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Articles on this Page
- 05/04/16--22:10: _Five IMPRESSIVE HIG...
- 05/18/16--15:19: _BIG DATA about SMAL...
- 05/26/16--06:07: _BEHOLD: The GAME OF...
- 06/01/16--09:01: _Echinoderm Research...
- 06/15/16--07:37: _Sea Urchin Biomimic...
- 06/26/16--11:01: _Stunning Highlights...
- 06/30/16--22:12: _Five GREAT Polychae...
- 07/08/16--07:08: _Pycnopodia Watch! C...
- 07/13/16--15:16: _Astropyga The Radia...
- 07/28/16--20:33: _The Crown of Thorns...
- 08/10/16--19:17: _HYMENASTER Deep-Sea...
- 08/23/16--15:43: _Gorgeous Closeups o...
- 09/14/16--06:03: _Taxonomy: Lurking b...
- 09/21/16--06:36: _Unravelling the sec...
- 09/30/16--07:46: _A Guide to Inverteb...
- 10/13/16--07:28: _New Species of Sea ...
- 10/29/16--05:32: _#SEASLUGDAY2016: Nu...
- 11/29/16--23:05: _Trenches: Death Sta...
- 12/17/16--11:05: _Starfish Guide for ...
- 02/01/17--07:43: _Brittle Stars that ...
- 03/06/17--06:23: _Highlights from the...
- 03/17/17--07:45: _Okeanos Tropical Pa...
- 04/25/17--06:35: _Okeanos Follow-up: ...
- 05/08/17--10:37: _Brittle Stars of (s...
- 05/16/17--05:44: _Tremaster mirabilis...
- 05/18/16--15:19: BIG DATA about SMALL Echinoderms! Ophiuroids & their HUGE impact!
- Deep-sea species diversity is shaped by energy availability (i.e. thermal energy and nutrients)
- Continental shelf to upper-slope species richness consistently peaks in tropical Indo-west Pacific and Caribbean (0–30°) latitudes, and is well explained by variations in water temperature.
- Deep-sea species show maximum richness at higher latitudes (30–50°, i.e. polar regions), where they are concentrated in areas with high carbon export flux and regions close to continental margin (richness drops as you get away from the land).
- Global brittle star richness, in terms of species, peaks in the tropics at "shallow" continental shelf depths (20-200 m) and upper slope depths (200-1200 m). These peaks drop when you get below 2000 m depths.
- Data are consistent with a hypothesis that deep-sea species richness is maintained by species migration from shallower regions. i.e., "high energy areas feed low energy areas"
- Historically we have looked at tropical areas as the focus of conservation efforts, but if we TRULY want to conserve deep-sea habitats we will need to consider the areas which show DEPENDENCE on the shallower regions for diversity.
- How are all the different groups related? (e.g., how are basket stars related to other brittle stars?)
- How did they diversify? Where?
- What kind of habitat did they diversify into?
- Which brittle stars form actual, NATURAL biological groups?
- 06/30/16--22:12: Five GREAT Polychaete Names! for #PolychaeteDay
- 07/08/16--07:08: Pycnopodia Watch! Cautious Optimism about Sunflower Stars!
- 08/10/16--19:17: HYMENASTER Deep-Sea Slime Stars from the Atlantic and Pacific!
- 08/23/16--15:43: Gorgeous Closeups of Australian Starfishes!
- 09/14/16--06:03: Taxonomy: Lurking behind all the Big Announcements!
- 09/30/16--07:46: A Guide to Invertebrate Zoology on Twitter!!
- October 8 – Octopus Day, for all the eight-armed species
- October 9 – Nautilus Night, a time for all the lesser-known extant cephalopods
- October 10 – Squid Day/Cuttlefish Day, or Squidturday, covering the tentacular species
- October 11 – Myths and Legends Day, for all the fantastical cephalopods of movies, literature and legend.
- October 12 – Fossil Day
- 10/13/16--07:28: New Species of Sea Stars from the North Pacific and BEYOND!
- 10/29/16--05:32: #SEASLUGDAY2016: Nudibranchs eat ALL THE THINGS!
- 11/29/16--23:05: Trenches: Death Stars vs. Sea Stars! (thank you again Paris!)
- 02/01/17--07:43: Brittle Stars that Steal Food From Jellyfish!
- 03/06/17--06:23: Highlights from the recent NOAA Okeanos Explorer Samoa Expedition!
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.
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.)
They pretty much spent the whole day going from one chimney to the next..and none were disappointing!
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...
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!
Let's face it, there has been a LOT of amazing stuff on these dives...
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....
1. Echinoderms, including brittle stars live ONLY in the oceans. No freshwater, or land relatives.
2. Brittle stars are EVERYWHERE. They are one of the most numerically abundant groups of echinoderms known.
The Nature paper is sort of the "other shoe" that has dropped with big discoveries. (Remember that
echinoderms have five shoes!)
Dr. O'Hara's other BIG news in recent years has been the announcement of this: a comprehensive family tree of the ophiuroids!
|image from Museum Victoria: http://researchdata.museum.vic.gov.au/brittlestar/www/o_lym.htm|
These efforts are some of the latest results from Tim O'Hara's "Big Data" ophiuroid work!
Remember that the fundamental basis for ALL of these projects has been Tim's skill in TAXONOMY of brittle stars. Many of these species were difficult to identify and reconcile without skills in how to tell them apart. Here was an account of Tim's work at the Museum national d'Historie naturelle in Paris! He identified over 1000 specimens while I was there.
Other past efforts from Tim's lab:
Here's the time he and his student worked on the mystery of cryptic species in the Australian biscuit star Tosia australis!
Here's his research on discovering the distribution of brittlestars in lateral bands
As many of you picked up on last week, I've been busy working on starfish at Museum Victoria in Melbourne working with my colleague Dr. Tim O'Hara, one of the world's leading authorities on ophiuroids! aka the brittle stars and basket stars!
He's had a BUNCH of big research news drop lately (here's the link to last week)
While talking to Dr. O'Hara he informed me of of some neat, NEW SPECIES he's described from the deep-sea habitats of the South Pacific New Caledonia in late 2015! These were just too neat to pass up a post on!
I've reported in earlier posts (here) about working with Dr. O'Hara on echinoderms in the Paris collections!
All of these species were published in the Memoirs of the Museum Victoria, vol. 73: 47-57 published in 2015. Co-authored by Caroline Harding, also at Museum Victoria! This article is OPEN access and can be downloaded HERE.
1. The Impeller Brittle Star
As Dr. O'Hara tells the story, he was once called upon to aid a ship's engineer during his attempted crossing of the Bass Strait on the yacht Irene. A similar looking impeller failed the yacht's engine thus indelibly impressing its shape onto his mind's eye!
Fast forward many years.. and Dr. O'Hara is describing this new amphiurid brittle star from the deeps of New Caledonia.
The large shields on the disk trigger a memory that reminds him of the impeller's shape! and voila!
Enter: Ophiodaphne impellera
2. The Game of Thrones Brittle Star: Ophiohamus georgemartini!!
Probably the most STRIKINGLY amazing brittle star Dr. O'Hara described was this one, a new species in the genus Ophiohamus (family Ophiacanthidae), collected from a depth of 275 meters off New Caledonia!
Here's a nice shot of it holding onto this sponge stalk... Note that its most striking feature? Those big crazy spines that are coming off the disk!
I've done similar profiles for the researchers in Paris at the Museum natioinal d'Histoire naturelle (here)! I think this gives everyone a bit of insight into the many different crew members which staff the various roles in the big research seen in scientific papers. And Dr. Tim O'Hara's lab has had a good week for "big research paper drops" with more to come!!
Just as a refresher though.. Here's a pic with the BIG project that Tim O'Hara's lab has been working on for the last several years: the BIG ophiuroid (aka the brittle and basket star) phylogeny! aka the "family tree" of the ophiuroids!
As I've mentioned previously, the new phylogeny is a BIG deal. It involves a group with over 2000 species which has been a taxonomic headache to scientists for over 100 years. Their research has literally turned this whole field on its head! (if brittle stars had a head!)
The tree clarifies which groups show support for being "real" and elaborates on how different brittle star and basket groups are related to one another. It will almost DOUBLE the number families!!!
The tree was made using a phylogenomic data set. This is different from a lot of the molecular trees made in the last 20 years because it includes a whopping 425 genes and over 60 taxa! (other trees generally use only 3 to 10) You can see the big paper as published in Current Biologyhere.
The Echinoderm researchers at Museum Victoria includes a diversity of workers!
1. Dr. Andrew Hugall
Where Tim O'Hara provides the "Ophiuroid Taxonomy and context", Dr. Hugall is the phylogenetics and analytical guru part of the "Big Ophiuroid" team. Although he is currently working on marine invertebrates, he worked previously on birds, discovering "Accelerated speciation" in highly colorful birds, a paper which was published in Nature in 2012. You can see that here.
2. Lupita Bribiesca
Lupita is a PhD student at the University of Melbourne and got her undergraduate degree from the Universidad Nacional Autónoma de México. She's not only very proficient in computer coding and analysis but she's already a prolific author in echinoderm systematics! Especially in anchialine cave echinoderms!
3. Skipton "Skip" Woolley
I featured Kate Naughton's work on the blog back in 2009 when she and Tim O'Hara discovered a brooding "cryptic" species of the Australian Biscuit Star Tosia using molecular tools to understand the relationships of Tosia australis along the Australian coast. (see this story here)
Since then Kate has received her PhD and continued to do her awesome work combining ecology, taxonomy and molecular phylogenetics at Museum Victoria.
|photo by John Keesing|
5. P. Mark O'Loughlin and Deep Sea Sea Cucumbers
One of the most established echinoderm researchers at Museum Victoria was actually Tim O'Hara's original mentor!
Mark O'Loughlin has been a fixture of the "marine invertebrates" scene in the Melbourne/Victoria area of Australia for decades. He's published a huge volume of work on echinoderms, including sea stars and sea cucumbers. Here's his profile at ResearchGate!
here's a sclerite from a new species of "sea pig" (Family Elpidiidae) that Mark is currently working on from the the Great Australian Bight (979 m)
My thanks to the Museum Victoria for my visit! About 1000 specimen lots identified!
Although I talk about several different inspriations, two of the stories below focus is the elaborate jaw mechanism in sea urchins known as Aristotle's Lantern! A nice basic definition can be found at the Echinoid page on The Natural History Museum in London (here).
Aristotle's Lantern is this weird yellow piece in the picture below. These sit over the mouth opening and the "teeth" or jaws of the sea urchin emerge through the bottom..
This illustration gives you an idea of the orientation
ALL of the stories below are part of a field known as biomimicry!
Basically, taking the idea/engineering from ACTUAL biological structures that have demonstrated effectiveness and reverse-engineering them so that they can be used in industrial or other applications!! Urchins have been quite the inspriation of late! Here's a round up of some of the recent and more interesting ones!
1. Self Sharpening Blades/Knives!
Instead of "suction" as had been believed for decades, it turns out that urchin tube feet work on a chemical adhesive basis! In other words,, they STICK instead of SUCK! You can go through a brief summary of these details here.
These provide a lot of potential for marine adhesives if the means of adhesion can be understood and "reverse-engineered"!
Other posts in the "What good are echinoderms" series to be found HERE
This last week has been a busy one-made even more momentous with all of the very AMAZING observations made by this last leg of the Okeanos Explorer as it explores various seamounts and other sites in the Marianas Islands! A whole bunch of information on the geological setting and the various study areas can be found on their website here.
entire mission overview can be found on NOAA Okeanos Explorer pages here and of course the LIVE VIDEO is on click away! (when they are broadcasting-usually from about 6pm to midnight Eastern time)
But what are some of the more SPECTACULAR animals they have been seeing?? Here's a highlight of the ones I consider just singularly amazing!
1. Big White Lyrocteis-like Benthic Ctenophore (aka comb jelly)
The last year or two has seen a HUGE awareness of these strange animals. Basically they are the bottom version of swimming comb jellies aka ctenophores. Although gelatinous, they are possibly VERY distinct from proper jellyfish.
We have seen a fair number of these on earlier Okeanos dives (as we see here) and I've written a post (here) about Lyrocteis aka the "Harp comb jelly" which occurs widely in the Pacific.
This newly discovered white animal has a very different surface texture and so far has NOT been observed to extend its feeding tentacles! It has the same "rabbit ears" or "harp" shaped body as Lyrocteis but is it even the same thing?? Interesting!
2. Stunning sea anemone in the family Aliciidae!
Fortunately Dr. Chris Kelley of HURL had seen one of these before. The withdrawn version of a seldom seen sea anemone in the family Aliciidae.
Here's a picture from the HURL database showing it extended. You can see the knobs on the body. Beautiful..but wow. Unusual.
3. The Sea Anemone (from) Liponema!
ANOTHER bizarre sea anemone. These go by the common name "pom pom anemones" or "tumbleweed" anemones... Why? Because they actually have a very loose connection to the bottoms and can actually ROLL along when they want to move!!
This pic from Pagan Volcano and Supply Reef from about 336 m
|Image borrowed from Actinaria.com http://actiniaria.com/liponema_brevicornis.php|
This splendid picture taken in the famous Mariana Trench from a dizzying 5, 775 meters! DEEP!
An aspidodiadematid urchin, possibly Aspidodiademafrom Eifuku Seamount, 420 m. Want to learn more about these urchins with crazy long spines that act as walking legs?? GO HERE.
7. And some New Species of Snails...
This is what's called a slit shell snail or a member of the family Pleurotamariidae. Long story short: deep-sea snails but with similar shells observed in the fossil record. This gives them "Living Fossil" status and their beauty and color makes them valuable to shell collectors..
The one the Okeanos Explorer has been seeing? Probably a new species according to Chong Cheng at JAMSTEC (@squamiferum on Twitter).
according to Dr. Terry Gosliner at the California Academy of Sciences!
Those yellow balls on the body extensions? Apparently those are luminescent organs! Not previously seen in this genus..making this a very likely NEW species (thanks to Dr. Gosliner for the determination!)
And anyway.. THERE's MORE to COME!
Dr. Fauchald passed away in April 2015
Here is a great post on Dr. Fauchald's academic legacy at the museum and beyond...
But the Invertebrate Zoology Department at the National Museum of Natural History honors his life's work with an INTERNATIONAL and MUSEUM wide education celebration of his favorite animals: POLYCHAETES! If you are in the DC area feel free to visit Ocean Hall or the Q?rius Center to see specimens and displays about polychaete worms!!
Meanwhile, I honor International Polychaete Day with a polychaete worm-themed post!! Here's the one I wrote up last year that revealed polychaete facts you may not have known!
And don't forget this is a TWITTER thing also!! Hashtag #InternationalPolychaeteDay
Hereis the Storify Of International Polychaete Day from Last year!
Among the points I made? that many polychaetes are actually named for greek nymphs, goddesses and other mythological characters!! Today.. I focus on that topic and share the etymology of some awesome looking polychaete worms!!
Probably one of the first polychaete worms I was able to recognize on sight was this gorgeous animal! Also known as the "sea mouse" the genus Aphrodite described by Linnaeus in 1758 is arguably one of the most distinctive of marine invertebrates.
It is of course named for the famous Greek Goddess of Love, Beauty and Sex. But I suspect what made her name particularly apt, was that she was born from the foam of the sea (aphros).. the complete name Aphrodite means "Risen from the Foam"
|Image via Wikipedia: https://en.wikipedia.org/wiki/Aphrodite#/media/File:Sandro_Botticelli_-_La_nascita_di_Venere_-_Google_Art_Project_-_edited.jpg|
Its many iridescent bristles and unusual shape have made it one of the more memorable animals to encounter in an Invertebrate Zoology laboratory or field trip. These and the various members of this family (the Aphroditidae) occur primarily in cold-water habitats and can be encountered in a wide range of habitats, from SCUBA diving to bottom trawls in the Antarctic!
And is any animal more deserving of the name? Stunning.
Perhaps one of the most strikingly beautiful fire worms (a type of polychaete with very inflamatory setae) is named for the female name Chloe. Given that the name was assigned by none other than the famous French naturalist Lamarck in 1818, the name may be in reference to Chloe from the Greek story Daphnis and Chloe
Chloeia is a worm with large, colorful bristles and occurs throughout the tropical Atlantic and Indo-Pacific, certainly the beauty of its namesake!
3. Swima & Flota
The genus name Flota would seem to similarly suggest "float" in Latin..
There is of course a GREAT story surrounding Swima that you can watch in the MBARI video below but essentially Swima, with one particularly appropriate species, Swima bombaviridis can actually relelase GLOWING BOMB of BIOLUMINESCENCE as a defensive mechanism!(read more here)
You can read MORE about both of them at MBARI's feature story!
Rewatching yesterday's #okeanos dive— Carina M. Gsottbauer (@CarinaDSLR) September 24, 2015
Swimming #polychaete worm = BRILLIANT#Hawaii, ~2200m pic.twitter.com/JoLv1wiwU5
2. Syllis & the SyllidaeHere's your dose of #deepsea#mondaymotivation ! Let out your inner party polychaete! #okeanospic.twitter.com/gRssgff9Q8— Amber Cobley (@cobbers_ocean) April 25, 2016
Another bunch of polychaete worms whose name was apparently inspired by a classical mythological nymph is Syllis! Who was a naiad nymph from Greek mythology! (here)
|Disclaimer: Statue of a generalized classical nymph intended to represent concept and NOT a statue of Syllis!|
1. All the Worms named for Kristian Fauchald!
International Polychaete Day honors Dr. Kristian Fauchald, but EVEN IF the event were to pass, his name has been immortalized into the polychaete literature!!
and here's actually ONE of a LIVING specimen!! Sphaerodorium fauchaldi!
|Image from the Bergen Museum: From their page on the First International Polychaete Day: http://invertebrate.b.uib.no/2015/06/30/the-1st-international-polychaete-day/|
2013 as I blogged about here and it became suddenly noticeable by MANY scientists on the west coast from Canada to California. Due to a massive population explosion there followed a catastrophic die off in British Columbia which I documented here, with pictures courtesy of Jonathan Martin.
In the intervening years, the Starfish Wasting Disease "event" had taken on a HUGE stage. UC Santa Cruz now monitors the health of west coast asteroids on their website (here).
The first Sea Star Wasting Symposium was held earlier this year in Seattle. A meeting which I attended and reported on here.
Perhaps one of the most significant losses following the massive starfish wasting disease epidemic that hit the west coast of North America (and possibly parts of the east coast) was the apocalyptic loss of the iconic sunflower sea star, Pycnopodia helianthoides.
When I was growing up on the west coast, there were sunflower stars that were HUGE!! Tall tales would report them reaching two and a half, then THREE feet across! But most were a good dinner plate size.
These animals were voracious predators and for starfish, moved quickly across the intertidal and subtidal...
Sunflower Stars are an ecologically important species.
Unfortunately, populations of this species were DEVASTATED by the starfish wasting disease epidemic. More so than almost any of the other species, the sunflower stars were more often than not, completely removed from local areas along the coast.
Ecologically this has had VERY significant ramifications. Recent ecological studies, such as this 2016 paper in PeerJ by Schultz et al have indicated that green sea urchin abundance in British Columbia has increased FOUR FOLD!
This has agreed somewhat with anecdotal observations by naturalists on Twitter observing sea urchin abundance in California...
Ever since the disappearance of Pycnopodia sea stars, the purple urchins have become very common - coincidence...? pic.twitter.com/LohVivn8YJ— M. Sid Kelly (@MSidKelly) June 12, 2016
Those of us who are most familiar with the West coast fauna.. divers, naturalists, scientists, citizen scientists, beach goers, students, fishermen, anyone with an intertidal or subtidal ID guide was suddenly NOT seeing this species. It was and still is a significant and sad loss.
And so.. observations of THIS species have had a SPECIAL significance..
BUT today, a colleague of mine, Ms. Brenna Green observed THIS. A juvenile Pycnopodia helianthoides in Northern California!! According to her, one of the first she's seen in a good long while!!
I was directed to iNaturalist which has been monitoring observations of ALL asteroids on the west coast.. There were only 60 observations of Pycnopodia since 2014!!- so only about 20 per year that are reported Note also-some of those observations were from areas that are distant from the primary Sea Star Wasting Disease areas (such as Alaska).
Make no mistake, that's a very low number... but surprising considering that they were considered completely gone from some areas..
But they ARE still out there. And are still popping up..
An anecdotal skim of Flickr and Twitter shows that small sunflower stars have been popping up over the last year or so...
From Titlow, Tacoma, Washington from February 29, 2016
The diadematid ASTROPYGA!
Common names of these urchins include "radial urchins" and "fire urchins."But many refer to echinothuriids in the genus Asthenosoma as "proper" Fire Urchins, for obvious reasons.. but mainly because they are VERY painful to get stung by..
Astropyga also appears to have a rather painful array of spines but I'm unsure if these pack quite the toxic wallop that Asthenosoma does..
Astropyga includes four known species, one in the tropical East Pacific and another in the Indo-Pacific and two in the tropical Atlantic. All are known to occur primarily from relatively shallow to mesophotic depths as we saw recently on a Bishop Museum expedition to the "Twilight Zone" (here)
But even within the widely occurring Indo-Pacific species. A. radiata there appears to be quite a bit of color variation from the dark colors seen below to the lighter ones like this
The genus name can be broken down to "Astro" meaning star and "pyga" which refers to rump or buttocks.. so the name literally translates to "Star Butt"!!.
Why? Well, you see this giant bulb on the surface? That's an extension of the intestine called the anal sac. That's where the POOP comes out! I've talked about that here. So, basically some wry taxonomist looked at the anal sac and the pentagonal symmetry and decided "yes. The STAR ASS!"
All the images below are probably A. radiata from the Indo-Pacific.
Astropyga scavenging on dead fish!(Lembeh)
Based on a round up of papers I could locate, A. radiata has been reported primarily as a scavengers, feeding on algal debris and other stuff from sediments, etc. But if this image is accurate (and not posed) they occasionally much on dead fish as well. This is actually consistent with other sea urchin feeding habits, so I feel comfortable in presenting it here..
This speaks for itself. As with other echinoderms I've shown here (such as the sea cucumbers) just because you see white fluid being emitted its not actually clear what sexes of the species are present. The fluids likely represent BOTH sperm AND eggs.
Astropyga moves surprisingly quickly!
While I haven't actually seen one of these alive and close up, its pretty clear that even for sea urchins they are capable of a surprisingly brisk sprints! and across some unusual terrains to boot!
That's quite a lot of coordination of spines and tube feet at play..
my first underwater timelapse from prodtv on Vimeo.
And finally, one of the things that we LOVE to watch urchins doing? POOPING! Something that is arguably part of their namesake! Here's the time I corrected New Scientist on their mistaken urchin pooping picture!
Here's a whole post on echinoderm anuses for your reading pleasure!
Image from Wikipedia, taken by Jon Hanson, in Thailand: https://en.wikipedia.org/wiki/Crown-of-thorns_starfish#/media/File:Crown_of_Thorns-jonhanson.jpg
But genetics DOES indicate that there are multiple "cryptic species" across this animal's wide range in the Indo-Pacific..
and the ANUS of course! That's the dark spot, probably surrounded by spines... this shot is nice because it not only shows off the papulae (the gills) but also the pedicellariae (the red tweezer like structures)
And the ORAL surface!
Strangely enough, the top surface of Acanthaster is remarkably well known but how many people have actually seen the ORAL surface where the mouth is???
In addition to the tube feet all converging at the mouth, you also see the oral spines projecting into the mouth itself!
|From 2001. Hymenaster pentagonalis from the Hawaiian Islands region. Image by H. Reiswig|
My first exposure to LIVING Hymenaster was back in 2001 when I was working with Craig Young on an expedition to study glass sponges in the Hawaiian Islands (see pic above)
I got an opportunity to collect a bunch of deep-sea asteroids at that time and saw my FIRST deep-sea slime star!!
and a few minutes after, I discovered for the first time that, just like their shallow-water cousins, Hymenaster could emit mucus just as effectively!! In other words SLIME!
|Image by H. Reiswig.|
The name Hymenaster translates from the Greek into "Hymen" and "aster" or "Membrane Star" which as we shall see is pretty fitting.
The body is almost transparent. You can see the five radiating tube foot grooves plus the mouth and some spines and etc. in the surface areas which you can sort of see through.
|Hymenaster sp. from Maro Crater (Hawaiian Islands)|
Hymenaster occurs all throughout the world: Atlantic, Pacific, Arctic, Indian and Antarctic (i.e. the Southern) Ocean. The genus includes approximately 60 species.
Hymenaster lives primarily in very DEEP water (1000-8400) with some species occurring in the DEEPEST of ocean depths, setting records for starfish deep-sea occurrence (here). The deepest known Hymenaster was recorded from 8,400 meter depths aka the ULTRA abyssal!! But some, such as the shallow Hymenaster pellucidus take advantage of the cold water in the Arctic and can occur in as shallow as 128 meters.
The problem with many of these deep-sea pictures is that the diagnostic characters used to ID them are from characters that are either on the underside, along the tube foot grooves or actually INSIDE the body. Color, shape and surface texture all seem to vary..so it can be difficult to "nail down" which species is which..
Unfortunately, these animals don't hold up well after collection. Here's one after the delicate touch of a robot submersible. Think about what what a delicate animal like this looks like AFTER a trawl net has dragged it for about an hour on the sea bottom!
There is nearly NOTHING known about the biology of these animals. What do they eat? What is the slime used for? What is the gelatin-like body an adaptation for? Where do the species live? Are they separated by depth? How have they evolved?
ALL of the observations below have screengrabs via the Okeanos Explorer program!!
The deep Pacific is a VAST area. Images below are mostly from North Pacific observations..undoubtedly there remain many MORE species further south.
A Pink One from the southern region of "Bank 9" in the Hawaiian Islands region
here was an ENORMOUS one from the Hawaiian Okeanos that was HUGE about 20 cm across!
This one nicely illustrates the osculum, which is that big center hole on the surface which is how water enters the cavity surrounding the body surface thus bringing water/gases to the papulae (i.e. the gills) within..
It gave us a nice show with its opening and closing osculum!
This is what I previously identified for HURL as H. pentagonalis..but it doesn't seem to match the orange one at the top of the post above in terms of color or texture. So, possibly something else.
and yet ANOTHER Hymenaster species (I think??) from Salmon Bank in the Hawaiian region. White with flyffy surface texture!
A recent image of Hymenaster sp. from McDonnell Guyot in the Wake Island region. Same genus but the surface texture is VERY different..
Its also entirely POSSIBLE that SOME of these Atlantic species might actually be the SAME ones as the Pacific ones.. There are some similarities below with the ones above..
Contributions herein by photographers: Bill, Tony Brown, Beth Heap, Leander, Richard Ling, Lox Pix, Morley Mason, Andrew Newton, Matt Nimbs, Valguille and especially SASpotato!
|image by Peter Southwood, via https://en.wikipedia.org/wiki/Goniasteridae#/media/File:Nectria_ocellata_P2133340.JPG|
Scientific Names vs. Common or Popular Names: What's Required
There are actually a set of internationally recognized CODES (i.e. rules) for describing species and governing their use. These codes are overseen by the International Code of Zoological Nomenclature (here) and although they are not much more than a regulatory organization, they do try to keep everything from going taxonomic kablooey!
Basically, it is these rules that dictate HOW a lot of organisms in the world get scientific names. So, simply SAYING that a new organism is called "A blue Baboo Fish" won't cut it. It actually has to be supported by evidence and published in a PEER-REVIEWED journal and given a proper scientific name in the proper format (in Latin, etc.). ONLY THEN is such a name considered valid.
Common or popular names (e.g., "blue tang" or "cushion star") have their uses but ultimately, scientists depend on the specific context of having a unique identifier associated with a particular organism. Mainly because common names are EXTREMELY variable. I've talked about the insanity of the term "cushion star" here before..
BUT a number of other rules are also at play in order to keep the process of naming new species orderly...
Nomen Nudum aka Why we don't know the name of the President's Fish (yet!)
Have you ever noticed that there's often a significant time lag between the time someone ANNOUNCES that they have DISCOVERED a new species and the time that new species is ACTUALLY described??
probably saw the news that there was a fish species named in honor of President Obama (here), who dramatically expanded the Papahānaumokuākea Marine National Monument.
Note that while some accounts actually went so far as to cite the genus name (Tosanoides) nowhere will you find the FULL name until its published in the literature. Is it a liberal conspiracy? NOPE. Its Taxonomy!
If they actually announced the full species it would create a nomen nudum, which is kind of like the taxonomic equivalent of a time-space anomaly from Star Trek. That means there's a proper scientific name flying around WITHOUT a proper scientific description.
When written out completely, the full format of valid scientific names display a reference to the original author and date of the paper which described it. Thus, the full name of one of my species
"Circeaster arandae Mah 2006" refers to a paper in 2006 in which I described the species Circeaster arandae.
Getting back to the nomen nudum however, Note that this does not necessarily invalidate the name. But it does open the name up for other unscrupulous (or unknowing) individuals to inadvertently use the name, thus "taking away" the name from the author's original intent. (or in the worst case, stealing the name from the original author).
Another real example...
You might have seen this little guy for example. A new species of dumbo octopus that one of my colleagues Stephanie Bush is working on out at MBARI/Monterey Bay Aquarium.
In an interview she alluded to the fact that the animal is SO cute that she might call it "adorabilis." She called it that informally as part of an interview but the media took the name and pretty much made it stick.
SO many news outlets have now used this name that it has turned up everywhere..but it has NOT been described or published in a scientific journal as of this date (Sept. 2016). This is not strictly a nomen nudum but conceivably, someone might mistakenly cite it in a scientific journal somewhere.
If that happens, then BOOM. It has entered the literature. This still does not mean that Dr. Bush cannot use the name..but it DOES mean that if someone else happens to use the species name "Opisthoteuthis adorabilis" that will "steal" the name away from her because ANOTHER scientist will have justified a species using that name in compliance with the ICZN code..
If by chance the name was published TWICE and in proper compliance by BOTH authors then a new situation arises. In that case the name published first has priority... A great segue into a discussion of SYNONYMY...
Synonymy aka Why you have to be careful if you "bought" a new species
Probably one of the most important of the codes in the ICZN is that of "priority" which basically states that the OLDEST (i.e. the FIRST) name established for a species is the correct one. All subsequent names of the SAME species are essentially considered redundant and their use is suppressed once that assessment is made (but there are exceptions on occasion-better explained at another time).
That seems pretty straightforward. But in truth, it can get pretty unfairly brutal.
There's a LOT of new species that are named in "good faith", sometimes even with very strong data that for whatever reason are ultimately deemed to be "redundant" and are suppressed in the literature.
So that means if someone described a new species with a shoddy (or in some cases, almost NO details) description-but it was ADEQUATE, followed by a second description that was just an objectively BETTER account, that FIRST author gets credit and the other species get put into the list of "redundant names" aka the synonymy.
While this consideration is always important, one of the biggest trends this becomes relevant for is the "Buy a new species name" thing that has been done recently to raise funds for further research, or otherwise charitable causes... Scripps Institute of Oceanography advertised the honor of naming a new species for $5,000 (see worm below as an example) whereas other places have gone over into bidding wars over $7,200! This ebay auction won the rights to name this new species of moth for $12,600.00
But its STILL possible, sometimes even if nothing was done wrong... Science is an ongoing process and although taxonomy has kind of a reputation for being a bit stogy the truth is that it IS quite dynamic and taxonomic changes are common place (much to the annoyance of those who use species names!)
Can you name a new species from a picture?
Okeanos Explorer is a research vessel operated by NOAA that broadcasts LIVE streams of its deep-sea research over the internet. I'm one of the "shoreside talent pool" which answers questions from the scientists on the ship AND from the public. (see #Okeanos on Twitter for some of my live-tweets from the dive).
A question that came up recently from my last Okeanos round, was whether or not a new species could be described ONLY from a picture or video rather than a specimen???
Uh.. No and yes.
For MOST (nearly all) cases, some kind of voucher is necessary. Why? Because we require EVIDENCE to describe a new species. Measurements. Observations of the skeletal (or non-skeletal) structure. Analysis of different features. DNA. Any one of thousands of kinds of data which permit us to carefully contrast the known species of organisms from one another.
At the very least, a specimen must be examined so that we can carefully discern why its gross morphology is different from other similar species. These specimens are conserved. They are saved in museums for future generations to reference and retained for hundreds of years.
HOWEVER. In some RARE instances, there IS an allowance for new species to be described ONLY from a picture. It used to be invoked for exceptional cases-rare and endangered species for example.
But just a FEW months ago Neal Evenhuis at the Bishop Museum in Hawaii made the case that in some cases, a photo ALONE is enough to describe a new species-given PROPER evidence. (Scientific paper is here)
The octopus seen by Okeanos was identified because it was an "incirrate" octopus (as identified by NOAA researcher Mike Vecchione) which had NEVER been seen at that depth before. Almost certainly a new species
The conservative scientific approach in publications would be to indicate it IS a new species but without a proper name (e.g., Octopus n. sp. 1)
BUT it can't be properly characterized because a LOT of octopus characters are internal and require direct comparison (unlike the South African bee example above which COULD be identified and characterized).
Also, while unlikely, its POSSIBLE that there is a specimen of this animal somewhere in a museum somewhere in the world which has already been published. Without reconciliation of all these disparate factors, one risks creating redundant names which are essentially permanent and creating possible confusion.
Thus, identifying a species directly from ONLY a picture would be more direct but not as thorough and does not give us enough data to properly assess it. But yes, there are exceptions.
Identifying species only from pictures also invites the possibility of abuse and reckless taxonomy which could impede and hopelessly confuse the work of legitimate scientists during a time when there is a dire need for workers to be be studying Earth's biodiversity...
Species named after celebrities & pop culture? What's up with that?
This also made scientific names pretty straightforward. I've documented the word origins of MANY starfish species before (such as here) Some make great stories in and of themselves
Most scientific names are based on descriptive terminology. So, for example, the name Acanthaster , which is the scientific name of the Crown of Thorns starfish (learn more about this genus here), literally translates into "thorny star" from the Greek acanth- and the Latin -aster meaning star. Many of these names were sort of an open book...
"noted scientist of the day", for example Luidia-the starfish is named for Edward Lhuyd who called himself Luidius.
Although you would think that naming a genus would be better than a species (because a genus is higher up in the taxonomic hierarchy), in fact, its not. Higher level names tend to be made into synonymies more frequently than species. Species tend to stick around for quite awhile longer..
It USED to be that many of these names would stick to people known to the scientists: wives, children, close confidants and good colleagues and certainly this continues to be the case. I've named MANY species after close friends and colleagues.
As we have gotten into the 20th and 21st Century however, we NOW see increasingly the role of pop culture influencing taxonomists! There are a number of reasons: Some think it makes taxonomy more relatable, some have found genuine inspiration from popular entertainment, others have many MANY species and have just "run out" of Latin names.. an endless list from a huge pool of scientists.
Sometimes the people/characters as names are directly influential! As with Yoda above. the genital flaps of that acorn worm (an enteropneust) were VERY reminiscent of Star Wars Jedi Master Yoda! The ICZN is actually surprisingly flexible in allowing for "translating" terms into taxonomic names... And hence its namesake! From a character created in the late 20th Century into an ancient dead language! No problem! (if you know how)
We have flies named after Beyonce, wasps named after Shakira and trilobites named after Mick Jagger! You can see a full list of names here on Wikipedia.
and of course the brittle star named after George RR Martin of Game of Thrones!
Taxonomists are diverse. No longer done by ONLY classic stodgy, out of touch scientists-but hip, trendy nerds as well! .. it is done by many students and dynamic individuals who follow popular trends.. and we will likely see more and MORE of these pop culture names in the future....
thanks to Monica M. who asked me the question about Obama's fish! that inspired this post.
via the NOAA photo library http://www.photolib.noaa.gov/htmls/expl6751.htm
Here's some video to give you an idea of what it looks like/how it moves, etc. (I would watch without sound to enjoy the zen of the animal)
IF the name doesn't sound familiar, the animal's distinctive appearance definitely stays glued in your head after you've seen one! Imagine a big blobby sea cucumber with what looks to be a HUGE LOBE sticking out of its hind end!
Note the image above contrasted to this diagram showing mouth (top) and anus end (with lobe-bottom).
The genus Psychropotes is derived from the Greek for Psychros which means "cold or frigid" and "potes" which honestly, I could not find a definitive translation for... One root translated to "flight"? possibly alluding to the ability of this species to swim...And another colleague tells me it might mean "dweller". Ah well, one mystery at a time!!
Psychropotes includes 11 species which occur widely, all around the world in the Atlantic, Pacific, Indian and Southern (but not in the Arctic) oceans in the deep abyss of the world's oceans! That means roughly 2000 to 6000m. They are the deepest of the deep! Considered "classic" deep-sea inhabitants they were collected and described from the HMS Challenger's historic mission.
These can be pretty BIG animals!! as this image from a recent MBARI expedition demonstrates. (with deep-sea biologist Greg Rouse for scale!)
|From MBARI https://twitter.com/sarahkeartes/status/593979334056022016|
Note the one above with the shorter, forked "lobe" Is it the SAME species as the purple one shown earlier? Is this variation? (such as what we might see in humans who live in different parts of the world) Or are these separate species?
|Figure 2 from Gubili et al. 2016|
|Figure 3 from Ghibili et al.|
What further mysteries does Psychropotes have in store? I anxiously await the next paper!
....now if I could only figure out what the "potes" part of Psychropotes means!
— Libby Ross (@Libby_Ross) January 27, 2013
|from ebay http://www.ebay.com/itm/Psychropotes-varipes-Stuffed-Toy-sea-cucumber-peluches-Kuscheltiere-Japan-Eboshi-/271795943477|
It surprised me that SO MANY have since become established. I remember many years ago when it was less than 6 people and most of it was secondary to blogging!
Invertebrate Themed Twitter Events
#TrilobiteTuesdays. Held every Tuesday. If you are into Paleozoic arthropods then Tuesdays are YOUR thing!
#WormWednesday: Held every Wednesday. These bring forth all manner of worm-like phyla: Polychaeta, Annelida, Nematoda, Platyhelminthes, Acoela, and so on and so forth..
#SpongeThursday: Held every Thursday. Love the Porifera? the Hexactinellida? Go forth and
enjoy/post about them!
Honorable mention goes to #FossilFriday which is mostly about Dinosaurs and vertebrates..but you get some ammonites and other invertebrates in there pretty regularly...
#CephalopodAwarenessWeek. aka #CephalopodAwarenessDays Every year from October 8 to 12. You can keep on updates at @cephalopodday. Basically 5 days celebrating EACH class of cephalopods and then some...
#SeaSlugDay. Held every year on October 29th in honor of Dr. Terry Gosliner's birthday! Celebrate by posting images, videos and links to all manner of shell-less marine gastropods! Nudibranchs and their kin! My post from last year.
And of course #Okeanos when the NOAA vessel Okeanos Explorer goes into research/streaming mode! in which case, there are new deep-sea invertebrate posts for several hours every day for about 2 to 3 weeks!!
Various Twitter accounts/Persons with Invertebrate themed content
|from the USNM Invertebrate Zoology FB page @InvertebratesDC|
This will be a fairly subjective list-I focused mainly on marine groups and those with academic or otherwise focused content that I thought was appropriate. Activity was also a consideration. Some accounts looked essentially inactive and were not included.
Let me clear that there are a LOT of accounts which have a broader focus that regularly include Invertebrate Zoology themed tweets, including aquariums, natural history museums, etc. and frankly those have so many followers its unnecessary to give them much more publicity anyway..
There were MANY, many individual accounts of photographers, naturalists, educators, scientists, etc. who for one reason or another I just couldn't include for the sake of space, focus, etc.
And there are some topics, for example about coral reefs, there's a TON of coral-related accounts and I simply could not list them all... A search on Twitter's search engine will get you all of those names pretty quickly though.
So, please don't take an omission as an offense. In fact, if you've got an IZ twitter account that you'd like me to know about, please let me know and if I think its appropriate, I'd be happy to include it.
As a side note: my search for these Twitter accounts took me to some interesting places and its curious to see how many of of the phylum or other taxonomic names have made it into popular use: band names, student groups, social clubs, business organizations, video games, so on and so forth...
Invertebrate Zoology department of the NMNH at the Smithsonian @InvertebratesDC The official account for one of the most active Invertebrate Zoology departments in the world.
Heidi Gartner. @RBCMInverts.Collection Manager at the Royal British Columbia Museum Invertebrate Zoology dept.
Annelida & Segemented Worms
Dr. Christoph Bleidorn @C_Blei. Evolutionary biologist at the MNCN in Madrid
Dr. Conrad Helm. @conrad_helm. Sars International Center at the University of Bergen. Works on the systematics of segmented worms.
Brachiopod research at the Natural History Museum in London @NHM_Brachiopoda.
Bryozoan research at the Natural History Museum in London @BryozoanNHM This is, I daresay, the finest Twitter account about bryozoans I have seen to date!! Both fossil and living!
Dr. Allen Collins, NMFS/Invertebrate Zoology NMNH. @tesserazoa. Specialist in jellyfish systematics, sponges and metazoans relationships.
Australian Coral Reef Society. @AustCoralReefs. Official twitter account of the Australian Coral Reef Society.
Dr. Casey Dunn, Brown University. @caseywdunn. Evolutionary biologist at Brown with a special eye towards siphonophores! He also produces Creature Cast videos.
Dr. Cheryl Lewis Ames, @boxjellytalk. NMNH/University of Maryland, box jelly expert.
Coral Morphologic. @CoralMorph. Strong visuals, images, videos of cnidarians and many other invertebrates.
Gates Lab @GatesCoralLab.Coral Research at the Hawaii Institute of Marine Biology.
Dr. David Plachetzki. University of New Hampshire. @plachetzki. Cnidarian genomics.
Dr. Mercer R. Brugler @ProfBrugler. Professor at City Tech, SUNY, Taxonomy & Systematics of Black Corals & Anemones.
Medusozoa Columbia. @Medusozoacol. Jellyfishes of Columbia!
NOAA Coral Program @NOAACoral. Official Twitter account for the NOAA Coral Reef Conservation Program.
Dr. Rebecca Helm. @RebeccaRHelm. Woods Hole Oceanographic Instition. Jellyfishes and all manner of swimming cnidarian.
Dr. Paulyn Cartwright @pcart. Professor at the University of Kansas specializing in Cnidarian Evolution.
Dr. Andrea Quattrini. @quattrinia. Harvey Mudd College. Studies deep-sea corals.
Miranda Lowe, @NatHistGirl. Principal curator of Marine Invertebrates at the Natural History Museum in London.
Dr. Tammy Horton, Amphipod taxonomist at the Discovery Collections in Southampton @tammy_horton.
Adam Hadsall. @_Nezumiiro_ Tweets #craboftheday and many other items of carcinological interest!
Chris Mah, Research Associate at the NMNH. @echinoblog.I work on sea stars but know stuff about things.
David Clark. @Clarkeocrinus.A great account for enjoying Paleozoic and fossil stalked crinoids!
Fossil Worms (Miscellaneous)
Luke Perry. At the University of Bristol in the UK/Natural History Museum. @Cambriannelids.Works on Cambrian worms, primarily annelids.
Hemichordates, deuterostomes, etc.
Dr. Chris Cameron. @InvertEvo at the University of Montreal.One of my colleagues who studies the evolution and development of deuterostomes, especially hemichordates.
Dr. Dave Rudkin, @RudkinDave. Royal Ontario Museum. Studies Paleozoic arthropods and other fossil invertebrates.
Dr. Michael Bok at the University of Hawaii @mikebok. Studies Vision in invertebrates.
Dr. Anna Phillips, Curator of leeches and parasitic worms at the NMNH, Smithsonian. @Annalida500.
Dr. Mark Siddall Curator at the American Museum of Natural History. @theleechguy.
Dr. Sebastian Kvist, Curator at the Royal Ontario Museum. @sebastian_kvist. Annelid & leech systematics.
Dr. David Hayes. @Gnarly_Larvae at Eastern Kentucky University. Works primarily on molecular ecology and freshwater mussels.
Freshwater Mussels. @WeNeedMussels.What more can you ask for? A Twitter account entirely devoted to Freshwater mussels!
ALCES: The AUT Lab for Cephalopod Ecology and Systematics. @ALESonline. Devoted to studying cephalopod biology, especially deep-sea squids
Research account for fossil cephalopods at the Natural History Museum in London. @NHM_cephalopoda
CIAC-The Cephalopod International Advisory Council. @cephCIAC. The Cephalopod International Advisory Council is a scientific group for cephalopod researchers worldwide
Dr. Louise Allock. @DrShmoo at the National University of Ireland, Galway. Deep-sea octopuses!
The Octopus Newsletter Online (TONMO) @cephs A hub for cephalopod research and interest.
Dr. Stephanie Bush, Monterey Bay Aquarium. @podlett.Deep-sea Octopus biologist/systematist at MBA.
Mollusks-Gastropoda (shelled snails & slugs)
Dr. Chong Chen, Biologist at JAMSTEC who works on deep-sea snails @squamiferum.
Jessica Goodheart. @sluglife28. PhD student at the University of Maryland/NMNH.Studies sea slug systematics and behavior.
Dr. Kevin Kokot, @kmkocot. University of Alabama. Mollusk & metazoan phylogeny.
The Blaxter Lab (Dr. Mark Blaxter, University of Edinburgh),@blaxterlab. Nematode, tardigrade and other invertebrate genomics/genetics.
Nemerteans (Ribbon Worms)
Dr. Jon Norenburg, dept. chair of the Invertebrate Zoology dept. at the NMNH. @Jnorenburg and @nemertinator (personal account) Specializes in ribbon worms and meiofauna.
Iberian Nemerteans. @nemertan. Truth in advertising. A Twitter account about ribbon worms based in Spain.
Twitter account for the American Society of Parasitologists @AmSocParasit All parasites. All the time.
Tommy Leung, Parasitologist who authors the "Parasite of the Day" blog. @The_Episiarch
Leann Biancani, @LeannMBiancani PhD student at the University of Maryland and the NMNH. Studies the biology and relationships among pelagic invertebrates, including amphipods and polychaetes.
Dr. Steve Haddock, MBARI. @beroe Dr. Haddock is an expert in ALL manner of pelagic deep-sea invertebrates.
Dr. Richard Kirby, based in Plymouth, United Kingdom. @planktonpundit. A wonderful account with regular images and videos of planktonic/nektonic and other related organisms.
Platyhelminthes & Flatworms
Dr. Ulf Jondelius @ulfjo, specializes in aceolomorph "flatworms" at the Swedish Museum of Natural History.
Dr. Jean-Lou Justine, specialist on free-living land flatworms at the MNHN in Paris. @Plathelminthe4 If you are REALLY into Bipalium and other terrestrial, free living flatworms this feed is for you!
The Polychaeta Database @WpolyDB Twitter account of the World Polychaete Database (WoRMS)
ケムシ屋 @alciopidae. I don't have a full name unfortunately. A Japanese polychaete taxonomist (Cirratuliformia/Alvinellidae/ Myzostomida/Opheliidae/Polynoidae etc...)
Dr. Helena Wiklund. @helena_wiklund, University of Gothenberg, Germany. Polychaetes and annelid diversity.
Maddie Brasier. @Madsbrasier. Studying Antarctic polychaetes.
Dr. Shinri Tomioka. @Capitellico PhD student at Hokkaido University in Japan studying polychaetes.
Dr. Torkild Bakken. @TorkildBakken.Marine biologist at NTNU University Museum, polychaetes and other deep-sea diversity.
Porifera (the sponges)
Twitter account for deep-seasponges.org @Deepsea_sponges You don't get much more specific than this, where deep-sea Porifera are concerned!
Dr. Jackson Chu @jwfchu. Glass sponges and benthic ecology.
The Pawlik Lab @PawlikLab at the University of North Carolina, Wilmington. Sponge chemical ecology and biology.
Dr. Ana Riesgo at the Natural History Museum in London. @anariesgogil Sponge researcher at the British Museum.
Dr. Bob Thacker at Stony Brook University. @thackerbob Ecology and systematics of sponges, Involved with the Porifera Tree of Life Project.
The International Society of Protistologists! @protistologists . Pretty much all in the title.
Psi Wavefunction.@PsiWavefunction.Protist blogger and scientist.
Dr. Daiki Horikawa. University of Tokyo. @daikidhori Tardigrade biology & genomics!
The first few specimens of this species were collected by the Monterey Bay Aquarium Research Institute from Taney Seamount (off the coast of San Francisco) from abyssal depths (over 3000 meters!).
|photo by J. Sharei|
|image by Alexander Semenov|
|Note: this image probably does not accurately represent the feeding biology of dorid nudibranchs|
5. Echinoderms (such as brittle stars)
I begin with that most sinister of predatory nudibranch: the echinodermativore! To be sure, the number of sea slugs that are known to feed on echinoderms is a relatively short list-but probably one of the most gorgeous is this Indo-Pacific one: Kalinga ornata!
4. SHRIMP! I wrote about Melibe on SeaslugDay last year. and I've already shown this video of Melibe viridis capturing this shrimp.. but its VERY impressive. So you get it again...
3. Bryozoans & various Cnidarians (hydroids, anemones, etc.)! Among the most typical of foods fed upon by nudibranchs are the many, many types of encrusting and/or otherwise sessile animals that live on and around nudibranchs, ranging from small, colonial animals to huge tube-shaped sea anemones!
Here's a nice pic, for example, of a dorid nudibranchOnchidoris muircata feeding on a bryozoan colony. Bryozoans aka "lace animals" are a phylum of colonial invertebrates that form very delicate skeletons. They are fairly common in many areas as encrusting, colonial forms.. MANY nudibranch species seem to feed on them...
Not sure which species this is..but you can see they've pretty efficiently cleared off the living tissue from the bryozoan skeleton
This species, Crimora coneja was imaged in Oregon feeding on the bryozoan colony here. You can see the stark white regions around the nudibranch where it has fed, versus the lighter, fuzzier areas around the edges.
Nudibranch feeding on sponge from BIOPIXEL on Vimeo.
Its always interesting how many people are fascinating not just by predation but "cannibalism" which when applied to the animal world seems to mean when one "type" of animal feeds on the same or similar "type" of animal. (i.e. sea stars that feed on sea stars) and not just one species feeding on itself (as it does in humans).
Its not as common but there are several noteworthy nudibranch predators that feed on OTHER nudibranchs...
The formidible Navanax from the North Pacific for example.. They seem to be quite effiicient at swallowing their prey whole! If these were the size of say, a dog or a wolf we would be VERY afraid of them!
I've always loved the name of this nudibranch. It has a nice ring to it!
In the tropical Indo-Pacific, there is another formidable predator, those slugs in the genus Gymnodoris, which as we'll see feed not only on other sea slugs but have progressed up to vertebrates as food!
1. SLUG EAT FISH!
This really WAS the most amazing thing to discover. It turns out there's a dorid nudibranch called Gymnodoris nigricolor (name translates into the "black Gymnodoris) which attacks and EATS the FINS of certain FISH!
These slugs basically crawl onto a goby and begin to eat their way down a fin spine, gnawing off the meat on the fin. Some have called this behavior parasitc but I think of it as more predatory. I suppose its really kind of both.
My friends over at BlennyWatcher have a nice little account of this with links, etc. here.I've included a VIDEO of this behavior at the bottom!
DOES seem to show the same kind of off-set position on a starfish! It IS one of the first things you notice about the disk when you look at it!
Its normal for the tube foot groove to have defense or other kinds of structures right on the edge of the "trench"
In some groups, we see more... pronounced structures that one might compare with the anti-fighter craft on the Death Star's surface..
Man the embattlements! Turbo lasers to the defense! Starfish don't QUITE have the anti-X-wing capabilities of the Death Star but what they DO have....
Its not QUITE clear what pedicelllariae do however. They look jaw or even clam-shaped, sometimes with numerous teeth on each piece.
These look more analogous to "turbo lasers" in that they are extended well off the surface of the starfish's body.
|Photo by Matt Kiefer via Wikipedia:|
Today's post is a kind of response to a fairly common request I get via email: "Can you help me ID this species of starfish from the Philippines?" (paraphrased)
A question I get from divers, photographers and students who actually live in the Philippines. And strangely enough I get it quite frequently and there are surprisingly few resources to help people with pictures.
In the past I have done variations on this by crowd sourcing images off places like Flickr and YouTube and its been awhile since I've done an "on line field guide." So I thought it would be a good time for another one!
With the exception of Acanthaster brevispinus (above), EVERYTHING below is taken from Flickr and recorded as being from the Philippines by the photographer.
The Philippines has a rich, RICH diversity of sea stars (as well as many, other marine animals) and so this "guide" won't be complete, but it includes several of the most frequently encountered species which are photographed and put on the web.
If you are looking for professional taxonomic monography of Philippine sea stars a good place to start is the work of Walter K. Fisher at the Biodiversity Heritage Library. HERE.
There are many, MANY published ID guides to the Indo-Pacific area and I've identified species in many of those books. But these days, images of sea stars and other marine animals are so prolific, it became clear that it really wouldn't take much to curate a collection of these to provide help for people who want to know what the animals were who didn't have expertise to the published accounts..
Another place to look for a nice crowd-sourced inventory of sea stars from the Philippines or anywhere is at iNaturalist! Go HERE. Identifications are not always from experts but its a good place to start.
I always like to remind folks when actually in the field.. look but don't TOUCH (or at least put it back!)
So here we go in reverse alphabetical order....
Euretaster attenuatus.This species belongs to the family of sea stars which are best known as "slime stars" in cold-water habitats.There's only been one account of the tropical species using "slime" as a defense and it wasn't really in a scientific journal.
This species has a distinct hole in the center of the disk called an osculum which allows water into the surface of the disk which is kind of like a circus tent that covers over the ACTUAL surface of the animal underneath (see the blog link above).
Its a species we know very little about. Another species, Euretaster insignis is usually what gets encountered in the Philippines. This image however most resembles E. attenuatus which was first described from New Caledonia. This is possibly a new record!
This species occurs widely around the Indo-Pacific, extending into the Indian Ocean with many, MANY color variations. Food, biology, etc. are poorly known.
As I've written about before here, this is one of the most heavily fished sea stars in the Indo-Pacific. Not just for tourist baubles but also for the aquarium trade. Its a handsome species and frequently gets "volunteered" for tourist pictures, beach moments, and aquarium scenes.
Nardoa frianti The genus Nardoa is named for the Italian naturalist Giovanni Nardo as I discussed in a post WAAAY back in 2008
There are MANY species. And they are often quite complicated. Even this one with its distinctive tubercles (the bumps) is conceivably part of a broader species complex. To make things even more complicated, you will sometimes see Nardoa species with these big bumps in the genus Gomophia.
Nardoa sp. similar to "N. novaecaledoniae" This one has flattened or at least, MORE flat plates relative to Nardoa frianti (above).
The exact species ID for this animal can't be made from a picture like this because we need to see the underside in order for the precise details. It LOOKS like a species that I would call Nardoa novaecaledoniae but there are several other possibilities. Close up on the underside would be necessary.
They have relatively solid surfaces with spiny surfaces. There is relatively little known about their general biology.
Luidiidae. There's only one genus in this family,Luidia and I've written about the general biology of the group here. The genus named after Edward Lhuyd, a Welsh naturalist.
Most members of Luidia are 5 armed..but for whatever reason, the ones in the tropics are often BIG and have more than 10 arms!
Luidia avicularia?Interesting to see this one since it doesn't usually occur at shallow depths. But the color pattern matches.
Luidia maculata This is a fairly large predatory starfish, often found buried below the surface of the sand.
We know very little about it.
Echinaster callosus I've seen this species often mixed up with Nardoa frianti, above. The big difference is in the texture of the "puffy" structures on the surface. Nardoa's bumps are just that- hard bumps covered by granules.
The surface of Echinaster callosus is covered by a bunch of big colorful puffy pin cushions. The big blobs are soft and each surround a sharp spine. When dead, they often deflate.
Colors are quite pretty and variable...
This species appears, at first to be fairly non-descript but a lot of things are going on with this species. In addition to the asexual reproduction and arm regeneration, this species is also often the host to benthic comb jellies! You can read more about that here.
Acanthaster planci (or A. cf. solaris). The notorious Crown of Thorns starfish has recently been studied using molecular techniques and revealed to actually be SEVERAL species. The one occurring in the Pacific has been referred to an older name, Acanthaster solaris. But presumably there are still several details to work out..
|Ophiuroids on Jelly in Mozambique. Photo by Andrea Marshall, Daily Mail, http://www.dailymail.co.uk/~/article-3990782/index.html#i-570251ad33a88841|
1. How many different types of Jellyfish species does Ophiocnemis marmorata occur ON??
The paper reports at least five or six, including at least 3 species of Rhopilema, Cephea cephea (the cauliflower jellyfish), Netrostoma and Aurelia aurita. But other internet records and social media show further hosts.. such as this hydrozoan, Aequorea from Thailand..
|From Chaloklum Diving in Singapore, http://www.chaloklum-diving.com/marine-life-koh-phangan/corals-more-cnidaria/true-jellyfish-scythozoa/scythozoa-other-jellyfish/|
And here's a blog that documents this brittle stars on the "hairy" jellyfish. Lobocnema
|Image by Thomas Peschak, https://www.thomaspeschak.com/|
Its also worth noting that the brittle stars stay on the medusae ONLY within their home range. Many of these jellies, such as Aurelia (i.e. moon jellies) actually go beyond tropical settings and they really aren't seen on jellies in cold to temperate waters..
3. So, what are the brittle stars EATING??
The authors used a novel new method which basically breaks down the organic components of specific isotopes (Carbon and Nitrogen) and looks for how much of those isotopes is present in the subjects versus that which is provided by the environment.
Long story short: The data indcates that most of the food sources in Ophiocnemis seems to come from PLANKTONIC SOURCES! (i.e. the mesozooplankton) and NOT from the medusae itself and there were not any observations of Ophiocnemis filter feeding (i.e. arms up in the water).
And so the authors suggest that they are what's called KLEPTOPARASITES (a great word-really!). In other words, they take food directly away from the jellyfish out of the mouth or the oral arms, stealing or scavenging food from the jellyfish which are known as big pelagic predators.. What would be called "indirect food sources"...
There are several reports of other brittle stars that practice "kleptoparasitc" behavior.. i.e. moving down into the feeding arms or near the mouth and stealing food directly from the host. Some of it might not be a big deal to the host.. scraps and etc.. but meaningful to the ophiuroids..
|Image by Ron Yeo at Tidechaser, http://tidechaser.blogspot.com/2012/03/brittle-stars-ophiuroidea-of-singapore.html|
4. Growth and Settlement..aka Living on a Changing Jellyfish World
|Image by Ron Yeo at Tidechaser http://tidechaser.blogspot.com/2012/03/brittle-stars-ophiuroidea-of-singapore.html|
That wraps up #Okeanos American Samoa expedition! Never fear, next expedition to explore Pacific MPAs starts March 7. We'll be back soon! pic.twitter.com/nTlBkF0NRG— NOAA Ocean Explorer (@oceanexplorer) March 1, 2017
Most of what I'll present here are animals, but in the deep regions of the ocean, single-celled organisms that are basically HUGE amoebas can develop fairly LARGE structures out of sediment. I've written about them here. Some are called xenophyophores but it turns out that there's a fair diversity of them.
Here's at least one structure observed on Utu Seamount at about 3030 meters!
those spines emerging off the edge makes it a deadly deep-sea umbrella!
Cnidarians are of course-those animals with stinging cells and radial symmetry. Jellyfish, sea anemones, hydras, hydroids and so on.They account for a huge diversity in deep-sea habitats!
This "cosmic jellyfish" has been making the rounds. Its been identified as Benthocodon hyalinus by my colleague Allen Collins at NMFS. It was observed on Utu Seamount at about 3006 meters!!
Dandelion siphonophore, seen at 2500m depth in Rose Atoll. #Okeanos back at Rose Atoll today, but starting at 700m. ROV on bottom in ~3hrs! pic.twitter.com/CXB4wnl4SQ— NOAA Ocean Explorer (@oceanexplorer) February 25, 2017
Probably the BIG, weird star of this leg was this BIZARRE blobby tree shaped thing! Turns out its a bizarre sea anemone in the family Aliciidae! Its tentacles had been withdrawn...
we saw one of these during the Marianas expedition LAST year! Which makes the one above a likely DIFFERENT species from the other one we saw which had yellow buttons rather than white ones..
Dr. Dave Pawson at the National Museum of Natural History was apparently stung by one of these (only 6 inches long) and reported that each of these buttons are batteries of STINGING cells which can cause painful stings that last for several hours!! (click here)
ROV scoop flipped one of these critters over & iIndividual gills (arrows) mean MONOPLACOPHORAN!— Carina M. Gsottbauer (@CarinaDSLR) February 24, 2017
~3800m, Utu Seamount, Samoa #okeanospic.twitter.com/xKALOOeCtR
Octopus! So, of course we are always fond of cephalopods when they turn up! This white translucent octopus species was observed at least twice on the dive at relatively "shallow" depths between 380 and 400 m. This first shot was from Tau seamount.
Note that the webs of skin between the arms were translucent!
but for now, here's some striking "spiny-skinned" friends that I saw...
This funny beast which I think was in the Deimatidae? Note that as with many deep-sea sea cucumbers, the body wall was translucent and we can see the sediment eaten by the animal THROUGH the body wall!
I blogged about this genus of sea cucumber and the number of species there might in the world oceans!
Rewatching today's #okeanos dive:— Carina M. Gsottbauer (@CarinaDSLR) February 24, 2017
A sea cucumber singing the song of its people ;)
~3900m, Utu seamount, Samoa pic.twitter.com/EiIkoxCgRD
A sea urchin the family Pedinidae I think? Lovely greenish coloration!
The crab benefits from the protection and the zoanthid gets driven around by the crab for dispersion, food, etc.. Interesting commensalism!
Before I get into the cool pix.. remember NOAA OPERATES Okeanos Explorer!! NOAA has been threatened with severe budget cuts. CONTACT YOUR CONGRESSIONAL REP AND TELL THEM THAT NOAA IS AN ESSENTIAL Agency!
1. PELAGOTHURIA! The "TRUE" swimming Echinoderm!!
I have written about this amazing animal before when I found an image of it misidentified as a jellyfish in the Galapagos Rift 2011 Okeanos photo gallery and have written at some length about swimming sea cucumbers here.
Basically, almost all sea cucumbers and indeed most echinoderms are benthic..that is they live entirely on the sea floor and never get into the water column the way fish or jellyfish do.. Yes. Some sea cucumbers can swim but ultimately they return to the bottom.
Pelagothuria is unique because it LIVES SWIMMING in the water column! Similar to the way a jellyfish does. As a result of its strange lifestyle, it has MANY bizarre adaptations and looks unlike most other sea cucumbers much less other echinoderms!
Its not a commonly encountered animal..and we live in a wonderous time that we can see several minutes of HD video of this seldom seen animal swimming by...
The video for this can be found HERE: http://oceanexplorer.noaa.gov/okeanos/explorations/ex1703/dailyupdates/media/video/dive08_seacuke/seacuke.html
2. The strange irregular urchin Phrissocystis! From Polo Seamount, about 2100 m we saw one of the most seldom seen spatangoid urchins known! These are highly evolutionarily derived sea urchins which live by digging through and swallowing sediment looking for food.
Although they are bristling with spines, they are actually quite delicate. One collected many years ago apparently collapsed as soon as it was brought out of the water in the submersible collection box!
It was quite large with an unusual texture to the stalk and the cup...
5. The enigmatic sea star Tremaster mirabilis Here's another strange one! A sea star that basically looks like a bowl on the top of a table!
We've seen these before on Atlantic Okeanos dives (see that here) and I wrote about this animal many years ago before people started seeing them alive..
There is nominally ONE species present in almost every ocean in the world.. they've been found in the Atlantic, around New Caledonia, near Hawaii and in the Antarctic. Not sure if they've been found in the Indian Ocean.
Interestingly, these were found in astonishing abundance on one of the seamount dives
5a. The Deep-Sea Slime Star HYMENASTER
From Titov Seamount was this glorious, glorious deep-sea SLIME STAR, in the genus Hymenaster.
I've written about the shallow water representatives of this genus here. and explored the diversity of Hymenaster in the deep-sea here
*EXTRA! and of course a bunch of weird sea cucumbers!!
A deimatid sea cucumber with many tentacular extensions, this one from Swains Atoll
and this one from Titov Seamount but they look to be similar if not identical
This one has been seen repeatedly rearing back and presenting what I think is its mouth into the water. so maybe feeding?
A red one from Polo Seamount
Mostly I call in on starfishes or echinoderm biology..but I do have a broad interest in deep-sea biology. And I just LOVE seeing observations like the one above: a weird animal doing something no one is familiar with!
And the BEST thing about Okeanos Explorer? EVERYONE can enjoy it along with you!! Here's a BUNCH of Sea spider observations from the Atlantic Okeanos Explorer in 2014!
...BUT of course, our ship and shore-side scientists can't know EVERYTHING. We'll often observe an event, many of us make note of it in case we see it again and often times we'll move on.... forgetting about it until such a time when the observation comes up again.
ONE such observation was one from 2014 on the Atlantic Physalia Seamount wherein we observed a sea spider in the genus Colossendeis sp. with its proboscis (that's the long cigar shaped feeding tube) stuckINTO into this hydroid (an animal similar to a Hydra from freshwater)! Was this feeding? Was it NEW?
|Physalia Seamount in the North Atlantic|
Most sea spiders are pretty tiny and are less than about an inch (2 cm) across and its not unusual for them to be quite cryptic. So even though they can be present, you really DO have to look for them...
Here a photoessay of tropical, shallow water species by scientist/photographer Arthur Anker displaying some spectactular colors! Here's a spectacular male carrying eggs..
Many live in shallow water but are never seen (hidden and small)... but that's NOT a problem with the deep-sea and Antarctic species! There's one frequently encountered genus: Colossendeis which is one of the largest known sea spiders reaching a leg-to-leg diameter of over 50 cm! that's almost a FOOT and a HALF!
Most members of Colossendeis live in the proper deep ocean abyss: roughly 1000 to 5000 m and also in Antarctica where the cold-waters allow them to occur in relatively shallow water settings.
Note also the sizeable cigar shaped projection at the top end! That's called the PROBOSCIS! That will be important later! That is presumably what they use to feed.
So, were the observations something unusual? Has science encountered something like that before??
But much to my delight: YES! There WAS a previous account of sea spiders feeding! and WOO HOO! It turns out my friends at the Monterey Bay Aquarium Research Institute in Moss Landing, California actually observed something JUST LIKE THIS in 2010!!! Here was their blog post about it!
The paper, by Caren Braby, Vicky Pearse, Bonnie Bain and Bob Vrijenhoek was published in Invertebrate Biology in 2009, 128(4): 359-363. and it documented "Pycnogonid-cnidarian trophic interaction in the deep Monterey Submarine Canyon"
They observed the same genus, Colossendeis, but at least two species, C. gigas and C. japonica feeding on commonly encountered sea anemones in the deeps of Monterey Canyon.
Braby et al.'s observations were the first for deep-sea Colossendeis (as opposed to Antarctic) species. Her team's work focused on their feeding on the deep-sea "pom pom anemone"Liponema brevicornis, an unusual sea anemone which literally "rolls" along the bottom of the deep-sea in a manner similar to a tumbleweed!
After the last 2017 Okeanos leg in the Phoenix Islands, I rounded up a BUNCH of the sea spider-feeding observations and decided to share them here as a comparison! Who knows? perhaps it will inspire a further paper!
Remember that NOAA's Okeanos Explorer program has captured these images and made them available for EVERYONE's enjoyment! Please remember that the next time someone talks about government funded science!
Winslow Reef: This one had its proboscis firmly ensconced into this flytrap anemone and was apparently sucking something out of it! The rather lethargic looking appearance is likely the result of being on the receiving end of whatever is going on here...
And ANOTHER on Winslow Reef! that was QUITE a dive! Here's another flytrap anemone with a sea spider attacking it! As we saw earlier from Monterey Canyon, sea anemones and other cnidarians seem to be one kind of preferred food!
Baker Island we saw one attacking what was identified as a cup coral...The proboscis seemed to be "drinking" pretty heavily on this one...
Howland Island.....and just for good measure they saw this one crawling over a glass sponge
More Atlantic Feeding? Here we had a sea spider in the Atlantic Nygren Canyon which has been identified as Pallenopsis (thanks to Bonnie Bain), climbing and possibly feeding on this sea pen.
So, unfortunately I'm not really a sea spider taxonomist, so beyond the genus Colossendeis, I'm not sure how many species we are looking at here..but images such as this inspire many questions: Is predation specific to species? Or generalized? How significant are these events to the ecosystem?
Do sea spiders attack the big colonial corals as well?
Stay tuned for the next exciting episode!
(video captured by 2011ACVVV)
Spines in these brittle stars is sharp and often with jagged edges..so capturing something soft-bodied isn't TOO surprising..
squid not escaping the brittle star @ jarvis island, se.#okeanos— soren 💬 (@roomthily) May 6, 2017
oh. oh no. pic.twitter.com/81YLCv6cfj
Yes! Most of us don't think of sea stars OR brittle stars as capturing fast moving or SWIMMING prey! Strangely enough, THIS WAS CAUGHT ONCE BEFORE!!
Once, back in 1996 at the San Francisco International Echinoderm Conference Dr. Steve Stancyk and C. Muir at the University of South Carolina and Dr. Toshihiko Fujita of the National Science Museum in Tokyo presented some fascinating data showing the very abundant deep-sea brittle star Ophiura sarsicapturing and then swarming over and DEVOURING fish and shrimp as they got too close to the abundant carpets of brittle stars on the deep-sea bottom!!! Here was my blog post about back in 2008!
I remember seeing the presentation of this talk at San Francisco State University. The room was Standing Room ONLY! EVERYONE had to see the famous video of the brittle stars capturing swimming prey!!
Since I wrote that introductory post in 2008 not only have I learned more about it-but we've now seen it ALIVE all over the Atlantic and the tropical Pacific thanks to the livestream videos of Okeanos Explorer!
Brief Introductory Details: Tremaster is a starfish in the family Asterinidae, that puts in the same family as "bat stars" and a bunch of other sea stars you probably recognize from shallow waters and home aquariums. Go read this account on this huge and diverse group, which I wrote a while back...
|image via Flickr by Ed Bierman|
Katie published this great paper on feeding biology and ecology of deep-sea asteroids collected off the coast of Canada in the North Atlantic in Deep-Sea Research in 2013. I blogged it up here.
During the course of Katie's research she collected a fair amount of cool "anecdotal data" which amounts to singular observations and some other stuff which furthers the "natural history observation" of a starfish about which we know very little! So her observations along with some further observations from the 2017 research legs of the NOAA Okeanos Explorer, some further homework on my part and voila!
Let us learn MORE about the weird starfish Tremaster mirabilis!
1. It eats coral (possibly)
Probably one of the BIGGEST questions I had for such a strange looking sea star! As we'll see, this species is seen quite a bit and yet one of the most immediate questions about it seemed elusive!
Fortunately Katie Gale was quite lucky and was able to capture and image of this specimen of T. mirabilis taken by the fine people who operate the Remotely Operated Vehicle ROPOS/DFO. Gale's paper cites this image showing our mysterious starfish feeding on CORAL!
Specifically the octocoral Acanthogorgia!
BUT we have THIS image taken on Whaley Seamount during Leg 3 of the Okeanos Explorer mission at 875m!
Could its location on the rock surface be because its near a yummy food source? Another coral predator to add into our understanding of deep-sea coral ecosystems???
2. Time lapse movement and??
This probably seems like a common sense thing-we KNOW starfish move albeit VERY slowly. and can actually show some behavioral complexity (here)
Katie nabbed some of this GREAT video showing this species moving around its aquarium and more importantly NOT attacking this sea anemone in the aquarium.
This is actually an important point because we know MOST starfish CAN move but they often don't.
So, ACTUALLY capturing it doing so gives us some insight into what they do when we aren't watching them..
If we sped the movement of this "constellation" of Tremaster mirabilis up, would we still see no movement? or is it a Times Square of Deep-Sea Starfishes???
It USED to be that everything we knew about this species was taken from museum specimens and indeed we are STILL dependent on samples from throughout the world for new records of where many species live.
There is some question about whether or not this one species "Tremaster mirabilis" is actually one species or possibly several 'cryptic' species disguised by the fact that all the individuals observed all appear to be the same.
The external characters vary only slightly and its not unusual for a widely occurring species to demonstrate some... variation throughout its range. However, when we examine dead museum specimens we are often missing data such as color and behavior which can be important. Especially when its range where it lives is at least THREE oceans!
Tremaster is a moderately occurring deep-sea species.. occurring roughly between 200 and 600 m
Thanks to submersibles such as Okeanos Explorer we now have VIDEO and ON SITE (in situ) observations of LIVING animals!
Tremaster mirabilis is supposed to be one species..but as you can see there is a SLIGHT difference in body form..
North & Central Atlantic:An image from Nygren Canyon (top) and the lower image from Puerto Rico. Note there's more of a "skirt" around the edge versus the Pacific ones.
Throughout the tropical Pacific
And interesting brick colored one from Pau Pau seamount
and this interesting lighter colored individual from Baker Island..
Another place where Tremaster shows up? Antarctica and nearby...
Also had a nice Tremaster mirabilis (the ‘orange peel star’, we joke on #AugSurvey) pic.twitter.com/Mw38CCmtjY— Claude Nozeres (@cnozeres) September 16, 2016
4. There are Jurassic Fossils
As if dealing with living animals weren't enough, these intriguing beasts show a CLEAR relationship to at least TWO Jurassic fossils!
Bear in mind that the Jurassic is quite a LONG time ago. These sea star were living in the world's oceans while dinosaurs roamed the Earth!
AND like its modern descendents-these were quite spread out. Antarctica versus Switzerland!
Here's Protremaster felli, from the Jurassic of Antarctica! Described by Andrew Smith and T. H. Tranter in Geology Magazine 1985
|Image from the Wikipedia file: https://commons.wikimedia.org/wiki/File:Mesotremaster_felli.jpg|
5. What does "Tremaster" actually mean? And"brood chambers"??
FINALLY! What does the genus "Tremaster" actually MEAN anyway?"aster" is obviously "star" but it turns out "Trema-" refers to "aperture" or OPENING!
When Addison Emery Verrill described this genus in 1880 he made allusion to these FIVE openings present in each interradius! These were one of the distinctive characters he used to diagnose his (then) new genus!! and "mirabilis" of course refers to "wonderful"
Here's a photo of the underside of a Tremaster specimen.. the openings are indicated by yellow circles!
So, as it turns out if you look more CLOSELY at these openings, they are actually OPENINGS into chambers present INSIDE and THROUGH the body wall and open up on the TOP:
Here are images of a dissected individual from the underside showing these openings (i.e. these are close ups of what's in the yellow circles above)
Thus, the openings appear to provide an opening for water to circulate into these chambers which could serve any number of purposes.. Possibly to aerate the "brood" chambers? Or perhaps they assist in the degree of arching the dome-like shape is capable of?? Filter feeding? Predation??
One of the great things about science is how it marches on! Its been 9 years (!!) since I wrote that first post and I LOVE that what in addition to what I've learned from reading, there has ALSO been genuine progress in learning NEW information on the biology of these animals.. And one of these days we will more FULLY understand it and its strange signficance!