5 Cool, Weird Brittle Star Behavior Captured on video/pictures!

Ophiuroids (aka serpent stars and brittle stars) do some pretty remarkable things, BUT They are often tiny and cryptic so we don't get to see the cool array of things they do.

Flickr and YouTube have provided us with a HUGE quantity of imagery of interesting aspects of ophiuroid biology. Here is a sampling of the ones I found worth sharing!

1. Swollen Disk! This is the deep-sea serpent star Asteronyx! which live with arms wrapped around deep-sea cnidarians, such as sea pens. But this one has a fully inflated disk! When we study them in the lab, these are deflated and flattened. What do they do with them when inflated?  Why? 

This one is probably a different species, but it gives you an idea of how these live...with their arms wrapped around a cnidarian called a sea pen..

2. Brittle Star Burrowing!?  See those two brittle star arms emerging from the burrow?? That means the disk is buried within the sediment. But WOW! Look at the sediment being dumped out of that burrow in a continuous string! Maybe something else is in there putting that out? or is the brittle star doing that??


One of the rays of an amphiurid. Note the tube feet/spines fully occupied by sediment as it digs its way into the bottom.


That arm is probably part of this critter.. an amphiurid brittle star


3. Brittle Stars Feeding: Tube feet in ACTION!! How often do you get to see a brittle star in full feeding action??


and even MORE ophiuroid feeding action!!!


4. Brooding Brittle Star CT SCAN! Here is an internal CT scan of a BROODING ophiuroid! The ones inside the disk are juveniles!


5. Brittle Star "SWIMS"! This looks like Ophiocnemis, the brittle star which seems to find itself hitching a ride in jellyfishes! I've written about these here! 

Ophiarachna Predatory Brittle Star FEEDING ACTION!

(photo by David Witherall)

Happy 4th of July! Some neat video for you guys this week!

So remember from a few years ago I wrote this post about the giant, green predatory ophiuroid Ophiarachna incrassata. Here's the post from 2008 where I outline O. incrassata's remarkable predatory behavior when feeding on fish!

Now in 2011 we have some video that shows some similar feeding in what looks to be a different species of Ophiarachna!

Caveat! These are aquarium observations. Animals in captivity don't necessarily eat what they would eat in the wild. But there remains some insight into watching them feed...

Here we see a light colored Ophiarachna (does not look like the green O. incrassata) apparently attacking a tiny porcellain crab identifed by the videographer as Actaeodes tomentosus



Here's a couple of nice ones showing Ophiarachna feeding on some fish and showing some rather dramatic disk deformation!



Here's Ophiarachna feeding on what looks like broken basket star arm bits


Here's a nice one of O. incrassata. Note at 0:58-59 after feeding- the disk shows the food deforming the top surface of the disk creating that weird "tent" sticking out of it..

Feeding a Green Brittle Star from Carlito on Vimeo.


Here's a nice view of the oral surface of what the videographer calls "Ophiarachna megacantha"

Commensal Crabs RIDE that starfish!!!

Thanks to Anna and BlennyWatcher.com!


This is probably the first time that these swimming crabs have been observed living commensally on Luidia maculata (or possibly on ANY starfish).

When people talk about commensals (crabs or whatever) living on a larger host, its often assumed they are taking advantage of things like food (from what the sea star eats) and protection..but here's ANOTHER potential "win" for the crab-TRANSPORT (aka dispersal).  Is this possibly how these crabs get around from one place to another??

Note also how the animal keeps on arching up?  It doesn't seem to be expelling gametes (as has been documented here before) so maybe its not all too fond of the crab attention and trying to shake them off??

Ride the Luidia Express!

Wow! Have a great weekend!

Wow! Urasterias Vs. Amphipods! BONUS Echinoblog!

Last night I found this..

A video that shows the Arctic asteriid starfish Urasterias linckii just PLOWING into a field of creepy caprellid amphipods!  This looks like it might be feeding or possibly the opposite-defending itself?. Are the pedicellariae "batteries" on the side being used? Do these species typically interact?  Many mysteries!

As a caveat-this video could have been staged, obivously some time lapse was used, not sure. but it IS pretty cool and is I think the first time I have EVER seen Urasterias alive in a video! So, enjoy!

here's some better pics of the animal itself I found on Flickr

Photo by Alexander Semenov

And a close up of the MANY pedicellariae. They are quite abundant and pretty frakking HUGE!

Photo by Alexander Semenov

If you want to why/how the pedicellariae might be used in feeding click first on this intro post  and then there's this earlier post about asteroids feeding on moving prey! (and on Labidiaster-the king of starfish predators on moving prey!)

I've spoken recently of how the diving community and the many, many legions of marine photographers have captured SO much on the Internet-often without realizing what they've done! And here is another GREAT example! 

Pt. 2! Snails and the Starfish that love to eat them!

More escape responses! This time snails (i.e., gastropods) and some "extreme" behavior on their part to get away from predatory starfish!

Japanese Astropecten vs. snails!

The neat snail escape response to the sand star Astropecten begins at 1:30!  Honestly, I've never seen a snail pull the ol' push myself out of the way with my foot maneuver!

Pycnopodia vs. abalone! 

Here's a few videos of abalone escaping the large Pacific Pycnopodia helianthoides!



This one shows that even brief contact with a sunflower star will ellicit the escape response..

Scale Worm Helps Snail! Biting Starfish (Pycnopodia)!  I missed this one I don't know-but COOL!  the good part begins at 0:55

And here's an escape response ellicited by the sea slug Dendronotus!

Cockles and the Starfish who like to eat them! A nice gallery of escape responses!

Here's a neat escape response that was captured on Flickr between a Florida cockle and the sand star Astropecten! Images captured by "The LivingSea.com"  Plus some video of Pacific cockles being chased by sunflower stars!


Here, we see Astropecten articulatus in contact with the cockle (Trachycardium egmontianum)

The cockle is alerted! And it extends its large muscular foot to begin its escape!

 The foot pushes the cockle away!
 

And aWWAAAAYYYY it goes!
 
And away!


On the Pacific coast, different species of predatory starfish (in this case the sunflower star Pycnopodia helianthoides) also feed on cockles.. an identical response is observed..


Here's a really nice one


Here's one that literally does a judo like flip on Pycnopodia!


here's a decent one with a wacky sound track..


Here's a variety of responses to both cockles AND scallops!  (the scallops are the one that "jet" away using their excurrent siphons)

An amazing Black and White Sea Urchin film/video from... 1928???

Found this stunning Black and White video/film called "Les Oursins" which shows what I believe is the spatangoid  Echinocardium cordatum and other sea urchins..



The description reads

Réalisé en 1928, et donc muet, ce film est un des premiers grands exemples de l'art singulier de Jean Painlevé. Grâce à des techniques de prises de vue originales, mais surtout à un sens de l'image et du rythme, il parvient à décrire de manière extrêmement précise et pédagogique les caractéristiques d'une espèce animale, tout découvrant les beautés étranges, fascinantes, parfois comiques que permet l'observation d'êtres auxquels la plupart ne trouverait aucun intérêt. Chez lui, sens de la beauté et exigence savante se renforcent mutuellement.

Which translates to English as

Produced in 1928, and therefore silent, this film is one of the first great examples of the singular art of Jean Painlevé. Through techniques of original shooting, but mostly a sense of image and rhythm, he manages to describe with extreme accuracy and pedagogical characteristics of an animal species, whilediscovering the beauty strange, fascinating, sometimes comedy that allows the observation of things which most would find uninteresting. Home, sense of beauty and scholarly requirements are mutually reinforcing.

I know nothing about French filmmaking..but this is pretty amazing footage.. 

Spawning Sea Cucumbers! They look dirty but they're really not!

So, following up my account of asteroid spawning underscoring behavior that is often seen but not really well-studied, here's something similar from the tropical sea cucumber oeuvre!

How does the posture help? Does it assist in optimal fertilization? Why don't all species assume the posture?

Its worth noting that even though a lot of the YouTube descriptions say they are "males releasing sperm" the truth is that there's no way to sex sea cucumbers from external appearance (that I know of).

So, what you're seeing below is either eggs OR sperm. I.e., gametes or reproductive cells are being produced...by either males OR females..

hmm..this one might be interpreted badly if you have a smutty mind..

Giant WORM Wednesday! "Bobbit Worm" Eunice spp. BIG Raptorial Polychaete videos!

I have been running late this week with air travel and various museum starfishy things-but I will have something good soon! I promise..

In the meantime-some cool, hi quality videos of Giant Raptorial polychaetes that have been available lately...

catches a fish at 0:39

The Bobbit Dance from Walter Marti on Vimeo.

yeah, not echinoderms-but sometimes its good to be diverse, eh?

This may or may not be the infamous "Bobbit worm" (Eunice sp.) first referenced (to my knowledge) by curators Terry Gosliner and Gary Williams in their book Coral Reef Animals of the Indo-Pacific. Wikipedia has a reference to "bobbit worm" but I'm not sure if this is a specific species or one of several...... (For those who don't know the story of John and Lorraine Bobbit -look here..)

These worms were so named because of their spring-loaded jaws which they used to capture and kill MOVING prey...like FISH.

For the sake of reference (size) these get to be over 2 feet (about 60 cm) LONG and can be about 1-1.5 inches (2.5-2.8 cm) in diameter. They get BIG.

Watch this one catch a fish AND an octopus (near the end)

Bobbit Worm - Dinner time from liquidguru on Vimeo.
others... Bobbit worm in slow motion, high definition stock video footage HD 1080p, Lembeh Strait, Indonesia. ECV0006 from Eric Cheng on Vimeo.

Bobbit worm at night, high definition stock video footage HD 1080p, Lembeh Strait, Indonesia. ECV0005 from Eric Cheng on Vimeo.

this one comes with some an ....overly descriptive intro but has shows some nice behavior..

and some older ones..

Sea Cucumber Behavior via teh Intarwebs! Look at all the things they do!

I am still catching up with my life following my return from Hawaii last week, so here's a bunch of cool sea cucumber videos showing various aspects of behavior!

from JAMSTEC- a relatively new video of a deep-sea swimming cucumber (Tonia informs me that these are Benthothuria!)

A second swimming sea cucumber, Benthothuria, at 1:02 (I've shown this one before-but its such high quality I never get tired of it!) And thanks to Neptune Canada for reminding me about it!

Here is a video of an infamous pearlfish! The oh-so popular fish that lives in the rectal cavities of sea cucumbers! Go here to check the blog on this out if you haven't already!

Some soothing if priapulic holothurian spawning action (looks like tropical Pacific!)

This one almost seems to be dancing to the music!

And today because you always complain that I never take you anywhere nice, here's a fun little song about evisceration...

Back soon with more goodies!

Marthasterias vs. food! Scallops and Clams on the RUN!

Happy Holidays to Everyone!

Yes, its that time of the year..and I hope everyone has made their way to wherever they were going for the holidays! I'm still taking a little time off, but here's a bunch of neat videos of the Atlantic sea star Marthasterias glacialis attacking various clams and scallops!

Most mollusks can detect the "odor" or presence of predatory starfish immediately and many species can implement an extreme or emergency type behavior (i.e. an escape response) in order to escape being eaten. This can be quite different from the regularly encountered behavior associated with these species.

This one has the ol' "I am a clam with a big FOOT that I use to push myself away" response!


M. glacialis Vs. Scallop! (aka Coquille Saint Jacques)


"Un amor gourmand" aka "Greedy Love" (I think?). TWO starfish species for the price of one! Marthasterias pursuing a scallop (with a dramatic soundtrack) followed by some cool Astropecten burrowing video! Some interesting French narration follows...


Happy New Year (Bonne annee!) to Everyone from the Echinoblog!

Holiday Treat! Japanese Astropecten burying/unburying video!

I just HAD to post this.. VERY cool Japanese Astropecten unburying itself in reaction to some food.. A little holiday treat!!

Happy Holidays from the Echinoblog! Here's a little break...

So, between my being snowed in at the Paris airport and being delayed for awhile from travel and other general holiday transit issues, the echinoblog will be been pretty quiet this week... But I won't leave without giving people something! So, here's a little set of videos that mainly features some neat looking sea slugs!

*gasp* yes. Just letting the echinoderms take a little holiday rest..... So, enjoy!

A tropical sea slug, called Kalinga ornata that in one video tries to feed on a brittle star...


and here's just a cool video of it


and here's just one weird-ass sea slug called Melibe viridis


Happy Holidays to everyone from the Echinoblog!

ASTROPECTEN aka SAND STAR videos!!!

I had hoped to put together something more ambitious this week, but alas, forces have worked against me. But NEXT week and for the few weeks? Something SPECIAL ..as the Echinoblog blogs from EUROPE!! As I work from the world famous Museum national d'Histoire naturelle in PARIS, FRANCE!!

But for now, enjoy these very keen videos of the sand star Astropecten which is found in various tropical shallow water environments on sandy bottoms around the world...

From Japan, an outstanding video of what looks like Astropecten polyacanthus gliding gracefully over a sand bottom to a French sound track!


From Tarifa, Spain, a neat vid of what is identified as Astropecten aranciacus...


An Astropecten sp. from Changi!

Painted sand star from Ivan Kwan on Vimeo.

and another one from Japan, being flipped over and turning back...

Japanese deep-sea cuke poops! then Flies! Sand Dollars eating! Sea Urchin Escape Artist!

and what would Thursday be without a new vid of a deep-sea swimming sea cucumber pooping and then taking off!


and from the same Youtube channel.. a sea urchin escape artist!


This Japanese sand dollar (Astriclypeus manni, I think..)eats uh...something that is probably shrimp meat...


and these aren't echinoderm videos..but wow! If you enjoy the Echinoblog-these will appeal to you..

Octopus escapes from Jar!


When Giant deep-sea Isopods ATTACK!


and the BEST for last! You have probably NEVER seen this. Giant frakkin foraminifera and their pseudopods movin around' in time lapse!

Hawaii-swimming sea cucumber and oh yeah..some sponges and stuff...

A great swimming sea cucumber is on this at about 0:39 or so....

TITANIC TURN OVERS!! When Big Multi-Armed Starfish in ACTION!!!

The giant Indo-Pacifc sand star Luidia maculata...in life and then disturbed, turned over and then, righting itself. This one is pretty amazing .....

This week is a short week because of Memorial Day on Monday and various other factors have conspired against me! So..today is videos of GIANT multi-armed starfish from various places TURNING themselves over!!

For some reason, people are always fascinating watching starfish do this! WHY? I don't know. But for some reason its better when the animals are huge, multi-armed freakish starfish monsters!!! GO!

Here's Coscinasterias calamaria from Australia...

Starfish sped up 10x from Andrew Newton on Vimeo.

Here is a Japanese Solaster sp. correcting its position...


And of course what compilation of big multi-armed starfish is complete without PYCNOPODIA-the Sunflower Star!


Could starfish behavior have some kind of practical applicaton?? Like say as a model for ROBOTS???

Hat tip to my Japanese robot/starfish fans out there!

BASKET STAR VIDEOS!! Gorgonocephalus and relatives in motion! Yow!

As a follow up to this week's earlier post on Gorgonocephalus- Today we have some nice videos of Gorgonocephalus and its relatives in the Gorgonocephalidae! (i.e., other basket stars!)

Enjoy!

A nice Gorgonocephalus time-lapse! (try to ignore the silly music)


Probably not Gorgonocephalus but possibly something related...


Not Gorgonocephalus but probably something related... pt. 2

Sea Urchin Video FRIDAY!

Here's some sea urchin videos to tide everyone over for the three day weekend! Happy Columbus Day!

Red Sea (Strongylocentrotus franciscanus) Urchin Barren-Cal Fish & Game ROV video



Fire Urchins from the Indo-Pacific!


Purple Sea Urchins (Strongylocentrotus purpuratus) from Santa Cruz with some Pisaster giganteus action going on at the end...


Echinus acutus from the Aquarium de l'institut Océanographique de Paris

Friday Crinoid Video Spectacular!

So..I am still preparing for the cruise next week...so here's videos about crinoids!

Something REALLY special...a brittle star living ON a crinoid... look closely at the dark, black thing humped over the center. (the crinod is red-ophiuroid is black)


Dense crinoid forests from the Monterey Bay Marine Sanctuary in California!


Swimming Antarctic Crinoids


Pretty nice video of a swimming crinoid in the Philippines...