It’s a big week for Dr. Solomon David and the GarLab at the University of Minnesota: Dec. 16-20 is the third annual Gar Week. It’s a seven-day celebration of some of the strangest fish to ever swim, those of the Lepisosteidae family. For David, a scientist and assistant professor, and the students in his lab on the St. Paul campus, Gar Week is when they get to unleash their enthusiasm for these misunderstood fish across America and social media.

David has been studying and sharing his love for gar for several years. Beginning in 2017, as an assistant professor at Nicholls State University in the Louisiana bayou region, his “GarLab” gained renown for important research and novel science communication. In 2022, with the people behind popular social media accounts at the Oklahoma Department of Wildlife Conservation, he launched Gar Week, which now includes partners at the U.S. Fish and Wildlife Service and elsewhere. It’s a week of science communication dedicated to little known and often misunderstood fish.

Two species of gar call the St. Croix River home: the longnose and shortnose; the longnose is more common in the St. Croix, while the shortnose seems to prefer the muddier Minnesota River. They turn up from time to time on fishing lines, as anglers reel in a toothy, armored species that is older than most dinosaurs, and little changed from 100 million years ago. The largest and probably best-known gar species is called the alligator gar, and they look like a giant reptile with fins instead of feet, but alligator gar are not found farther north than St. Louis. The gar’s cousin the bowfin also lives here, an eel-like creature of backwaters, and has also not changed much since the Paleozoic Era. Together, gar and bowfin are called holosteans.

This is the GarLab’s first Gar Week based in Minnesota. Last spring, David, his family, and his lab moved up the Mississippi River from Louisiana to the University of Minnesota, where he has brought his knowledge and passion to a state that he says is leading the way on managing native “rough fish.” He is now teaching, overseeing a busy lab in Hodson Hall, staffed by students from undergraduate to in pursuit of PhDs, and leading research projects.

“I’m really excited to be in Minnesota, where the legislature, the DNR, and a lot of people are invested in this work,” he says. “We have the most comprehensive native fish law in the country, and other states are looking to us.”

But, while Minnesota has new policies in place to protect native rough fish, there is simply a lack of basic scientific information about many of the species, making it difficult to change things like fishing seasons and harvest limits. Also, most anglers and the general public know little about gar and many other species of native fish, and aren’t very invested in their conservation. David and the GarLab are here to help.

Primitive predators

Holosteans have evolved very slowly over millions of years, but have unique adaptations to the difficult places they like to live.

“Gars are so unusual,” David says, explaining why he first fell in love with them and is still passionate. “Most people can’t believe they exist here in Minnesota.”

Gar are notable for their long snouts filled with sharp teeth — rather than a hard bite, they thrash their heads back and forth to get the necessary force to impale a fish on a tooth, and then swallow it whole. Bowfin have a serious set of teeth, too. At their most basic level, holosteans are predators, eating any other fish, crustaceans, or other creatures they find.

They are built to kill, a wolf of the water, or a miniature Megalodon. Like most such predators, they are critical to keeping the food web in balance.

“They will usually eat what’s most abundant,” David says. The fish help harmonize the ecosystem, ensuring its diversity and resilience.

Another reason gar seem so dinosaur-like is their armored body. Their scales are made of a material similar to tooth enamel, structured like chain mail, giving them hardened defenses against predators.

“You have to use a tin snips to get through it,” David says.

One of gar’s and bowfin’s most unusual abilities is not very fishlike: they breathe air same as you and me. Like most fish, they have gills for absorbing oxygen from the water and a swim bladder that helps them maintain buoyancy. But unlike most fish, holosteans’ air bladders are packed with blood vessels that absorb oxygen, allowing them to regularly surface and take a gulp of air before returning to the underwater world.

This unique ability is useful in their preferred habitat: backwaters and other shallow, slow-moving areas that often have warm, stagnant water very low in oxygen. Most fish can’t live long in such an environment, but that just leaves more territory for the gar and bowfin.

Indigenous people have long had a relationship with the fish. Gar are the subject of a special ceremony and dance of the Chickasaw people, who live among them in the southern United States. Archaeological evidence shows that gar scales were historically used for arrowheads by people of many tribes.

By and large, however, these unique fish have been mostly ignored by anglers, fishery managers, and scientists for the past couple hundred years. Not anymore.

Starting with a census

One of the GarLab’s first major undertakings in its new Minnesota home will be studying gar and bowfin in three rivers: the St. Croix, Mississippi, and Minnesota, as well as three additional lakes in the state. The species they will study were identified as priorities for research by the DNR in a report it produced for the legislature last year. Funding for the project is expected next summer, from the Minnesota Lottery.

“These long-lived species play crucial roles in Minnesota waters by maintaining ecological balance, serving as hosts to freshwater mussels, and serving as environmental indicators,” David wrote in the grant request.

The research will cover a lot of water and use some advanced methods to learn a lot about the fish. It will begin with dozens of boat trips, using nets and electroshocking to collect samples, temporarily detaining hundreds of fish. Established practices like weighing and measuring each specimen will help establish baseline data about the status of the population. That information can then be fed into computer models that help inform sustainable harvest levels and other management decisions.

“We just don’t have a lot of basic life history or population data,” David says. “We need to start establishing baselines, looking at a few rivers and lakes to begin estimating population sizes.”

Many fish will also get part of their tail fin clipped, which allows the team to analyze it for stable isotopes. These findings will shed light on the fish’s place in the complicated aquatic food web. The different types of elements will help scientists understand what the fish are eating and where they are eating it. A small percentage of the fish will be euthanized for analysis that requires it. By extracting special bones from the fish’s ears, the researchers can determine their age, helping understand growth rates, lifespan, and more.

When the project is completed in 2028, Minnesotans will know much more about some unique fish. There will also be many more questions to come.

Floodplain fish

Tracking gar and bowfin populations is kind of like getting an annual physical exam for the health of an entire river and its watershed. By monitoring these species, scientists can see if anything is interfering in their life cycle, if there are any subtle changes in the ecosystem to cause concern.

Holosteans have a particular dependence on “connectivity,” how different parts of the river system are linked. Part of this is floodplain connectivity — that the river can and does occasionally spread out across the flat floodplain that surrounds it. Submerged floodplain is important for gar’s and bowfin’s reproduction cycles, access to food, and more.

“Gars depend on aquatic connectivity,” David says. “Floodplain connectivity is important for the whole food web.”

Floodplain connectivity happens to be an important issue for the St. Croix. Throughout gar’s native range, dams and levees cut off connections, blocking gar from the places they need in order to persist as a species. Changes on land like agriculture and development can affect runoff, and changes to the climate can affect precipitation amounts and timing, influencing how a river is affected by its own flow.

If greater- and faster-than-average floods affect a river, the current carves deeper down into its channel. The farther the water digs down, the greater the distance to the floodplain, making it harder for water levels to reach the floodplain, creating a feedback loop that can change the fundamental functions of a river. But when there are gar, there is hope.

Last month, David was back in Louisiana working on a project with The Nature Conservancy and U.S. Fish and Wildlife Service. They captured several alligator gar and contributed to an experimental effort to track restoration success through gar populations.

The international conservation organization and federal agency have been working together to restore floodplains along the lower Mississippi, and they’re monitoring the gar population to help measure their success.

In Minnesota, The Nature Conservancy has been engaged in similar work to protect and restore floodplains for the past several years, focusing on reforestation of floodplains in the face of invasive plants and other problems. Gar could benefit, and play a role in tracking the effort’s success.

Student scientists

Studying and working for the GarLab means lots of time on boats, at the bench, dissecting fish, analyzing data, writing up results, caring for live fish in the lab’s extensive aquariums and holding tanks, and many other tasks. It also means a dedication to connecting the wider world to the wonders of gar.

Three students were in the lab one recent afternoon, sitting around a bench, typing and talking, surrounded by fish both alive and dead. Alyssa Rausch is working on her PhD dissertation focused on how the lives of gar and bowfin in northern and southern climates both differ and are similar, with an eye toward being able to predict how the fish might respond to future climate change. Ella Chmielewski is a senior who plans to make a career sharing science with the public, and Jenna Pearson is an undergrad with a lifelong love of under-appreciated animals, from sharks to gar.

While their work produces important knowledge about fish and the places they live, science communication is also incorporated into everything they do. It’s part of what David teaches, in addition to fish biology. For the students, the communication work is difficult but fun. Crafting a post for social media that will stand out to their audience and convey accurate and compelling information is not as easy it sounds. The lab has a big online following and a widespread reputation for creative communication.

“You know a ton about these fish but have to think, how can I reach people?” Rausch says. “It’s really important to push yourself.”

One important strategy David has pioneered and is a key aspect of Gar Week and a lot of GarLab’s communications is not to take the subject to seriously. There are lots of silly memes, puns, dad jokes, and just plain goofing around. That’s not because the professor and his students aren’t steadfastly committed to research and conservation, but because a positive, playful voice can carry a long ways in the noisy online world.

”The more fun you have with it, the better it works,” Pearson says. “If scientists have fun with it, others will too.”

Evolutionary envy

While gar have been largely ignored for the past century or so, they may have much to teach us. They have survived and thrived on Earth for 300 times as long as humans. How they have managed to do that is an important question.

Besides their ancient appearance, coat of armor, air-breathing ability, and important connections to floodplains, there is another enticing mystery about the evolution of holosteans. It may have important implications for medical research.

”Bowfin and gar have the slowest rate of evolution among any vertebrate with a jaw,” David says, referring to a certain species classification, leaving out things like lampreys. “Something is holding back mutations.”

To illustrate this point, the scientist points out that two gar species that separated from a common ancestor about 100 million years ago are still closely enough related that they can reproduce and create fertile offspring. It’s unlike any other known relationship in the world.

Because holosteans have evolved so slowly, scientists believe the fish have some type of repair mechanism that corrects mutations in their DNA, the usual driver of evolutionary change. If that capability can be understood and replicated, it could potentially help develop drugs to treat cancer in humans, which is also essentially an issue of DNA mutations. Working with Yale University, the GarLab is helping advance research into this promising possibility.

These tough, toothy fish are often called “living fossils,” for their primitive appearance and the fact their cousins can be found far back in the geologic record. How a species can survive the cataclysmic events of eons is a question worth asking.

Balancing act

Native fish like gar still keep many secrets to themselves. With the state of Minnesota at the forefront of a nationwide rethinking of fish management and research, David and the GarLab will be trying to reveal many of those mysteries. They will also provide a lot of the knowledge needed to keep these species safe.

“We learn basic stuff about these fish all the time,” David says. “We’re a hundred years behind walleye or largemouth bass.”

From dams to water pollution, overharvest to floodplain loss, the challenges facing gar, bowfin, and all aquatic wildlife are manifold. One of the biggest threats to holosteans is how little we know of their lives.

And while popular sport fish species have been the subject of much research and public discussion over the years, maintaining a healthy population of any species is about more than just bag limits and season dates. The food web must be in balance, species that aren’t popular for sport-fishing must be seen as important, and aquatic connections must be maintained.

“We need to take care of the entire ecosystem,” David says. “That’s a big job and we’re just at the beginning.”