Recent Catch of a Bocourt Swimming Crab in Apalachicola Bay

Recent Catch of a Bocourt Swimming Crab in Apalachicola Bay

In early November a local crabber, Kevin Martina, brought an interesting catch to the Franklin County Extension office in Apalachicola. Kevin and his brother Kenneth Martina fish for blue crabs in Apalachicola Bay and they came across what appeared at first glance to be a red-colored blue crab. In all their combined years of working crab pots, neither of them had seen a crab like this. On closer inspection at the Extension Office, there appeared to be some differences from a blue crab, other than the striking red coloration. It was the innate curiosity of our Extension Office Manager, Michelle Huber, that led us to the discovery that the crab was a species with a native range spanning Jamaica and Belize to Santa Caterina, Brazil. After Michelle showed photos of what she had found on her phone, we reached out to colleagues at the Apalachicola National Estuarine Research Reserve (ANERR) and told them we might have a Bocourt swimming crab (Callinectes bocourti). I told them that I could find no range maps indicating this species lived in our region. The nearest US Geological Survey data points for the species in the Gulf of Mexico were Alabama to the West and the Florida Everglades to the South. It was not long after the ANERR staff reached out to the Fish and Wildlife Conservation Commission that we received interest in confirming the identification and officially documenting the Bocourt swimming crab find.

Bocourt Crab

Bocourt Swimming Crab – USGS/South Carolina DNR


The first documented occurrence of a Bocourt swimming crab in the US happened in 1950 in South Florida. Since then, there have been rare finds in AL and MS and more common occurrences from South Florida all the way up to North Carolina on the Atlantic Coast. Theories about how they arrived include possible transport of larvae in ships’ ballast water or a natural expansion of range with the aid of various ocean currents like the Gulf Stream or by hitching a ride on floating debris from the Caribbean. Ecologically speaking, Bocourt crabs and our native blue crabs have virtually the same dietary habits and both species occur together throughout some parts of their native range. Even though there is likely some competition for food and refuge habitat, it doesn’t appear at this time that one of these crabs would dominate the ecosystem over the other. It also is not evident that Bocourt crabs are reproducing and established in the Northern Gulf of Mexico to-date.

If you are a commercial crabber in the Florida Panhandle, or happen to fish a few recreational traps, we would be interested to know if you have seen this species before. Location data and any good photos of specimens would go a long way to help monitor the species occurrence in our region. You can reach out to me at Elovestrand@ufl.edu or contact your local County Extension office to pass the info my way. Happy crabbing!

The Tale of the Atlantic Tripletail

The Tale of the Atlantic Tripletail

The Atlantic Tripletail (Lobotes surinamensis) is a very prized sportfish along the Florida Panhandle. Typically caught as a “bonus” fish found along floating debris, the tripletail is a hard fighting fish and excellent table fare. Just as the name implies, this fish is equipped with three “tails” that help aid it in propulsion; and also help contribute to their strong fighting spirit. In addition to the caudal fin, tripletail have very pronounced “lobed” dorsal and anal fin soft rays that sit very far back on the body, giving it the appearance of three tails (triple-tails).

Tripletail Art

Atlantic Tripletail (Lobotes surinamensis) – FWC, Diane Rome Peebles 1992

Tripletail are found in tropical and subtropical seas around the world (except the eastern Pacific Ocean) and are the only member of their family found in the Gulf of Mexico. Tripletail can be found in all saltwater environments, from the upper bays to the middle of the Gulf of Mexico. In the Florida Panhandle, tripletail begin to show up in the bays beginning in May and can be found up until October/November. They are masters of disguise, usually found floating along floating debris, crab trap buoys, navigation pilings, and floating algae like Sargassum. When tripletail are young, they are able to change their colors to match the debris, albeit it is usually a variation of yellow, brown, and black. Adult tripletail can change color as well, but the coloration is not as vibrant as the juveniles. Floating alongside debris and other floating materials protects them from predators and gives them food access. Small crustaceans, like shrimp and crabs, and small fish will gather along the floating debris, looking for protection, giving the camouflaged tripletail an easy meal.

Tripletail or leaf?

Baby Tripletail or Leaf?  – Thomas Derbes II

Tripletail are opportunistic feeders that are what I classify as “lazy hunters.” Tripletail will hang out along any floating debris and wait for the food to come to them. They typically will not chase their prey items too far and will abandon the hunt if they expend too much energy. Since they are opportunistic feeders, their diet varies widely, but they cannot resist a baby blue crab, shrimp, or small baitfish like menhaden (Brevoortia patronus) that might visit their floating oasis. When further offshore, it is not uncommon to find many tripletail “laying out” on sargassum or floating debris. I personally have seen a dozen full-sized tripletail inside of a large traffic barrel 25 miles offshore that saved a skunk of a deep-dropping fishing trip.

Oyster Farmer holding a Tripletail fish

Tripletail Caught Off An Oyster Farm – Brandon Smith

When targeting tripletail, anglers will typically sit at the highest point of the boat (some anglers have towers for spotting tripletail) and cruise along floating crab trap buoys, pilings, and sometimes oyster farms looking for Tripletail. These fish are very easily spooked, and a slow, quiet approach is best. Once in casting distance, toss your preferred bait (I typically want to have baby crabs or live shrimp when targeting tripletail) close to the floating structure, but not too close to spook the fish. You can usually watch the fish eat your bait (another added bonus) and once you set the hook, the fight is on! In the state of Florida, tripletail must be a minimum of 18 inches and there is a daily bag limit of 2 fish per person. Be very careful handling tripletail as they have very sharp dorsal and anal fins and their operculum (gill cover) is also very sharp with hidden spines.

So next time you’re out fishing and see something floating, make sure you give it a good look over. There might be a camouflaged tripletail that you can add to your fish box!

tripletail fisherman

Tripletail Caught While Working Oyster Gear – Thomas Derbes

Half Shell Oyster Oddities

Half Shell Oyster Oddities

Oysters are not only powerful filterers, they also provide a home and habitat for many marine organisms. Most of these organisms will fall off while the oysters are being harvested or cleaned, but some will stay behind and can be found inside or outside of your oyster on the half shell. Seeing some of these creatures might give you the “heebie jeebies” about eating the oyster, they are perfectly safe and can either be removed or, in some cases, consumed for luck. These creatures include mud worms (Polydora websteri), “pea crabs” (Pinnotheres ostreum or Zaops ostreus), and “mud crabs” (Panopeus herbstii, Hexapanopeus angustifrons or Rhithropanopeus harrisii).

Mud Worms (Polydora websteri)

mudworm

A Mud Worm in an Oyster – Louisiana Sea Grant

One of the more common marine organisms you can find on an oyster is the oyster mud worm. These worms are typically red in color and form a symbiotic relationship with the oyster. Mud worms can be found in both farmed and wild harvest oysters throughout the United States. These worms will typically form a “mud blister” and emerge when the oyster has been harvested. Even though the worms look menacing and unsightly, they are a sign of a fresh harvest and a good environment. Mud worms do not pose any threat to humans and can be consumed.

If you find a mud worm on your next oyster and are still unsure, just simply remove the worm and dispose of it. Dr. John Supan, retired professor and past director of Louisiana Sea Grant’s Oyster Research Laboratory on Grand Isle, mentioned in an article that oyster mud worms “are absolutely harmless and naturally occurring,” and “if a consumer is offended by it while eating raw oysters, just wipe it off and ask your waiter/waitress for another napkin. Better yet, if there are children at the table, ask for a clear glass of water to drop the worm in. They are beautiful swimmers and can be quite entertaining.”

“Pea Crabs” (Pinnotheres ostreum or Zaops ostreus)

“Pea Crabs” are in fact two different species of crabs lumped together under one name. Pea crabs include the actual pea crab (Pinnotheres ostreum) and the oyster crab (Zaops ostreus). These crabs are so closely associated with oysters that their species name contains some form of the Latin word “ostreum” meaning oyster! Pea crabs are known as kleptoparasites and will embed themselves into the gills of an oyster and steal food from the host oyster. Even though they steal food, they seem to pose no threat to the oyster and are a sign of a healthy marine ecosystem.

A Cute Little Pea Crab – (C)2013 T. Michael Williams

Pea crabs are soft-bodied and round, giving them the pea name. Pea crabs can be found throughout the Atlantic coast, but are more concentrated in coastal areas from Georgia to Virginia. While they might look like an alien from another planet, they are considered a delicacy and are typically consumed along with the oyster. If you are brave enough to slurp down a pea crab, you might just be rewarded with a little luck. According to White Stone Oysters, “historians and foodies alike agree that finding a pea crab isn’t just a small treat, it’s also a sign of good luck!”

“Mud Crabs” (Panopeus herbstii, Hexapanopeus angustifrons or Rhithropanopeus harrisii)

Smooth Mud Crab – Florida Shellfish Lab

Just like pea crabs, “mud crabs” is another name for two different species of crabs commonly found in oysters. These crabs, the Harris Mud Crab (Rhithropanopeus harrisii), Smooth Mud Crab (Hexapanopeus angustifrons), and the Atlantic mud crab (Panopeus herbstii) to name just a few, reach a maximum size of 2 to 8 centimeters and are hard-bodied, unlike the pea crabs. Mud crabs can survive a wide range of salinities, but need cover to survive as these crabs are common prey for most of the oyster habitat dwellers, such as catfish (Ariopsis felis), redfish (Sciaenops ocellatus), and sheepshead (Archosargus probatocephalus). These crabs are not beneficial to an oyster environment as they will seek out young oysters and consume them by breaking the shell with their strong claws. If you find a mud crab in your oyster, this is one to dispose of before consuming. However, these crabs typically live on the outside of an oyster and are typically only found when you buy a sack of oysters and do not have an effect on the quality of the oyster.

Don’t Be Afraid

Hopefully this article has helped shed some light on the creatures you might experience when shucking or consuming oysters. Here is a helpful online tool to help identify some marine organisms associated with clam and oyster farms (Click Here). While most of the organisms can be consumed, we recommend the mud crabs be disposed of due to their hard shells. Remember, some of these organisms can bring you luck and with college football season around the corner, some of us might need all the luck we can get! Bring on the pea crabs!

References Hyperlinked Above

Stingray Pupping Season

Stingray Pupping Season

I was recently conducting a survey for diamondback terrapins from my paddleboard in a small estuarine lagoon within the Pensacola Bay System.  Even if we do not find our target species during these surveys – I, and our volunteers, see all sorts of other cool wildlife.  On this trip I was treated to nesting osprey, a kingfisher, large blue crabs, and even a swimming eel.  But one neat encounter was the numerous stingrays.

The Atlantic Stingray is one of the common members of the ray group who does possess a venomous spine.
Photo: Florida Museum of Natural History

They were lying in the sand and grassbeds, lots of them, and they all seemed to be of one species – the Atlantic stingray.  My brain immediately went to “breeding season”, but when I checked the literature, I found that it was not breeding season, but pupping season – the babies were being born.

Atlantic Stingray (Dasyatis sabina) are true stingrays in the family Dasyatidae.  This means they do possess the replaceable serrated venomous barb that makes these animals so famous.  They are one of the smaller members of this family.  Females can reach a disk width of two feet while the smaller males will only reach about one foot.  Atlantic stingrays are a warm water species, migrating if they need to find suitable temperatures.  They have been found in water as deep as 80 feet but are more common in the warmer shallower waters near shore.  They are very common in our estuaries and being euryhaline (they tolerate a large range of salinity), are found in freshwater systems.  There is a population that lives in the St. Johns River.  Atlantic stingrays feed on a variety of benthic invertebrates and have special cells in the nose to detect the weak electric fields their prey give off while buried in the sediment.  They also like to bury in the sand to ambush prey as they move by.

Breeding occurs in the fall.  The smaller males possess two modified fins called claspers connected to their anal fins that are used to transfer sperm to the female.  The males have modified teeth they can use to bite the fins of the females.  They do this to hold on and make sperm transfer more successful.

The females do not begin to ovulate until spring.  So, though they receive the sperm in the fall, fertilization does not occur until the spring.  Instead of laying eggs, as some rays and skates do, baby Atlantic stingrays develop within the mother.  This is not the same as mammals, who produce a placental to feed the developing young, but more like an internal egg with no hard shell.  The embryo is attached to, and feeds from, a yolk sac.  Gestation takes about 60 days at which time the yolk sac is depleted, and the young must emerge.  Birth usually occurs in late July and early August, and each female will produce 1-4 small pups whose disk are about 10cm (4in.) wide.  It was this birthing/pupping period I witnessed.

I returned the following day to search for terrapins and the number of stingrays was significantly fewer.  It may be that the birthing process is fast, and the adults leave the coves afterwards.  It may have been because that day was the day Hurricane Debby was making landfall east of us and the water levels were abnormally high – something the rays may have noticed and decided to leave – I am not sure.

I was really hoping to see the young rays swimming around – I did not – but plan to search again soon.  Stingrays make many people nervous. I witnessed several adult rays whose tails had been cut off – which is very unfortunate – but they are actually cool creatures and fun to watch while paddleboarding.  Maybe I will see a baby soon.

 

References

Dasyatis sabina. 2023. Florida Museum of Natural History. https://www.floridamuseum.ufl.edu/discover-fish/species-profiles/dasyatis-sabina/.

Johnson, M.R., Snelson Jr., F.F. 1996. Reproductive Life History of the Atlantic Stingray, Dasyatis sabina (Pisces, Dasyatidae), in Freshwater St. Johns River, Florida. Bulletin of Marine Science, 59(1): 74-88.

The Estuary’s Natural Filtration System Part 2

The Estuary’s Natural Filtration System Part 2

In Part 1 of The Estuary’s Natural Filtration System article, we discussed the major contributors to natural filtration inside of the estuary. These examples included oysters, marsh plants, and seagrasses. In Part 2, we will discuss the smaller filter-feeding organisms including tunicates, barnacles, clams, and anemones.

Tunicates

Sea Squirt

Pleated Sea Squirt – Photo Credit: Don Levitan, PH.D. FSU

Tunicates, also known as sea squirts, are very interesting marine invertebrates and can be easily confused for a sponge. There are many different types of tunicates in the estuaries and can be either solitary or colonial. You might’ve seen these at an aquarium attached to different substrates, and when removed from the water, their name sea squirt comes into play. Tunicates have a defense mechanism to shoot out the water inside their body in hopes of being released by any predator.

Tunicates are filter feeders and intake water through their inhalant siphons and expel waste and filtered water through their exhalant siphons. Tunicates can filter out phytoplankton, algae, detritus, and other suspended nutrients. The tunicate produces a mucus that catches these nutrients as it passes through, and the mucus is then conveyed to the intestine where it is digested and absorbed.

An invader to the Gulf of Mexico, the Pleated Sea Squirt (Styela plicata), hitched rides on the hulls of ships and found the Gulf of Mexico waters very favorable. You can sometimes spot these organisms on ropes that have been submerged for a long period of time in salty waters. Even though they are non-native, these sea squirts can filter, on average, 19 gallons of water per day.

Barnacles

Barnacles along the seashore is a common site for many.
Photo: NOAA

One organism that seems ubiquitous worldwide is the barnacle (Genus Semibalanus and Genus Lepas). The Genus Semibalanus contains the common encrusting barnacle we are accustomed to seeing in our waterways along pilings, submerged rocks, and even other animals (turtles, whales, crabs, and oysters). The Genus Lepas contains Gooseneck Barnacles and can be seen attached to flotsam, floating organic debris, and other hard surfaces and have a stalk that attaches them to their substrate. Interesting fact, certain gooseneck barnacle species are eaten in different parts of the world.

This image from a textbook shows the internal structure of a barnacle. Notice the shrimplike animal on its back with extendable appendages (cirri) for feeding.
Image: Robert Barnes Invertebrate Zoology.

Barnacles have over 2,100 species, are closely related to crabs and lobsters, and are a part of the subphylum Crustacea. At first glance, you might not think a barnacle is closely related to crabs, but when you remove the hard plates surrounding it, the body looks very similar to a crab. Barnacles also have life cycle stages that are similar to crabs; the nauplius and cyprid developmental stages. Inside of the hard plates is an organism with large feather-like appendages called cirri. When covered by water, the barnacles will extend their cirri into the water and trap microscopic particles like detritus, algae, and zooplankton. Barnacles are at the mercy of tides and currents, which makes quantifying their filtering ability difficult.

Hard Clams

Clam Species

Clams of North Florida – UF/IFAS Shellfish

Even though not as abundant in the Florida Panhandle as they were in the 1970’s – 1980’s, hard clams (Mercenaria mercenaria and M. campechiensis) can still be found in the sand along the shoreline and near seagrass beds. These clams are also known as Quahogs and are in the family Veneridae, commonly known as the Venus clam family, and contain over 500 living species. Most of the clams in the family Veneridae are edible and Quahogs are the types of clams you would see in a clam chowder or clam bake.

Being the only bivalve on this list does not make it any less important than the oyster or scallop on Part 1’s list. In fact, a full-grown adult Southern Quahog clam can filter upwards of 20 gallons of water per day and have a lifespan of up to 30 years. Clams also live a much different lifestyle than their oyster and scallop cousins. Clams spend the majority of their life under the sand. Their movement under the sand helps aerate and mix the soil, which can sometimes stimulate seagrass growth.

Right outside the Florida Panhandle and in the Big Bend area, Quahog clams are commercially farmed in Cedar Key. Southern Quahog clams are also being used for restoration work in South Florida. Clams are being bred in a hatchery and their “seed” are being released into Sarasota Bay to help tackle the Red Tide (Karenia brevis) issue. According to the project’s website, they have added over 2 million clams since 2016, and the clams are filtering over 20 million gallons of seawater daily.

Anemones

Tube-Dwelling Anemone Under Dissection Scope - UF/IFAS Shellfish

Tube-Dwelling Anemone Under Dissection Scope – UF/IFAS Shellfish

Anemones are beautiful Cnidarians resembling an upside-down, attached jellyfish, which couldn’t be closer to the truth. The phylum Cnidaria contains over 11,000 species of aquatic animals including corals, hydroids, sea anemones, and, you guessed it, jellyfish. Anemones come in many different shapes and sizes, but the common estuary anemones include the tube-dwelling anemone (Ceriantheopsis americana) and the tricolor anemone (Calliactis tricolor), also known as the hitchhiking anemone. If you have ever owned a saltwater aquarium, you might have run into the pest anemone Aiptasia (Aiptasia sp.).

Anemones filter feed with their tentacles by catching plankton, detritus, and other nutrients as the tide and current flows. The tentacles of the anemone are lined with cnidocytes that contain small amounts of poison that will stun or paralyze the prey. The cnidae are triggered to release when an organism touches the tentacles. If the anemone is successful in immobilizing the prey, the anemone will guide the prey to their mouth with the tentacles. Just like the barnacle, anemones are at the mercy of the tides and currents, and filtration rates are hard to calculate. However, if you ever see an anemone with food around, they move those tentacles to and from their mouths quickly and constantly!

In Parting

As you can see, there are many different natural filters in our estuary. Healthy, efficiently filtering estuaries are very important for the local community and the quality of the waters we love and enjoy. For more information on our watersheds and estuaries and how to protect them, visit Sea Grant’s Guide To Estuary-Friendly Living.

Upcoming Event: Panhandle Outdoors Live at St. Joseph Bay on June 21st!

Upcoming Event: Panhandle Outdoors Live at St. Joseph Bay on June 21st!

The University of Florida/IFAS Extension & Florida Sea Grant faculty are reintroducing their acclaimed “Panhandle Outdoors LIVE!” series on St. Joseph Bay. This ecosystem is home to some of the richest concentrations of flora and fauna on the Northern Gulf Coast. This area supports an amazing diversity of fish, aquatic invertebrates, turtles and other species of the marsh and pine flatwoods. Come learn about the important roles of ecosystem!

Registration fee is $40. You must pre-register to attend.

Registration link: https://www.eventbrite.com/e/panhandle-outdoors-live-st-joseph-bay-by-land-sea-tickets-906983109897

or use the QR code:

Meals: Lunch, drinks & snacks provided (you may bring your own)

Attire: outdoor wear, water shoes, bug spray and sunscreen

*If afternoon rain is in forecast, outdoor activities may be switched to the morning schedule

Held at the St. Joseph Bay State Buffer Preserve Lodge: 3915 State Road 30-A, Port St. Joe

8:30 – 8:35 Welcome & Introduction – Ray Bodrey, Gulf County Extension (5 min)
8:35 – 9:20 Diamondback Terrapin Ecology – Rick O’Connor, Escambia County Extension
9:20 – 10:05 Exploring Snakes, Lizards & the Cuban Tree Frog – Erik Lovestrand, Franklin County Extension
10:05 – 10:15 Break
10:15 – 11:00 The Bay Scallop & Habitat – Ray Bodrey, Gulf County Extension
11:00 – 11:45 The Hard Structures: Artificial Reefs & Derelict Vessel Program – Scott Jackson, Bay County Extension
11:45 – Noon Question & Answer Session – All Agents
Noon – 1:00 Pizza & Salad!
1:00 – 1:20 Introduction to the Buffer & History – Buffer Preserve Staff
1:20 – 2:20 Tram Tour – Buffer Preserve Staff
2:20 – 2:30 Break
2:30 – 3:00 A Walk in the Mangroves – All Agents
3:00 – 3:15 Wrap up & Adjourn – All