Eels of the Florida Panhandle

Eels of the Florida Panhandle

Eels… when that name comes up most think of either the vicious moray eels or the famous electric eel.  Moray eels do exist in the Florida panhandle, and we will talk about them.  Electric eels do not, they are found in the Amazon River system.  That said, we do have eels here – quite a few.  There are at least 18 species found in six different families.  Most are 2-3 feet in length, though the Banded Shrimp Eel (Ophichthus) can reach six feet.  About half of them are found offshore on the middle and outer shelves, the other half can be found in the inner shelf and estuaries, a few species swim into freshwater.  Shrimpers often catch them when trawling and occasionally anglers will catch them with rod and reel.

 

Eels superficially resemble snakes and sometimes are confused with them.  I have been told more than once that we do have sea snakes here.  We do not.  What people are finding are one of the 18 species of eels in the area.  We do have snakes swimming across our estuaries, but we do not have sea snakes.

 

Eels differ from snakes primarily in that they, being fish, possess gills – not lungs.  Most eels do have sharp teeth, the morays are famous for theirs, but no eels are venomous – so no worries there.  Most of our eels have very small scales or are completely scaleless and are often very slimy and difficult to handle.  They have been used as bait and one species, the American eel (Anguilla rostrata), has been used for food.

The Anguilla eel, also known as the “American” and “European” eel.
Photo: Wikipedia.

 

The American eel has an interesting life history.  They spawn in the Sargasso Sea, an area in the middle of the Atlantic Ocean.  Their developing leptocephalus larva are thin, flat, and transparent in the water.  They drift with the ocean currents into the Gulf of Mexico and eventually into our estuaries.  I have found them along the shores of Project Greenshores (in Pensacola Bay) during certain parts of the year.  From here they work their ways into our local rivers where people encounter the large adults.  I have found them living in submerged caves near Marianna and many locals have found them at the bottom of our rivers.  When time to breed, the adults will leave and head back to the open Atlantic to begin the cycle again.  An amazing trip.

Moray eel.
Photo: NOAA

 

Moray eels are famous for the nasty attitudes and vicious bites.  They are more tropical and associated with offshore reefs, though the ocellated moray (Gymnothorax ocellatus) is often caught in shrimp trawls.  They live in the crevices of the reef ambushing prey.  Some, like the green moray, can get quite large – over six feet.  Like all eels, they have very powerful muscles and sharp teeth.

The shrimp eel is common on our inner and middle continental shelf.
Photo: NOAA

 

Conger eels are very common despite few people ever seeing them.  There are six species and they frequent the middle continental shelf, so are rare in estuaries.

 

There are eight species of snake, or worm, eels.  These are more common on the inner shelf and the coastal estuaries.  Many prefer muddy bottoms where they bury tail first to ambush prey swimming by.

 

The majority of these marine eels have a large geographic distribution.  Their larva can be carried great distances in the currents and their need for sandy or muddy bottoms can be met just about anywhere.  They appear to have few barriers keeping them from colonizing much of the Gulf and surrounding waters.  Most fall into the category we call “Carolina Fish”.  Meaning their distribution occurs from the Carolinas, throughout the Gulf of Mexico, south to Brazil.  There are a few species that can tolerate the lower salinities of the estuaries and one, the Anguilla eel, that can even venture into freshwater.

 

There are few species restricted to the tropical reefs, such as the morays.  But morays are found on our smaller middle shelf and artificial reefs in the northern Gulf.  Though found in parts of the Atlantic Ocean, Hoese and Moore1 reported one species of conger eel, Uroconger syringus, as only occurring near south Texas in the Gulf of Mexico.  What barriers keep it from colonizing other Gulf habitats is unknown.

 

Eels are true fish that we rarely encounter.  Encounters are usually startling but exciting at the same time.  They are pretty amazing fish.

 

Reference

 

Hoese, H.D., R.H. Moore. 1977. Fishes of the Gulf of Mexico; Texas, Louisiana, and Adjacent Waters. Texas A&M University Press, College Station TX. Pp. 327.

Tarpon in the Florida Panhandle

Tarpon in the Florida Panhandle

This is a famous fish.  If you look back at the old tourism magazines of the early 20th century you will see a lot about tarpon fishing in Florida.  As a matter of fact, some say that tarpon fishing was the beginning of the tourism industry in the state.  Also known as “silver kings”, they put up a tremendous fight which anglers love, particularly on lighter tackle.  It is a sport fish, not sought for food, so catch and release has been the rule for years.  But those who seek them will tell you it is worth the fight even if you must release it.

Tarpon have been a popular fishing target for decades.
Photo: NOAA

Tarpon (Megalops atlantica) are large bodied, large scaled fish, with a deep blue back and silver sides.  They are a large fish, reaching over 8 feet in length and up to 350 pounds.  They tend to travel in schools and are often associated with other fish, such as snook2.

 

It has always been thought of as a “south Florida fish”.  As mentioned, down there it is a popular fishing target for tourist and residents alike.  Many charter captains specialize in catching the fish and they have been featured in fishing programs.  But you do not hear about such things in the Florida panhandle.  Hoese and Moore1, as well as the Florida Museum of Natural History2 both indicate that they are in fact in the Florida panhandle.  As a matter of fact, this fish has few barriers and has the distribution of the classic “Carolina fish” group.  That includes the entire eastern seaboard of the United States, the entire Gulf of Mexico, and the Caribbean1.  The Florida Museum of Natural History indicates they are found on the opposite shores of the Atlantic Ocean and may have made their way through the Panama Canal to the Pacific shores of the canal.  Within this range they are known to enter freshwater rivers.  They seem to have few biogeographic barriers.

 

I grew up in the panhandle and remember hearing about them swimming in our area when I was younger.  Fishermen said they would throw all sorts of bait at them.  Artificial lures, live bait, cut bait, you name it – they tossed it… the tarpon never would take it.  Catching one here was almost impossible.  The flats fishing charter trips for tarpon in south Florida would not happen here.  I remember once diving in Pensacola Bay near Ft. Pickens.  We were looking for an old Volkswagen beetle that had been sunk years ago when at one point the water became very dark – almost like storm clouds had rolled in.  When my buddy and I both looked up we saw a school of very large fish swimming above us.  We were not sure what they were at first but as we slowly ascended, we realized they were tarpon.  It was pretty amazing.

 

An interesting side note here.  In 2020 tarpon were once again seen swimming around the Pensacola area but this time they WERE taking bait.  There were several reports of tarpon caught off the Pensacola Fishing Pier and inside the bay.  Why change over all this time?  I am not sure.

The ladyfish (or skipjack) is the smaller cousin of the tarpon, but puts up a good fight as well.
Photo: University of Southern Mississippi

Tarpon belong to the family Elopidae which also includes another local fish known as the “ladyfish” or “skipjack” (Elops saurus).  This is a much smaller fish reaching about 3 feet (and that would be a large ladyfish).  The scales of this family member are much smaller, but the fight on hook and line is just as large.  The characteristic that places these two fish into the same family (and these are the only two in this family) is the hard bony gular plate found between the right and left side of the lower jaw (in the “throat” area).

Like tarpon, it is not prized as a food fish but more of a game fish.  It has the classic wide distribution of the “Carolina fish group” – the eastern seaboard of the United States, the Gulf of Mexico, down to Brazil.  Like the tarpon, it is found in brackish conditions but is not mentioned in freshwater.  Again, few biogeographic barriers for this fish.

 

Both members of this family provide anglers young and old with a lot of enjoyment.

 

1 Hoese, H.D., R.H. Moore. 1977. Fishes of the Gulf of Mexico; Texas, Louisiana, and Adjacent Waters.  Texas A&M Press, College Station TX. Pp. 327.

 

2 Discover Fishes. Tarpon. Florida Museum of Natural History. https://www.floridamuseum.ufl.edu/discover-fish/species-profiles/megalops-atlanticus/.

 

3 Discover Fishes.  Ladyfish. Florida Museum of Natural History.  https://www.floridamuseum.ufl.edu/discover-fish/species-profiles/elops-saurus/.

Gars of the Florida Panhandle

Gars of the Florida Panhandle

Like the ancient sturgeon, this is one strange prehistoric looking group of fish.  I’ll say group of fish because there is more than one kind.  For many, all gars are alligator gars.  There is an alligator gar but there are others.  Actually, the longnose gar may be seen more often than the alligator gar, but many do not know there is more than one kind.

 

Gars are freshwater fish, but several species have a high tolerance for saltwater.  The alligator gar (Artactosteus spatula) has been reported from the Gulf of Mexico1.  They are elongated, slow moving fish with extended snouts full of sharp teeth – very intimidating to look at.  But swimming with gars in springs and rivers, I have found them to be oblivious to me.  Snag one in a net however, and they will turn quickly and could do serious harm.  While fishing my grandson had one come after his bait once and that was pretty exciting, but it is rare to catch them on hook and line.  Many who fish for them do so with bow and arrow.  Their skin is covered with tough ganoid scales.  You really can’t scale them; you have to skin them.

Alligator Gar from the Escambia River.
Photo: North Escambia.com

 

In the book Fishes of the Gulf of Mexico, by Hoese and Moore, they list four species of gar in the northern Gulf.  As the name suggests, the longnose gar (Lepisosteus osseus) has a long slender snout and has spots on the body.  It is the one most often seen by people visiting our springs, rivers, and the one most often seen in our estuaries.  It can reach a length of five feet3.

 

The famous alligator gar (Artactosteus spatula) has a shorter snout and spots are usually lacking.  If they do have them, the are usually on the fins.  This is a big boy – reaching lengths of nine feet and up to 100 pounds2.  They are common in coastal estuaries and even the Gulf, though not encountered very often.

 

The spotted gar (L. oculatus) also has a short snout but has spots all over its body.  It prefers the rivers and will enter estuaries only where the salinities are low.  It is smaller at four feet4.

Spotted Gar.
Photo: University of Florida

The last panhandle gar is the shortnose gar (L. platostomus).  This species too prefers rivers and may enter low salinity bays.  It has a short snout and lacks spots.

 

There is a Florida gar (L. platyrhincus) not found in the panhandle but exists along the central and south Florida gulf coast.  It seems to have replaced the spotted gar in this location5.

 

The biogeography of this group of fish is interesting in that it is an ancient like the sturgeon, it existed during a time period when much of Florida would have been underwater.  The general range of gars is the entire eastern United States.  They prefer slow moving rivers, or backwaters of faster rivers, and are common in springs.  As mentioned, a few species will venture into saltwater and can be found around the Gulf of Mexico.  But with several species there has obviously been some speciation over time.

The common longnose gar.
Photo: University of South Florida.

The longnose gars have one of the widest distributions within the group.  They are found in most river systems across the eastern United States and all of Florida.  It seems to have few barriers including saltwater.

 

Alligator gars have a similar distribution but seem to be restricted from the peninsula part of Florida.  The Florida rivers where they are found are all in the panhandle and are all alluvial rivers – muddy and not tannic like the Suwannee.  This could be due to required food that prefer alluvial rivers, pH (pH is lower in the tannic rivers), or something else.  Though they did not disperse into central and south Florida, they did extend their range westward down into Mexico.  And, as mentioned, have been reported in the open Gulf of Mexico.

 

Spotted gars follow a similar distribution to the alligator gar.  Much of the Mississippi River basin, Florida panhandle, and west to Texas – but they are not found in peninsular Florida.  Pre-dating the emergence of peninsular Florida from the sea, there was some barrier that prevented them from dispersing south when the landmass did appear.

 

A different species appeared in peninsular Florida along with the longnose gar – the Florida gar.  It is found in central and south Florida and has dispersed a little north along the Atlantic coast to Georgia.

 

This is an interesting group of ancient fish.  Some are commercially harvested and have suffered from human alterations of river systems.  They are amazing to see.

 

 

1 Hoese, H.D., R.H. Moore. 1977. Fishes of the Gulf of Mexico; Texas, Louisiana, and Adjacent Waters. Texas A&M Press, College Station TX.  Pp. 327.

 

2 Discover Fishes.  Florida Museum of Natural History. Alligator Gar. https://www.floridamuseum.ufl.edu/discover-fish/florida-fishes-gallery/alligator-gar/.

 

3 Discover Fishes. Florida Museum of Natural History. Longnose Gar.  https://www.floridamuseum.ufl.edu/discover-fish/florida-fishes-gallery/longnose-gar/.

 

4 Discover Fishes.  Florida Museum of Natural History. Spotted Gar. https://www.floridamuseum.ufl.edu/discover-fish/florida-fishes-gallery/spotted-gar/.

 

5 Discover Fishes.  Florida Museum of Natural History.  Florida Gar. https://www.floridamuseum.ufl.edu/discover-fish/florida-fishes-gallery/florida-gar/.

Sargassum

Sargassum

Sargassum washed ashore after a storm on Pensacola Beach. Photo credit: Carrie Stevenson, UF IFAS Extension

I am sure it drives the tourists a little crazy. After daydreaming all year of a week relaxing at the beach, they arrive and find the shores covered in leggy brown seaweed for long stretches. It floats in the shallow water, tickling legs and causing a mild panic—was that a fish? A jellyfish? A shark? Then, of course, high tide washes the seaweed up and strands it at the wrack line, shattering the vision of dreamy white sand beaches.

But for those visitors—and locals—willing to take a closer look, the brown algae known as sargassum is one of the most fascinating organisms in the sea. The next time you are at the beach, pick some up and turn it over in your hands. Sargassum is characterized by its bushy, highly branched stems with numerous leafy blades and berry-like, gas-filled structures. The tiny air sacs serve as flotation devices to keep the algae from sinking. This unique adaptation allows it to fulfill a niche at the top of the water column, instead of growing at the bottom or on another organism.

The sargassum fish blends incredibly well into its home within sargassum mats. It uses handlike pectoral fins to move around. Photo credit: Reef Builders

Sargassum tends to accumulate into large mats that drift through the water in response to wind and currents.  These drifting mats create a pelagic habitat that attracts up to 70 species of marine animals.  Several of these organisms are adapted specifically to life within the sargassum, reaching full growth at miniature sizes and camouflaged in shape, pattern, and color to blend in.  These very specialized fauna include the sargassum crab, the sargassum shrimp, sargassum flatworm, sargassum nudibranch, sargassum anemone, and the sargassum fish! The sargassum fish (Histrio histrio) is in the toadfish family, a group of slow-moving reef fish that pick their way through coral and algae by using their pectoral fins like hands. Sea turtle hatchlings will spend their early years feeding and resting within the relative safety of large mid-ocean sargassum mats.

The small air-filled sacs of sargassum allow it to float on the surface, becoming the basis of a teeming ecosystem. Photo credit: Carrie Stevenson, UF IFAS Extension

Over time the air sacs  lose buoyancy and the sargassum sinks, providing an important source of food for bottom-dwelling creatures.  If washed ashore, many of the animals abandon the sargassum or risk drying out and dying.

In general, most of the larger, familiar seaweeds like sargassum are brown algae.  Brown algae (including kelp and rockweed) have colors ranging from brown to brownish yellow-green.  These darker colors result from the brown pigment fucoxanthin, which masks the green color of chlorophyll.  Extractions from brown algae are commonly used in lotions and even heartburn medication!

Sturgeon in the Florida Panhandle

Sturgeon in the Florida Panhandle

This is one strange, primitive, dinosaur-looking fish.  They have large scutes embedded in their skin that give them an armored look.  They are big – reaching 14 feet in length and 800 pounds (though the Gulf sturgeon does not reach the large size of their cousin the Atlantic sturgeon).  They resemble sharks with their heterocercal caudal fin and possess long whiskers (barbels) suggesting a benthic mode of feeding.

Sturgeon are large fish. The barbels (whiskers) are for finding prey buried in the sediment. Notice the raised ganoid scales of this ancient creature.
Photo: U.S. Fish and Wildlife Service.

Panhandle residents know them from their impressive leaps as they head upriver for spawning in the spring.  The loud splash from one of these leaps can be heard for a long distance and is a concern for boaters who may be zipping up and down one of the local rivers on a jet sky, or even a bass boat.  When in college, we asked one of the professors – “why do mullet jump?”.  He paused for a second and responded – “for the same reason manta rays jump”.  There was another longer pause.  Understanding what was going on we took the bait and asked – “okay… why do manta rays jump?” – “we don’t know”.  However, that was in 1980 and a lot has been learned since.  We know that not only do mullet and mantas leap, but baleen whales and sturgeon do as well.  It is believed that baleen whales leap to communicate during the breeding season.  Since sturgeon breed in panhandle rivers, it is believed that this is the reason they may do so.  Scientists have also found it helps adjust their swim bladders with internal gas making them more buoyant in the water.

 

Like salmon, sturgeon swim up rivers to breed and spawn in the spring.  Fertilization is external and the gray-black eggs are laid on the substrate at the bottom.  The newborn and adults spend the remaining spring in the rivers, and the adults do not feed at this time.  In summer all head for the estuaries where the adults begin feeding with a vengeance.  They feed on a variety of benthic invertebrates and prefer sections of the bay that are well oxygenated.  Sturgeon spend the summer and much of the fall in the bays until the temperatures begins to drop at which time they head into the open Gulf of Mexico.  The spring, they find their breeding rivers and the reproductive cycle begins again.  This is a long-lived fish, reaching up to 50 years in age.

 

As far as the biogeography of this species, it is an interesting one.  They have been around for about 200 million years.  This was about the time the whole “Pangea” movement was going on – Florida did not look like Florida then.  There was an opening between what is now the southeastern United States and the Florida peninsula.  The water moving through this was called the Georgia Seaway or the Suwannee Channel.  This allowed marine species to easily move from the Atlantic to the Gulf of Mexico.  It was believed the current in this seaway was significant enough to keep silt and clays from reaching what would be become peninsula Florida, which was probably a submerged region of islands at the time.

 

During those times the Atlantic sturgeon (Acipenser oxyrinchus) inhabited this region, using southeast rivers for breeding.  About 25 million years ago global land mass changes began a period of ice formation that encouraged sea level to drop and the peninsula portion of Florida was exposed – the Florida people know today.  However, this new peninsula isolated populations of sturgeon (and other fish at that time) from reaching each other.  As time moved on, different genetic changes occurred in both populations to produce offspring that varied from each other.  These external morphological changes were enough to let you know they were different, but genetically they are close enough to still breed.  In these situations, they have deemed “subspecies” of each other.  The Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) and the Gulf sturgeon (Acipenser oxyrinchus desotoi).  It is the Gulf sturgeon we find along the panhandle.  This process of producing new subspecies and species due to population isolation over time is called speciation.

 

Another interesting trend is the original range of the Gulf sturgeon was from the Texas/Louisiana border to about Tampa Bay.  This suggest that the fish took advantage of numerous rivers for breeding but there was a barrier as you reach the tropics.  Whether that barrier was climatic (temperature) biological (food source) or something else I am not sure.  With the high concentration of sturgeon in the panhandle you might think they require the alluvial rivers of this region.  But sturgeon are as common in tannic rivers, such as the Suwannee and Yellow Rivers, as they are in those alluvial ones, such as the Escambia and Apalachicola.

 

Today, their range is even smaller.  They are now found only in the rivers between Louisiana/Mississippi border to the Suwannee River.  This range reduction is probably due to habitat alteration (much of it human induced – such as dams) and overharvesting (the eggs of the sturgeon are used for caviar).  Today all species and subspecies of sturgeon are protected by the endangered species act.

 

Because this is an ancient fish, the biogeographic story of the sturgeon is an interesting one and shows how speciation occurs over time with all life.  They are really cool fish and, if you have not seen one leap yet, I hope you get to.  It is pretty amazing.

 

 

References

 

Florida’s Geologic History, University of Florida IFAS, https://edis.ifas.ufl.edu/publication/UW208.

 

NOAA Species Directory, Gulf Sturgeon, https://www.fisheries.noaa.gov/species/gulf-sturgeon.

 

NOAA Species Directory, Atlantic Sturgeon, https://www.fisheries.noaa.gov/species/atlantic-sturgeon.

 

Sturgeon, Florida Fish and Wildlife Conservation Commission, https://myfwc.com/conservation/you-conserve/wildlife/sturgeon/#:~:text=When%20the%20ambient%20pressure%20changes,to%20communicate%20with%20other%20sturgeon..

Cobia: An Amazing Fish and Fishery for North Florida

Cobia: An Amazing Fish and Fishery for North Florida

image of two fish tracking tools

Cobia Researchers use Transmitters as well as Tags to Gather Data on Migratory Patterns

I must admit to having very limited personal experience with Cobia, having caught one sub-legal fish to-date. However, that does not diminish my fascination with the fish, particularly since I ran across a 2019 report from the Gulf States Marine Fisheries Commission titled “Management Profile for Gulf of Mexico Cobia.” This 182-page report is definitely not a quick read and I have thus far only scratched the surface by digging into a few chapters that caught my interest. Nevertheless, it is so full of detailed life history, biology and everything else “Cobia” that it is definitely worth a look. This posting will highlight some of the fascinating aspects of Cobia and why the species is so highly prized by so many people.

Cobia (Rachycentron canadum) are the sole species in the fish family Rachycentridae. They occur worldwide in most tropical and subtropical oceans but in Florida waters, we actually have two different groups. The Atlantic stock ranges along the Eastern U.S. from Florida to New York and the Gulf stock ranges From Florida to Texas. The Florida Keys appear to be a mixing zone of sorts where Cobia from both stocks go in the winter. As waters warm in the spring, these fish head northward up the Atlantic and Gulf coasts of Florida. The Northern Gulf coast is especially important as a spawning ground for the Gulf stock. There may even be some sub-populations within the Gulf stock, as tagged fish from the Texas coast were rarely caught going eastward. There also appears to be a group that overwinters in the offshore waters of the Northern Gulf, not making the annual trip to the Keys. My brief summary here regarding seasonal movement is most assuredly an over-simplification and scientists agree more recapture data is needed to understand various Cobia stock movements and boundaries.

Worldwide, the practice of Cobia aquaculture has exploded since the early 2000’s, with China taking the lead on production. Most operations complete their grow-out to market size in ponds or pens in nearshore waters. Due to their incredible growth rate, Cobia are an exceptional candidate for aquaculture. In the wild, fish can reach weights of 17 pounds and lengths of 23 inches in their first year. Aquaculture-raised fish tend to be shorter but heavier, comparatively. The U.S. is currently exploring rules for offshore aquaculture practices and cobia is a prime candidate for establishing this industry domestically.

Spawning takes place in the Northern Gulf from April through September. Male Cobia will reach sexual maturity at an amazing 1-2 years and females within 2-3 years. At maturity, they are able to spawn every 4-6 days throughout the spawning season. This prolific nature supports an average annual commercial harvest in the Gulf and East Florida of around 160,000 pounds. This is dwarfed by the recreational fishery, with 500,000 to 1,000,000 pounds harvested annually from the same region.

One of the Cobia’s unique features is that they are strongly attracted to structure, even if it is mobile. They are known to shadow large rays, sharks, whales, tarpon, and even sea turtles. This habit also makes them vulnerable to being caught around human-made FADs (Fish Aggregating Devices). Most large Cobia tournaments have banned the use of FADs during their events to recapture a more sporting aspect of Cobia fishing.

To wrap this up I’ll briefly recount an exciting, non-fish-catching, Cobia experience. My son and I were in about 35 feet of water off the Wakulla County coastline fishing near an old wreck. Nothing much was happening when I noticed a short fin breaking the water briefly, about 20 yards behind a bobber we had cast out with a dead pinfish under it. I had not seen this before and was unaware of what was about to happen. When the fish ate that bait and came tight on the line the rod luckily hung up on something in the bottom of the boat. As the reel’s drag system screamed, a Cobia that I gauged to be 4-5 feet long jumped clear out of the water about 40 yards from us. Needless to say, by the time we gained control of the rod it was too late; a heartbreaking missed opportunity. Every time we have been fishing since then, I just can’t stop looking for that short, pointed fin slicing towards one of our baits.