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The Living Sea Shells: a Photo Gallery of Sanibel Island Seashore Creatures

This winter, Cristina and I spent a crazy week at the beach in Sanibel Island, Florida. An unusual combination of events, including a huge offshore storm and a red tide, caused millions of creatures, both alive and dead, to wash up on the beach. It was unlike anything I had ever seen.

Seashells of Sanibel
Millions of creatures, living and dead, washed up on the beach on Sanibel Island. These are the seashells of Sanibel

It allowed me, for the first time, to meet the living creatures behind all of Sanibel’s beautiful seashells. Did you ever wonder what lives in seashells?

During the week, we developed a Guide to Ethical Sea Shell Collecting, and after witnessing the many functions that discarded sea shells serve in the environment, we concluded that the most environmentally-friendly shell collection of all would be to collect them with my camera.

Here is my virtual shell collection, a photo gallery of some of the many beautiful sea creatures and living shells we found on Sanibel Island, Florida. Enjoy!

If you’re a shell collector, you might also enjoy our article, How to Tell if a Sand Dollar, Starfish, Egg Case, Urchin, or Sea Shell is Alive or Dead.

*This article may contain affiliate links. We receive a small commission at no extra cost to you.*

Where to Stay in Sanibel

Before you go looking for the sea shells of Sanibel you need a place to stay!  We stayed for a week at the beautiful Sanibel Moorings. The apartment was excellent and the resort has a private beach access. Click here to check current prices and availability.

If you want something more like a private colorful cottage on the beach, with lots of Florida vibes, then look no further than Castaways Cottages. Ask for a cottage right on the beach or at the marina and make your dreams come true! Click here to check current prices and availability.

You can also find lots of vacation rentals in Sanibel.

Photo Gallery of Living Sea Shells of Sanibel

Long tide pools formed in the sand and strange little animals were going about their business as if they were still on the bottom of the ocean. Here are some of the “living sea shells” of Sanibel I encountered.

The Baby’s Ear shell is a popular shell with collectors. But the living animal is even more interesting. Unlike most mollusks, the living creature is so fat that it can’t pull all the way back into its shell!

living Baby's Ear sea shells, Sanibel Island, Florida
Two live Baby’s Ear shells in a tide pool.

Another favorite with collectors is the humongous Horse Conch shell. These are the largest mollusks (and shells) that your are likely to find on Sanibel.

live Horse Conchs on Sanibel Island, Florida
A pair of gigantic living Horse Conchs, the largest mollusk you’re likely to find in Sanibel.

The body of a horse conch is a brilliant red-orange when alive.

A live horse conch on the beach on Sanibel Island, Florida
A live Horse Conch has a beautiful bright red-orange color

Many mollusks that live in spiral shells have what is called an “operculum” which is a hard flat piece of shell-like material attached to the bottom of the foot and is used as a little door to close themselves inside. You can see the Horse Conch’s operculum in the first photo above and it is especially visible on this large living Lightning Whelk below.

The Lightning Whelk is the only left-handed spiral shell you are ever likely to find in Florida.  How to determine if a shell is left-handed or right-handed? Hold the shell with the spire pointing upward and the canal pointing downward (as in the photo below). Then imagine you are going to curl your hand into the opening. Which hand would you use? In this case, it is the left hand, making the Lightning Whelk a left-handed shell. If you ever find a left-handed shell that is not a lightning whelk, then you have discovered a truly rare oddity!

living Lightning Whelk sea shell, Sanibel Island, Florida
a live Lightning Whelk with the operculum tightly closed.

Here’s another cool shell with a a tiny little operculum tightly shut. It’s called an Apple Murex.

Live Apple Murex with operculum on Sanibel Island, Florida
You can tell this Apple Murex shell is alive because the operculum (the tiny “door”) is tightly blocking the opening.

The Sharks Eye shell is another popular seashell with collectors. The living animal can inflate the size of its body using water and deflate it again to fit back inside the shell. It is a serious predator and eats many other kinds of mollusks.

a live shark's eye shell on Sanibel Island, Florida
A live Shark’s Eye shell

The Lettered Olive shell appears very glossy when its alive because the mantle extends around the shell. The markings on the shell are supposed to look like hand lettering.

a living Lettered Olive shell on Sanibel Florida
A live Lettered Olive (Oliva sayana) shell

One of the most beautiful living creatures I discovered was a True Tulip. The body of the living animal looks like a dark starry sky.

a live True Tulip shell, Sanibel Florida
The living animal in a True Tulip shell looks like a sky full of stars.

Here is another live tulip called a Banded Tulip, leaving a cool track as it moves across the sand.

live Banded Tulip shell trail, Sanibel, Florida
A living Banded Tulip shell moving across the sand.

Finding an empty Spiny Jewel Box shell is pretty rare but it’s even more unusual to find a live one like this.

Living Spiny Jewel Box shell washed up on the beach in Sanibel Island, Florida
A live Spiny Jewel Box waiting for the tide.

Probably the most active living shells I encountered were Figs. Almost every living Fig I saw in the shallow tide pools was twisting and stretching and displaying its fascinating anatomy. Here are couple of the more interesting poses I captured.

living Figs sea shell, Sanibel Florida
a beautiful live Fig displaying its fascinating anatomy, including the head and eye spot.

And this one was the craziest of all. As best I can tell, this Fig is a male because he is displaying his large penis!

the penis of a gastropod, displaying the anatomy of a Common Fig shell, Sanibel, Florida
The anatomy of a male Common Fig (Aka Paper Fig) shell displaying the penis

There were hundreds of huge living Cockle Shells opening and closing in the shallow water of the tide pools and siphoning food from the water.

Sipon tubes of Van Hyning's Cockle, Sanibel Florida
A live Van Hyning’s Cockle showing siphon tubes, filtering plankton from the water.
A living cockle shell opening its shell in a tide pool, Sanibel Florida
A live cockle opening its shell among dead pen shells.

There were also lots and lots of huge fan-shaped Pen Shells washed up on the beach and I even managed to find a couple of live ones.

Live Stiff Pen shell with foot extended, Sanibel Florida
A live Pen Shell extending its foot in a shallow pool.

Dead Pen Shells are used by many other species of shells to anchor upon. One of the most interesting is the Slipper Shell.

A stack of living Slipper Shells on Sanibel Island, Florida
Live Slipper Shells stacking up on top of a dead Pen Shell

Slipper Shells pile on top of each other for mating purposes. Males stack up on top of a female and reach downward to fertilize her. But the most amazing part is that Slipper Shells can change sex. When the female at the bottom dies, the next male up will transform into a female!

Below is a stack of Slipper Shells on top of a living Ponderous Ark. The black fuzzy-looking stuff is part of the Ark’s outer layer of shell called the “periostracum”.

A live Ponderous Ark shell with a stack of Slipper Shells on it, Sanibel Island, Florida
Living Slipper Shells stacked on top of a living Ponderous Ark shell.

But my favorite living shell of all was the Florida Fighting Conch. If you’re still having a hard time feeling a connection to these little mollusks, just look into the eyes of this Florida Fighting Conch as she waits for the tide to rise so she can return to the sea.

the face and eyes of a Florida Fighting Conch, a marine snail in its shell on the beaches of Sanibel Florida
Looking into the eyes of a Florida Fighting Conch in Sanibel.

 Crabs on Sanibel Island

My favorite crabs on Sanibel were the hermit crabs. We saw dozens of them, occupying spiral shells of all sizes, from tiny to gigantic. Hermit crabs require ever larger shells to move into as they grow, which is the main reason we recommend you don’t take too many spiral shells from the beach in our Guide to Ethical Shell Collecting.

This hermit crab lives in a fig shell.

Hermit crab in a fig shell on the beach, Sanibel Island, Florida
A hermit crab peeks out of a Fig shell that any collector would be proud to have.

Here’s a different species of hermit crab living in a Florida Cone Shell, although the shell looks a bit too big for this little guy.

A Florida Cone Shell with a hermit crab inside, Sanibel Island, Florida
Hermit crab in a Florida Cone Shell

Here’s a hermit searching desperately for the right-sized shell shell to move into.

a live hermit crab outside of its shell on Sanibel Island, Florida
A hermit crab in a tide pool searching for a new shell to move into!

And I found this gigantic hermit crab dead on the beach. He probably couldn’t find a big enough shell to move into. Just another reason not to take all the big horse conch shells.

giant red hermit crab that died outside of its shell . Washed up on beach in Sanibel, Florida
Giant red hermit crab with no shell that we found dead on the beach in Sanibel.

There was a wide array of other crabs on the beach as well. I spotted this beautiful calico crab in a tide pool.

a living Calico Crab on Sanibel Island, Florida
live Calico Crab in a tide pool on the beach.

Along with a bunch of different crab species washed up dead.

a dead Stone Crab washed on Sanibel Island, Florida
A dead Stone Crab
Dead Spider Crab covered with barnacles on Sanibel Island, Florida
a dead Spider Crab with huge barnacles on it.
beautiful red and green crab on Sanibel Island Florida
Unidentified crab, but very pretty!

This last crab is not technically a crab at all. The Horseshoe Crab. It is actually more closely related to arachnids. When I first found it, it was lying on its back and slow waving its many legs in the air. It may have been flipped over by a wave.

bottom side of a horseshoe crab, Sanibel Island, Florida
Upside down horseshoe crab

I carefully turned it over and watched it make its way back into the ocean.

Horseshoe crab on the beach in Sanibel Island, Florida
Horseshoe Crab making its way back to the ocean

The right way to turn over a horseshoe crab is to flip it over from the side, not by the tail. The tail is used in navigation and is their only means of attempting to flip themselves over so it’s best to not risk injuring it!

Other Cool Seashore Creatures Found on Sanibel Island

There were dozens of other species, both alive and dead, covering the beach. Here are just a few of the fascinating seashore creatures I discovered.

This is a Nine-Armed Sea Star that I found upside down on the beach. You can see it is in the process of regenerating one of its missing arms.

nine armed starfish regrowing a limb
Nine-armed sea star (starfish) regenerating an arm

There were a bunch of other sea star species but my favorites were the beautiful little Brittle Sea Stars I found.

banded brittle sea star, Sanibel Island, Florida
Brittle Sea Star
pink Brittle Sea Star starfish next to red algae, Sanibel Island, Florida
a beautiful pink Brittle Star next to some red algae

Here’s a crazy photo of the arm of sea star that had been bitten off to reveal some of the inner starfish anatomy, the digestive glands and the ampulla that inflate the tube feet.

starfish anatomy ampulla and digestive glands, sanibel island, florida
Sea star anatomy showing digestive glands and ampulla

Here’s an amazing Mantis Shrimp that I found alive in a tide pool and returned to the ocean.

A living Mantis Shrimp on Sanibel Island, Florida
A live Mantis Shrimp on Sanibel Island

Even the worms were cool. This is a tube worm that uses bits of shell to create a protective tube around itself.

marine tube worm casing found on the beach in Sanibel Island, Florida
Tube worm on Sanibel

This one is known as a Peanut Worm. The first has its proboscis out and the second Peanut Worm has its proboscis in.

Peanut worm with proboscis on Sanibel Island, Florida
Peanut worm with proboscis out
A live peanut worm with proboscis in, Sanibel Island, Florida
Peanut worm with proboscis in.

Some other cool creepy crawly critters included huge Sea Cucumbers…

A big sea cucumber on Sanibel Island, Florida
A huge Sea Cucumber in a tide pool on Sanibel.

these weird orange blobs known as Sea Pork…

sea pork, sanibel island, florida
Sea Pork on the beach in Sanibel

Sea Pork is actually a colony of tiny animals called tunicates.

There were beautiful pieces of red whip coral known as “Sea Whips”.

red Sea Whip coral on Sanibel Island, Florida
a red “Sea Whip”, whip coral

thousands of beautiful urchin shells…

How to tell if sea urchins are alive or dead
Colorful dead sea urchins, Sanibel Island, Florida, USA

(By the way, we got so many requests for this crazy photo of sea urchin shells that you can now buy this sea urchin print on Fine Art America! Big canvas prints look especially nice!)

various anemones…

Sea Anemone on Sanibel Island, Florida
an unanchored sea anemone in a tide pool on Sanibel

living sand dollars…

living sand dollar on Sanibel Island, Florida
a live Sand Dollar burrowing in the sand on Sanibel

and my big prize was this bizarre creature which, as best I can tell, is some kind of bristle worm or fire worm. It was foraging through the tide pools and moved gracefully and delicately.

live Fireworm on Sanibel Island, Florida
a beautiful fireworm/bristle worm scavenging in a tide pool on Sanibel Island.

It was bit sad to see the thousands of fish that were killed by the red tide (more correctly termed a harmful algal bloom) and washed up on the beach. But it did allow me to see a few strange species that I haven’t managed to identify.

Dead box fish killed by red tide on Sanibel Island, Florida
A box fish washed up on Sanibel
weird fish with big mouth and little feet killed by red tide on Sanibel Island, Florida
a weird little fish I’ve never seen before killed by the thousands by red tide on Sanibel

And this fish, the weirdest of all, appeared to be some kind of eel.

scary eels washed up from red tide on Sanibel Island Florida
several of these scary-looking eels washed up after a red tide on Sanibel
scary eel with sharp teeth washed up on Sanibel Island, Florida
closeup of the creepy eel washed up on Sanibel Island

All in all, it was a fascinating and educational week in Sanibel and I highly recommend a visit. I hope you enjoyed my virtual shell collection!


If you want to learn more about shelling on Sanibel Island, please check out our Guide to Ethical Shell Collecting.

Do Whale Sharks Have Teeth?

Are Sharks Mammals or Fish?

Enjoy the photo gallery? Pin this image!

The living shells of Sanibel Island, photo gallery. A virtual shell collection
living shells of Sanibel Island, photo gallery
Hal Brindley at the Antarctic Circle

Hal Brindley

Brindley is an American conservation biologist, wildlife photographer, filmmaker, writer, and illustrator living in Asheville, NC. He studied black-footed cats in Namibia for his master’s research, has traveled to all seven continents, and loves native plant gardening. See more of his work at Travel for Wildlife, Truly Wild, Our Wild Yard, & Naturalist Studio.


Tuesday 6th of April 2021

On vacation in FL right now and was blown away by all the shells in the beach. So I was surfing the internet and came across this. Very cool! I learned a lot here! Thank you for what you do!!


Friday 13th of September 2019

Wonderful and informative photo gallery. Great source for the drawings and paintings I want to do of the living mollusks within their shells. Watch the grammar though. When you abbreviate something like "It is best to flip it from its side, not the tail..." the proper abbreviation for "it is" is "it's," not "its." The contraction "its" is for the possessive form of "it." Very informative commentary anyway. Thank you for your photos and comments.


Monday 22nd of July 2019

Those pretty looking sea urchins are purple sea urchins


Monday 30th of April 2018

I very much enjoyed reading your article except why be biased and say 'evil' eel at the end instead of using the correct name like any other sea creature on this article. I enjoyed looking at the pictures otherwise.

Hal Brindley

Monday 30th of April 2018

Hi Lauren, you make a valid point. I should have said "scary-looking" because, you have to admit, it would make an awesome monster in a really scary movie. I assure you I don't think eels are evil (or any animal for that matter) and I definitely don't want to bias any other readers into thinking that so I'll change it. However, I'm willing to bet you are actually biased TOWARD eels because you have "moray" in your email address, so do you happen to know what species this is? Because I can't find it anywhere! Thanks for reading, -Hal


Sunday 29th of April 2018

I love this site and the beautiful pictures you have taken. You have done a fantastic job partraying the beauty of nature in Sanibel!

Hal Brindley

Sunday 29th of April 2018

Thanks Carrie, so glad you enjoyed it! -Hal