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These are a few of my favorite species: Paulasterias mcclaini “McClain’s 6-armed fleshy star”

Dr. M — Tue, 21 Apr 2015 19:19:25 +0000

Image from Mah et al. (2015)

Today is a very exciting day. Indeed, today is one of the best days ever! The next step in my evil science plans for total world domination to unlocking science achievement level 10 is now complete. Thanks to Chris Mah (@echinoblog), one of the world’s leading experts on starfish, there is now a species named after me. I may die but my species, Paulasterias mcclaini, will live on forever. BWAHAHAHAHAAHA.

Why would Dr. Mah name the coolest species of starfish ever after me? Well I’ve agreed to not let out details about his secret superhero identity in the arrangement. Kidding. Along with David Clague, I invited Chris to join us an expedition in 2009 to visit the Northeast Pacific of Washington and Oregon aboard the Monterey Bay Aquarium Research Institute’s Western Flyer.

Image from Mah et al. (2015)

I don’t jest when I say this coolest species of starfish ever. Others may raise an eyebrow to such a statement but there are many reasons.

1. The species is named after me.

2. The species is named after me.

3. Paulasterias mcclaini along with Paulasterias tyleri are part of a brand new family of starfish, Paulasteriidae, the first new family erected in this group of starfish, Forcipulatacea, since the 1800’s. See the evolutionary tree below. You can see these two new species are quite unique genetically from others in the group.

4. The other species and family is named after deep-sea biologist Paul Tyler. Paul’s contributions to deep-sea science are wide spread, novel, and significant. Paul, along with John Gage, literally wrote the book on deep-sea biology. I studied and reread the book many times over years. It has served as inspiration to me and countless others. I also have another important connection with Paul. Years ago my first submersible dive was with him in Harbor Branch’s Sealink. Needless to say I’m in fantastic company.

5. Despite echinoderms being a major player in most of the deep sea, no members of been collected as primary members of hydrothermal vent settings. P. mcclaini and P. tyleri are the found either near vents or in proximity.

6. Number 6…well it’s six armed. Five-arm starfish need to learn how to represent.

7. P. mcclaini don’t give a damn. It’s found on rock, mud, pillow lava, vent chimney fragments, and even hydrothermally altered clays interspersed with bacterial mats.

8. P. mcclaini don’t like the heat. It’s not found actually on vents where it’s hot and toxic. This starfish doesn’t need that kind of subprime real estate.

9. Especially on the larger specimens this bad boy starfish has thick, fleshy skin. Indeed, the body is covered by a layer of fleshy, spongy tissue that obscures the plates comprising the body. I realize this sounded cooler before I wrote it down.

10. Better yet, this starfish is armored and ready for battle. Spinelets cover the entire body.

11. Finally, P. mcclaini might be set on total global domination. Chris Mah sates, “A six-rayed pink species with inflated arms has been observed by the Okeanos Explorer on two ROV imaging expeditions, in the North Atlantic (August 2013) and in the Gulf of Mexico (April 2014). This species is possibly identified as Ampheraster alaminos; however, it shows superficially similar body colour and shape to P. mcclaini gen. et sp. nov. “

Mah, C., Linse, K., Copley, J., Marsh, L., Rogers, A., Clague, D. and Foltz, D. (2015), Description of a new family, new genus, and two new species of deep-sea Forcipulatacea (Asteroidea), including the first known sea star from hydrothermal vent habitats. Zoological Journal of the Linnean Society, 174: 93–113. doi: 10.1111/zoj.12229

The post These are a few of my favorite species: Paulasterias mcclaini “McClain’s 6-armed fleshy star” first appeared on Deep Sea News.

Three Reasons Why Fukushima Radiation Has Nothing to Do with Starfish Wasting Syndrome

Dr. M — Mon, 30 Dec 2013 17:01:49 +0000

This invited post is authored by Chris Mah, a Smithsonian National Museum of Natural History researcher. Chris is one of the world’s leading experts on starfish and echinoderms in general. He created and writes for Echinoblog, a one stop reading place for everything echinoderm. You can find him at Twitter at @echinoblog.

In September 2013, I broke the story about a mass sunflower starfish (Pycnopodia helianthoides) die-off in British Columbia. This developed into further accounts of Starfish Wasting ‘disease’ which is now recognized as “Starfish Wasting Syndrome” (because the nature of the causative agent is unknown) and since been reported from California and now Washington state.

The “disease” causes white lesions and tissue necrosis (death and decomposition), eventually resulting in arm loss and overall body collapse (the “wasting” part of the disease’s name). The disease has been observed in multiple starfish species but seems to have been noticed most heavily in sunflower starfish (Pycnopodia helianthoides) and ochre stars (Pisaster ochraceus).

Some have become concerned that there is a direct influence from Fukushima. Much of this seems unlikely. Deep-Sea News (among many other sources) have presented excellent reviews of data that can help the rational person make sense from some of the confusing deluge of misinformation.

Here, I continue this theme. Addressing a concern that has been brought up by many. But really, three simple observations discount any direct relationship….

Starfish Wasting Disease/Syndrome (SWD/SWS) pre-Dates Fukushima by 3 to 15 years. This is probably the most self-evident of reasons. One of the earliest accounts of starfish wasting disease was recorded from Southern California (Channel Islands) in 1997 (pdf). The account of SWS in British Columbia was first documented by Bates et al. in 2009, and their data was collected in 2008. Fukushima? March 2011.
Starfish Wasting Syndrome Occurs on the East Coast as well as the Pacific. Many of the accounts alleging a Fukushima connection to Starfish Wasting Syndrome forget that there are also accounts of SWS on the east coast of the United States affecting the asteriid Asterias rubens. There is no evidence (or apparent mechanism) for Fukushima radiation to have reached the east coast and therefore the Fukushima idea is again not supported.
No other life in these regions seems to have been affected. If we watch the original British Columbia Pycnopodia die-off videos, and the later Washington state die-off vidoes, one cannot help but notice that other than the starfish, EVERYTHING else remains alive. Fish. Seaweed, encrusting animals. etc.

the WA video

A survey of Washington state released recently. Note the sea anemones, algae, and crabs. All in apparent good health.

Viewing ANY of the pictures or videos from other accounts shows that only the sea stars are affected. If there were waves of Fukushima radiation pouring onto the coast-and “melting” all the starfish as some folks would suggest, EVERYTHING would be dead. Not just the sea stars. Note also that all the divers involved in these surveys have reported NO ill effects.

Unfortunately, we have no data on the actual agent that causes SWS. Within the grand realm of possibility there is always a (slim?) possibility there is a connection with Fukushima, but nothing we’ve seen gives us any reason to think that.

More Likely Reasons?

Speculation has suggested bacterial or viral sources. But invertebrate diseases can be complicated. The disease only seems to affect sea stars. Nothing else. This implies a biological cause with a very specific relationship. Possibly a bacteria or virus. But just as possibly some other type of infection resulting from a protist or fungi?

It also seems possible that it could be a disease similar to coral bleaching, where subcuticular bacteria of sea stars (as documented here) might be affected adversely. Or perhaps a combination? In conjunction with some environmental change, such as water temperature? The original series of papers by Amanda Bates indicated there was an association of the diseae with water temperature.

Our study of this event has just begun. Ongoing data collection and research have started. We shall see where it takes us…

The post Three Reasons Why Fukushima Radiation Has Nothing to Do with Starfish Wasting Syndrome first appeared on Deep Sea News.

California Coastal Climate Change Research

Kevin Zelnio — Tue, 11 Dec 2012 10:19:40 +0000

Was just sent these great informative short videos about research being done to understand how climate change affects coastal communities. Coastal organisms live in areas with much day to day variation. There are the changing tides, the amount sun exposure, and also shade from tidal zone seaweeds and rock crevices. This makes coastal animals, like bivalves and sea stars, and their ecology important indicators of how climatic changes affect the future of some ecosystems. Enjoy and feel free to post any questions you may have!

The post California Coastal Climate Change Research first appeared on Deep Sea News.

A sucker for convergent evolution

Alistair Dove — Thu, 04 Oct 2012 14:42:46 +0000

Recently Chris Mah, that most passionate advocate of all things with pentaradial symmetry (i.e. echinoderms: urchins, starfish etc.), wrote an excellent blog post about how starfish tube feet don’t work the way you think they do. He was right, at least in my case; I had always assumed that they were suckers, and that the adhesion of a starfish to a smooth surface was essentially the sum of a few thousand tiny suction cups. The truth, as he elegantly illustrates, is that the tube feet are more like tubes of glue – secreting at least three different adhesive molecules into the tiny space between the foot and the surface. I urge you to go and read his whole post, it’s tops.

Neobenedenia girellae, a capsalid monogenean

As I read Chris’ post I was immediately struck by the convergent similarity with monogenean platyhelminths (of course I was. How could you NOT be, right? OK fine…I’m a worm nerd…shut up). These are a class of entirely parasitic flatworms that live on the external surfaces of fish, sharks and rays. Specifically, the attachment method of starfish tube feet is very similar to that used by capsalid monogeneans to stick to their fish hosts. If you think about it, this may be an even taller order than that faced by the starfish: fish skin is wet, it’s covered by a constantly sloughing layer of mucus, and the whole shebang is moving through the water all the time, which adds an element of drag that must be overcome if the worm is to stay attached.

To achieve this, capsalids have not one but two attachment organs. At the back is a large sucker or haptor (at the bottom in the adjacent pic), which has a giant pair of central cantilevered hooks, a flap or valve around the edge and a ring of tiny hooks at the periphery (too small to see in the photo). The whole thing acts much like a tent, where the central hooks act like tent poles, the valve is like the fly layer on the tent, and the peripheral hooks are like the tent pegs around the edge of the tent. As the central hooks dig in to the skin, and lift up the center of the haptor, suction is created, with the seal maintained by the flap (or valve) and the tiny hooks that hold it to the skin.

That’s all well and good, but not very similar to the starfish deal, right? You’re right, the similarity there is with the other attachment organ that capsalids have, at the front end. These, variously called lappets or cephalic lobes, are 1 or 2 flat pads that the worm uses to temporarily attach to the fish while the back end is detached and moved to a new location, inchworm-style. Thus the method used by the lappets has to be effective but also quick.

Close examination of how the lappets do their thing using electron microscopy and chemical tests shows that it is an adhesive-based system. In other words, the worms temporarily glue their front ends to the fish while they move the back. There are at least two separate secretions involved: one that glues the lappet down (perhaps after reacting with components in the mucus), and a second, solvent secretion that releases the glue. All of this takes place in a fraction of a second, serving to glue and detach the worm to/from a wet and mucus-covered fish skin so it can move along without being dislodge by the drag of water movement. This has also been proposed as a key way to ensure that the worm finds the right host – if it tries to glue to the wrong host, the chemicals don’t react properly and no adhesion occurs, Surely a remarkable attachment method like this has some industrial applications? Well maybe, time will tell, but it’s certainly a great example of the guiding principle that pure science is just applied science waiting to happen.

Conceptually, both starfish and flatworm use an epoxy-type approach, where multiple secretions are mixed to react together and create an effective chemical bond, which is then released on command by a different, solvent secretion. In both echinoderm and flatworm, which are only very remotely related, evolution converged on the same solution for temporary adhesion in the marine environment, with remarkable, almost instantaneous bonding and release that equals or exceeds the best humans have come up with. Whenever that happens, biologists should sit up and take notice, because it tells us something profound about the best solution for a given problem among the many challenges of successful life in the sea.

The post A sucker for convergent evolution first appeared on Deep Sea News.

The icy colder finger of death

Alistair Dove — Wed, 23 Nov 2011 18:57:00 +0000

I just can’t wait until the BBC series Frozen Planet airs here in the states. Take this clip for example, which the BBC released today. It shows a “brinicle”, which is a sort of underwater icicle that forms under sea ice in winter. As the surface ice freezes, it preferentially takes up fresh water, leaving the salt behind in a dense, supercold brine that sinks through the water column. The plume of sinking brine freezes the surrounding seawater, creating a sort of tube of sea ice extending down to the bottom. Look at how it spreads out along the bottom, trapping sluggish benthic invertebrates that get caught in its path. Its one of the more amazing bits of footage I’ve seen. Why in FSM’s name would you watch Glee when there’s stuff like this happening in the real world?

H/T to @stevesilberman on Twitter (his blog)

The post The icy colder finger of death first appeared on Deep Sea News.

On common names

Alistair Dove — Wed, 19 Oct 2011 22:41:17 +0000

Staring into one of the aquarium’s exhibits “I like these new Mastigias jellyfish”, I said, absently.
“Sea jelly”, my colleague corrected (with a certain smugness, I might add).
“I beg your pardon?” I replied.
“Sea jelly. They’re sea jellies now.”
“Oh, are they?”
“Yes, like sea stars.”
“I’m sorry?”
“Sea stars.”
“Jellyfish are like sea stars?”
“Sea jellies!”
“Jellyfish are like sea jellies? I thought you said they were the same thing?”
“No, no, no, sea jellies are like sea stars.”
“How do you figure that? One of them is all gooey and tentacular and such, while the other is sort of crunchy and has five arms that don’t much resemble tentacles at all”
*sigh* “NO! jellyfish became sea jellies and starfish became sea stars”
“Ah, I see….I think.”
“Good.”
“And…um…when did …when did this happen?”
“When did what happen?”
“When did invertebrates suddenly begin transmogrifying into other things?”
*quizzically* “Well they didn’t … change … exactly”
“They didn’t? I thought you said jellyfish became sea jellies. I’m pretty sure I remember your saying that. It was a pretty distinctive thing to say.”
“Well I did, but…”
“But what? Did they become sea jellies or not? I mean, I try to stay abreast of major changes in invertebrate systematics, and this sounds like something I should probably have heard about. Last I checked, jellyfish were still Phylum Scyphozoa”
“Sea jellies.”
“I’m sorry?”
“Sea jellies.”
“No, jellyfish are Scyphozoa. I’ve never even heard of sea jellies before just now, I have no idea what phylum they’re in.”
“No, no, they just changed the name, that’s all.”
“What?! Scyphozoa is no more???”
*gritting teeth* “No…jellyfish. They changed the name for jellyfish.”
“What, all of them??”
“YES”
“Wow, how’d I miss that?”
*ignoring me* “They changed the common name ‘jellyfish’ to ‘sea jelly’”
“Who did?”
“Who did what?”
“Who changed jellyfish to sea jelly?”
“Oh, well….um…I don’t know exactly. I…um…I just heard that somewhere.”
“You heard it?”
“Yes.”
“You heard it.”
“Mmhmm.”
“I see.”
“Yep.”
“And were these the same people who changed starfish to sea stars?”
“Er… I guess so, I don’t really know.”
“Seems important don’t you think?”
“What does?”
“Changing the commonly-accepted name for large groups of invertebrates. Seems like something someone in some sort of position of authority ought to be doing.”
“I guess.”
“And are they?”
“Are they what?”
“Are they in a position of authority?”
“Well, I don’t rightly know. I just…I read somewhere…”
“Why?”
“Why was I reading? What an odd question!”
“No, why did they change the name?”
“You mean jellyfish?”
“Yes”
“I think it was to reduce confusion”
*pause*
“ORLY?”
“I beg your pardon?”
“Nevermind. So you’re saying they changed jellyfish to sea jelly to reduce confusion?”
“Yes.”
“Confusion with what?”
“Fish.”
“Huh?”
“Fish.”
“People were confusing fish and jellyfish?”
“Yes. I mean … I guess. I don’t really know.”
“You don’t know the difference between a fish and jellyfish?”
*scowling* “Of course I know the difference!”
“Well, why change the name then? Was there a sudden epidemic crisis of taxonomic confidence among today’s youth?”
“A what?”
“Forget it. Look, we can’t have mysterious groups of anonymous people just going around changing the names of large groups of cnidarians just because T-Ball Nation can’t tell the difference between bilateral and radial symmetry”
“T-what?”
“T-Ball Nation. You know, Generation Text.”
“You’re a strange person, you know that?”
“Yeah, well at least I can tell the difference between a fish and a jellyfish”
“I KNOW THE BLOODY DIFFERENCE BETWEEN A FISH AND A JELLYFISH!!!”
“Good for you, but you really should try to calm down a bit, maybe…”
“I’m perfectly calm.”
“…consider decaf or, y’know, meditation.”
“I. Am. Perfectly. Calm.”
“Well OK there sport. Anyway, let’s go on to the next tank. I heard they’ve got some lovely sea cuttles…”

The post On common names first appeared on Deep Sea News.

ZOMG GIANT WURMZ N SEESTARZ FEEEDING FRENZY!1!1!!!1

Kevin Zelnio — Thu, 26 Nov 2009 15:11:12 +0000

Seriously cool footage at the BBC. Also with a nice little accompanying article that you should read.

In the sequence filmed for the Life series, the invertebrates gather in a frenzy to feast on a seal carcass that has sunk to the ocean floor.

So much food may only arrive in one place once in a decade.

The nemertine worms (Parbolasia corrugatus) are able to puncture the seal’s skin with their proboscis, opening up the carcass, so that worms and marine isopods such as woodlice can enter to feed.

The starfish feed more slowly – by pushing out their stomachs through their mouths.

As a sea star pushes its stomach against the seal’s skin, it secretes digestive juices that dissolve the seal’s tissue.

The post ZOMG GIANT WURMZ N SEESTARZ FEEEDING FRENZY!1!1!!!1 first appeared on Deep Sea News.

We Will Miss You Peter!

Dr. M — Sun, 16 Aug 2009 10:30:51 +0000

The post We Will Miss You Peter! first appeared on Deep Sea News.

TGIF: Echinoderms Aren’t So Bad

Dr. M — Fri, 26 Jun 2009 15:44:49 +0000

This animation from Daniel Brown at Biochemical Soul makes me come close to actually liking echinoderms. Well..at least I still like them more than mammals. Seriously, a great animation that clearly illustrates the development of starfish.

The post TGIF: Echinoderms Aren’t So Bad first appeared on Deep Sea News.

TGIF: Early Edition

Dr. M — Wed, 08 Apr 2009 02:21:04 +0000

Sometimes something crosses my laptop too good to reserve for Friday. First, you need to know about Charlie the Unicorn. Watch 1 and 2 (which features scuba diving unicorns). The latest installment that I eagerly present finally features an underwater theme and I could not be happier. A wonderful sing along is available at 3:27. Remember the seastar REALLY REALLY LOVES YOU. I will post the lyrics to the song as soon as I find them. UPDATE: The are below the fold…hat tip to Jason R.

LYRICS

When you’re feeling all alone
The world’s a drone
And nobody’s shown any love to you

When your heart is cold as stone
Just change your tone
Get rid of that groan and the world will too

Come swordfishes, love you
Jellyfishes, love you
Starfish, I LOVE YOU
You know it’s true
Catfishes, love you
Carpfishes, love you
Blowfish-, STARFISH REALLY LOVE YOU
In the ocean blue

[Rap]
Lungfish, blackfish, alligator, icefish
Armorhead, hammerhead, anaconda, flathead
Manta ray, sting ray, fangtooth moray
Goblin shark, grass carp, round river bat ray
Noodlefish, hagfish, man o’ war, ladyfish
Black eel, baby seal, sprat, koi, electric eel
Lamprey, pejeray, yellow-edged moray
Salmon shark, sleeper shark, featherbacked eagle ray

Well, you can ignore this plea
That’s fine with me
But one day you’ll see that my words are true
Oh, if you find that you agree
I guarantee
That you will soon be feeling the love too

And, swordfishes, love you
Jellyfishes, love you
Starfish, I WANT TO BE WITH YOU FOREVER
You know it’s true
Catfishes, love you
Carpfishes, love you
Blowfish-, STARFISH LOVE ME LOVE ME
In the ocean blueee

The post TGIF: Early Edition first appeared on Deep Sea News.