Sunday, February 13, 2011

New genera and species of Antarctic Starfish! Stories behind the species!

What is this crazy thing?

So, just last week my NEW monograph on the goniasterid starfishes of Antarctica was published in the journal Zootaxa (Mah 2011, 2759:1-48)!

What does "monograph" refer to? Basically, its a scientific catalog to all of the starfishes in the family Goniasteridae found in the Antarctic and adjacent waters.

On the outside, the paper is pretty formal, very technical, and pretty dry, but this is by necessity. It is a scientific paper afterall, and it needs to have a professional feel to it. Its written primarily for my colleagues and my colleagues to come...

If I've done a good job, this is a paper that scientists will be able to refer to for decades (if not longer) to come.

Some of the species I've referred to were described in the 19th Century!! And yes..I had to refer to those paper in order to further write about them.. (this is not unusual in our field though..)

Below, I'd like to give a little "behind the scenes" action on various cool highlights of the paper! Especially since you may have seen parts of the story from before....

1. Where did the Specimens Come from? Okay, in one sense, you know the starfish came from Antarctica (as I mentioned it above), but how did they come into my care, handling and publication?

Remember this blog post with the US Antarctic Research Program back in 2008?
A whole buncha starfish specimens had just been returned to the museum from our colleagues in New Zealand.

Each one of those barrels above? FILLED to the brim with Antarctic starfishes!!

Bear in mind, that some of this material was collected almost 40 years ago! It found its way into various hands for study...and then stored and then off to study again! Until, finally the material has come back to the museum.
I was tasked with not only identifying and helping to sort them..but to research and PUBLISH on them as well.

There's a certain logistical hump to get over at first, as the specimens get sorted out, cataloged and so forth. But after all is said and eventually come down to a few you don't recognize. And others that represent significant new discoveries compared to what's known!

and THAT is what leads to publication.

This paper then, is the kinda-sorta "final chapter" of what happened in my earlier blog! ("parenthesis" because often times naming new species is often the BEGINNING of a story...)

So what's in it?

The paper presents an overview of 19 species and 10 genera. Some of those species are pretty rarely seen. Here's a few of them...

2. Meet some New Species!! (and a new genus!)

So, there were three new species that I described in the paper! ONE of them was so unusual that I actually had to describe a new GENUS to put in!!

For comparison with what you may be more familiar with, the genus for humans is Homo (which means "man"), vs. the full species which would be Homo sapiens. (which means "wise man").

Let me introduce you to Eratosaster jenae!
Its primary distinction for being new? Its got all of those cool spines on the body surface.

Plus, its overall body shape and the many plates that make up the surface area arranged in a substantially different way from any other known genus of goniasterid starfish.

Hence, it gets a new genus AND species.
The genus, which is a noun, breaks down to Eratos, which is Greek for "lovely" and -aster for "star", so the Lovely Star. Its a dang pretty animal. And so that's what I called it.
and the species? (or more precisely speaking-the specific epithet) "jenae"? Refers to my colleague Dr. Jen Hammock, who administered the US Antarctic Research Program.
As seen above, Jen is providing scale for a giant starfish that I've used in my blog before..

How did I end up making her the namesake for my new species (full name is Eratosaster jenae which translates roughly to Jen's Lovely Star).

Scientists who name species, can assign names after individuals they feel have made an important contribution to their research, or sometimes to society-sometimes colleagues or celebrities. It varies.

Dr. Hammock oversaw the USARP through a lot. she provided supervision for interns, visiting scientists, cataloged specimens, managed the USARP (now folded into the USNM database (here to see) and many other things. So, I was happy to name something after her. :-)

The 2nd new species: Chitonaster trangae!

It belongs to the genus Chitonaster which was described by Walter Percy Sladen as part of the original H.M.S. Challenger expedition results in 1899!!

The name is Greek for "tunic" which probably alludes to the fact that there's kind of a thin layer of pulpy skin over the surface, which is in turn covered by spines or granules.

Sort of like this one....
(Chitonaster cataphractus)

So, the problem with Chitonaster was that it hadn't been worked on since the late 19th/early 20th Century. NONE of the species had been compared to one another and over the last 90+ years or so, there had just been a kind of built up inertia.

The specimens were NOT matching up with all the descriptions! So, some detective work was needed.

Apparently, what had happened, was that this new species had been identified for many decades as one of the deep-sea species. No one ever really worked up the differences.

This new species? Apparently, it lives in MUCH shallower water and differs most prominently from the deep-water species in that it has papulae!

In other words, it has a lot of tiny, little fleshy pouches that that extend through the body wall that facilitate the animal's ability to "breathe".

How can you tell? Here's a dissected "top" of the animal removed. See all of the white spots? THOSE are where the "gills" extend through the top of the body surface.

This is a view from INSIDE the body top surface.
Here's one labelled... "P" is for papulae!
It turns out that this species with the papulae is one of the most COMMONLY encountered species of Chitonaster in the Southern Ocean!

AND as it turns out, its new! This new species was likely collected and handled by scientists for years before being recognized as distinct!

Who did I name this beast after? USARP research assistant Trang Nguyen who greatly contributed cataloging, processing and lending her great care to the USARP collections!
And finally, the 3rd new species..Pillsburiaster calvus!
The genus name is named for the R/V Pillsbury, which was the research vessel for the University of Miami, followed by "aster" for star..

This new species is named calvus which means "bald", which alludes to the bald spots on the marginal plates.

2. Did you know that scientific names can be made to vanish? Meet the Synonymy!!
So, most people know about the "powers" of taxonomists to name new species. But did you also know that some names can be made to "vanish"??

Its not uncommon for some evidence to show that two described species are the same thing. This means that one of those names is unnecessary and needs to be "put away", lest the multiple names lead to chaos!

There are actually a series of internationally agreed upon regulations which operates the International Code of Zoological Nomenclature, a set of rules dictating how different names are regulated.One of those rules states, that when you've discovered that a name is basically the same as another, it becomes a synonym of the name described by the first person who described the valid name.

Case in point...this beast. Originally this species was described as Pentoplia felli in 1971.
Its kind of a weird looking animal. Its genus name means "Five Weapons". Because of these weird pedicellariae on the underside...

Unfortunately, though, Pentoplia is pretty much identical with Chitonaster (see above). And thus, was this name SUNK!

Thusly, it was made a synonym of the original name described by WP Sladen in 1899! The new "combined" name? Chitonaster felli! (This assumes that no evidence in the future makes Chitonaster felli a synonym of some other species!)

3. And then, there's the RARE stuff....
Finally, let's look at some Antarctic species that are pretty rarely encountered (i.e., less than 6 species known...)

Sphaeriodiscus mirabilis
(previously known only from one specimen in the south Indian Ocean)
Cladaster analogus is a large, handsome beast known from only one or two specimens since its description in 1940 by famous Stanford marine biologist Walter K. Fisher!!
Its got some pretty cool pedicellariae (those are those lip-shaped things) and spine action going on, on the underside!!
Also..there's an identification key (to help recognize the various species) and a checklist!!!

How exciting is THAT?


JohnnyScallops said...

Pretty cool stuff. I wonder, since these are cataloged specimens, any ideas about abundance/distribution of any of these? Do you think you would find some of the rare specimens again if you tried?
Also, with warming there is the looming threat of deepwater crabs moving onto the Antarctic shelf, thoughts on what that might mean to the starfish?

ChrisM said...

Distribution of deep-sea animals is often patchy. One or two in one area-but then hundreds in another.

It would probably be more accurate to say that these species are "rarely encountered" rather than rare since we don't have any data on their ACTUAL abundance in the wild.

There are circumstances where 40 years have passed where you get nothing. But then one lucky cruise-nabs you 100 specimens. And you never see them again. So, yes. There's definitely the possibility that one could see rare species (and specimens again). But its also possible that might not happen again in your life time.

Based on the whole model of "Paleozoic style" ecosystem..the presence of more crabs in the Antarctic would most immediately affect soft-bodied organisms such as the giant worms or the soft-bodied starfish. Some of the suspension feeding forms-crinoids, asteroids, etc. with their long vulnerable arms would also be likely affected.

In theory, the long term effects would be that they would be wiped out. So, it would seem that the prospects for such an ecosystem do not look good...But there are any number of other unanticipated factors when considering a scenario such as that one. I would perceive it as negative-but the actual outcome might be quite different.

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