Wednesday, December 17, 2014

A simple guide to Tropical "cushion stars"! Halityle vs. Culcita spp.!!

From Wikipedia.. they are GREAT! Go give them some money! 
Today.. a short instructional on tropical "cushion stars" which is a common name I HATE because it just describes so many different types of sea star species..  BUT if any one starfish species COULD be the "rightful" bearer of THIS common name, its the one called Culcita.

Why?  Because its name is LITERALLY translated as "pillow or cushion" but for comparison, there's another similar looking beast called Halityle regularis. I see the two mistaken for one another all the time.. so here's the two genera for comparison...

This one is Halityle regularis. One species known, widely occurring from the Indian Ocean (Madagascar) to southern Japan (the Ryukyu Islands) and Australia and New Caledonia.

Interestingly, there are two colors I've seen on Flickr... This red one from Indonesia.

versus this more purple one... Not sure if this is simply an artefact from the lighting of the photography... Here's another one that seems more deeply purple..


Haltyle has a very strongly defined net-like diamond pattern on the top surface and with the distinct colored region on the oral sufrace...


Here is Culcita
In terms of appearance, Culctia is a bit chubbier, and more compact, but the patterns on the surfaces are more cloud-like and are not as distinct.


Especially on the oral surface, which depending on species is a bit rougher, almost spiny



Culcita  has THREE species, C. schmideliana from the Indian Ocean and C. coriacea, which is known primarily from the Oman region and finally the most widely occurring species C. novaeguineae which is found all over the Indo-Pacific. But mostly the Pacific.

We don't know that much about Culctia, but we know a little. The most widely occuring species, C. novaeguineae also eats coral but nowhere near the volume or severity that the dreaded crown-of-thorns starfish does.. Culctia's role is just as important though, in that it aids in community structure.. It feeds on certain kinds of coral and this influences how coral colonies grow...

As I've written about before, when they are young, they have a more flattened, pentagonal shape.. and as they grow, they "inflate"...
Here's a living one for comparison..

Here is the Indian ocean species, Culctia schmideliana  which is distinguished by the very large, dark granules/nodules on the body surface..

As with all the species, there appears to be some variation in color and degree of granular presence...



Culcita coriacea from the Gulf of Oman...These seem to have these larger dark regions and without the large granules but a more overall even surface..


And finally, the most widespread species in the Pacific 
Culcita novaeguineae
C. novaeguineae is HIGHLY variable.. it comes in MANY colors throughout its very wide range, in the Pacific, including Hawaii, Japan, the Philippines, Singapore, New Caledonia, and elswhere....which suggests it is possibly a bunch of cryptic species...

Surface on these is largely covered by granules or tiny spinelets....None of which seem to get very large.

Some, such as this Japanese individual have tiny spinelets...

Based on Flickr photographer "Nemo's great uncle", the Japanese name "マンジュウヒトデ饅頭" roughly translates into "steamed bun starfish".

Mmmm...steamed bun... Awesome...

Colors in this species are HIGHLY variable.. what is the significance? Different species? Different food? Simple random variation??



More RED spines!! (Thailand)

Some interesting color contrast between the top and oral (bottom) surfaces..
in spite of their massive appearance, they are surprisngly flexible..

Here's one arched pretty strongly and doin' the cushion star equivalent of TEH SEX!! Gametes GO!!!

And on that note! Happy holidays from the Echinoblog!! I will be more irregular with posts over the next two weeks...

Tuesday, December 9, 2014

WHAT is going ON HERE? A galloping herd of urchin! CRAZY Maretia planulata heart urchin aggregation!


Every once in awhile, I think that I might finally have run out of stuff to share with people and THEN something magic happens. Some fantastic new video or pic pops up and WOO! The diversity of echinoderms and the infinite resourcefulness of the Internet pop out of nowhere with some magic NEW biology to share!!

Case in point is this video, which was shot by "Dive Yos" showing various cool inverts spotted during a dive in Bali. The video was posted 2 months ago...

It starts with a few typical things, a sea anemone, sea horses, etc. a lot of typical fare...but then we see one, two, four heart urchins, six... and then at 0:27 into the video?  BOOOM!!! You got this HUGE heart urchin stampede!!!

Best as I can tell, these are the heart urchin, Maretia planulata, described by Lamarck in 1816. This species of urchin lives throughout the tropical Indo-Pacific, from Tanazania to the Marshall islands...

They live in relatively shallow water on the surface of sandy bottoms.

Here's what one individually looks like.

Heart urchins are "irregular urchins" which are closely related to sand dollars. I wrote up a post on a related animal called Echinocardium, which you can find here




But WOW! What is going on with this HUGE aggregation??

As I've written before, other "regular" urchins sometimes form "urchin barrens" when the ecological balance of a particular region is out of whack and you have TOO many of them eating EVERYTHING in sight...

I have no idea if this huge "herd" of urchins is "natural" or not..

But the thing is, Maretia is a heart urchin (aka a spatangoid). They are sediment feeders, so they don't really eat kelp.  I suppose the absence of some predator might be the cause. And the huge numbers could STILL deplete food in a given region, but this high abundance seems to be a regular thing.

There are other websites which have also observed that they occur in high numbers like this... Such as this one displaying this aggregation.
Photo by Geoffrey Bertrand, on his website
The most I could find on the literature about this 'herd' of urchins was from 1986. Thomas Suchanek and Patrick Colin in the Bulletin of Marine Science , vol. 38(1): 25-34, noted that this species was abundant reaching 100-200 per square meter!!!  and that they processed "massive amounts of sediment"

I would love to know more about whatever is going on here. Or maybe this will be the beginning of someone's Phd thesis? Don't know. But the thought of 100s (thousands?) of these things galloping along the bottom of the Indo-Pacific sandy bottoms is just... farking AMAZING!

Announcement for the 15th International Echinoderm Conference in Mexico!!

Coming up Next year is the 15th International Echinoderm Conference to be held in Playa del Carmen Mexico!

The official IEC website for this conference is here:  http://www.icmyl.unam.mx/15iec/

Twitter: https://twitter.com/@15iec
Facebook: https://www.facebook.com/15IEC

The conference theme will be: “Echinoderms: from molecules to continents”.

The IEC is held about every 3 years, and rotate around the world. The last one (the 14th IEC) was held in Brussels, Belgium.  A full overview of Echinoderm Meetings and Conference Proceedings can be found here. 


Monday, December 1, 2014

The Strange Deep-Sea Ophiuroids of Paris! Featuring Dr. Tim O'Hara!


Bonjour once again!! So, my trip to Paris has all but ended and I'll be returning to the United States in a few days. The trip has been a challenging one. The laptop crashed and was out of the loop for two weeks and left me without a computer for data collection and etc..

So, much of my trip has been "old school".. working with paper and notes labelling jars with species names as best as I can...
Although data collection has not been as efficient as I like, I have done the Paris Museum (my host) some good by identifying a massive number of specimens in the collection...
I not only got through many of these older specimens but several of the newer ones as well...
All said and done, I've identified around 900 specimen lots for the museum. Given that Paris probably contains the largest collections of asteroids in the world, that is no small feat!!

But one of the GREAT things about this trip is that my visit, inadvertently overlapped with a trip being undertaken by one of my colleagues. Dr. Tim O'Hara at the Museum Victoria in Melbourne, Australia!! One of the world experts on ophiuroid systematics and ecology! 

I have written about Tim's work before:
  1. This new species of the Australian starfish Tosia, which was described by one of his students.
  2. This fantastic biogeographic pattern in brittle stars which he published several years ago! 
  3. Tim was also the one who identified and, in part, documented "Brittle Star city"
Tim and I are friends from waaaay back. We worked together in the museum in 1999 before either of had our PhDs and its strange to think of that being almost 15 years ago...  

I had a great chance to learn about weird brittle stars from Tim and so I did!!

Learning about weird, deep-sea brittle stars with Dr. Tim O'Hara from Museum Victoria! 
Tim was working with deep-sea biologists at the Paris Museum who are interested in New Caledonia.  (I am one of them).  Some may remember that this time last year, a huge new marine reserve was created in the New Caledonia region. 

Thus, Dr. O'Hara's ecological and taxonomic expertise was brought to bear... not only to identify brittle stars...
but ALSO to share his new cutting edge research with the greater scientific community! A recent paper by Dr. O'Hara has used cutting edge "Next Gen" technology, using over 425 genes to reconstruct the "family history" of the Brittle Stars.  

Its noteworthy not only for the fact that he used an exhaustive amount of genetic data, but he was able to sample and identify ALL the brittle stars necessary for the study! Not an easy feat when you can count the total number of brittle star  taxonomy experts in the world on one hand! 

Here is Tim giving the presentation to a full room of French scientists and colleagues (myself included) in the Paris Museum...

The important part of ALL of Tim's work is being able to identify all of these strange, deep-sea brittle stars from distant parts of the world...  and he was happy to share several of these with me...

1. Amphiophiura insolita!! Don't know much about it, but its got a spectacular rose-like disk pattern...
This specimen of Amphiophiura bakeri was huge! Almost 2 cm across! It looked like an egg had grown five arms! 
2. These two different species of the deep-sea Ophiomusium make it easy to see why brittle stars are so difficult to work with and identify.
                           
                            

3. The tiny male living on the large female Ophiosphaera insignis!!  Notice all the white arrows.. Those point out the arms of the tiny, smaller male.  He lives on the female.

Its unusual for there to be two distinct sexes in echinoderms. In this case, it is thought that this might be a pattern similar to that observed in anglerfish. The male is essentially a parasite on the female. 


4. One of the strangest of deep-sea ophiuroids is almost never seen by most people. This is the ophiuroid Ophiomyces, which has this bizarre sac-like disk membrane..  



Its certainly freaky enough that its hard to believe that the picture really captures what the animal looks like, so here's an actual specimen. Its only a few cm across..
Here's one museum specimen, which as treated with metal for scanning electron microscopy...Its still kind of a surreal looking animal....
  

5. A related brittle star is this genus, Ophiotholia, which differs in having funny little hooks on its spines... but has a more distinctly conical disk and specimens are always found with arms locked upwards.

Again, a fairly small animal, only about 1-2 cm across. The drawn image on the left is from a plate of this species from the HMS Challenger vs. the right one which is an actual specimen...

       
And amazingly, thanks to all of his molecular work, Tim now also has a very good idea where these strange critters go in the big "tree" of ophiuroid evolution!! 

Ophiuroids are just a whole bunch of crazy sh*t that just makes my mind POP!!  

Monday, November 24, 2014

The Funky Octopuses of Paris Pt. 2!!

Bonjour! Greetings to everyone from Paris! My apologies for the brief silence. Trips do not always go as planned and my laptop decided it had other plans a couple of weeks ago. "Technical difficulties"..  Ah well.. C'est la vie!

As I am trying to get stuff done before my return to the United States, I thought I would offer a follow up to my artsy octopus post from last year (here)

As a bit of contrast, here was a hyper awesome (and realistic) brass octopus at the gates to the Institute d'Oceanographie....
But I think most of the rest of these are more reminiscent of "dumbo octopuses" which we saw recently on the Okeanos Explorer... 
These are placed all throughout Paris and its often a treat to go hunting for them in various corners of this wonderous city! 

They  are all the work of a street artist, GZUP Stretart (his facebook page is here) But many are goofy or otherwise "interpret" popular media icons.. 

Here for example.. ZOIDBERG!! 
Johnny Depp as Jack Sparrow! 
Oprah? I believe?  (Reader Claire clarifies that this is in fact Rhianna! thanks!)

The Mouse! 
And just more....
An interesting one....

Meh...


!!!!!!!
TROLL! 
More sciency stuff next week...! after I've gotten more caught up! 

Tuesday, November 4, 2014

Gorgeous Goniasterid Starfish! & some Cousteau Connection??

 Bonjour from Paris! This week: a new post looking at some cool specimens I'm looking at while researching at the world famous Museum national d'Historie Naturelle!   Home of Lamark and many other natural history legends!

Today...two neat specimens with some interesting commentary and history, respectively...

First, a rarely encountered species & some taxonomic commentary... 

Paraferdina sohariae! It LOOKS like Fromia monilis, but isn't....  (as I said here awhile back..)
They Key is in the arrangement of spines (or the lack thereof) on the underside of the tube foot groove...

which is unfortunate, as you often don't see people with pictures of these in the wild...
This looks like Paraferdina 

Here's a "proper" Fromia monilis.. similar but with smaller marginal plates and more slender arms. 

I will be going back to Flickr, where I will be beating my head into a hole in the wall, trying to figure all these different things out now... 

A starfish from Cousteau?? 
Here's some cool shots of the Atlantic "cookie" star Peltaster placenta, which I 'm showing you, to give you an intro to ANOTHER specimen of this species below... These generally live at SCUBA depth and much deeper...
A pic of this species alive...Note how the disk is much more swollen
I showed you the pic above, so I could share a cool specimen of this species I found... 
 WOW! Look at the name of the collector! Could this be THE Calypso of Jacques Cousteau fame??? 

The MNHN is of course, the "national repository" (i.e., where they put all their stuff) of France, in the same way that the Smithsonian is the national repository of the United States. So, yeah, in theory anything they collect would be here. 
The tag indicates "1964 (May), Greece".  Cousteau was in the nearby Red Sea in 1964 shooting his epic "Le Monde Sans Soleil" aka The World without Sun in 1964!! Could this have been collected before or perhaps as an excursion by the Calypso away from Red Sea??
What other interesting specimens will present themselves?? 

BONUS: And if you like the food porn? Here's some fresh, hand made donuts from a Farmer's Market.. Mmmmm....

Tuesday, October 28, 2014

Five Invertebrates that would be Terrifying if they were Bigger!

The secret of the big terrifying jaws is #1 below! 
HALLOWEEN! Every year, I like to use the season's festive theme to try and highlight some cool invertebrate diversity! Last year I did an overview of creepy worms and the year before that, I did an overview of spooky things that echinoderms (my research focus & subject of this blog's love) are known to do. 

So, note that I actually am using REAL aspects of these animal's biology that make them, creepy, terrifying, spooky, whatever. Unlike SOME places.. I won't just find some weird looking, random animal and just SAY its spooky or creepy. It actually HAS to do something worthy of the name!

This year: a theme that often comes up with invertebrates: Predators that would be terrifying if they were larger!! 

So, this is a pretty popular trope and frankly, there are ALREADY a bunch of huge, oversized marine invertebrates that freak people out. You will doubtlessly see some tweets about those beasts this week.

Here are some of my picks for invertebrate PREDATORS that to me, have earned the RIGHT to be optioned for movie rights! or other fantastic treatment!  So, nothing that is weird looking but harmless (I mean, c'mon, BASKING SHARKS? SHREWS?)

There were MANY to choose from of course and so perhaps next year I'll present more of them. But for now, here's some good ones.....

5. Arrow Worms (phylum Chaetognatha)
Imagine the oceans filled with fast-swimming, transparent worms with sharp spines for teeth on their head, and which can effectively "see" in a 360 degree field of view AND attack and devour prey several times their own size.

Bodies are transparent and with unusual "eyes" that are arrayed in 5 directions, essentially giving them a full field view (360 degrees). Fortunately, these "eyes" lack lenses and are thought primarily to be used for orienting to light and dark.
They feed with these big nasty hooks that emerge off the front of the head!!  Some are even known to do so with venoms like tetrodotoxin, the potent toxin from puffer fish.

Arrow worms have been documented as having capture prey several times their size...like fish!
Here's an interesting video that shows the spines extending from the head on a Japanese species... 
Sadly, or perhaps fortunately for us.. these are pretty small. Ranging from less than half an inch with monsters up to 4 inches! 

But what if they were HUGE????  Honestly, I think one movie from 1998Deep Rising had these things, which swam through the water at a good clip. and the spines were KINDA chaetognath like! 

So, yes! We want MORE ARROW WORM MONSTERS PLEASE!!! 
Via Wikipedia
4. Cone Snails.  Does everyone know what cone snails are? Marine snails that use a modified tooth like a harpoon + very potent toxins to capture their highly mobile prey. Often times, vertebrates like fish..

Some of them, however, rather than using the proboscis to directly paralyze prey, will use this  highly modified "net" which is presumably, a modified feeding proboscis.. 
Yikes.. imagine what that would be like if cone snails were bigger..like bear or even elephant sized! 

3. Rhizocephalans! Barnacle Parasites that take command of your Body! 
Imagine  a fleshy parasitic network that works its way into your body, commandeering your all your bodily functions, INCLUDING your gonads, such that all you do is produce eggs to make NEW parasites.

These don't really NEED to be bigger..but merely adjusted to parasitizing MORE than crabs.

These have been written about in some detail by Rebecca Helm over at Deep Sea News. Her account is quite chilling. I recommend reading it in the dark, while you are alone with some seafood....
Or, watch this video from Casey Dunn's "Creature Cast" series which also very ably explains the life of this creepy parasitic barnacle... 


2. LEECHES! This is kind of a cheat, since I put leeches into my "Creepiest Worms" post last year.  I just thought this was kind of awesome... 

1. Labidiaster annulatus, the giant 50 armed star of the Antarctic!
This is one of my FAVORITE beasts.. which I wrote up here, early on in the blog (and on numerous other occasions).
But the short story:  Giant 1.5 foot wide starfish with 50 arms, catches krill and other prey with arms!!                  

The surface of the starfish, especially on the arms is covered by THESE.. 

Jaw like structures called pedicellariae which act as "bear traps" to capture krill and other prey if they get too close to the arms. 
Thanks to Bob Ford & Taylor Steed of Frederick University for the SEM pics
These are ALREADY pretty big. About 1-2 mm. But look at those fangs!!  and the shanks on the teeth!

Can you IMAGINE if this critter was DOG or even BEAR sized on the land????  Catching everything from tiny mammals to birds!!! 


For the Next few weeks: Echinoblog Returns to PARIS!