New Species of Sea Stars from the North Pacific and BEYOND!

This week I announce a NEW paper in the latest issue of the journal ZOOTAXA describing a new genus and THREE new species of deep-sea starfishes! Vol. 4175 (2): 101-141 

You may recall back in 2009 when I accompanied the Monterey Bay Aquarium Research Institute (MBARI) on a 10 day cruise exploring the North Pacific on the Juan de Fuca and Gorda Mid Ocean Ridges off the Oregon coast. Here was the cruise website.  I blogged about it here.

When we returned from the expedition I was VERY excited because we had collected MANY specimens and several were either new records of rarely seen species or outright NEW species!

I would like to give a big shout out to MBARI because almost EVERY thing they send me turns out to be a NEW species!  Here's a new coral-devouring star I named after MBARI geologist Dave Clague  and here was a poraniid starfish that was observed climbing up a black coral (antipatharian) to devour it

One of my favorite undiscovered starfish was this one, Paulasterias macclaini which I had to describe a whole FAMILY and genus in order to accommodate it!  This species was named for Dr. Craig Macclain, at Deep-Sea News, who had invited me on the cruise.

I wrote about it here.  But he was VERY happy to write up something about it on Deep-Sea News! (here)  

Well, describing that 6 rayed star took quite a bit of effort but there were many, MANY more species to understand!!!

We also collected many of the more 'non-descript' stars that we encountered as well as several others which turned out to be UNDESCRIBED species!! 

And YES its literally taken me almost 6 YEARS to get all of this done. As I've discussed before (here), it can sometimes take quite awhile for a species to be formally described.

 One report made the case it takes an average of 21 YEARS for a specimen to go from collection to publication! (I've summarized it here)

The starfish I reported on in my Zootaxa paper are members of the Goniasteridae, the most diverse family of sea stars, which includes over 260 species in 65 genera!  Most goniasterids live in relatively deep-water (continental shelf and deeper) but historically, there haven't been many of them known from abyssal and lower bathyal (i.e., >1000 meter) depths.

Only recently have we been seeing better collections of these animals from these depths. As I've reported below, some were collected from below 4000 meters!

Sibogaster nieseni! 
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!).

It is named for one of my former advisors from San Francisco State University: Professor Tom Niesen (now emeritus)! Author of the Marine Biology Coloring book and noted intertidal naturalist/ecologist along the California coast! 

He gave me my first shot at grad school and happily, his advice and instincts correctly guided me through my early years as a Masters degree student!

photo by J. Sharei

It seemed VERY appropriate to name this species, from off central California, after someone who has done so much to educate others about the significance of the invertebrates of the coast!! 

Interestingly, as I was in the process of writing it up, I suddenly became aware of multiple specimens of similar individuals from OTHER oceans in museums where I was NOT expecting to see them!

This one for example, turned out to be almost identical to the Pacific one I was working on but was from the tropical ATLANTIC! and even one from the deeps of Indonesia... 

Also, unusual is how, such a moderately big animal (about 4 to 5 inches in diameter) could have gone undescribed for so long?  But given how deep it was found (2100 to 4175 meters !) its been well "hidden"! 

This species is likely the deepest member of the Goniasteridae known.

and like several other abyssal species, such as the deep-sea sea cucumber Psychropotes, occurs widely, sometimes in multiple oceans

Ceramaster pointsurae! 

This was a tiny little species that I think we collected as part of something else.. perhaps sampling sediment or some other part of the physical environment.

BUT it turns out that it is likely a new and distinct species with some resemblance to the shallow-water species of Ceramaster (aka the cookie stars) in shallow waters..

This species was found during my 2009 trip on the President Jackson Seamont at about 1975 meters! 

This species is named for the Moss Landing Marine Laboratories retired vessel, the Point Sur which was finally retired in 2014. 

I spent many a day sorting deep-sea invertebrates on the deck of the Point Sur and I was saddened to hear about its retirement.

Bathyceramaster careyi! New genus and NEW species! 

Figuring this one out required a bit of detective work, as it turns out...

Several years ago when I was working as a technician for the California Academy of Sciences, I had the pleasure of studying a newly deposited collection of deep-sea starfishes from Oregon State University.

It turned out, that one of the species in the collection was a rarely known species called "Mediaster elegans" collected by oceanographer Drew Carey. To the best of the knowledge of the workers at the time, it was thought that this was a new occurrence, since the original specimens were only known from South America (collected in 1905). 

But as it turns out, after comparing Carey's specimens with the newly collected material by MBARI AND the original type series (i.e., the specimens on which the species was based) it turned out there were actually TWO species present, "Mediaster elegans" (original name) AND this one!  And the one seen by Carey in 1972 was actually undescribed! So, what I'd argue was actually "Mediaster elegans" turns has not actually been seen until now...

and not only that, it had to be placed into a new GENUS in order to be correctly described! 

Boom! NEW genus described! New SPECIES described!

This species was ultimately found to occur throughout the North Pacific between 1700 and 3363 meter depths! 

With this one, named for Dr. Andrew Carey, formerly of Oregon State University! 

The gut contents described by Carey's paper in 1972 suggests that this species feeds on deep-sea sponges.

The paper outlines several goniasterids from the North Pacific at depths below 1000 meters, including several which have not been seen since their description. 

Now that the new genus Bathyceramaster has been described, I can also follow up with a note I made on one of the recent Okeanos dives to Wake Island! 

This white goniasterid we saw at about 2000 m MIGHT be Bathyceramaster, but I'd need to more closely examine the surface to be sure. But if the closeups of the surface texture were correct.. I think maybe??

New discoveries that lead to new questions!! 

What are they eating down there? How do they get so big? Why do some of these species always seem to be alone when you see them? 

My thanks to the Monterey Bay Aquarium Research Institute, the California Academy of Sciences'  Department of Invertebrate Zoology and the Museum national d'Historie naturelle in Paris! 

Gorgeous Closeups of Australian Starfishes!

Greetings! This week, I thought I would share some GREAT closeups of the textures and plates on some sea stars from one of my favorite places in the world-AUSTRALIA! 

If you would like to see more of photo essays like this I've done one here and another one here about the oral plates on sea stars and this more recent one on Acanthaster planci, the crown of thorns! 

These were all taken from images on Flickr, and so the original photographers can be found merely by rolling over the image itself. What's great about them, is that the images were taken from LIVING animals, and so their colors remain vibrant! Nothing here is photoshopped.

Contributions herein by photographers:  Bill, Tony Brown, Beth Heap, Leander, Richard Ling,  Lox Pix, Morley Mason, Andrew Newton, Matt Nimbs, Valguille and especially SASpotato! 

An asterinid, Patiriella I think?

Here is a close up of the papulae or gills on Plectaster decanus 

The rest of the animal looks like this. Gorgeous.

Some goniasterid beauties! Pentagonaster dubeni

Lovely plate architecture on Tosia australis

From above, these are the surface plates of the goniasterid genus Nectria

and here's what the rest of the goniasterid Nectria looks like!

image by Peter Southwood, via https://en.wikipedia.org/wiki/Goniasteridae#/media/File:Nectria_ocellata_P2133340.JPG

A stunning yellow one!

The very distinctive button like plates on Asterodiscides sp. 

and from the same animal, the large penultimate marginal plates, which are distinctive of the genus.

Some nice spination from what looks to be Coscinasterias

Uniophora granifera! One of my favorites!

Paris 2015: The Starfish Mouth in Abstract

                          

Bonjour and Greetings! My apologies for missing a post last week! I am currently on a research visit at the world famous Museum national d'Histoire naturelle in Paris! Between jet lag and getting my work set up, things got away from me!                                                                                     

This week, A collection of starfish mouths! Echinoderm anatomy often fascinates people. The symmetry is one reason, but also the very intricate architecture and unusual textures. 

 I've done a prior post similar to this with tropical shallow water starfish here. 

Here is a collection of close ups and abstracts from echinoderms in the Tokyo Museum.

Here's an assortment of mouths & mouthparts from the collections of sea stars in Paris! I see the adaptations for survival in these structures.

Spines serve a protective function in many species but are also part of how the animal feeds. The full range of how these structures function is not clear. In contrast, other mouths are surrounded by granules or plates presenting a somewhat different interpretation.

but certainly.. these might even evoke more artistic interpretations from others!

Euretaster, a tropical slime star. Spines galore!

From Luidia, a multi-rayed sand star

From the Antarctic Odontaster.. note the big "teeth" on each plate. These are thought to function in sponge predation.

Protective mouth plates on Lithosoma

On a tropical oreasterid

On the sand star, Astropecten

 On a "cushion star" Peltaster placenta

From the tropical cushion star Culcita novaeguineae

A deep-sea mud star, Plutonaster

 Deep sea goniasterid, Nymphaster

 A deep-water oreasterid! 

Goniasterid Starfish LOVE to eat Octocorals!

Okeanos Explorer has begun Leg 4 into the Northern Hawaiian Islands and their last stream on Sunday was chock full of amazing vistas full of deep-sea (about 400-500 m) sea pens and corals! 

Probably one of the most exciting parts of these cruises is that I'm able to actually watch my favorite starfish species, some of which I described, in ACTION! Feeding on what turns out is their favorite food: octocorals!!

I've documented sea stars feeding on octocorals from the Atlantic Okeanos expeditions before (here).  and many of the species are the same.

Sea pens are big fleshy octocoral colonies that look sort of like an aquatic "quill" or pen. Here's one called Ptilosarcus, which occurs in shallow water from about SCUBA depth. 

Octocorals are specific type of cnidarian, which have eight arms on each polyp. They have a whole diversity of body forms and can be more colonial, such as this gorgonian or more like a big fleshy stick like the sea pens seen above..

The majority of the sea stars that we have observed feeding on octocorals are in the family Goniasteridae. As a generality, they look like this.

                                    

A big peripheral ring of plates frames their body. They can be anything from completely pentagonal to more star shaped. Many are covered by spines whereas others are not..

Among the best known of shallow-water goniasterid octocoral predators is the so called "spiny star" aka Hippasteria phrygiana (aka Hippasteria spinosa, etc.), which used to be known by MANY species before being recognized as one wide-spread species which occurs in three oceans! (here). 

This species occurs at SCUBA depth (and deeper) and many, involved studies have documented how these animals are important parts of ecosystems due to their predation on sea pens.

Thus, it makes a lot of sense that several of the deeper water species of Hippasteria, such as this Hippasteria imperials seen by the Okeanos Explorer should be a fairly active predator on deep-sea sea pens! 

Disks are swollen with water...

Here is just a gorgeous shot showing a seemingly endless vista of sea pens with these two large, Hippasteria imperialis roaming around like they own the place! 

BUT, Hippasteria imperialis isn't the only goniasterid starfish which feeds on octocorals. Many of its relatives, both close and far are also pretty active predators on deep-sea octocorals..

This big guy is Hippasteria muscipula! A species I just described last year! (here) It would seem to occur over a pretty wide depth range..from several hundreds to several THOUSANDS of meters!

They seem to be primarily predators on bamboo "corals" which are octocorals in the family Isididae.

and there was THIS stunning image showing H. muscipula but with 3 polynoid worms crawling around on its body surface. This is unusual, since polynoid worms usually crawl on the oral surface in the tube foot grooves..

Another closely related Hippasteria-like sea star which we've seen in the Hawaii region is the genus Evoplosoma.  

We've seen plenty of examples of Evoplosoma feeding in the Atlantic as well as parts of the Pacific. 

This shot is just awesome. We can see its stomach and tube feet hard at work clearing off the meat from the bamboo coral's stalk..

BUT that's not all! We've encountered multiple goniasterid species apparently feeding on coral! 

1. Astroceramus eldredgei

This was a new species I described recently and named in honor of Dr. Lu Eldredge formerly of the Bishop Museum. Observations by the Hawaiian Undersea Research Laboratory showed this very handsome animal munching on the blue plexaurid octocoral Astromuricea theophilasi.

Its a relatively shallow water animal (about 266-429 meters) compared to some of the other goniasterids here... None known below 500 m.

2. Calliaster pedicellaris

This species was described by Walter K. Fisher in 1906 and VERY rarely seen since then. 

3. Circeaster pullus

Here's another species I described back in 2006 and named in honor of Dr. Craig Young at the Oregon Institute of Marine Biology. It was observed perched on this coral skeleton where it was presumably feeding..

Have not seen any of these on the Okeanos dives as yet though.

4. Circeaster arandae? 

This one was a surprise because it very much looks like a species I described in 2006 from Madagascar!!  But it lives in deep, DEEP water (>1000 m) which is consistent with my earlier account. But weird to find it so far off..

How many more octocoral predators will we see??