There are lots of weird and interesting species left to discover, and two of the richest sites will be the deep sea and Antarctica, both difficult of access. Last week the University of Lincoln, Nebraska news site released some cool findings of the ANDRILL team (Antarctic Drilling Program), which is headquartered on their campus. And they couldn’t be weirder: groups of sea anemones (animals in the phylum Cnidaria along with corals, jellyfish, and other groups) living upside down on the Ross Ice Shelf of Antarctica!
The discovery was actually published last December in PLOS ONE (reference and free download below). The scientists found the species by accident, using a 4.5-foot (1.4 m) robotic vehicle moving underneath the ice shelf at the location shown below, with the blue dots showing where they found the hanging anemones. They were just exploring and didn’t expect to see any new animals.
As the paper reports, the robot-mounted camera found two groups of anemones living about 6 km apart. The anemones have most of their bodies inside the ice, with the tentacles hanging below. They were described as a new species, Edardsiella andrillae (after the project). It’s one of only two species in the genus found in the southern hemisphere; the rest are in the north. And it’s the only species of sea anemone known to actually live in ice. Further, individuals hang upside down, which as far as I know is not done by any other anemone.
Here’s what they look like hanging from the ice. Imagine the surprise of the investigators when they saw this!:
(From Fig. 2 of paper): A. Close up of specimens in situ. Image captured by SCINI. B. “Field” of Edwardsiella andrillae n. sp. in situ. Image captured by SCINI. Red dots are 10 cm apart.
Specimens were collected and preserved, and the paper describes their appearance and anatomy, but I won’t bore you with the details (the picture above is sufficient). They did see some other stuff, as reported in the news blurb (my emphasis):
“They had found a whole new ecosystem that no one had ever seen before,” Rack [Frank Rank, an author] said. “What started out as a engineering test of the remotely operated vehicle during its first deployment through a thick ice shelf turned into a significant and exciting biological discovery.”
In addition to the anemones, the scientists saw fish that routinely swam upside down, the ice shelf serving as the floor of their undersea world. They also saw polychaete worms, amphipods and a creature they dubbed “the eggroll,” a 4-inch-long, 1-inch-diameter, neutrally buoyant cylinder that seemed to swim using appendages at both ends of its body. It was observed bumping along the field of sea anemones under the ice and hanging on to them at times.
The anemones measured less than an inch long in their contracted state — though they get three to four times longer in their relaxed state, Daly said. Each features 20 to 24 tentacles, an inner ring of eight longer tentacles and an outer ring of 12 to 16 tentacles.
After using hot water to stun the creatures, the team used an improvised suction device to retrieve them from their burrows. They were then transported to McMurdo Station for preservation and further study.
Because the team wasn’t hunting for biological specimens, they were not equipped with the proper supplies to preserve them for DNA/RNA analyses, Rack said. The anemones were placed in ethanol at the drilling site and some were later preserved in formalin at McMurdo Station.
I’m curious as hell what “the eggroll” is. Any guesses?
This finding of the anemones, of course, raises a lot of questions:
1. How the hell do these things dig themselves into the ice? As the paper puts it more politely, “The means by which these animals burrow into the ice shelf is unclear, as are the physiological mechanisms that enable them to live in ice. Burrowing by sea anemones has been described as a process of serial expansion and deflation of the pedal disc or digging with the tentacles; neither of these strategies would seem possible in solid ice.”
2. What do they do when the shelf melts? It’s likely that some of these animals inhabit parts of the shelf that melt during the Antarctic summer. What do they do then?
3. How do they survive the bitter cold? The authors didn’t find any morphological features that suggested evolution for cold tolerance, but of course most of the adaptations would be biochemical and physiological.
4 What do they eat? The news release suggests plankton, which is logical, but we don’t yet know.
5. How do they reproduce? The authors are puzzeld about “the means by which Edwardsiella andreillae achieves it [sic] relatively large numbers.” Related species reproduce asexually by splitting transversely. The authors note that this could be tested genetically, for it predicts groups or clusters of genetically identical organisms. In contrast, sexual reproduction (also occurring in anemones), followed by migration of larvae and then colonization of the ice would create populations that are more genetically diverse.
I’m sure the authors (who are funded by the National Science Foundation) will get money to pursue these questions. And other scientists, as I’ve reported before, have found weird and undescribed species in Antarctica. At least on that continent—and in the neotropics—we’re in no danger of exhausting the supply of new species. But we are in danger of destroying them before they’re described, and that goes for both polar and neotropical groups.
h/t: Robert
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Daly, M., F. Rack and R. Zook. 20013. Edwardsiella andrillae: a new species of sea anemone from Antarctic Ice. PLOS ONE, Published: December 11, 2013; DOI: 10.1371/journal.pone.0083476
My wild speculation is that the anemones burrow into the ice using some form of chemical process, perhaps increasing salt concentration next to their bodies which would melt the ice immediately next to them.
One would suppose that they reside in water that does not freeze, so it is not going to be colder than 0c to -1c is it?
As jerry says, they look doomed if we carry on the way we are. A DNA test would show when they split from their norther cousins – I would guess a long time ago, but presumably they will have had ancestors that became adapted to the ice life around 30 mya?
Imagine the slow extinction of reptiles & marsupials in Antarctica as the ice sheets spread north.
Just discovered this hilarious & pathetic nonsense! Forgive me for polluting this website with creationist bollocks but – teally! “The Evil Secular View”…???!!!
http://500questions.wordpress.com/2013/05/23/46-how-did-marsupials-migrate-from-noahs-ark-to-australia-and-the-americas/
Forgive me! – he is a sceptic – had not read all the way down! Nice one though…
I’ve had a read of his site (500 Questions) and it’s worth a look. He’s actually a lapsed Christian who is still trying to find the answers – as he says, he’d love to find some proof of God’s existence – but he’s approaching it in what I’d call a rational fashion. And most of the answers he’s getting don’t favour God.
And most of the answers he’s getting don’t favour God.
Imagine that!
I know how you feel, Dominic–I have my doubts about constantly intruding anti-religious and anti-creationist commentary into the science posts (which I love reading, by the way) on this website. Nevertheless, I do.
Anyhow, these critters living underneath the ice shelf appear to be explicable in a straightforward manner by evolution, and completely inexplicable (except by divine caprice) by creationism.
Thanks for the link!
They reside in water that is frozen!
Water with a seawater composition of salts is in equilibrium with ice (which is almost fresh) at about -2 Centigrade. On those facts depend a lot of things, from the thermohyaline circulation system of the non-Antarctic oceans, to the spectacular plumes of freezing water imaged on recent (I think BBC) wildlife photography in the Antarctic.
A DNA test would only show when they split from their (presumed) northern cousins if the northern cousins had had extensive DNA work done on them too. Which may or may not be the case.
My geological guess would be to look at the opening of the water passage between Patagonia and Antarctica, around 15 Myr ago ; that allowed the establishment of the circum-Antarctic current, and with it the thermal isolation of the polar continent, and the rapid increase of it’s ice sheets.
Thanks – that sounds plausible.
Given that the alternative is some sort of energetic thermal or mechanical process, that’s the way I’d bet too.
I’d substitute “salt” with some mix of organic gunges which have the same effect. A few % v/v of an alcohol would probably be sufficient to let them … corrode (sounds the correct word) their way in at a relatively low energy cost.
I picked “salt” based on the idea that salt-enriched water is already available and I figured there must be some (magic happens here) way for them to concentrate it from the water. But I really have no idea. Is it easier to manufacture alcohol or to separate water/salt? I suppose they could have some symbiotic bacteria fermenting something to make alcohol.
Pretty much any [solute] that you mix with a [solvent] will lower the freezing temperature of the mixture compared to pure [solvent]. That’s generally true, true for “table salt” and “water”, and I can’t think of a counter example. But I’m not certain that there aren’t counter examples.
There are a number of metabolic processes that involve formation of alcohols from simpler molecules (you can consider sugars, and therefore carbohydrates, as poly-alcohols), so my fairly rudimentary knowledge of metabolism suggests that this is a pretty basic to all lifeforms.
So, there’s no fundamental reason for preferring one process over another.
Shoggoths
The ice-dwelling anemones more closely resemble miniature Great Old Ones to me. But of course, where they are shoggoths cannot be far behind…
I think that would make them Little Young Ones, actually….
b&
sub (I have to; this is the first time in a week I’ve received any posts from WordPress!)
What are the red dots for? Scale comparison?
The Figure 2 legend says “Red dots are 10 cm apart.”
They fire two collimated laser beams (well, laser pointers) off into the wilderness from the ROV ; if they strike a surface parallel to the plane of the camera, you know that they’re 10cm (or whatever) apart ; if the surface is oblique, then the dots are separated differently ,but you can normally work that out from the changes in geometry in the original video that this is screen-shotted from.
This is wonderful. I remember seeing upside down fish swimming beneath rock shelves during a scuba dive in Jamaica, somewhere near Discovery Bay.
I’m going to suggest they don’t burrow into the ice rather they attach to the ice as juveniles then the ice builds up around them. Or something.
Sub
I’m guessing the eggroll is a holothurian.
I agree. Probably a sea cucumber. They can be counted on to turn up in relatively barren areas, and to look like an eggroll or a perchance like a turd.
A sea cucumber and egg roll? How civilised! Crusts cut off, with a little doiley?
Yes… but picking up sea cucumbers can trigger their famous defense . It ruins the party.
I love the inappropriateness of the first comment on the soundtrack : “OMG it’s having babies.” OMG, the inappropriateness!
Of course they hang upside down, they are at the south pole! Isn’t everything south of the equator upside down to us northerners? We probably look upside down to them!
+1.
Had planned that comment. Must get up earlier
Upside down anemones make sense because there will still be phytoplankton and small zooplankton passing in the water column and they need a substrate. But what advantage is there to using an inverted “floor” as a fish?
To eat things in proximity with the surface of the ice.
Right, but why can’t they do that in the conventional orientation?
Because their mouths would be pointed away from the food.
Open water predators often use dangly bits to snare prey. Upside down helps them to dangle would be my guess.
Note to self: no skinny dipping in open waters!
b&
Skinny dipping in Antarctica has been done. It’s likely to be decidedly sub-tropical. Not exactly toasty warm in a pair of speedos either.
Upside down (downside up) is sort of irrelevant when you live by capturing floating bits of whatever that happen to collide with your arms. These guys are upside down because the surface they are attaching to is floating. They gain some protection by being partially dug into the substrate (superstrate?) and can probably pull completely into the ice if threatened (speculating on that). I doubt that gravity has anything to do with their lifestyle, except for the fact that ice is less dense than water and thus floats.
And of course since they’re floating, gravity could be said to not really exist for them (if they’re roughly the same density as the water). So right-way-up or upside down wouldn’t be of great significance.
Upside down (downside up) is sort of irrelevant when you live by capturing floating bits of whatever that happen to collide with your arms. These guys are upside down because the surface they are attaching to is floating. They gain some protection by being partially dug into the substrate (superstrate?) and can probably pull completely into the ice if threatened (speculating on that). I doubt that gravity has anything to do with their lifestyle, except for the fact that ice is less dense than water and thus floats.
I was wondering if annemones have been found hanging from the roofs of sea caves?
Seen them myself. So unremarkable as to not have thought to photograph them.
Deep in sea (or land) caves tends to be more barren – less fresh circulation with new food the further in you get.
I imagine the delight of the investigators when they saw this.
I’ve seen juvenile firemouth cichlids swimming along a tree branch, out in open water,orienting to the tree branch. On their sides beside it, or upside down below it.
“… they were not equipped with the proper supplies to preserve them for DNA/RNA analyses, Rack said. The anemones were placed in ethanol at the drilling site and some were later preserved in formalin at McMurdo Station.”
Does ethanol and formalin degrade (or fails to stop degradation of) DNA/RNA? Does this mean we can never do DNA analysis on any of those specimens collected in jars in the 19th century?
That’s my understanding. Even modern specimens that are alcohol preserved are not much use for DNA extraction.
Wonderful news for ice moon habitability!
‘Simple, my young apprentice.’ The simplest hypothesis based on the biological description is that the ice grows with the specimens. [See also #6.]
They only need to move to keep up with a growing water-ice “iceode” [mean surface analogous to geode]. They can even encourage ice growth by organic means, I suppose. (But from the images such mechanisms on a massive scale doesn’t seem likely, too even water-ice interface.)
If the ice melts (with or without organic counter-mechanisms), they may end up on the bottom instead. Has anyone checked?
IIRC the ice-water interface is the most productive volumes, it holds a lot of organics and specimens. I hadn’t thought of it, but it makes sense that sedentary animals tries to inhabit.
I don’t think the ice grows at the bottom. It would be melting there, in contact with salt water. Ice grows via snowfall.
But yes, the ice/water interface is highly productive.
You may be correct. I have no detailed knowledge of glacier and/or ice floe behavior.
That would be a nice test of the “simple” hypothesis.
“If the ice melts (with or without organic counter-mechanisms), they may end up on the bottom instead.”
And, of course, if the ice doesn’t grow at all.
So, are there any left alive? From reading the above, it sounds like the first thing they did to a newly discovered species was to “preserve” them to death, or even to extinction.
If a species are a handful of individuals left in one locale, it would likely go extinct any day anyway.
Biologists have sampled populations for hundreds of years, yet few have concerned (of sorts) trolled them for their research.
My understanding (not expert) is that preservation in ethanol does not degrade DNA, But formalin does. There has been DNA recovered from old specimens preserved in alcohol, but never in formalin.
Plant people don’t want alcohol anywhere near the specimens they’re going to get DNA from. I collect plant material for DNA sampling by various people, and the preferred method is always silica gel drying. They’ll also take air-dried if done quickly.
In the olden days, like 20 years ago, when working in the tropics we’d routinely douse specimens in a 50% alcohol solution for preservation in the field. Those specimens are not popular with people who want to extract DNA. But, without methods like that, you’ll lose everything under some circumstances. Or get ugly moldy messes. If stuck without good drying facilities, I’d probably use alcohol again, though I try not to now.
Reblogged this on Mark Solock Blog.