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How did you first learn about gar?
I was always interested in dinosaurs. If you think of prehistoric animals, of course dinosaurs come to mind, but gars have been around since the late Jurassic period. I first saw a gar in an issue of Ranger Rick. I was about 11 years old, flipped to the middle, and saw this fish that looked like an alligator with fins. It had this really primitive, ancient look to it. And I thought 鈥�wow, this is really cool.鈥�
It was an alligator gar. I read everything I could about that group of fish 鈥� the gars. It really just captivated my attention and imagination during that time. Luckily, I circled back by the time I got into grad school and was able to study gars for my master鈥檚 and dissertation research. I鈥檓 still chasing my childhood fish fascination today.
How many different gar species are in the U.S.? Where are they found?
There are only seven gar species alive today, but there were more earlier in the fossil record. Today, they鈥檙e found from southern Canada all the way down to Costa Rica, and mainly in the eastern half of the United States. Gars used to range into Africa, Asia, and Europe鈥攚hat we call a Pangeaic distribution.
Can you remember the first time you came across what you might consider a 鈥渕ega鈥� gar?
Definitely. I was a graduate student at the University of Michigan. I went to New Orleans for a conference about gar. Dr. Allyse Ferrarahadput together a symposium. I was excited to meet a bunch of people who were studying gar, including agency folks from the U.S. Fish and Wildlife Service and Louisiana Department of Wildlife and Fisheries. At the end of the conference, Dr. Ferrara and her grad students said, 鈥�Hey, we鈥檙e heading back to Thibodaux to do some field work鈥ou interested in joining?鈥�
They said, 鈥�We鈥檙e going to be sampling alligator gar.鈥� And I was like, 鈥�WHAT?!?鈥� I quickly got on a computer, changed my flight, and made sure I could be part of that.
It was January 2009. Another guy from Canada and I were like the northern gar guys down there. And we willed them to be caught. We were like, 鈥淲e need to see these alligator gars.鈥� Sure enough, we got one that was just under five feet long.
Man, I mean seeing an alligator gar for the first time in the wild鈥hat鈥檚 definitely imprinted on my memory. And it was at this small university in southeastern Louisiana. In 2017, a job opportunity came up there and now I鈥檓 down here working on gar alongside Dr. Ferrara and other researchers at Nicholls State University.
The alligator gar is the largest gar species alive today. As far as I know, it鈥檚 the largest even compared to fossil gars. They can easily get up to eight feet long; maybe even close to 10 feet historically, but we don鈥檛 have great records of that. They can weigh over 300 pounds.
I often describe them as 鈥渁lligators with fins instead of legs,鈥� but gars have actually been around longer than alligators. So I think we should be calling alligators 鈥済ars with legs instead of fins鈥� if we want to be fair to who came first.
They鈥檝e got these diamond-shaped armored scales covering their body and their face is extremely bony. That long snout is filled with lots of sharp conical teeth.
In addition to their size, one of the things that makes them successful is that they鈥檙e air breathers. Not a lot of fish do that. It allows them to persist in environments where more conventionally respiring fish can鈥檛. They鈥檝e also got armor-plated ganoid scales made up of a material very similar to the enamel on our teeth.
They鈥檙e coming with the 鈥�gar-mor鈥� as we like to call it. These traits in combination have helped them be successful for such a long time鈥娾€斺€妎ver 150 million years.
Can you tell us more about the scales? What are the advantages and disadvantages?
They鈥檙e not quite impenetrable, but that tough hide is very difficult to get through if you鈥檙e a predator. The scales are interlocking 鈥� almost like chain mail. With that comes a bit less flexibility compared to fish with ctenoid or cycloid scales. Gars may not be able to turn on a dime, but they鈥檙e much more flexible than we give them credit for 鈥� they can manage a little S-curve or C-shape bend.
They鈥檝e got poisonous eggs, right? Is that unique to gar and what about them makes them poisonous?
The short answer is: we don鈥檛 know exactly what makes them poisonous. Dr. Gary Lafleur and his lab down here at Nicholls State have been looking at gar eggs and trying to determine the specifics of their toxicity. I think a study that came out in 2020 that determined it might be a particular phospholipid. But we don鈥檛 know if it鈥檚 bacterial-based or if the fish are producing it (this would be extremely rare). What else is unusual is that bowfin鈥娾€斺€妕he closest relatives to gars鈥娾€斺€奾ave edible eggs (these two groups are still separated by a decent chunk of time between divergence).
What鈥檚 also interesting about gar egg toxicity is that they鈥檙e toxic to mammals, birds and invertebrates, but not to other fish or some reptiles. You would think if your eggs are going to be toxic, why not have them be toxic to the animals you鈥檙e sharing the environment with? Gars spawn in relatively shallow water that鈥檚 extremely warm. Our working hypothesis is you don鈥檛 find those conventionally respiring fish there (like bluegill or other egg predators), but you do find crustacean predators like crawfish. And water birds. So we think maybe that鈥檚 how that toxicity might have evolved. Humans: don鈥檛 eat gar eggs. You鈥檙e going to get violently ill.
What challenges are gars facing?
One of the big threats is definitely habitat loss. As we鈥檝e dammed rivers and leveed in certain sections of flood plains, we鈥檝e cut off gars from their spawning areas. That鈥檚 caused issues with their population鈥攋ust like with paddlefish, sturgeon, and other migratory fishes that need access to floodplains and to spawning grounds. It鈥檚 a plight of a lot of freshwater fishes.
There鈥檚 also this idea that gars eat game fish. In most cases that鈥檚 just not true. Gars are predators鈥娾€斺€妕hey鈥檙e going to eat what鈥檚 most abundant. In many cases they鈥檙e eating shad and other forage fish. In some cases it鈥檚 panfish or game fish but, if that鈥檚 what鈥檚 most abundant in the system, we need predators to maintain balance in any given fish community or the broader ecosystem.
I think that lends itself to the poor reputation of gars. I say they鈥檝e had a historically bad reputation, but really, if you go back further in time, Native Americans and other indigenous people used to eat gar. They still eat gar. They make jewelry and arrowheads out of the hides. They were much more highly utilized. Then, when we think of a more colonial perspective, different fish took a higher ranking. I think it鈥檚 a matter of perspective with how gars have been treated over the years. Now we鈥檙e trying to improve that reputation, showing they have value as food fish, bring balance to ecosystems, and even recently showing they have value for genomics work and potentially for biomedical research.
You mentioned they need floodplains to spawn.
A lot of times we think of these longitudinal migrations, right? We think of salmon swimming upstream to the spawning grounds. And some gar species do something similar鈥攍ongnose gar in some areas do leave the mainstem river and swim into the tributaries. But further down south, alligator, longnose, spotted, and shortnose gars perform lateral migrations. When water levels rise in the spring, gars move out onto the floodplains. They take advantage of that seasonal floodplain inundation. It allows them to use additional habitat for spawning, feeding, and nursery areas.
In some areas, alligator gars will actually use inundated terrestrial vegetation to lay their eggs. The adults then eventually move off the floodplain and back into the mainstem. So in some rivers, alligator gars actually require floodplain inundation to successfully spawn. In other areas鈥攃oastal environments鈥攖hey may not be as dependent on that.
It鈥檚 really the population level that鈥檚 important when we鈥檙e thinking about conserving these species. We modify and regulate rivers for different purposes. Obviously where people live we don鈥檛 want those areas to be flooded. But where we can return rivers or floodplains to more natural cycles of inundation, that鈥檚 beneficial for fish, and also for water birds and other wildlife.
Learn about the other gars!
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