Monday, October 12, 2009

Astrosarkus: Discovering The Great Pumpkin Starfish! FIRST VIDEO of this species ALIVE!

(photo thanks to Yoichi Kogure, Japan Sea National Fisheries Research Institute)

This week! A Fall-October Starfish Treat!

Back in 2003, I described an amazing new genus and species of deep-sea oreasterid starfish in the Bulletin of Marine Sciences called Astrosarkus idipi from the "sub-reef" region (known by some as the "Twilight Zone") in the South Pacific and Indian Oceans in about 67-200 meter depth. It was one of the most physically stunning starfish I had ever seen. Not only was it the color, but it had the texture, and SIZE of a pumpkin!

But here was a new GENUS and SPECIES that was easily one foot across (=0.3 meter) and about 4-5 inches (~0.1 m) THICK. It was ENORMOUS.

How had such a LARGE starfish evaded description for so long??? Apparently, this particular depth range had been inaccesible to the two conventional types of collection gear-trawl nets and SCUBA gear.
The "sub-reef" zone was inaccessible to trawl nets and too deep for conventional SCUBA gear. With the advent of submersibles and deep-diving type "re-breather" gear , scientists could suddenly access a part of the ocean that had previously been poorly understood. The first specimen was sent to me by Pat and Lori Colin, the biologists at the Coral Reef Research Foundation in Koror Palau, which they had collected their specimen using "re-breather" SCUBA type gear.

I had NEVER seen anything like it before.
After that initial specimen I started my PhD and ended up surveying museums all around the world and discovered TWO more of these animals during my travels..
(photo thanks to Yoichi Kogure, Japan Sea National Fisheries Research Institute)

The journey of discovering these animals was an adventure...

In Hawaii, I discovered the second-known specimen in a 10 gallon bucket that had been in storage since the 1980s. If it were not for the lack of air-conditioning, I would not have been fiddling with the floor fan and discovered the bucket that was sitting underneath it!

Oddly enough, this specimen had also been collected in Enewetok by Pat Colin!

Years later in Europe, I
discovered a second dried specimen from the southern Indian Ocean on a specimen shelf among starfish that had been stored in a marine biology laboratory in Belgium! I began to describe the animal in detail.
The specimen actually had to be x-rayed so I could get some idea of what it looked like The animal's skeleton was almost COMPLETELY reduced.
Most of the animal was made up of a thick, smooth meat that was criss-crossed with channels that opened into the body cavity and opened out to the body surface.

There was almost NOTHING of the externally expressed skeleton that one would normally use to identify it!
(From my 2003 paper on Astrosarkus)

So, how did I finally determine what it was? Thanks to help from Dan Blake, my PhD advisor at the University of Illinois at Urbana-Champaign, I was able to identify the individual skeletal pieces as unique to the Oreasteridae!

The unique type specimen, the HOLOTYPE was ultimately deposited into the Invertebrate Zoology collections at the Smithsonian's National Museum of Natural History.
Oreasterids are a group of widespread tropical starfish which have heavily built up skeletons. Familiar members of the Oreasteridae include genera, such as Culctia and Protoreaster, which I have written about in the past.

Recently, my colleague, Yoichi Kogure at the Japan Sea National Fisheries Research Institute was able to collect a NEW specimen of this species from Japan!

The paper (Kogure et al. 2009. Journal of the Biogeographical Society of Japan 11: 73-76) documents a substantial range extension of this species from Enewetok, Palau, and the southern Indian Ocean to Japan and American Samoa!

Amazingly, the Japanese captured FOOTAGE of this animal while it was still alive!! And here courtesy of the ROV cameras of SNK OCEAN CO., LTD. in Japan is the FIRST video of Astrosarkus idipii ALIVE!! The animal remains alive at an aquarium in Okinawa, Japan.

Less than SIX specimens exist in museums around the world! Not a commonly encountered animal to be sure! 

Its often thought that the great undiscovered numbers of new species are likely to be small and cryptic.. Here we have not only a new species, but a new GENUS that is HUGE.

And we're STILL learning about it. What does it eat? How does it reproduce? How old is it?


Wing Leung said...

hello, finally to find it. i am also a love of the sea diver, can i ask one used by the film, to let more people know it too! thank you,

Gypsy Sparrow said...

I just saw one of these off the southern coast of Tanzania! I was wondering what kind of starfish it was. I'd never seen anything like it!

ChrisM said...

Gypsy, you probably saw this related species: Culcita schmideliana

Astrosarkus lives quite deep