Did you know that there were two different DOSINIA shells that wash up from the Gulf Of Mexico on to the shores of Sanibel, Captiva and Southwest Florida? In my last post, I showed you so much BEACH BLING that washed up after high west winds and teased you with two DOSINIAS as well. It’s pretty common to see DISK DOSINIA (Dosinia discus) seashells on our beaches but it’s very difficult to tell them apart from their sister and more elusive shell… the ELEGANT DOSINIA (Dosinia elegant).
To identify most bivalve shells, it’s easier to look at their interior since the biggest differences show on the inside around the hinges and also where the MOLLUSK itself connected to the shell. But… just like the outside shape, color and thickness- the interior is so similar too on these shells that it’s still so hard to tell them apart.
The easiest way for me to distinguish the differences of the DISK DOSINIA from the ELEGANT DOSINIA is by looking closely at the outside grooves on the shell. The DISK is on the left and the ELEGANT is on the right of all of my photos. Now it’s a little easier to see a difference, right?
Notice how fine the grooves are on the left shell (DISK) compared to the coarse grooves of the shell on the right (ELEGANT). If you rub your thumb nail along the out side of each shell you can definitely tell the difference .
I know you can’t run your thumb over these shells I showed you in the photos but I hope I showed you enough detail so that you could identify each one in person. But let’s just see if you can still spot the differences in CYBERSHELLING! YAY! Okay, here goes…. How many ELEGANT DOSINIAS can you find in this next photo?
Hopefully, now you will be able to pick up a DOSINIA and impress your friends and family by telling them which type of DOSINIA you just found. (heehee)
Thanks so much for this article! I will certainly be pulling my Dosinias out to rub their grooves!
Nice post! I could see three of the elegant dosinias in your group shot, but I did not have the patience to examine the image methodically, so there may be more. :)
I would say in my experience that the elegant is usually a lot less abundant than the disk. They are both beautiful shells though.
On the elegant, up near the hinge line at the anterior end, you can see (especially on the interior view) that the shell margin sort of curves “up” a little bit, in a way that does not occur on the disk dosinia. It makes the valve look a little more cheerful — like it is smiling. :)
Thank You for this. I never have been able to clearly understand the difference but your explanation helped tremendously!
I think I found 5–but I kept losing track of where I was! :-)
Pam, you see the universe in a grain of sand, and beauty and grace in a snail. You find wonder in the subtle differences in Nature. I thank you for every cheerful word you write, and for a 5-minute vacation almost every day. I could not imagine that I would ever find one of your cherished carrier shells. How do I find something that looks like a melted DQ ice cream cone, I wondered. In chilly windy January I found two carriers, and under my zoom camera lens I discovered that one carrier had a tiny perfect pair of pink kittens paws. Without you I would never have thought to look for the universe in that squashed ice cream! Thank you!
Gina, Gina, Gina…. How I LOVE your comments. I always feel so honored when you write such beautiful (and fun!) words about my posts. Im so thrilled for you that you found TWO melted DQs!… with cool sprinkles. LOL too cute, girl!
So, back to the subtle differences in Nature in general, and in dosinias in specific. I got out my bucket of dosinias last night, and with Professor Pam’s lesson at the ready, I rubbed their ridges, fingered their ruffles, considered their weight and thickness, examined them under magnification, and looked for smiley faces in their umbos. My considered opinion is, and I think that I’m with MurexKen on this one, … they are “clams” and belong in spaghetti sauce, ’cause these puppies all look the same to me…
However, thank you for your reference about the Arrow Dwarf Triton being related to the nutmeg. It took me months of research to identify my triton, which I finally found on Dr Leal’s laminated sheet from the Shell Museum; but without your nutmeg comment, I would never have looked for the hatched texture of the shell. HA! Another happy moment of discovery.
So I failed Dosinias 101, but scored on my Arrow.
LOL u r too cute! I betcha u don’t have any elegant dosinias…. That’s why u can’t tell the difference. I bet u only have disk dosinias. This was the first time I was able to clearly identify them- they just aren’t as common. No worries, if u can find a melted DQ u will find an elegAnt one day. :) :)
I love these ‘educational’ articles! More, please. An article about the differences in the various drills and the Ribbed Cantharus would be much appreciated. Thanks for all your work on this blog!
I count 5 too. Pam, you’ll have to let us know the answer after everyone comments.
Thank you for the great info.
Susan, I noticed that little up-turn on the inside too. I’m glad you confirmed that it is not just my imagination. :)
I still think that the Disc (which I have called Elegant for so long) is the more elegant of the two. But, still, happy to now have it correct. Thanks again for the continuing education classes…I know that you award certificates of completion to your grateful students.
Now Pam we will all have our “groove thing going on”!!!!!!!!!!!!! : )
Pam, excellent post. Dare I say groovy or maybe even elegant? Unfortunately, some of the Dosinia shells seem to have groove densities between the two extremes. Apparently, they have not read the shell ID books.
Hahahah GROOVY!!!!
The grooves of the dosinia always remind me of the those in a music record. Definitely groovy!
I took many of these home the last time I was there. They make great wind chimes.
Thanks once again for new info about my favorite hobby- shelling! I can’t pass up a dosinia and now I’m challenged to see the differences. I still dream of finding the tiny angel wings in the peat at low tide on Cayo Costa with you – so precious! We are getting another blizzard in Iowa tomorrow – enough!!
Corly, I loved that day on Cayo costa too!
Thank you for the info. I love those shells!
BTW…I am packing my bags tonight for a quick trip to Sanibel. I’ll be there Friday afternoon and will be shelling through Wednesday morning. It will be a nice break from snowy Cleveland. Hope to bump into you.
I’ll be shelling mostly around the lighthouse area.
Thanks for oinfo RE: WRACK – is this what we call “sea lettuce” . makes a mess on the beach and have to wade out to go swimming. And yes you have to look at the “Mess” that sits on beach at low tide, you really find some goodies.
Janet/AZ
Hi, Pam. Thanks for your posts that are both entertaining and educational! The reader comments are always so positive and often helpful, too.
Took a short walk on the beach in Galveston yesterday, and picked up four *Dosinia* shells as souvenirs of our visit. Wanting to write the species name, I thought it best not to rely on my memory of the name and ID from decades ago, and your post helped show that 3 were *Dosinia discus* and 1 *Dosinia elegans*! Thanks!
Note: I’m guessing your original post was sabotaged by autocorrect for the less familiar species, which is *Dosinia elegans* (as opposed to *Dosinia elegant*.