Tuesday, December 17, 2013

The Ocean's Holiday Tree Ornaments! Stunning Scanning Electron Microscope Pictures of PLANKTON!

Radiolarians! A colored SEM image. Photo by John Cravens
Happy Holidays! Who loves a Christmas tree decoration? And has broken one in their lifetime?
Vintage Christmas ornaments
Well, in the real world, we get to see LIVING glass (or sometimes chalk) boxes that might pass for ornaments! But you need to shoot electrons at them to get something like a similar effect! Scanning Electron Microscopes are the gift that keeps on giving!

Here is a diatom called (appropriately) Skeletonema. This one occurs in Florida waters..Image by FWC-Fish & Wildlife Research Institute
Skeletonema (scanning electron micrograph)
Another FWC diatom fr. Florida called Odontella aurita. More on its biology here.
Odontella aurita (scanning electron micrograph)
The following are SEM images of foraminifera (shelled amoebas) taken by the National Museum of Wales..
foram shell
Tubulogenerina narghilella.
Image: Ian McMillan, Cardiff University.
foram shell
Another foraminifera: Halkyardia minima. Image by Ian McMillan, Cardiff University.
You know what people like?  COCCOLITHOPHORES!!  These are algae which have calcium carbonate (i.e. chalk) skeletons which under the surreal view of an SEM appear like this...
Coccolithophores  scanning electron microscope of Emiliania huxleyi coccospheres and loose coccoliths from a bloom in the South Atlantic.
Image by Sea Surface OA cruises.
Scanning electron microscope of Emiliania huxleyi: coccospheres and loose coccoliths from a bloom in the South Atlantic. 
Cretaceous coccolithophores!
Image by Jessica Matheson
Here's a nice conglomerate of Umbilicosphaera sibogae from the folks at Zeiss microscopy!

Happy Holidays! Echinoblog is off next week ! 
(thanks to Chris Taylor and Rhi L. for corrections!)

Tuesday, December 10, 2013

SAND ANGELS! Astropecten The starfish that dig it!

Astropecten articulatus, Stafford Beach, Cumberland Island National Seashore, Camden County, Georgia 1
Image by Alan Cressler
So, y'a know how people do this snow thing? SNOW ANGELS?  Drop yourself in some powder and go wild!
Well, la-dee-da! Starfish can do that TOO! Except, not in snow. not in the winter. Not on land.  In sand. in mostly tropical shallow to temperate waters. So there.

I am referring to the widely known "sand star" called Astropecten, which includes over 100 species present all over the world, in tropical to temperate waters.   Go here to see some awesome pics of Japanese Astropecten and related spp. Most occur in shallows but some live in deeper-waters.
Image by Kevin Bryant
Astropecten is often confused with Archaster typicus aka the "fake Astropecten" aka the "typical star" aka the "other sand star." Go here to see the difference. But one important difference? you will NEVER catch Astropecten pseudocopulating! Bfah!

Here's a nice image of Astropecten indicus from Singapore, illustrating the animal next to the star-shaped impression it makes in the sand.
Plain sand star (Astropecten indicus)
Image by Kok Sheng
Here is an excellent photo sequence of a species of Astropecten from Iran, showing a full range of sitting on the sand and burying itself.
Hiding Starfish
Image by Hamed Saber
Burial in Astropecten can be quite rapid. It accomplishes this via a combination of its pointed (rather than suckered) tube feet in conjunction with its many spines which are moveable and are used to help push itself into the sand. Astropecten is among the fastest of known starfish. 
Image below of an Astropecten from Singapore.
Orange sand star (Astropecten sp.)
Image by Wildsingapore. 
Pictures are nice. But why stop there?  Here's a quick 30 second video of Astropecten from Singapore burying itself and vanishing before your very eyes!
Which famous Simpsons gif meme does Astropecten remind you of?

This one is probably one of the best videos of Astropecten burying and reburying itself. A video from the Enoshima aquarium of A. polyacanthus

Although they dig, they are not, strictly speaking, infaunal. They live buried right under the surface of the sand...
Astropectinidae>Astropecten Sea star 39
image by Bill & Mark Bell
Where, they are often digging through the sediment trying to find goodies to eat, such as this clam. But really whatever they find, they will swallow and devour. Note that Astropecten and its relatives LACK an eversible stomach (that you might see in other starfish). So they literally can ONLY swallow their prey..   This image is fr. A. aurantiacus in the N. Atlantic somewhere..
Prédation Astropecten aurantiacus

As I mentioned, Astropecten occurs widely around the world. And is quite diverse.  Here is Astropecten articulatus from Georgia (south coast of the US)
Astropecten articulatus, Stafford Beach, Cumberland Island National Seashore, Camden County, Georgia 1
Image by Alan Cressler
Astropecten sp. from Singapore. Cool racing stripes! 
Painted sand star (Astropecten sp.)
Image by Wild Singapore
Here's a pic of Astropecten latespinosus from Japan
Image by Yoichi Kogure! 
The substrate/sediment type can vary also.. Some live in very fine sediments, such as this Italian Astropecten, possibly A. irregularis
Image by comunerimini
Astropecten aurantiacus in sandy sediment...
Star Fish/ Astropecten aurantiacus
Image by Archipelagos Institute of Marine Conservation
Whereas others live in fairly coarse, sandy type sediments.. such as this Astropecten bispinosus from Greece.
Image by sarsifa
Astropecten sp. Not sure where this was taken..I think the Mediterranean? But again, coarse sediment.
Sea star , Astropecten sp.
Image by Dimitrious Poursanidis
Astropecten sp.
Image by Dimitrious Poursanidis
What's that you say? You wanted to see more fabulous video of Astropecten from around the world burying themselves in sand? YOU GOT IT.


Wednesday, December 4, 2013

Where do those starfishes & Sand dollars on Holiday decorations come from?

Wonderful Image by Krystle D
December Greetings! As we get into the holiday and Christmas season, I always get certain questions which pop up around this time of year, asked by the public. One of the common ones I receive around now is (paraphrased) 
"Where do those starfish and sand dollars on holiday decorations come from?" Usually followed by "Are they alive?" and etc... 

So, let me take a trek through several recurring photos of holiday decorations and show you species by species how they compare. 

I have written before on where these decorations come from. A prior overview on starfish here.  A prior account on sea urchins (and sand dollars) here. 

A general rule about echinoderms used in decorations: WHAT YOU SEE ARE NOT SHELLS, THEY ARE MUMMIES (dried endoskeletons). 
Xmas in the 21st century: Death with Santa hat in Leipzig
Image by Werner Wittersheim
A bit of a refresher on basic echinoderm anatomy. All of the distinctive features one sees in echinoderms- spines, tubercles, the various shapes and etc. are covered by epidermis, in other words, SKIN.

So, yes, in order to get one of the starfish dried and made into a wreath? It has to be killed. (that's one of the questions I get about these by the way...)

So unlike say, shells which are secreted outside or independently of the animal's body, echinoderms have an internal support that is analogous to the skeleton in vertebrates. Their tissue is actually infused into this skeleton. 

I've said this before many times. Here and here.  I've always found the whole concept of putting echinoderms onto holiday decor as kind of macabre unless you're that guy who puts dead, dried frogs on your Christmas tree, which is perfectly fine....

1. "Knobby Starfish" Holiday Wreath
This is one, I've been seeing around is adorned with large, "Knobby Starfish"
These are Protoreaster nodosus, a species which occurs in the Philippines, Singapore, and all throughout the North-Central tropical Pacific.
Knobbly sea star (Protoreaster nodosus)
Image by Ria Tan (Wild Singapore)
Estrella de mar de xocolata: Protoreaster nodosus
Image by Pau Estrada
Protoreaster nodosus is an abundant and easily encountered species where it occurs. It is harvested in several places for tourist and gift making decor. A whole industry is oriented around fixing (ie treating with formalin), drying and exporting dried starfishes. I've briefly discussed this here and here

dried starfish
So, there is a fishery of this species, even if people don't eat them. There has been some ongoing work to determine if the species is sustainable (such as this paper by Bos et al.2008).  I'm not sure the results are encouraging. 

2. Pisaster ochraceus & the "Coastal Wreath"(thanks to Gail for the tip!)
Thanks to the wonders of the Internet and directed marketing, I clicked on the link to this item ONCE. And it now shows  up on ALL of my social media and other shopping pages...

The picture actually shows up on several different gift and other sites, which I'll decline to name. But two species are observered here. the starfish is Pisaster ochraceus aka the Ochre Star from the Pacific NW coast and the sand dollar Mellita (prob. Mellita quinquiesperforata ).

Its not unusual for Pisaster to turn up dressed up as any number of awful, tacky holiday decorations

Here again, is a pic of the animal alive to remind you of the contrast...
Ochre star (Pisaster ochraceus)
Image by TVN
Ochre Seastars (Pisaster ochraceus) Feb 19, 2012. Patrick's Point SP., Humboldt Co., CA (1)
Image by RJAdams55
So, the ochre star, the ecologically important keystone predator, which feeds on mussels and so forth. This species, among several others, is currently under attack from starfish wasting disease
Image from Iamheretokelp
So, perhaps it is NOT the best species to be turning into garish Christmas and holiday ornaments, eh??

3. "Starfish Wreath" from Linckia laeviagata.

A starfish tree? really?

Linckia laevigata aka the "Blue Linckia"(although it does occur in other colors) is one of the most heavily fished sea star species in the tropical Indo-Pacific.

Blue Starfish
This species is "fished" for both holiday trinkets AND the aquarium trade and is probably NOT a good sustainable species for those industries...
Linckia laevigata a, Phi Phi Kho Bida Nok, 100217 (jp)

3. Archaster typicus
This treats the two specimens at the top of the "wreath".. these are another species which is widely occuring the tropical Pacific.
This species is seen frequently in the Philippines and in Singapore. Wild Singapore has a nice summary of its biology here  Images below from Wild Singapore..
Common sea star (Archaster typicus)

Common sea star (Archaster typicus)

4. Sand Dollars: Mellita spp. 

Mellita spp. are from the tropical Atlantic coast, the Gulf of Mexico, Florida, etc. in shallow water.
Sand dollars are sea urchins! And here's more on that.   Those holes in the body (ie. the skeleton also known as the test) are called lunules  and they are pretty nifty.

Another commonly encountered species in holiday decorations. Sand dollars, especially these species have the most "benefit of the doubt" because its not unusual to encounter their dead skeletons as beach wash.

Although one has to wonder how much collecting one needs to have enough to create a regularly marketable wreath such as the ones I've been seeing marketed on the Internet...

I'm pretty damn amazed at just how WIDESPREAD these get via the tourist industry. I've literally seen these sand dollars shipped across the country and across the WORLD for sale at tourist shops.

Here is what they look like with all the original spination and such...
kbh ca
kbh cz
and we even got video!

5. Echinometrid? "Sea urchin tree"?

Maybe Echinometra from Australia?  Not sure. Like sea urchins, the tests can be gotten as beachwash.. but not regularly. So, I'm thinking these were likely harvested...

Image from NOAA photo library
The websites for "urchin trees" and such were running these items for anywhere between 70 to 150.00.  But cripes! 150 dollars for sea urchin tree???

So to recap:
1. Starfish decorations are mummified remains of living animals, which had to be killed in order to get you a holiday wreath. I wouldn't lick them.
2. Many of the species used in these industries from the tropical Pacific are probably not sustainable fisheries.
3. Personally, I just think decorating starfishes like Santa Claus is tacky. So, please. just stop. Use sea shells or give people candy. People like candy.
4. Sand dollars are okay. Still possible to kill them for use as decorations. But also possible that they were collected beachwash.
5. Good grief. Who pays 150 dollars for holiday decorations made from beachwash??? or mummified starfish remains??? You know what's good for 150 dollars? chocolate.Send to the Echinoblog. Or charity. charity is good.