. The classic Starfishes of Japan by Seitaro Goto, 1914. Go here.
6. Deep-Sea Starfishes from the Tropical East Pacific (Mexico, Baja California, etc.) . Ludwig 1905. Go here.
This week I am travelling and distracted.. so here are some gorgeous marine invertebrates from Australia! Pics from "Billunder" on Flickr! (which you can go see for yourself here)
Blue Pycnogonid! (sea spider)
Another pycnogonid with eggs!
An amazing Ceratosoma nudibranch
A blindingly colorful Asterodiscides ("firebrick star")
The papulae (gills) from the arm of Plectaster decanus aka the "mosaic star"
There's something about sea cucumbers which seems to make them attractive as hosts for various other animals.
Some sea cucumbers got clams that live in their throat...
The sea cucumber anal region seems to be popular as a place to live as crabs and of course, pearlfish find good homes there..
This week.. More animals that have made sea cucumbers hosts to their lives!!
This scale worm above was identified as Gastrolepidia clavigera, living on its host sea cucumber (apparently Bohadschia graeffei). Image by Arne Kuilman.
This one by Theresa Legler, shows another polynoid worm, but it looks like a different genus/species...
Another similar looking polynoid. Image by Kevin Lee.
This one, by Ben Naden, seems to be taking advantage of the rough skin texture...
Snails! Most of the snails shown here appear to be members of the Eulimidae, which are a diverse group of snails, which has apparently adapted a parasitic lifestyle. Many of them live on echinoderms. I review some of them here.
Eulimids basically feed on their hosts. They have a proboscis which is inserted into the bodywall and used to suck out precious bodily fluids and other nutrients!
Here's a neat pic by Eunice Khoo showing several embedded in the epidermis.
A different kind of snail, Melanella sp. living on the sea cucumber Thelenota ananais.
Images below by "wj", what looks to be another set of eulimid snails, feeding on the sea cucumber Colochirus.
and let us not forget that eulimid snails (in this case-the genus Stilapex) ALSO inhabit deep-sea sea cucumbers... (from the sea pig post)
|(from the New Zealand R/V Tangaroa weekly log, photo cred-Stefano Schiaparelli, NZ IPY-CAML)|
Happy New Year! I'm slowly getting caught up with life and finally have time for something meaty!
So, first for 2014 an overview on brittle star (aka ophiuroid) diversity! How many? Where do they live? I wrote a parallel post for starfish last year. You can see it here.
As with the article on starfish, this one is based on a recent PLOS One paper which is freely available for download here. It was written by the three TITANS of brittle stars! Sabine Stohr at the Swedish Museum, Tim O'Hara at the Victoria Museum in Melbourne Australia and Ben Thuy at the University of Göttingen, in Göttingen, Germany. The data from their paper is based on the World Ophiuroidea Database.
So, one quick bit of clarification. This article is about brittle stars aka ophiuroids. NOT starfish. Starfish are a different (albeit closely related) group of echinoderms. I provided a brief overview of how to tell apart brittle stars from starfish here. Note however, that you'll often hear people refer to them as "brittle starfish" or some such thing. Nope. "brittle stars" is good and fine.
Note also that some common names refer to different KINDS of ophiuroids. "Brittle stars" tends to refer to the more conventional types of ophiuroids, such as the ones here and like those above.
1. How many species of brittle stars are there??
In terms of species, brittle stars are by far the MOST diverse of all the living echinoderms. Sea stars follow up in 2nd place (n=~1900 species), followed by the sea cucumbers (Holothuroidea, n=~1250), then sea urchins and sand dollars (n=~950 species) and finally, the living crinoids (n=~600 species).
This has never been a big surprise to invertebrate zoologists. Brittle stars live EVERYWHERE. Under rocks, in the mud, on corals, under corals.. even ON JELLYFISH.
2. How many different KINDS of brittle stars are there?
|Fig. from Stohr et al.|
There are 270 genera in 16 different families. So, there's a fair diversity of body plans within the Ophiuroidea but not as much as say, in starfish (which have 370 genera broken up into 36 families). So the bulk of diversity in brittle stars appears to be at the species level. That sounds consistent with their apparent overall strategy of diversification into whatever habitat or niche seems to make itself available, given how many places on the marine bottoms they can be found. There's a high number of species that avails itself of ecological niches.
But more on that below...
3 Which groups of brittle stars are the most diverse??
The MOST diverse of brittle star families? The Amphiuridae! An example shown above, courtesy of the wonderous Arthur Anker! As of 2013, there were 467 accepted species.
Amphiurids are burrowers and diggers. They find their way into mud, sand, any kind of loose sediment that they can shelter in and under. Once dug in, they throw their arms up through the sediment and out into the water to "fish" for organic particles and other food.. As shown here...
Although amphiurid brittle stars vary in size, many of them are tiny, tiny little critters that fit easily into cracks, crevices and nooks in rocks or other underwater habitat. They live EVERYWHERE.
And the 2nd place winnah??? The Ophiuridae, with 344 species
We know a fair amount about them, but considering how MANY of them there are? WE probably don't know enough. For example, we didn't know until the 1990s that Ophiura (below) could display some rather vicious predatory behavior...
3. Where do brittle stars live?
Stohr and colleagues have very nicely mapped out the number of species by different biogeographic zones around the world. Their breakdown as follows:
831 species! HIGHEST diversity is in the tropical Indo-Pacific.
400 species! North Pacific! The temperate/cold-water band including North America and Asia.
350 species! The South Pacific-the temperate water zones around Australia, New Zealand and etc.
333 species! The West Atlantic.
319 species! The Indian Ocean! Examples of new species from the Indian Ocean? Here.
237 species! The North Atlantic
199 species! South Africa
183 species! East Pacific
123 species! Antarctic
120 species! South America
73 species! Arctic
What's MOST interesting about these? When one looks at the species diversity by depth, the MOST diverse areas? the Indo-Pacific, South and North Pacific? A significant amount, sometimes more than 50% of the diversity of these faunas is from the deep-sea (>200 meters!).
Tim O'Hara has been working on the zonation and patterns in deep-sea ophiuroids for quite awhile. Here is an example of some of his work...
5. How long have brittle stars been around??
Most sensible scientists would agree that ophiuroids and asteroids diverged at some point in the Paleozoic with modern-looking brittle stars appearing sometime in the mid to late Paleozoic, some 440-485 million years ago or so. So, yes. Brittle stars have a very old lineage as do most echinoderms. Older than dinosaurs and certainly older than humans.
But most "good" fossils of brittle stars are largely observed in Mesozoic rocks. There are actually quite a lot of brittle star fossils out there but many of them were identified using pretty substandard taxonomy by geologists using out of date identification concepts (long story)..
Author Ben Thuy for example, has been able to take the skeletal elements from living brittle stars and compare them with fossil skeletal elements, discovering the presence of deep-sea faunas in the Cretaceous and in younger rocks..
For people who appreciate brittle stars, we live in good times. We have three active brittle star workers, including that ever so rare beast... a brittle star paleontologist! And we now even have a new Japanese worker who specializes on basket and serpent stars
How long will it be until that 2,064 hits 3000?
Toxopneustes! aka the "Flower Urchin" is one of four species of Toxopneustes (all of which occur throughout the tropical Pacific). One species, Toxopneustes pileolus is one of the most frequently encountered and as such, this is the name most often applied to sea urchins that have the distinct appearance (as seen above).
Toxopneustes literally means "toxic foot"undoubtedly alluding to the MANY venomous pedicellariae that compose the animal's appearance. I'll explain "pedicellariae" more below..but just so you know what I'm talking about? ALL of those yellow circles and traingles in the picture above? Those are tiny little claws and each one of them is toxic. So be careful around these guys..
Toxopneustes has all of the other stuff that you see in other sea urchins, such as spines and tube feet.
The circles and triangles below are pedicellariae. Round means the pedicellariae are "open" and the triangular ones indicate the pedicellariae are either closed or are closig. The brown rods below that kind of look like toothpicks? Those are the spines, which are actually not themselves toxic (as far as I've read).
Toxopneustes has been known for quite a long time. The genus was described in 1841 by Louis Agassiz, so we've had some time to think about it.
This then, is the puzzle. Why do we seemingly know so little about it?? As we'll see, it has a formidable reputation as a highly venomous species and its a prominent tropical sea urchin but really, a lot of what we know essentially boils down to this....
1. Toxopneustes pileolus displays covering behavior.
I have discussed and blogged about "covering behavior" in the past (here). Toxopneustes is a "collector" urchin, which means that it shows the curious behavior of adding rocks and other debris using tube feet and/or pedicellariae to cover over itself.
Although the reasons are not well understood, it is thought that this could serve to protect the urchins from ultraviolet rays. In some cases with other urchins, its thought that the materials serve as defense, but given the highly venomous pedicellariae on this species, I kinda doubt that's the case here.
One paper, which studied the East Pacific species, T. roseus (here) suggested that the covering response protected the animals against wave surge while they fed on coralline algae in rhodolith beds.
2. Flower urchins spawn in the Spring and "undress" their covering materials to do it!
This one is self-evident since all animals have to reproduce. And most echnoderms spawn externally. But it was only recently in a paper by Andy Chen and Keryea Soong in Zoological Studies in 2009 which showed that they showed Toxopneustes pileolus"release" all of the materials obtained via their "covering response" before they spawn.
3. They hold the distinction of "World's most venomous" sea urchins
Here we have the #1 feature, this sea urchin is known for: its sting! One species in particular, T. pileolus is regarded by the 2014 Guinness Book of World Records as the "most toxic" of sea urchins (see lower left corner).
The poison is served via the pedicellariae which are all of those triangular and circular structures that you see on the surface of the urchin.. Here the pedicellariae are all agitated. How can you tell? Note that they are all triangular instead of round. That means they are closed and have been recently agitated...
Here's a diagram of one, showing the hard parts within all of the softer covering. Basically, each one is a claw that injects poison.
|From the Echinoderms of Panama Lifedesk by Simon Coppard|
|From this Japanese blog. Do not do this. It will hurt (I mean the pedicellariae. Going to the blog shouldn't hurt).|
On June 26, 1930, while I was working on a fishing boat on the coast of Tsuta-jima in Saganoseki, I scooped up with my bare hand an individual of the sea-urchin which had been carried up by a diver with a fishing implement on the water surface from the sea-bottom about 20 fathoms in depth, and I transferred the sea-urchin into a small tank in the boat. At that time, 7 or 8 pedicellariae stubbornly attached themselves to a side of the middle finger of my right hand, detached from the stalk and remained on the skin of my finger.Instantly, I felt a severe pain resembling that caused by the cnidoblast of Coelenterata, and I felt as if the toxin were beginning to move rapidly to the blood vessel from the stung area towards my heart. After a while, I experienced a faint giddiness, difficulty of respiration, paralysis of the lips, tongue and eyelids, relaxation of muscles in the limbs, was hardly able to speak or control my facial expression, and felt almost as if I were going to die. About 15 minutes afterwards, I felt that pains gradually diminish and after about an hour they disappeared completely. But the facial paralysis like that caused by cocainization continued for about six hours.
Here's one living on Toxopneustes pileolus with some eggs!
They actually CLEAR off the pedicellariae and spines and live on a bare patch of the animal surrounded by all the poisonous pedicellariae and etc.
How far/how long do they hitch a ride?
Do they feed on the tissue from the tube feet and pedicellariae?
Are those "bare patches" long term? Or are they only from acute attacks? (those crabs seem to be pretty comfortable there!)
Are the crabs as well camoflaged as they seem?
Interestingly, note also that the pedicellariae are all open and seemingly comfortable. Does that mean they are pretty cool with the crabs living on them that way? What do the urchins get out of it?
IS Toxopneustes REALLY the world's most venomous sea urchin???
Someone go find out and tell em' the Echinoblog sent ya! (unless you get stung-then uh.. it wasn't)
my big Sea Pig post (here) that really gave me an idea of just how far a blog that specialized on echinoderms (of all things!) could go.
So, its now been three years and I've had a chance to look at some numbers and trends. This has given me a chance to see exactly HOW my sea pig post has presented these animals into the public eye.
Now bear in mind, that the term "sea pig" actually refers to sea cucumbers in the family Elpidiidae, mostly in the genus Scotoplanes but several genera are similar and fit the bill pretty easily.
Prior to the late 20th/early 21st Century, before we had video and crisp pictures of these animals in their natural habitat, the number of people who even knew these animals even existed was something you could count on two hands. This included a small number of echinoderm taxonomists (no more than 6) and deep-sea biologists who had perhaps seen the dead ones or perhaps pictures from towed underwater cameras.
In 2009, I came across an unusual spike in readership (probably from a Facebook quiz) that was focused on a "sea pig" I had posted from a blog about a scientific meeting on image analysis. I rapidly figured out (thanks to some help from friends on Facebook) that people had seen this strange beast and wanted to know what it was. So, I took the July 4th weekend and wrote that up and posted it!
The result greatly impressed me. And then, hot on the heels of my post, Animal Planet followed up with a piece on Sea Pigs that same month! (July 2009)
Here are the Google Search trends graph for "sea pig"and the term "sea pigs". Basically, there is a HUGE spike in hits for July 2009 (when my sea pig post went up, followed by the Animal Planet post), and a significantly greater interest afterwards...
What do the numbers mean? Here's the explanation from Google Trends:
The numbers on the graph reflect how many searches have been done for a particular term, relative to the total number of searches done on Google over time. They don't represent absolute search volume numbers, because the data is normalized and presented on a scale from 0-100. Each point on the graph is divided by the highest point, or 100. When we don't have enough data, 0 is shown.Its fascinating to see how outreach and social media have affected the perception and awareness of a weird, little sea cucumber, which frankly, nobody gave a damn about throughout most of the 20th Century. And I'll be honest, research on this species has not perceptibly jumped but perhaps that's just a matter of time as inspiration and funds dovetail...
Where has the "concept" of sea pig gone? How have they entered into the culture?
1. There is ART.
They have replaced reindeer on Holiday cards!
Yeti Crab Santa by NocturnalSea on deviantART
I love this one.
Sea Pigs by HangingLeaf on deviantART
The Sea Pig as Meme.
Sea Pig Motivational Poster by XxweirdpersonxX on deviantART
2. There are toys (albeit Japanese candy toys)
3. Sea Pigs were on OCTONAUTS! (and were scientifically accurate!) My thanks to "Skymouse" who sent me this link!
4. and of course the famous "voice guy" from Buzz Feed and so on Ze Frank did one of his famous "True Facts about the sea pig" videos!
5. and MOST recently, Kronos Quartet has been inspired to compose music from/about/by Sea pigs??
Did I directly participate in getting sea pigs on Octonauts? No, but would Octonauts have a show featuring sea pigs without my blog back in 2009? Who knows? But its nice to know that contributions and/or influences from the Echinoblog can be seen in a variety of places.....
Have you seen some new art/statue/show/pop culture reference to sea pigs? Let me know! I'd love to continue seeing how sea pigs become part of popular culture..
3. Multiple posts about GIANT STARFISH!
Some are REAL...... But others are IMAGINED....
5. And of course TWO posts on Japanese Cephalopod Monsters in Pop Culture! Because they are awesome.
This one is more about Japanese kaiju in TV and film...
Konichiwa! Echinoblog is in Tsukuba, Japan (outside of Tokyo) visiting the National Museum of Nature and Science studying the deep-sea starfishes of Japan! How many new species await?
After arriving last week, I've finally gotten settled into my temporary home away from home!
I've gotten the impression from some folks who believe/perceive that scientists who travel abroad (or anywhere really..) are somehow living in the lap of luxury. I've lived across the board when traveling on the "science dime" and at least, for folks like me, fine dining and luxury hotel rooms are for a different class o' people...
so here is a little bit on Japan but also some insight on how I live when I travel. I am not atypical for the kind of science that I do...
1. Living the Scientist's Travel Life.
By now, I'm kind of a seasoned scientist. I've got a PhD, I'm older and less inclined to sleep on people's floors. Plus, when I travel, my status as a professional (and my personal preference) leads me to a proper room with a bed and so forth.
But when I was a grad student/younger post-doc I "paid my dues" and ran the gamut: I shared cheap hotel rooms with two or three others (sometimes I knew them), lived at the YMCA in the bad part of town, slept in Greyhounds, and lived my share of research visits in roach-infested rooms without air-conditioning in the middle of the summer and slept in fishing vessel sleeping quarters with a smell that never goes away....
So, its nice to get a simple, clean dorm room like this one. My thanks to the NMNS for having decent (and affordable) dorms for their visiting researchers! Yes. There's even a washing/drying machine in there! Fancy! (and for those concerned about expense, this room was supported by the NMNS, no US tax dollars are at play...)
Here's one of my rooms when I lived in Paris. Also nice. A bed. A window. Some closet space. Its nice to have a conveniently placed bathroom with toilet AND shower! (not always the case!)
For example, one leaves ones shoes at the door outside the main residence...This typically involves trading out for a pair of slippers, but as an American my feet are pretty big, so I end up walking around with socks!
Slippers are special to special rooms! Here in the restroom, you actually have a pair of special slippers JUST for using in the "water closet" (or W.C.) /toilet room.
And finally... someone at the Museum treated me to this neat, little thing: A Shrimp chip WITH AN ACTUAL SHRIMP!!