Snails and slugs belong to one of the largest phyla of animals on the planet – the mollusks. Mollusks are known for their calcium carbonate shells and seashell collecting along the shoreline has been a popular hobby for centuries. There are an estimated 50,000 to 200,000 species of mollusk worldwide. One group – the gastropods – have an estimated 40,000 to 100,000 species alone. This is the group that includes the snails and slugs.
Snails are soft-bodied creatures who produce a single, usually coiled, shell in which they live. The coiled shell has an opening called the aperture through which they can extend some, or most of their body. The elongated soft body “slugs” across the sea bottom searching for food which could be vegetation for some – like the small nerite snails found in our bays, or animals – like the venomous cone snails, or detritivores – like the periwinkle snails.
The Olive Nerite. Photo: Wikipedia.
Many species of local snails produce egg cases in which they deposit their developing eggs. These are often found while people are beach combing. The most frequently encountered locally are the tube-shaped clusters of the oyster drill, the coin shaped chain of the lightning whelk, and the one that – to me – resembles the top of a vase or jar belonging to the moon snail.
The egg case of the Lightning Whelk. Photo: Project Noah
The variety of snails found in the northern Gulf is immense – so, we will cover only a few of the more common.
Walking along the Gulf side, gazing down at the shells of snails washed ashore, one often finds the small ceriths. These tiny, elongated shells are small and look like a canine tooth. These are herbivores and detritivores.
Cerith Photo: iNaturalist
The Florida Fighting Conch is often found – but not always in whole condition. This is a true conch and herbivorous.
Florida Fighting Conch Photo: iNaturalist
One not as common while beachcombing, but more common while snorkeling is the olive snail. These are fast burrowing snails that feed on bivalves and carrion they may find. I often find trails crisscrossing the sandy bottom made by these snails just off the beach.
Olive snail Photo: Flickr
Over on the bay side of the barrier islands you have a better chance of finding live snails. One of the more common in the salt marshes is the marsh periwinkle. This small roundish snail is often seen on the extended leaves of the marsh grasses. It is here during high tide to avoid predators such as blue crabs and diamondback terrapins. At low tide they will descend to the muddy bottom and feed on detritus.
The marsh periwinkle is one of the more common mollusk found in our salt marsh. Photo: Rick O’Connor
The crown conch is another frequently seen estuarine snail. With spines extending from the top whorl – it appears to have a crown, and where its common name comes from. These are predators of the bay feeding on other mollusks such as periwinkles and oysters.
The white spines along the whorl give this snail its common name – crown conch. Photo: Rick O’Connor
The oyster drill shell is one of the more common shells you find hermit crabs in, but the snails are out there as well. As the name implies, they use a tooth like structure called a radula to bore into other mollusk shells to feed. They are particularly problematic for non-moving oysters – and where they got their common name from.
The shell of the oyster drill. Photo: Rick O’Connor
The only slug I have encountered on our beaches is the sea hare. These slugs can be a greenish or brownish color and are about six inches in length. They lack an external shell but do not move much faster than their snail cousins. They feed on a variety of seaweeds and the color of their skin mimics the seaweeds they are feeding on. Lacking a shell, they produce a toxin in their skin to repel would be predators. They also release ink like the squid and octopus cousins.
A common sea slug found along panhandle beaches – the sea hare.
This narrative only scratches the surface of the world of snails and slugs in this part of the world. Creating a check list of species and then seeing if you can find them all is great fun.
Lionfish slayers, divers, fisherfolks, and ocean lovers joined for an exhilarating 2025 lionfish tournament and awareness festival last weekend at Harborwalk in Destin, Florida.
The Emerald Coast Open is the largest lionfish tournament in the world. Lionfish are venomous marine fishes native to the South Pacific and Indian Oceans, or the Indo-Pacific region. Lionfish found along the southeastern United States coast, including the Emerald Coast of Florida, are not native. Lionfish are considered invasive species in the southeastern United States. With few natural predators and an ability to outcompete native species, lionfish can cause damaging impacts to native fishes, crustaceans, and the oceanic ecosystem overall.
The Emerald Coast Open and numerous partners, including Florida Sea Grant, support the lionfish tournament as an effort to reduce the number of lionfish along the Emerald Coast while educating and having fun. Amazing Emerald Coast volunteers (there were 35 this year) processed the lionfish—counting, weighing, and measuring. The lionfish are sold to buyers like restaurant owners who make delicious lionfish dishes, additionally spreading education about lionfish and lionfish as a yummy food source.
This year was a HUGE success! There were 7,180 lionfish brough in by 143 participants during the pre-tournament and an additional 13,322 lionfish during the main tournament. This means there was a total of 20,502 lionfish were removed from our local waters during the 2025 Emerald Coast Open!
Emerald Coast Open award categories included: most lionfish, biggest lionfish, smallest lionfish, guess the lionfish contest total, and restaurant week. Winners received $65,000 in cash prizes along with participant raffle for amazing prizes worth over $60,000. Winners for each category are listed here and on the Emerald Coast Open’s website and Facebook page.
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Most Lionfish
1st– DWM1- 2038 lionfish
2nd– Reef Madness- 1256 lionfish
3rd – Shark Quest- 1034 lionfish
4th – Sea Meat- 1029 lionfish
5th – Rubber Duck- 965 lionfish
6th – Covered in Blood- 909 lionfish
7th – In the Clouds- 817 lionfish
8th– DWM Spinal Tap- 695 lionfish
9th– Zookeeper Slayers- 477 lionfish
10th-Black Flag- 457 lionfish
Largest Lionfish
1st– In the Clouds- 17.2 inches
2nd– All Riled Up- 17.1 inches
3rd – Off the Deep End- 16.9 inches
4th – Pilot Plunder and Pillage- 16.7 inches
5th – Fin Reapers- 16.6 inches
6th – Hookshott- 16.5 inches
7th – Down N Out- 16.4 inches
8th– Opted Out- 16.3 inches
9th– Tie- Covered in Blood- 16.2 inches
10th-Tie- Rum Fish- 16.2 inches
Smallest Lionfish
1st– Looking Back- 2.87 inches
2nd– Todd’s Team- 3.11 inches
3rd – Tie- In the Clouds- 3.14 inches
4th – Tie- Blue Bucket- 3.14 inches
5th – All Riled Up- 3.38 inches
6th – DWM1- 3.54 inches
7th – Smokediver- 3.62 inches
8th– Shark Quest- 3.66 inches
9th– Tie- Zookeeper Slayers- 3.74 inches
10th-Tie- Off the Deep End- 3.74 inches
Guess Lionfish Total
Carole Donaldson- Guessed 13,300, which was 22 less than the actual 13,322 total
As far as familiarity goes – everyone knows about worms. As far as seeing them – these are rarely, if ever seen by visitors to the northern Gulf. Most know worms as creatures that live beneath the sand – out of sight and doing what worms do. We imagine – scanning the landscape of the Gulf – millions of worms buried beneath the sediment. For some this may be quite unnerving. Worms are sometimes “gross” and associated with an unhealthy situation. You might say to your kids “don’t dig in the sand – you might get worms”. Or even “don’t drink the water – you might get worms”. But the reality of it all is that there are many kinds of worms in the northern Gulf, and many are very beneficial to the system. We will look at a few.
The common earthworm. Photo: University of Wisconsin Madison
Flatworms are the most primitive of the group. As the name implies, they are flat. There is a head end, often with small eyespots that can detect light, but the mouth is in the middle of the body and, like the jellyfish, is the only opening for eating and going to the restroom. There are numerous species of flatworms that crawl over the ocean floor feeding on decayed detritus, many are brightly colored to advertise the fact they are poisonous – or pretending to be poisonous. And then there are species that actually swim – undulating through the water in a pattern similar to what we do with our hand when we stick it out the window driving at high speed.
But there are parasitic flatworms as well. Worms such as the tapeworm and the flukes are more well known than the free-swimming flatworms just described. These are the worms people become concerned about when they hear “there are worms out there”. And yes – they do exist in the northern Gulf. But what some people may not realize is that these internal parasites are adapted for the internal environment of their selected host and cannot survive in other creatures. There are human tapeworms and flukes, but they are not found in the sands of the Gulf.
The human liver fluke. One of the trematode flatworms that are parasitic. Photo: University of Pennsylvania
As the name implies, roundworms are round – but they differ from earthworms in that their bodies are smooth and not segmented as earthworms are. One group of roundworms is well known in the agriculture and horticulture world – nematodes. Some nematodes are also known for being human parasites – again, creating some concern. These include the hookworm and pinworm. Roundworms can be found in the sediments by the thousands – sometimes in the millions. The abundance of some species are used as an indicator of the health of the system – the more of these particular type of roundworms, the more unhealthy the system – again, a cause of concern for some when they see any worm in the sand.
The round body of a microscopic nematode. Photo: University of Nebraska at Lincoln
We will end with the segmented worms – the annelids. This is the group in which the familiar earthworm belongs. Though earthworms do not exist in the northern Gulf, their cousins – the polychaetae worms – are very common. Polychaetas are much larger, easier to see, and differ from earthworms in that they have extended legs from each segment called parapodia. Some polychaetas produce tubes in which they live. They will extend their antenna out to collect food. Many of these tubeworms have their tubes beneath the sand and we only see them (rarely) when their tentacles are extended – or when they extend a gelatinous mass from their tubes to collect food. But there is a type of tubeworm – the sepurlid worms – that produce small skinny calcium carbonate tubes on the sides of rocks on rock jetties, pier pilings, and even marine debris left in the water. This is also the group that the leech belongs to. Though leeches are more associated with freshwater, there are marine leeches. These are rarely encountered and do not attach to humans as their freshwater cousins do.
Diopatra are segmented worms similar to earthworms who build tubes to live in. These tubes are often found washed up on the beach.
Though we may be “creeped-out” about the presence of worms in the northern Gulf of Mexico, they are none threatening to us and are an important member of the marine community cleaning decaying creatures and waste material from the environment. We know they are there, and glad they are there.
Striped burrfish are fascinating to watch in the wild and in aquariums. Photo credit: Carrie Stevenson, UF IFAS Extension
I have a vivid memory of snorkeling the seagrass beds around Port St. Joe when I was an undergraduate marine biology student. Our field research lab involved completing a visual fish survey, using waterproof dive slates and pencils to record the number and species of any fish that swam past us. I was conducting my survey fairly rigorously until a 6” long striped burrfish (Chilomycterus schoepfi) moved into my field of vision. It hovered in front of me, looking over with its gigantic puppy-like eyes, and proceeded to gently nibble on everything in sight. There are very few fish one might characterize as “cute,” but this charismatic little guy was adorable. Completely abandoning the task at hand, I stopped counting other fish and proceeded to slowly swim behind this little burrfish as it fed and swam throughout the grass bed. It was completely unfazed by my presence—I stopped to watch while it ate, then used my flippers to slowly navigate behind when it started moving again. I must have followed this fish for 30 minutes, simply observing its behavior. I could have sworn it looked back and me and signaled, “come on!” with a fin every time it moved to another location. I’ve snorkeled countless times since then, but bonding with this little fish was such a singular experience that I can visualize it clearly almost 30 years later.
A Southern puffer (left) and striped burrfish (right) in side-by-side comparison. Photo credit: Carrie Stevenson, UF IFAS Extension
Hence, I’ve always had a soft spot for the striped burrfish. We occasionally pull juveniles up in a seine when taking groups out in the field, and they often puff up in response to the shock of being temporarily captured. Frequently misidentified as their Tetradont relatives, the Southern puffer (Spheroides nephelus), the burrfish is similar in size and habitat. However, they are fairly easy to differentiate by their dorsal color patterns. As the name implies, striped burrfish have brown stripes, while puffers have more of a mottled pattern. Both species have bright white countershading on their bellies (aka “ventral” side), helping them blend in with the sky above when viewed from below by potential predators. They also utilize similar defense mechanisms, filling their bodies with air or water when threatened so they physically expand, appearing bigger and more difficult to fit into a larger fish’s mouth. Burrfish also have rigid spines that point out from their bodies when in self-defense mode. This adaptation makes them more complicated to digest for a would-be attacker. Many members of this Order of fishes produce a dangerous neurotoxin, further deterring predatory attacks.
Striped burrfish expand their bodies to twice normal size when threatened. Photo credit: NOAA
To the human observer, it’s anything but intimidating to see a fish transform into a ping pong ball with fins, but the strategy must work because there are around 120 species of puffers and porcupinefish in the Order Tetraodontiformes that use this technique.
As young burrfish mature, their front teeth fuse into a tough “beak,” which they use to break through the shells of their prey. As I experienced while snorkeling, burrfish are slow swimmers, using their wide terminal mouths and large jaws to nibble on shellfish, sea urchins, and barnacles. Their characteristic body shape is boxy, built not for speed but to cruise reefs and grassbeds. Armored with spikes, poison, and the element of surprise, striped burrfish can afford to take their time and relax in the water.
If green algae are difficult to find in the northern Gulf because most prefer freshwater, and rocky shorelines, brown are difficult because the group prefers colder water, as well as rocky shorelines – but we do have some here.
Brown algae get their color because the ratio of photosynthetic pigments in their cells favors the xanthophylls – which produces a yellow-brown color. Like most macroscopic algae, they attach to the hard bottom using a holdfast and then extend their stipe and blade into the water column to absorb light. One group of brown algae are the largest of all seaweeds, the giant kelp Macrocystis. In the nutrient rich waters off California this seaweed will grow up to one foot a day and can reach heights of up to 175 feet tall. Since seaweeds do not possess true stems, or any wood, what holds this giant seaweed up are air filled bladders called pneumatocysts – structures found on other brown algae and are unique to the group.
The largest, fastest growing seaweed – giant kelp. Photo: NOAA
Many species are popular with seafood dishes, such as Nori. Others produce a carbohydrate known as algin that is extracted and used as a food additive. You may have heard “ice cream has seaweed in it”. What it actually has is algin. This carbohydrate acts as a smoothing agent for products. Solids should be solid – like frozen ice cream – but, as you know, we do not want our ice cream solid. So, for a period of time, the algin keeps the ice cream smooth and creamy. Algin is used in toothpaste, lipstick, and icing on cakes for the same reason.
But along the northern Gulf coast, brown algae are not common. Despite preferring marine waters, they do prefer colder water and, like most seaweeds, need a hard substrate to attach their holdfast. But by exploring our local rock jetties and seawalls we do find some. One in particular is the common rock weed – Dictyota. This sessile seaweed branches out and resembles small trees. But the most common, and most recognized brown algae on our coast is Sargassum.
The brown algae Dictyota. Photo: NOAA
Sargassum has found a way to deal with an environment where little hard bottom is present. Using the characteristic air bladders allows it to float at the surface to absorb the much needed sunlight. Because of this ability to float, Sargassum can be found all across the oceans, and often form large mats that cover miles of open sea and extend several feet down. It actually creates a whole new ecosystem in the middle of the sea. The major ocean currents rotate like a hurricane and, like a hurricane, the center – the “eye” – is calm. Within this calm huge mats of Sargassum collect. The ancient sailors called the center of the Atlantic Ocean the “Sargasso Sea”. But as the large currents spin, sections of this large mat “spin off” and are pushed across the ocean. Much of it heads towards Florida, the Gulf, and eventually to the northern Gulf.
If you grab a mask and snorkel and swim within the Sargassum before it reaches the waves, you will encounter a whole community of creatures that live here. Sargassum crabs, Sargassum fish, and even seahorses live within it. There are shrimps, worms, and even mollusks. When baby sea turtles head offshore after hatching, many seek out these Sargassum mats to both hide in, and feed within. They will spend their youth here before returning back to shore for different prey.
However, once many of these creatures sense the waves breaking, and now the mat is about to wash ashore, they will move to mats further offshore. That said, picking through the Sargassum on the beach may still yield some interesting creatures.
Sargassum.
In recent years the amount of Sargassum washing ashore has increased and become problematic – particularly in southeast Florida and the Florida Keys. At times, mounds three feet high have been found. Those communities are working on methods to deal with the problem. But here locally, these mats are a new world to explore.
They say life began in the oceans. We know that the lithosphere is cracked, adding new land, subducting land over time. But much of the lithosphere is covered with water – and here life began. Initially it had to begin on either rock or sand. The sand would have been produced by the weathering and erosion of rock. Obviously, this would all have had to occur over a long period of time. But the first forms of life would have to be able to find food and nutrition from a barren seafloor with little to offer. This would take a special community of creatures – ones we call the pioneer community.
It is believed that life began in the ocean. Phot: Rick O’Connor
Key members of these communities would have been the producers’ ones who produce food. What we know now is that producers absorb carbon dioxide and water and – using the sun as a source of energy – convert this into carbohydrates and oxygen. We have since learned that there are ancient forms of bacteria that can do this with hydrogen sulfide and other compounds. However, it started – it began. One problem with this model is that much of the world’s oceans are too deep for sunlight to reach. Thus, living organisms would need to be close to shore. Today we know two things. One, the ocean’s surface is covered with microscopic plant-like creatures (phytoplankton) who can float and reach the sunlight. Two, some of the ancient chemosynthetic bacteria (those that do not need the sun and can use other compounds to produce carbohydrates) live on the ocean floor.
The black smokers – hydrothermal vents – found on the ocean floor. Photo: Woodshole Oceanographic Institute.
Producers are followed by consumers, creatures who cannot make their own food and must feed on either the producers or on other consumers. There are plankton feeding animals – oysters, sponges, corals, and zooplankton. There are larger creatures that feed on larger plankton – manta rays, menhaden, and whales. There are consumers who feed on the first order of consumers – stingrays, parrotfish, and pinfish. And there are the top predators – orcas, sharks, and tuna. The ocean is a giant food web of creatures feeding on creatures. All creatures evolve defenses to avoid predation. Predators evolve answers to these defenses. Some species survive for long periods of time like the horseshoe crabs and nautilus. Others cannot compete and go extinct.
Horseshoe crabs are one of the ancient creatures from our seas. Photo: Bob Pitts
As we mentioned in Part 1 of this series – the hydrosphere is in motion. Different temperatures, pressure, and the rotation of the planet move water all over. These currents bring food and nutrients, remove waste, and help disperse species across the seas. Life spreads to other locations. Some conditions are good – and life thrives. Others not so much – and only specialists can make it. The biodiversity of our oceans is an amazing. Coral reefs, mangrove forests, and seagrass beds are home to thousands of species all interacting with each other in some way. The polar regions are harsh – but many species have evolved to live here, and the diversity is surprising higher than most think. The bottom of the sea is basically unknown. It has been said we know more about the surface of the moon than we do at the bottom of our ocean. But we know there is a whole world going on down there. We believe the basic principles of life function there as they do at the surface – but maybe not!
The magical lights of the deep sea. Photo: NOAA
Fossil records suggest life here began almost one billion years ago. The fossils they find are of creatures similar and different from those inhabiting our ocean currently. As we stated that the physical planet is under constant change – life is as well. It is a system that has been working well for a very long time. Over the last few centuries humans have studied the physical and living oceans to better understand how these systems function. They have been functioning well for a very long time. And though life began at sea – there was dry land to exploit – for those who could make the trip. That will be next.
