Its Sea Cucumber Spawning Time!

Image from the "FunSea" video below

Springtime! Springtime! Springtime! When fertile sea cucumbers realize that its the season to begin emitting their gametes into the water! Some sooner, some later..but it eventually becomes time!

Many echinoderms appear to adopt a particular stance when emitting gametes.  This bit I wrote awhile back shows sea stars and brittle stars standing up on their tippy toes for example. 

Theyposition themselves into the water column in order to take advantage of better water currents for their gametes to disperse. Or at least, that's what seems to be the case. This reproductive posture is actually not all that well understood.

So, its time for ANOTHER installment of sea cucumber spawning!!

One important thing to realize? That in spite of their shape and the color of the materials being emitted, we CANNOT identify the sex of the sea cucumbers in the pictures. 

This diagram nicely sums up the difference in reproductive material. One emits the male gametes while the females emit the egg. But its likely not the case that they are always this conveniently near one another..

This image borrowed from A snails' Odyssey blog here! Great info! 

The eggs and the sperm meet in the water and fertilize in the water column.  Once fertilization occurs, the fertilized egg matures into a specific sea cucumber larvae, known as an auricularia (sometimes referred to as the auricularia stage): 

And it is the above larval stage which undergoes several more stages of growth until it settles onto the sea bottoms and matures into an adult sea cucumber.

BUT to get there, the adults have to spawn! Here's a great shot of what seem to be at least 2 species of sea cucumbers from the Atlantic (Stetson Bank in the Flower Garden Banks, National Marine Sanctuary).

Since these guys are likely trying to take advantage of the same water current to carry their gametes to their destination, several individuals (from different species) are likely to find locations in the same general area. 

This one seems to have found a particularly safe area around some diadematid urchins...

From Japan, we have several very nice video captures of various sea cucumbers in spawning position...

Their postures are fairly arched and position the body well into the water column.

And here are further examples of sea cucumber species emitting gametes from around the world..

In stark contrast, some other species seem to be closer to the bottom during this period, with only part of the body raised off the ground.

Interesting that both of these are on sandy bottoms. Coincidence? Difference in species? Hard to say.
                   

IN CONTRAST, there's other deep-sea sea cucumbers, as presented in the NMNH Invertebrate Zoology blog,  which actually huddle together to optimize reproductive success (image from this new paper!)

An increasingly common sight on crowd-sourced media and on deep-sea exploration! Simple observations which remain a fertile area of study... (yes. I went there!)

What are the DEEPEST known echinoderms??

                     

The depth of the ocean has been in the news a lot lately. Here's Virgin Oceanic planning to send someone down to the bottom,  as well as this excellent infographic from the Washington Post about how deep a challenge MH370's recovery might be..  

and of course 2012 was James Cameron's big dive in the Marianas Trench!

Image from NPR

The other day this came up in conversation "Blah, blah... but its not like echinoderms occur in the deep sea? I mean, I've only seen them inshore, they are mostly shallow water aren't they??"  Au contraire mon frere!!
Echinoderms are DEEP. They live in the deepest depths of the ocean..

But how deep are we talking?? Most folks think of "deep" as anything beyond the intertidal.

Many biologists think of "deep-sea" as anything below 200 m, which is where roughly where light stops penetrating. But then you get beyond THAT... then you start entering the REAL deep sea... the ones where biologists start saying stuff like "THAR be where dragons have lease..."

Via Wikipedia! 

To me, this starts at around 1000 m..and these zones include

1. the Bathyal at roughly 700 to 1000 m
2. the Abyssal at about 2000 to 4000 m
3. the HADAL from 6000 to 10000 m

Basically, the true BOTTOM of the ocean is around 6000 to 10,000 meters. ABSOLUTE FARKING cold, dark, BOTTOM of the ocean.! And yes. Cameron's sub got down to 10,000 ish meters at the bottom of the Marianas Trench.  These are places where it is cold and dark. The coldest and the darkest in that there ocean!

Here is a chart from CNN (from the Cameron dive) which gives you a sense of scale about what these zones mean..

Image from CNN here

Echinoderms are among the DEEPEST living of all animals known on the planet. HOW DEEP? Which ones?? Let's find out!

Sources for this survey include Belyaev's "Hadal Bottom Fauna of the World Ocean", the former Online Echinoderm Newsletter World Records page and the Smithsonian NMNH specimen database!

1. Sea Urchins (Echinoidea) I start with one of the most familiar but also unfamiliar of sea urchin groups! There are many deep-sea urchins. Such as the echinothurioids (the tam o shanter urchins). or the bizarre Dermechinus.  Many of these urchins go deep, but still remain one of the "shallowest" of the Echinodermata. Many urchins occur at depths >1000 m but "only" go down to about 7000 meters.  Which urchins live at that 7000 meter threshold??

Pourtalesiidae: The "coke bottle" urchins! I have written about these bizarre deep-sea sea urchins before.  YES, these are sea urchins, albeit highly strange ones.

They have EXTREMELY thin and delicate skeletons, which can be almost paper thin. They live by burrowin through and digesting mud on the deep-sea bottoms. Records for the genus Pourtalesia sp. (usually only fragments are recovered) have been collected from 6,850 meters in the Java Trench.

2. Sea Stars (Asteroidea) Next up is my favorite group! They go deep but are not among the deepest. They go 2000-8000 m. That's not to say that there aren't a bunch of DEEP weird looking critters to look at! Here are the records!

Freyellid brisingidan starfish:  Freyastera sp. and Freyella sp. Brisingids are starfish that use their arms to pick food out of the water (more here). All the members of the Freyellidae occur in the VERY deepest depths. Typically below 1000m, but many occur between 4000-6000 m. But the deepest record for a freyellid was Freyella kurilokamchatica from 6860 meters.
                                      
"Mud Stars" Family Porcellanasteridae. NOW we're talkin. This entire family lives on muddy bottoms deep on the ocean floor, where they swallow massive amounts of mud for food. Similar to the mud star Ctenodiscus (here).  The specimen figured below from the NMNH collections is from 6, 250 METERS below the ocean surface!  Deepest record for this species, Eremicaster vicinus is from 7,614 meters! These live in the deepest abyssal-hadal bottoms around 4000 to 8000 meters.

Finally, Hymenaster, aka deep-sea slime stars. Here's a post about their shallower relatives. And you can always find more on my blog about them. Pic below is from 2000 m.

The deepest record for Hymenaster is for a species from 8,400 meters in the Kurile-Kamchatka trench!  So, Hymenaster (species remains undetermined) currently holds the record for deepest starfish. But who knows what new specimens and video remain to be discovered!

2.  Brittle Stars (Ophiuroidea)As with sea stars, their close relatives, the brittle stars don't seem to be quite as deep as some of the others but are still plenty deep. Plus, there's probably a bias of sampling as many brittle stars are tiny and more difficult to collect via nets and so forth..

The plate below is from this paper by Belyaev, G.M. & N.M. Litvinova, 1972: New genera and species of deep-sea Ophiuroidea. - Byull.mosk.Obshch.1spyt. rir. 77, 3: 5-20. (In Russian)

From Belyev & Litvinova 1972

The plate above conveniently displays three of the deepest occurring brittle star records known.

1. In the upper two boxes is Perlophiura profundissima, which has been collected between 2265 and 8015 meters.
2. Lower, left box is Homalophiura madseni, collected from 6156 to 7,230 meters! 
3. and finally in the lower right hand box is Bathylepta pacifica which occurs between 5740 and 8006 meters! (thanks to Sabine Stohr for tipping me off to the correct species!)

There's easily a dozen species of brittle stars found below 6000 meters! Probably more...

4. Crinoids (Crinoidea) Down to the deepest TWO groups! 

Bathycrinus carpenteri from the SERPENT website

Among the crinoids, stalked crinoids are famous members of the deep-sea fauna. There are fossils of stalked crinoids which date back to the Paleozoic and there's always been sort of an unusual mystique to them.  Members of the family Bathycrinidae are recorded from 8,175 to 9,050 meters in the Kurile Kamchatka Trench! 

Pictures of some of these very deep stalked crinoids ALIVE at 9000 meters were observed in Japan and reported on Deep-sea News awhile back

5. Sea Cucumbers (Holothuroidea)  So, which group takes the deep-sea CAKE for being deepest?? How could it be any other group than the Sea Cucumbers??? 

There's a LOT of diversity of sea cucumbers at the >5000 meter depth range. All of the swimming sea cucumbers live at these depths (click here) 

And of course, our old friends, the SEA PIGS!! (the one shown from 1500 m). Many members of the Elpidiidae, the group to which the sea pigs belong are among the deepest known. Several species occur as deep as 9,500 meters! 


But the winning sea cuke? the DEEPEST ones? Members of the Myriotrochidae, including Myriotrochus.  Records for these sea cucumbers go down to 10,687 meters!!! The NMNH has records of Myriotrochus bruuni from the Philippine Trench at depths of 10150 to 10190 meters! So yeah, if Cameron didn't see any of these when he was down there? That's HIS problem! 

This pic is from a Myriotrochus from the Kara Sea, but you get the idea.

this image from this Russian page 

This Russian Livejournal page actually has a nice photogallery of various cold-water deep-sea sea cucumber groups. Myriotrochids, molpadiids and sea pigs! Check it out..

There's a lot of weird stuff going on and through deep-sea sea cucumbers! Here's some of it.

So, yeah. Sea Cucumbers. Deep. And don't you forget it! 

Echinoderm & The Invertebrate Zoology Toys of Japan! Echinoblog Travelog Pt. 3

Japan is known for some of the biggest and most successful and widely known toys throughout the world. Giant robots! Godzilla! Pokemon! Sailor Moon! Hello Kitty!  For whatever reason, when you think about toys, Japan comes to mind.

During my travels, it's also become apparent how the interests of the people reflect on the diversity of toys that are available to everyone, from casually interested kid to hardcore collector.

Japan amazingly produces several toys of different species from not only the deep-sea but also from "deep time" with many fossils and so on. What makes these so amazing to me is that they were even made!  

Although some the plushies might have been made for a specific show, most were made for the general populace as either collectibles or items that interest the consumer.

To me, THAT is a huge message. There's folks in Japan who buy these because they think these creatures are interesting! You can even buy deep-sea biology books at 7-11 in Japan! 

1. Enypniastes! Take for example, the swimming deep-sea sea cucumber Enyniastes. You can read about this and other swimming sea cucumbers here. 

                                              

This amazing species is captured as a tiny highly detailed replica, known as a gashapon. They are obtained from specific gashapon machines, but these days most folks just buy them individually at special shops throught the "hobby" distrcts of Japan, such as Akihabara or at Nakano Broadway. 

These are highly detailed, come with a stand and are about 1-2 cm tall. 

Somewhat more specialized is the plushy Enypniastes obtained via the gift shop at the National Museum of Nature & Science! These are larger as you can see below...

2. Sea Pigs! Yup. they got em'... Remember my original post here??  Deep-sea sea cucumbers with legs that for some reason combine cute and creepy!

No fewer than TWO brands of sea pig gashapon (again, small highly detailed plastic models of Scotoplanes globosa)                 

This cool plush toy from the gift shop at the National Museum of Nature & Science in Tokyo!

3. We've all heard/seen of the famous Japanese giant plush Bathynomus/giant isopod toy! 

and yes, it is indeed soft and cuddly! Perfect for those cold nights when your teddy bears and undependable stuffed mammals have run out on you! 

BUT what about the Giant Bathynomus-inspired designer vinyl action figure! Stands a good 10 inches tall with ray-gun!

Made by and for collectors, I've seen diferent sizes and color variations of this toy...

 ranging from 60 to $600.00! Some of them even glow in the dark! 

Plush toys are gaining momentum, there's even a set of Paleozoic invertebrate plushies!!
    The National Museum of Nature and Science of Tokyo had a fun set of Paleozoic invertebrates made into plushies!  Here's a carpoid! (Paleozoic echinoderm) But there was a whole Cambrian set which I'm not showing here...
                                     
4. But the BIGGEST THING? small toys.  Also known as gashapon!  As mentioned earlier, tiny little 2-6 cm replicas of the real thing. Part of different sets following various themes for collectors..

For example, highly detailed Paleozoic invertebrates! Eurypterids and trilobites! (carpoids & others are also available).

Ammonoids! and more!

You want crabs and other crustaceans?  YOU GOT IT! Anatomically accurate tiny plastic replicas of different crab families! Calappids! Portunids! Leucotheids! There's actually a second set with various lobsters and so forth...

 You want NUDIBRANCHS? Done.

And of course there's a lot of your requisite whale, deep-sea fish, jellies and so on.. But here's a pretty cool commemorative set!  Remember back when they had FIRST footage of the living deep-sea giant squid Architeuthis?? 

Yup, a commemorative and official (by the NMNS), Architeuthis squid gashapon set! With sperm whales and everything!