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Florida’s Living Fossils

Florida’s widespread fisheries and diversity of species that exist are unrivaled in comparison to nearly any location around the world. Among many of the species within this diverse taxonomic group includes several that have displayed incredible evolutionary adaptations and resilience to survive over millions of years.

...it is unimaginable to think that sawfish still roam select waters, with Florida home to one of the last populations of breeding mud marlin.

Over the course of history, Florida has seen many changes not only in sea level and urbanization, but the native and exotic species that inhabit this great state have also undergone immense pressure regarding habitat encroachment and overfishing. With such dire circumstances for some indigenous species, both the state and federal government have stepped in to thwart extinction by enacting and enforcing rules meant to preserve dwindling species stocks. As an angler, it is imperative to mind these regulations if ever one  of the following is hooked or seen given their likely tenuous standing.

With prehistoric legacies intact along with paleontological records documenting their origins, these living fossils are a treat to happen upon in our home waters but please proceed with caution.

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Photography: FWC Fish & Wildlife Research Institute

Smalltooth Sawfish
Pristis pectinata

Known for its elongated rostrum that’s both a sensory organ and weapon, the sawfish is a species of ray that has survived since the Cretaceous period when dinosaurs ruled the world. In what would now be the Sahara Desert, flying reptiles with 20-foot wingspans, crocodile-like dinosaurs 50-feet in length and other massive predators fed on giant sawfish, lungfish and sharks in a prehistoric river system. The beauty of science and paleontology is that fossils paint a clear picture of the past and the incredible animals that once existed.

While there is still a lot to uncover, scientists have discovered the fossils of what is likely the first aquatic dinosaur—Spinosaurus.
Living on aquatic prey, this giant dinosaur’s fossils were found with 25-foot sawfish fossils in the near vicinity dating back nearly 95 million years. The Moroccan desert is no longer the fertile river system it was millions of years ago, but it is unimaginable to think that sawfish still roam select waters, with Florida home to one of the last populations of breeding mud marlin.

Euryhaline, or moving between fresh and saltwater environments in the warm water of select Atlantic and Indo-Pacific regions, five species of sawfish exist worldwide, yet only one species occurs in Florida waters. All face critically low population levels, with Florida’s smalltooth sawfish protected from harvest since 1992, listed under the Endangered Species Act since 2003, and protected by the Convention on International Trade since 2007.

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Sawfish are critically endangered and poorly studied, although scientists at the FWC Fish & Wildlife Research Institute have begun equipping sawfish with acoustic tags to aid in their recovery efforts.
Photography: FWC Fish & Wildlife Research Institute

Sawfish were once encountered across much of Florida, including the St. Johns River and Indian River Lagoon system, but now they are seen with the most prevalence along the southwest coast of Florida from the Charlotte Harbor estuarine system to the stained and relatively unexplored backwaters of Everglades National Park.

Sawfish seek out the slightest movement of prey in murky waters with their elongated rostrum that is covered with electrosensitive pores. If a prey item is detected, the sawfish makes excellent use of the rostrum’s 22- to 29-unpaired teeth on each side to stun and impale food items before consumption. Small eyes are an evolutionary result of muddy residential habitat with the rostrum being its main sensory device. With a skeleton made of cartilage, its skin is covered with dermal denticles leaving a roughness much like shark skin.

Little is known about sawfish, although researcher programs at the FWC FWRI are starting to uncover more data that will inevitably aid in bringing them back to once healthy, historic levels. If you encounter a sawfish as bycatch or spot one in its natural environment, FWC asks that you report the sighting to [email protected] and include the location, estimated length and any other relevant details.

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Although scientists aren’t exactly sure why, Gulf sturgeon routinely take to the air during the summer months causing potential harm to nearby boaters.
Photography: Thomas Hasenberger/Adobe Stock

Gulf Sturgeon
Acipenser oxyrinchus desotoi

Appearing in fossil records that date back more than 220 million years, there are two dozen sturgeon species worldwide, four in North America, with the Gulf sturgeon the only species encountered in Florida waters. While they have ancient origins, sturgeon haven’t changed much over the years. Yet with all they have seen come and go through history, they are now endangered and on the brink of extinction from overfishing and habitat degradation. Gulf sturgeon are most common in the Suwannee River and other spring-fed, free-flowing rivers, typically with steep banks and hard bottom along the Panhandle.

Gulf sturgeon are listed as a subspecies to the Atlantic sturgeon that emerged with the separation of the Florida peninsula over a million years ago. According to researchers it is estimated there are over 10,000 Gulf sturgeon that call the Suwannee River home in the summer and approximately 3,000 sturgeon in the nearby Choctawhatchee River. Sturgeon have survived years of evolution in a diverse array of habitats of which some are less than optimal, but they soldier on.   

Protected under the federal Endangered Species Act, Gulf sturgeon grow to 6-feet in length, weigh upwards of 200-pounds, and can injure or kill boaters caught in their leaping crossfire. One of the largest Gulf sturgeon ever recorded was caught in 1936 and weighed over 500 pounds.

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Photography: Joe Richard

Jumping prowess aside, the Gulf sturgeon is generally found in the state’s northwest rivers emptying into the Gulf of Mexico and all coastal Gulf portions east of the Mississippi River. Being anadromous, Gulf sturgeon will enter freshwater rivers from saltwater environments to spawn as individual females may produce between 200,000-500,000 eggs per cycle, spawning multiple times during her lifespan. Only a few eggs will see eventual maturity. Additionally, Gulf sturgeon have a very strong homing instinct and many return to their own natal rivers in the spring to spawn, further drilling home the importance of habitat protection.

Regarding harvesting, it is illegal in both federal and state waters to take or otherwise injure a Gulf sturgeon. Long lived, slow growing and late to mature, Gulf sturgeon were the perfect candidate for overfishing and that’s exactly what happened. By the late 1800s, populations had been reduced dramatically due to the profitability of caviar harvesting.

In Florida, a commercial fishery was responsible for the harvest of nearly 400,000 in the early 1900s. The species’ population was also severely depleted by habitat degradation from storm runoff, urbanization and the introduction of dams to local watersheds. Along the Apalachicola River below the Jim Woodruff Dam, a short-term fishery existed where anglers utilized snatch hooks to harvest sturgeon that congregated below the dam having blocked their upstream movement to historical spawning sites.

In 1991, the species was added to the threatened species list under the Endangered Species Act, with a harvest and possession ban in place across the U.S.

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While occasionally encountered by offshore anglers, most lancetfish are only observed after washing up on area beaches where they are quickly labeled ferocious sea creatures.
Photography: Doughertyphotos.com

Lancetfish
Alepisaurus ferox

Of all the living fossils found in Florida, the lancetfish is perhaps one that most will never encounter given its domain is the dark depths of our deepest offshore waters.

Classified as a large oceanic predatory fish that occurs in the epipelagic and mesopelagic zones, its genus Alepisaurus is a combined Greek word that translates to “skinless lizard.” Not much is known of this species, given its preferred habitat, but the teeth of fossilized lancetfish ancestors have been uncovered in Spain and derived from the early Cretaceous period when a relatively warm climate existed with sea levels creating numerous shallow inland seas.

Having survived the extinction of many other species, lancetfish are now divided into two species, long- and short-snouted, both exhibiting large, wide mouths and long, fanged sharp teeth. With a slender body and the ability to grow over 6-feet, the lancetfish’s watery muscling is not suited to pursuing prey in lengthy chases, and is more prone to ambushing smaller finfish, crustaceans and cephalopods in the dark depths of the deepest oceans worldwide. A pronounced dorsal fin that is twice as high as the body is deep enables the fish to make quick thrusts and tight turns to capture evading prey.

Stomach contents from fish caught as bycatch in swordfish and tuna fisheries reveal this species is cannibalistic, which is common to many opportunistic species that must survive in harsh environments. From the subtropical waters of Florida across the Atlantic to South Africa, to the Aleutian Islands in the North Pacific, Chile, Japan, Australia and New Zealand, lancetfish know no deep boundary.

Reproductively speaking, not much is known aside from adolescent gonads being hermaphroditic. Adults are oviparous, meaning eggs are laid with little or no embryonic development within the mother. Additionally, basic details of their lifespan, breeding and length of spawning season are still a mystery.

In Florida, lancetfish are most often encountered by daytime swordfish anglers plying the dark depths of the Florida Straits. Here, anglers often soak squid in 1,500- to 2,000-foot depths and occasionally bring lancetfish to the surface.

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