Purple Sea Snails a Curiosity on Florida Beaches

by BeachHunter on February 22, 2010

Lt. Gio Serrano, of Ft. Lauderdale Ocean Rescue sent me this photo of a purple sea snail found on the beach.

Lt. Gio Serrano, of Ft. Lauderdale Ocean Rescue sent me this photo of a purple sea snail (Janthina) found on the beach. Photo copyright Gio Serrano.

Eleven years of working on Fort Lauderdale Beach and Lt. Gio Serrano of Fort Lauderdale Ocean Rescue has never seen so many purple snails washing up on the beach. One has to wonder if the unusually cold and rainy El Nino winter has had a hand in this mass stranding.

Note that the snail seems to be blowing bubbles. Purple sea snails create a flotation raft out of these mucous bubbles so they can float along on the surface of the ocean, where they feed on and often hitch a ride on man-of-war jellyfish.

According to Dr. Blair Witherington in his book Florida’s Living Beaches, there are four species of purple sea snails that may be found on Florida beaches:

  • Common purple sea snail (Janthina janthina)
  • Dwarf purple sea snail (Janthina globosa)
  • Pale purple sea snails (Janthina pallida)
  • Globe purple sea snails (Janthina prolongata)

Below are some photos of Purple sea snails sent to me from Fort Lauderdale beaches by Marianna Armata of Full Circle Graphic Design, a design and production coordination service.

This is a great photo showing the pale upper part of the purple sea snail's shell, along with the bubble float it secretes. The other object in the photo with the "berries" on it is a piece of Sargassum seaweed. Photo copyright Marianna Armata.

This is a great photo showing the pale upper part of the purple sea snail's shell, along with the bubble float it secretes. The other object in the photo with the "berries" on it is a piece of Sargassum seaweed. Photo copyright Marianna Armata.

Here's a good view of the dark violet under part of the purple sea snail's shell with the bubble-float still attached. Photo copyright Marianna Armata.

Here's a good view of the dark violet under part of the purple sea snail's shell with the bubble-float still attached. Photo copyright Marianna Armata.

This appears to be a bubble-float that has become separated from the Janthina snail that created it.

This appears to be a bubble-float that has become separated from the Janthina snail that created it. Photo copyright Marianna Armata.

I love this photo with the water in motion-blur and the Janthina in focus. Photo copyright Marianna Armata.

I love this photo with the water in motion-blur and the Janthina in focus. Photo copyright Marianna Armata.

I always appreciated it when my web site visitors take the time to send interesting photos like the ones in this blog post. You can see Marianna Armata’s design portfolio here.

{ 30 comments… read them below or add one }

1 jozien February 25, 2010 at 1:13 pm

what a beautiful snail, i did not know snails came in such a beautiful color.
Hi David, On the festival a month ago, you met my friend Mary. She send me over here :)

2 beachhunter February 25, 2010 at 3:15 pm

Hi Jozien, thanks for stopping by my blog and leaving your comments. If you want to see some really beautiful snails, you can look up “Florida tree snails” on Google. They come in all colors with stripes.

3 marge February 27, 2010 at 5:57 pm

beautiful pix! that last one is stunning. marge

4 beachhunter February 28, 2010 at 6:47 am

Thanks for stopping by Marge. Yes, the last one is definitely my favorite.

5 rob March 1, 2010 at 7:29 pm

Thanks! My 4-year-old had to find out interesting facts about three sea creatures, and one of them was the sea snail. This makes for an interesting fact about something happening close to home! (And the pictures are awesome).

6 beachhunter March 1, 2010 at 9:29 pm

Discovery is great fun, isn’t it? Glad my post on sea snails was useful. And thanks to Gio and Marianna for sending in the photos. Sharing knowledge and experiences makes life better for us all.

7 Tootie March 2, 2010 at 11:49 pm

Beautiful pictures! Very interesting post.

8 beachhunter March 3, 2010 at 12:36 am

Thanks Tootie!

9 jupiter beach walkers March 10, 2010 at 5:09 pm

my sister and I were walking on the beach today and found a purple sea snail. I tried to throw it back into the water, but it kept coming back on the surf! Would it survive in an aquarium? I am just so excited that we found this site….now we know what it is! Just beautiful and fascinating info. Thanks so much :-)

10 Barbara March 10, 2010 at 9:46 pm

I collected many of these shells this past weekend on Islamarado Island in the Keys. The locals state they haven’t seen them for over 20 years, but this year they have had 2 huge “washes” of them in the past month. Happy to have found this site.

11 beach walking girls March 11, 2010 at 9:16 am

Found one on the dog beach in Jupiter! Kept throwing it back in to try and save it, but it didn’t work, it kept getting washed back. What an amazing creature. Too bad I didn’t have a camera! Was wondering if they could survive in a seaquarium?

12 beachhunter March 11, 2010 at 12:55 pm

I think they would survive in an aquarium if you know what to feed them. They eat jellyfish like Man-o-war, by-the-wind sailors, and probably blue buttons. Not sure where you’d get those or if they’d eat anything else. Thanks for leaving a comment and letting us know where they are being washed ashore. Very interesting.

13 Sharon March 18, 2010 at 11:59 pm

Hi!

Thank you SO MUCH for this post! While I am not in Florida (I am in Hawaii) I came across these snails today while at the beach with my daughters. At first I thought they were some kind of hybrid Portuguese Man-o-War…am happy to find out that they are snails! Amazing. I took a couple of pictures….not the greatest but would be happy to send them to you.

Am I wrong to assume that these snails are completely harmless?

Thanks again!

14 beachhunter March 20, 2010 at 3:17 pm

As far as I know the janthina snails are completely harmless. They actually feed on the Portuguese Man-o-war jellyfish. If you’d like to send a couple of photos, I’ll add them to this post. Thanks!

15 Bill Marcus April 3, 2010 at 11:42 am

Found several of them yesterday morning along the beach at Boca Raton Florida. They must have been feeding on Man of Wars which also had blown ashore in good supply. Very informative website. Thank you

16 Jim Birdsall April 3, 2010 at 9:36 pm

I found several of these interesting snails (dark purple) on the beach in Juno Beach, FL today. They came in with a lot of grass from the Gulf of Mexico, so I’m guessing that’s where they hang out. Where does the purple color come from ??? Maybe from the Men of War ? they hang out with… but where does their purple color come from – some very concentrated iodine, maybe… the dark purple “ink” that came out of the snails did not irritate my hands at all, although I didn’t get any in any sensitive areas.

17 Jim Birdsall April 3, 2010 at 9:41 pm

PS – I put them in a small container of ocean water, and they just float around, and look very weird. I think they would do OK in an aquarium, they probably would eat just about anything floating on the surface… I also have several pics, and can take more, if anyone’s interested…

18 beachhunter April 3, 2010 at 10:40 pm

Hi Jim,

Since Juno Beach is on the Atlantic Ocean, I think you meant to reference the Ocean rather than the Gulf of Mexico. Janthina snails are pelagic, which means they live in the open ocean. The larvae are free swimming, but the adults make bubble rafts and float at the surface where they feed on jellyfish. They are strongly associated with Velella velella [By-the-wind-sailor].

Floating organisms of all kinds tend to get caught up in weed lines and they blow ashore together.

The ink they secret appears to have been used in ancient times as writing ink and as a fabric dye.

If you’d like to send some pics, I’ll gladly add them to this post.

Thanks so much for taking the time to add to the discussion!

19 Linda Cassidy April 4, 2010 at 6:36 pm

Both my husband And I have lived in Florida since 1980 & have picked up many Variety’s of Shells on the Fla East Coast. Today April 4.2010 We Picked up a half Dozen of these Purple Sea Snails. They are very delicate. And were Found at Waveland Beach in Saint Lucie County Florida. We are Curious if they are a result of the recent Earth Quake activity Off of San Juan, P.R. Or El Nino, or both.

20 Eileen April 5, 2010 at 1:51 pm

My husband and I found a bunch of these on Boynton Beach on Easter morning. We’ve only been here for three years, but we’ve spent a lot of time on the beach and in the shallower waters collecting shells and haven’t ever seen these. There were just a ton of the By-the-wind-sailors and man’0 wars washing up and it looked like the snails washed right up with them. Unfortunately, they were pretty dead (and way smelly) by the time we got to them, so we cleaned them out and will enjoy the shells anyway.

21 Krista Morgan May 19, 2010 at 10:17 pm

Saturday evening, May 15, 2010, several of these snails washed ashore at Ft. Pickens, near Pensacola Beach, Gulf of Mexico. They were alive, spewing purple ink, bubble rafts inflated! I put them in a bottle of seawater and the beautiful little snails extended their grape-bubble-gum-colored heads. I tried to pitch them back without much luck. :( We have had an unusual (for here) amount of Man O’ War, By-the-winds, as well as truckloads of gossamer “barbs” from the Sea Butterfly. Those wonderful winds keeping the oil away from us have brought many strange visitors to our sugar sand beaches. Today we had literally hundreds of large brown rays that appeared to be migrating east along the shore.

22 Carolyn July 25, 2010 at 9:25 pm

In all of my years of beachcombing, I have never found a purple sea snail. Would anyone be willing to send me one? I must have been at the wrong place at the wrong time, because I have collected shells on the middle Atlantic coast, Sanibel, Abaco, BVI, and Galveston and South Padre Island. I can’t even find a shop that sells them. I think I may have missed my best chance on South Padre Island. There were many Portuguese Man o’War, but I didn’t know to look for the snails then. I am so envious of all the lucky people who’ve seen them.

23 Samantha October 20, 2010 at 6:18 am

I was walking the beach by chinamans hat in oahu hawaii yesterday with my family when i came across these sea snails they are so beautiful. Also there were lots of the baby manowar jellyfish wahsing on shore along with them. It was the first time i have ever seen either creature.

24 Lila November 27, 2010 at 2:57 pm

I found three of them just today. it is the first time in my life i see that kind of snail on beach. I found them on a Greek beach. The animal was still inside. I took it off and my fingers became purple. The dye stayed on my fingers for hours.

25 Richard February 3, 2011 at 1:37 pm

How or what is required to collect the dye from the
Janthina Janthina?

26 Miss Pam February 9, 2011 at 2:46 pm

I just had a student in my room who was showing me shells for a project they are doing in class. It looks like a volute family gastropod but very thin and dark brown to black in color. I know this is not a Florida species and I am wondering if it didn’t hitch a ride with the Man-o-wars that are coming onto the beach in herds. Any idea what it might be? I can include a picture of it later in another email
Let me know.
Thanks

27 beachhunter February 9, 2011 at 3:02 pm

Miss Pam, sure, send a photo to beachhunter[at]beachhunter[dot]net. Nothing immediately comes to mind as far as an ID. Although I do wonder if the shell might be old enough to have obtained its dark coloration from mineralization.

28 Janthina January 10, 2012 at 6:32 pm

Thank you for the pictures. I don’t live near a beach do you know where I can buy a Janthina Shell. Janthina is my name.

29 beachhunter January 15, 2012 at 11:21 pm

Hi Janthina. Sorry, I don’t have any idea where you could purchase a janthina shell. There must be web sites where shell collectors could be prevailed upon to give up one from their collection. Especially to a namesake.

30 Tracy October 28, 2012 at 5:30 pm

Thank you for posting this. The one in the Lietenant’s hand literally looks like a polished amesthyst! Gorgeous! If these are sturdy enough to wear as a necklace, a pendant made from a shell would look stunning on an amethyst necklace.

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