Wednesday, May 4, 2016

Five IMPRESSIVE HIGHLIGHTS from the Okeanos Explorer's Marianas Expedition!

This week I do a brief recap of spectacular views from the Okeanos Explorer Expedition to the Marianas Islands which began earlier this week. You can find out all about it on their website here.
Long story short, they are in the tropical North Pacific near Guam with access to some of the deepest trenches and canyons in the world!

This first leg began on April 20th and continues until about May 11th. They have been surveying many very deep canyons and seamounts which are at best, very poorly known and reach 5000 m depths or so!

Many, MANY amazing things have already been seen during the last seven days or so. Here's a recap of the things I thought were most fantastic. But check out their blog here.

Remember that the live video is broadcast here (via Youtube). The live broadcast begins fairly late if you are on the east coast, but usually around 5 or 6 pm.

You can also find many of these images from screengrabs on Twitter using hashtag #Okeanos or go to the Facebook underwater screengrab group here. 

1. STUNNING Gorgonocephalid Basket Star Fields
So, on May 2nd, the Okeanos Explorer visited Zealandia Bank, in relatively "shallow" depths about 650 to 250 meters. 

While surveying this area they discovered this AMAZING field of basket stars!! Apparently in the family Gorgonoceaphlidae. You can read one of my earlier accounts on other members of this family live and feed here. But short story: they have elongate arms with hooks that capture prey carried on the water currents.

At this amazing site we had...HUNDREDS  of these animals as part of a community of filter-feeding aniamls.
Here's what one looks like closer up.
But again, just spread out EVERYWHERE. At one point Diva Amon, the biology science lead indicated they had travelled about 100 m seeing basket stars to no end!
The animals in this area were all taking advantage of the current flow, including these isocrinid stalked crinoids and those little white corals.

At one point they mentioned that the water current above this field was about 1 knot, which means that the "drag" of this current against the bottom created a good habitat for filter feeding animals.

This area included other species of invertebrates.. starfish and so forth, which could have been feeding on the filter feeders or perhaps indirectly taking advantage of other benefits from the current flow (food, etc.).

Personally, this one was my FAVORITE thing to have seen. Just amazing.

2. Hydrothermal Vent Chimneys 
On May 3rd, Okeanos went to a suite of amazing hydrothermal vent chimneys!!!  These are places where hot geothermally heated water is vented out through the earth's crust. The dive went down to about 2000 to 4000 m. VERY deep.

This leaches out hot water with toxic minerals into the surrounding water. Surprisingly however, there are a great MANY animals which are able to process these minerals into food!

On this site, it included specialized limpets and other snails, as well as bythograeid crabs, shrimps, polynoid polychaete worms and much more! (as well as bacterial mats growing around the hot water and etc.)
But perhaps MOST impressive was how these vents formed chimneys which took on these very cathedral-like morphologies.


They pretty much spent the whole day going from one chimney to the next..and none were disappointing!

3. Likely New species of Carnivorous (Cladorhizid) Sponges
Probably some of the most commonly encountered animals on the Pacific Okeanos expeditions have been sponges (here for more). Chris Kelley at the Hawaiian Undersea Research Labs has mentioned that there are easily two dozen new species of glass sponges currently being described with more apparently being discovered!

But one of the more unusual sponge species discovered on these cruises are those in the family Cladorhizidae: enter the CARNIVOROUS sponges!!  Although they've been known to scientists for awhile, they only recently entered the public eye after the famous "Candelabera sponge" was discovered back in 2012. 

Cladorhizids occur pretty widely as it turns out. Here were two discovered by Okeanos Explorer during the Okeanos leg of this expedition.. Both collected and are probably new species.

Bizarre spines on this one...
This image shows some small amphipods and/or possible food caught on those spines...
This one has a very different body shape with more club-shaped projections....

4. Likely New Stalked Crinoid species!
Stalked crinoids are some of the most... evocative of deep-sea animals, mainly because of their status to some as so-called "living fossils."

Animals with similar morphology are well known from VERY old rocks (back to the Paleozoic) go here. And although these modern forms are different from those fossils forms, they DO share a certain similarity.

I ran these by some of my colleagues (who are stalked crinoid experts).. and this one for example was described as "totally crazy"

This one was apparently seen before from the Philippines/Celebes region and was identified as a new genus and species! All we have to do now is to collect it!

5. Impressive Acorn Worms (enteropneusts)
Acorn worms are one of those weird groups of worms that have been around for quite awhile and are known to biologists but only recently has there been very good imagery to show off how cool looking they are!

Some of the more striking deep-sea species were recently presented by the Monterey Bay Aquarium Research Institute back in 2011! see this) One Atlantic species of these worms was actually named for Star Wars Jedi Master Yoda! based on the large "ears" (actually genital flanges!) 

Okeanos saw this one recently, displaying a prolific amount of mucus and a very prominent amount of defecation as it plows through the sediment feeding on the organics!

Here we see mucus with sediment granules as well as poop inching its way long the intestine...

Let's face it, there has been a LOT of amazing stuff on these dives...

Honorable Mentions
This fantastic benthic ctenophore! I've discussed these in many posts before (go here) but this is a bottom living species of comb jelly, which are normally observed swimming...

They extend their very LOONG tentacles into the water to feed....One individual measured during the hawaiian expeditions went on for nearly a meter! 
This was a mystery. A bunch of soft, blobs. Still not sure what it is (foram? sponge? eggs?)..but enigmatic and intriguing.
This sea urchin popped up during the last hours of the hydrothermal vent dive (see aforementioned vent chimneys). A bit of a mystery....

And then yesterday near the mud volcano, we observed not just this large star-shaped trace mark in the sediment but ALSO this little brittle star!

Note how the disk has a kind of raised dark bump?? That's a feature that is pretty unusual for brittle stars. So possibly in the genus Ophiomyces or something else which could be entirely new..

If so, this would be one of the first times its been seen alive! 

Predatory Tunicates! 
These are actually Chordates like us, but usually tunicates are filter feeders that pick organics out of the water current..

HERE we have TWO genera of tunicates which have adapted to feeding on other ANIMALS!

This one is called Megalodicopia! These have modified their "in" siphon to form a HUGE mouth. Note the little tube on top?? That's the "OUT" siphon. Water goes, with food and flows out through the top (presumably at a higher pressure given how much narrower it is).
Another stalked predatory tunicate is this one: Culeolus. Same basic idea, except that the feeding bits are on a STALK... Water+food goes in one end and out the other!!

and of course, this beast!  yeah, yeah, the jellyfish, Crossota sp... always a crowd pleaser! 

1 comment:

Kelsey said...

Awesome images! Thank you for sharing.

I stumbled across this blog as I was looking into an interesting behavior of a sand star (Luidia foliolata) and I was wondering if you have observed this before.

In the lab I volunteer at, I noticed a sand star filled with air floating at the surface. I have never seen this before. Do you know if this is a common behavior?

Thank you so much for your time!