Critters of the Mangrove Tunnels and Mudflats
Critters of the SW Florida Mangrove Tunnels and Mudflats
Estuaries are where rivers and water from land meet the sea, and these vibrant places are packed full of life- in fact, 80% of seafood begins its life in these shallow protected waters. In Rookery Bay, and Southwest Florida in general, estuaries are a maze of mangrove trees whose roots hang in the water to provide shelter for small fish, oyster beds creating habitat and clean water, and mudflats where snails and sea stars roam in search of their next meal.
You are sure to see tons of critters when you join a biologist led kayak tour with Rising Tide Explorers – including everyone’s favorite- dolphins. But do you know about these other critters you are almost sure to see while paddling? Check out the Mangrove Tunnels and Mudflats tour for your best chance to see these fun friendly critters!
Horse Conch- This estuary all star is both the state shell of Florida and the largest snail in North America- growing a shell of up to two feet long! This snail is a fierce predator, eating clams and other snails like the lightning whelk and banded tulip. Keep an eye out for one on the edges of mudflats, they often look like a giant football on the bottom, and you may even see their bright orange body through the water. Horse conch are long lived animals and can live thirty years. Your guide is guaranteed to jump of of their kayak if a horse conch is found so everyone can have a look at this monster sized snail!
Kings crown conch – This snail grows to only five inches, but makes up for its small size with sheer numbers. You are guaranteed to see hoards of them on the oyster reefs, where the ridges on their shells help them blend in. These snails are predators, and eat other snails, small clams, and oysters.
Lightning whelk- Your are certain to see these around the oyster reefs hanging out with the kings crown conch. They are the second largest snail in the estuary, with shells reaching 16 inches long. They are easy to identify because they are the only snail with a left sided opening, an adaptation thought to help them elude one of their main predators the stone crab. The edge of their shell is very sharp and strong, and they use it to shuck open oysters and clams.
Banded tulip- A RTE guide favorite critter to find is the banded tulip. They can sometimes be found on the oyster bars, and their beautiful shells can be found washed up on the beach. Their bodies are a beautiful glossy black color with tiny white spots, reminiscent of the milky way. These predatory snails eat small clams and other smaller snails.
Mangrove Periwinkle- You are guaranteed to see this tiny snail on your kayaking tour, you may even end up with some in your kayak with you if you run into the mangroves. They are found abundantly on the branches and leaves of the mangrove trees throughout Southwest Florida. They can live outside of the water, and use their tongue to scrape algae and fungi off the mangrove leaves. Look closely at these little friends, their shells are beautifully striped.
Horseshoe crab- These creatures are older than dinosaurs and are more closely related to spiders than crabs. They eat worms, clams, and algae, and are most often seen in summer when they come ashore to breed. Everything about these creatures is a fun fact, including their super clotting blue blood that is used in the medical industry to ensure instruments are clean, and allows them to survive almost any injury. Horseshoe crabs can live to be more than twenty years old, and their tail is used to help them flip over, it is not sharp and it does not sting.
Hermit crab – several species of hermit crab can be found in Southwest Florida, but our favorite are the giant hermit crab- they grow to be massive and their bodies are a bright red color. Giant hermit crabs favor living in conch shells, and often will eat the conch and then use its shell as a home. They are omnivores, and also eat algae, clams, and anything else. They can live over thirty years in the wild, but like all hermit crabs they do not live long at all in captivity.
Mangrove tree crab- Don’t worry, its not a spider and it does not jump. These crabs spend their lives in the mangrove trees, coming down to the ground at low tide, and hanging out in the branches at high tide. They can breathe out of the water for long periods of time by keeping their gills wet, so they only need to occasionally rewet them in the water. You are guaranteed to see mangrove tree crabs if you look closely in the mangrove tunnels. They eat mangrove leaves, algae, and anything else they can scrape up, and can live ten years.
Fiddler crab- Before you launch, take a look at the ground in the forest and you will see legions of fiddler crabs at low tide. These short-lived crabs are well known for the male’s giant claw, which they use to attract females. They use their smaller claw to feed, picking up mud and bringing it to their mouths, as if they are playing the fiddle. Fiddler crabs live in burrows in the ground, and after they eat they roll their leftovers into a ball and push it out of the burrow, so keep an eye out for that clue.
Cassiopea- these upside down jellyfish live on the bottom of the estuary, with their arms facing up. They don’t have tentacles, and instead shoot their mild stinging cells into the water when they feel movement. They have a partnership with algae that lives inside of them, giving them nutrients and color, so they are found only in shallow water where the algae can get enough sun light. These jellies are found throughout the estuary, especially in summer, and look like a plate sized white flower or a head of cauliflower on the bottom.
Comb jelly- these jellies are lemon sized and football shaped, without tentacles. They do not have any stinging cells at all, and are not true jellies. They have shiny luminescent bands along their bodies that glow at night. They float through the water moving with the tides, filtering the water for the tiny plankton they eat. These are most often seen in the winter months in Rookery Bay, and are fun to pick up in a handful of water.
Pistol shrimp- You probably wont see this critter, but you can definitely hear them in the mangrove tunnels. The pistol shrimp’s specialized claw can snap with amazing speed, creating a sound loud enough to break a small glass and kill its prey at 218 decibels. The snap is so powerful that it creates a cavitation bubble that can generate heat almost as hot as the sun! Listen for snapping sounds as you paddle through the mangrove tunnels.
Sea Stars- In Rookery Bay we see the brown spiny sea star and the nine armed sea star. Sea stars are predators that eat small clams. Their feet are like turkey basters full of water, so when a sea star attaches to a clam its relaxed position (letting go of the turkey baster bulb) is suctioning on and pulling open the clam. The sea star almost always wins this war because the clam has to use energy to stay shut, so if the sea star holds on long enough the clam will get tired, open up, and become the sea star’s next meal.
So how can you improve your odds of seeing these critters? Your best bet is to schedule a biologist led tour at low tide with Rising Tide Explorers. You can call Rising Tide Explorers at (239) 734-3231 and we can make suggestions for you on the best tour time while you are in town. Our Mangrove Tunnels and Mudflats tour will give you the most time to walk around the mudflats at low tide to look for critters, and the most time spent paddling over shallow water where you may spot something interesting on the bottom.