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). 

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.

Image by Ria Tan (Wild Singapore)

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

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...

Image by TVN

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.

I wrote up a bit more on this species here. 

This species is "fished" for both holiday trinkets AND the aquarium trade and is probably NOT a good sustainable species for those industries...

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..

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...

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. 

The Sea Urchin Flame Wars of Theodor Mortensen!

Today, as they said on TV, a special "echinological" episode! Something a little offbeat...

I focus on a giant in the historical echinoderm literature-one Professor Ole Theodor Mortensen (1868-1952) who was at the Zoological Museum of Denmark.

Its not an understatement to say that Mortensen was a HUGE name in echinoderm biology. He published on every group and on multiple aspects-classification, larval biology and the list goes on...

Probably his most incredible achievement though was that he wrote this huge series of 15 HUGE books that established THE classification of sea urchins . Go here to read more about them.. 

But, all genius comes with a certain...eccentricity.

Mortensen could be a harsh critic and towards the twilight years he began to rather strongly express his dissatisfaction with the work of his fellow colleagues!

Some of the opinions stated are OUT IN THE OPEN and published in a book that he probably realized would persist for hundreds of years.

I found all of these quotes in just ONE volume (albeit the last one) of Mortensen's famous sea urchin monograph published in 1951... but much of his work spans several decades.

Some Background on Taxonomic Synonymy
To give you readers a bit of background MOST of these discussions are about what's called taxonomic synonymy.  You can read a full account here. 

Basically, this is when extra names are produced for the same species owing to
1.  Ignorance or mistakes (i.e., new "species"named without checking the literature to verify that the species name did not already exist)
2. Incorrect species assessments (the author may have seen a damaged specimen or simply had a species description that did not account for all the details)

Either way- the oldest name has priority over all the others. Its often the work of a dedicated taxonomists or systematist (such as myself or Theodor Mortensen) to make certain that there are NO "extra" names out there. And of course, that we as scientists, do not produce unecessary names cluttering up the place!

So, yes-a perfect profession for you very order-obsessed types!

The Wit of Theodor Mortensen!

To put you in his mindset (and to be fair to him) remember that he'd been working on these books for DECADES.  And this was after MANY years of having to deal with the various crazy "legalese" of taxonomic synonymy and nomenclature.

He often seemed particularly exasperated (a frustration I know well!) when his colleagues simply did not exercise the care or effort to publish their species names correctly.

I should also mention that for scientists-statements like this are VERY unusual..especially when you put them into, not just a journal, but a book....


Some of the most colorful comments were about his colleague-paleontologist Jules Lambert...

pg. 579-he starts with kind words..

I am exceedingly indebted to that work, as well as to many other works of Thiery and especially Lambert, works so full of learning about the fossil Echinoids. Without, especially the Essai de nomenclature raisonnee it would have been impossible for me to get an anyway adequate knowledge of the immense number of the fossil Echinoids.  

But then cuts loose!

But the way in which, particularly Lambert treats the nomenclature, arbitrarily adopting old, impossible names instead of names otherwise unanimously used in the whole echinological literature and thus changing the old good names and interchanging them-like the names Echinocyamus and Fibularia- or using them in quite a new meaning like e.g., Spatangus or Schizaster, and then impertinently, as a dictator, changing the names of the recent forms, about which he knows next to nothing, can only be characterized as a crime to science. 

Authors on recent Echinoids have in general neglected Lambert's nomenclatural changes, whereas his paleontological colleagues generally followed him through thick and thin. Alone Fourtau (Fortau was another researcher) ventured sometimes to defy the tyranny of Lambert. (!)

On the next page (pg. 580), we are treated to his opinions regarding Hubert Lyman Clark, a widely published  researcher at the Harvard Museum of Comparative Zoology

Image from the Smithsonian Archives.

In this connection it may be mentioned that H. L. Clark sometimes undertook quite absurd changes of names, as e.g., the name Echinocyamus pusillus changed into Echinocyamus minutus on the base of a very dubitable old text....

Mortensen frequently took HL Clark to task...here is a bit from pg. 37-38 (some details omitted for the sake of getting-to-the-point)

Apparently Clark did not take the trouble of reading Leske's description of his Spatangus ovatus...... It is also an offense...... to think that he could draw the very characteristic test of Maretia planulata so badly....on the whole, this Spatangus ovatus, badly figured and described, and without locality deserves only to be left entirely out of consideration as not recognizable. But Clark deserves to be seriously  blamed for having so inconsiderately inroduced such change of a common, otherwise universally used name.

Mortensen (pg. 85) was often sarcastic... (on a rival colleague's observation of behavior in a sea biscuit type irregular urchin)

Another observation by MacBride , Op. cit is that he has seen a young specimen climbing up the vertical walls of an aquarium as do regular sea-urchins; he sees herein proof that it must be a descendant from some Regular Echinoid. Well, yes, of course--What else could be the origin of the Irregular Echinoids!

But probably one of the most interesting "conversations" was Mortensen summarizing his differences  with noted marine biologist Alexander Agassiz.  At first, he is effusive with praise!!

A great step forwards in our knowledge of Echinoids was made by the grand work "Revision of the Echini" by A. Agassiz (1872-74). With immense learning and energy he cleand up the older literature on the recent Echini, examining the specimens in the various collections in the world. This work will remain classical, the foundation of the study of the recent Echini; and most of the photographic illustrations are simply perfect, nothing like it having ever been published. 

But then there is a turn in his opinion...

But much worse I found his second great work, the report on the Challenger Echinoidea (1881)..... going into a critical study of the work I could not help finding it--I cannot help saying it--a bad piece of work, not at all worthy the author of the "Revision of the Echini"...

Strong words! But not without repurcussions..

In my first larger work, the report on the Echinoidea of the Danish Ingolf Expedition I. 1904, I gave--rather unrestrictedly I admit--vent to my criticism especially of the Challenger Echinoidea, which resulted in a furious attack on me in Agassiz's next work, the "Panamic Deep Sea Echini", even accusing me of "gratuitous misrepresentation of facts" (Op. cit. pg. 25)..  I replied to Agassiz's criticism and proved its injustice, particularly the alleged misrepresenation of facts, which was of course, not at all justified, there being no misrepresentation at all....

Amazingly..there is more and much of it is spread throughout Mortensen's work.. His opinions and comments are a fun little "easter egg" that sometimes pop up when going through his monographs and published papers.

So there you have it! The old-fashioned version of Flame wars, easter eggs and the ultimate fan boy commentary.. on sea urchin papers!

Sand Dollars ARE Sea Urchins. Please make a note of it!

photo by Cheryl Moorehead

So, last week, I was contacted by an intrepid member of the public who was quite interested in finding out more about sand dollars.. But apparently, the curiosity of this fellow had been stymied by the internet!

GASP! Who would have thought that there could be a lot of questionable and apparently, conflicting information on the Internet!!!

A lot of info on these animals may be somewhat basic to the well-travelled marine biologist, but maybe not so much to the curious or intrigued student or aspiring beach scholar! So, I thought today I would explain some basic sand dollars "stuff" and clarify some of the mystery.

FIRST-some basic introductions........

So, everyone is at least passingly familiar with sand dollars.

Those funny "dollar shaped shells" that one often finds walking along a beach down by the sea shore. How often have you seen this familiar sight?

photo by Jdigeronimo66

So, let's clarify this first- and foremost.

Sand dollars are the skeletons from ANIMALS.

Specifically, they are Echinoderms, which is the group that includes starfish, sea cucumbers, crinoids, and of course... sea urchins.

When sand dollars are alive, they are covered with a "fuzz" and look like this..

photo by Cheryl Moorehead

But following a little erosion and/or natural "cleaning" of the "fuzz" what you get is the internal skeleton:

photo by Cheryl Moorehead

And what you are seeing? is an INTERNAL skeleton (aka an endoskeleton) This even includes the spines (i.e., the "fuzz") because ultimately all of that (body skeleton+fuzz) is covered by a thin layer of skin or epidermis.

The "fuzz" are actually the SPINES on a very strange looking sea urchin!

Sand dollars are ANIMALS, specifically they are sea urchins! (Class Echinoidea) 

Sand dollars belong to a group known as the Clypeasteroida. There are some 75 genera of sand dollars, 29 living and 49 fossil (following Mooi 1989) with quite a few species.

Most sand dollars live in tropical shallow-water places (e.g., Africa, Singapore, Indonesia, the Bahamas, etc) but a few do live in cold to temperate waters (e.g., Dendraster excentricus on the west coast of North America)

Sand dollars are NOT shells. Proper shells are deposited by organisms (such as mollusks) and are external to an animal's body.

And while we're discussing this, please note that sand dollars have ENDOSKELETONS rather than exoskeletons. That is to say, they are covered by skin and are considered "inside" the animal's body. A Sand dollar skeleton is known as a TEST.

So What makes a sand dollar a sea urchin??
Typically, we think of conventional sea urchins as looking kind of like this...

A big sized, ROUND ball covered by spines. These sea urchins often graze on algae an live out in the open on reefs or kelp beds. Often in large numbers.

These have historically been referred to as "Regular" urchins. They have long, well-developed Spines and well-developed teeth as part of a elaborate jaw called Aristotle's Lantern. You can see all of these features in this video...


Now, in CONTRAST....
Sand dollars are members of a specialized sub-group of sea urchins that are often referred to as the "Irregular Urchins" These urchins differ quite a bit from the so-called "Regular" urchins because they show a suite of adaptations to living in sandy/muddy/ bottoms!
In "irregular" sea urchins.. specifically sand dollars the following changes occur...

1. The body (i.e., the test) changes from round and radial (in regulars) to flat and bilateral (in irregulars) like this...

(photo by Electropod)

to something more like this, which you'll note has both a left and a right side..

(photo by Avian-Cetacean Press)

2. Spines in "regular" urchins are usually elongate and pointed. But those in "irregular urchins" (esp. sand dollars) are short and specially modified to help in moving sediment..like so...

Here's what a single spine looks like under SEM close up. Not pointed but with a more blunt tip...

(this image is from Mooi, 1990 in Paleobiology!)

3. The special jaw apparatus "Aristotle's Lantern" is modified!

In a "regular" sea urchin, the Aristotle's Lantern or Jaw (seen here from the inside with the rest of the body removed) is used to feed on algae and its positioned as such..

Here's a neat video that shows the oral surface-and you can see the jaw's teeth in action emerging from the mouth

In contrast..here's the jaw (aka the Aristotle's Lantern) from a sand dollar. The top has been cut away and you can see it from the inside (mouth facing bottom). Its been modified into basically, a "crushing mill" for grinding up sand and so forth.

Here's a picture to show you more of what the "jaw" is like in other species.

The individual pieces of the jaw (aka the Aristotle's Lantern -which are often broken) is probably what you hear rattling around inside when you pick one up off the beach...

Plus, you'll often see it used in "inspirational" art and the famous "Legend of the Sand Dollar" postcards and related paraphenalia like this one...

The "doves of peace" are the broken fragments of the Aristotle's Lantern, i.e, the jaw the animal used to crush and grind sand. The "Star of Bethlehem" is a neatly dissected, complete jaw from the inside of the sand dollar.

5. The Body shape has changed as the body as evolved from that of a "regular" to an "irregular" urchin.

The above tree is used from Mooi, 1990 in Paleobiology!

The overall shape has seen a flattening out in the upper right part of the tree where we see sand dollars relative to their more globose relatives.

If you want to read an excellent paper on the evolution of sand dollars, I would suggest checking out this paper by Rich Mooi in Paleobiology. Its from 1990 but has many interesting bits!

Finally..

Here's a kind of loosey goosey summary diagram  by Echinoblog Art Dept!

So again..

The "Regular" urchin or ancestor:

1. Grazes on algae or other items. Many live out in the open. Several species live on reefs or on kelp beds.

2. Test (the body) is round, globose and pentameral (that is -radial in 5 directions)

3. Spines are elongate.

4. The Aristotle's Lantern is larger and generally, is used to graze off bottoms

BUT if you compare the SAME features in Sand dollars and other "Irregular" urchins...

1. Lives on sandy or other bottoms with lots of sediments or mud.

2. Test is often flattened, and bilaterally symmetrical

3. Spines are shorted and appear "fuzzy" on the surface

4. The Aristotle's Lantern is flattened and specialized for grinding sand.

Remember that the above differences are morphological ADAPTATIONS that are specifically tied to living and digging through the sandy, bottom habitat.

The spines and Aristotle's Lantern see clear modification for a specific lifestyle... In many ways, this is a beautiful example of how morphology has changed as adaptation to a specific life mode.

Sand dollars have many NEAT adaptations to living on sandy bottoms.

For example, this one and this one are used to keep it from getting washed away..

Brittle stars that live ON sand dollars..

Cloning in sand dollar larvae as a defense!

Sand dollars are basically, REALLY strange sea urchins! Please make a note of it!

Treasure! The Funky and Exotic Sea Urchins of Paris!

I am continuing my ongoing blogs from Paris for the next month or so, where I am working at the Museum national d'Histoire naturelle!
When one thinks of Paris, one envisions all sorts of exotic and wonderous experiences- postcards, people, exotic burlesque shows, and food...
From the perspective of a biologist, the museum in Paris is EQUALLY exotic!

Why? Because the Paris museum (the French equivalent to the Smithsonian's National Museum of Natural History) receives MANY specimens from exotic, deep-sea locales around the world.

Because I don't typically get access to many of these specimens, I thought I would share some choice samples from the collections with all of you..

How exotic are these?

Well, to start-I'm not entirely certain that everything I'm showing you below has actually been described in the scientific literature... MANY new species await discovery in the French vaults..

Goniocidaris from deep-sea habitats in the tropical Indo-Pacific..

The most obvious feature here being the bizarrely shaped spines that look like big inverted umbrellas!

A second species of Goniocidaris (also from the deep-sea Indo-Pacific)

Instead of the large spines ending in big flattened horn-thing, these spines are lance-shaped and have a progression of smaller and smaller spines and flanges..

What do the unusual spine shapes do? How are they adaptive? Defensive? Reproductive?

I wrote a blog about a similar cidaroid sea urchin called Psychocidaris. (click here to see!)

Here's a big, deep-sea sea urchin the size of a pumpkin called Echinus melo!
Another large animal that we know practically nothing about...
And finally, we end with one of the more exotic sand dollars.. a genus called Rotula from the African coast in the tropical Atlantic..

Weird are the many strange flanges and holes! What do they do?

Well, in other sand dollars they deflect the hydrodynamic flow.. Go here to see this explanation!

and just for kicks..here's the bottom or ORAL SURFACE of one.. yes-even these weirdly shaped sand dollars have the tiny, "fur-like" spines covering them and with the channels that lead to the mouth...
More next week...as Echinoblog in Paris continues!