Image of a man holding a French River Bowfin in Ontario Canada.

3 Important Ancient Fish of Ontario: Bowfin, Gar, and Sturgeon

Do you love history, particularly living history? Imagine yourself swimming with living dinosaurs, or perhaps even holding one. While this may not be Jurassic Park, in Ontario you can get close to that experience by encountering some of the oldest living fish still swimming on Earth: Bowfin, Gar, and Sturgeon.

These three fish species have lived for hundreds of millions of years, surviving mass extinctions, ice ages and human impacts. These living fossils have remained largely unchanged, allowing us to glimpse the secrets of evolution and the history of life on our planet.

In this article, we will explore the fascinating features, behaviours and important roles of these ancient fish in Ontario’s aquatic ecosystem. We will also discuss the challenges and threats they face and the need to conserve them for our future.


Bowfins are fascinating bony fish native to North America and found in many areas of Ontario. Bowfins have various nicknames including mudfish, mud pike, dogfish, grindle, Grinnell, swamp trout, and choupique.

They are sometimes confused with the Northern Snakehead (Channa argus) who were originally native to China, Korea, and Eastern Russia before being imported to North America as food and pets.

Now, let’s see what separates Bowfin from other ancient freshwater fish and dive into some intriguing details about them:

Bowfin’s Ancient Origins:

Bowfins belong to the group of fish known as Halecomorphi, which first appeared during the Early Triassic around 250 million years ago. Previously people believed Halecomorphi had one surviving member of Bowfin (Amia calva) until a genetic study in 2022 by the New York State Museum and SUNY-ESF proved the existence of two surviving species in this ancient lineage. Their research found enough variation within the Bowfin genus to denote Amia ocellicauda or “Eyetail Bowfin” (proposed by Brownstein et al) as its second member. There’s currently more research being conducted since the report indicated the potential of two additional distinct surviving members within the Bowfin genus.

Currently, fossil evidence indicates that Amiiformes (the order to which bowfins belong) were once widespread across North and South America, Europe, Asia, and Africa. However, their current range is limited to much of the Eastern United States and adjacent Southern Canada.

Image of a man holding a French River Bowfin in Ontario Canada.
French River Bowfin in Canada. For more, see the IGFA Line Class World Record Trophy Bowfin from French River, Ontario.

Bowfin’s Physical Characteristics:

  • Bowfins have a mottled green and brown colouration.
  • They boast a long dorsal fin and strong conical teeth.
  • Females can reach a length of up to 75 cm (30 inches), while the largest bowfins weigh around 9.8 kg (21.6 pounds).
  • Males are usually smaller, growing between 45.7 and 61 cm (18 and 24 inches).
  • Male Bowfins will peacock to attract mates. See Why is the Bowfin is Green?
  • They are also distinguished by a black tail spot circled with an orange or yellowish ring around that spot to mimic the appearance of a fish’s eye and confuse predators.

Bowfin’s Ecological Role:

While some may consider them a “trash fish”, Bowfins are very unique and still misunderstood in their importance to the ecosystem’s biodiversity. Bowfins, like frogs, are indicators of a healthy ecosystem. They also mostly exist in ancient bodies of water and tributaries living lives similar to Largemouth Bass in swampy and sometimes turbid water.

Currently, Bowfins are considered generalist predators as a species, feeding on various small animals like amphibians, crustaceans, insects, snakes, and other fishes. Yet, recent studies in the Laurentian Great Lakes from the University of Windsor indicate some Bowfin have developed a “[…] high degree of individual specialization […]”. Meaning, some Bowfins are more selective of their prey.

However, the study also admitted to needing more research on their dietary habits and environmental relationships. For now, as a species, Bowfin helps control the populations of smaller fish to maintain the habitat’s ecological balance.

What you should know:

  • Bowfins are stalking, ambush predators that often venture into shallow waters at night to prey on fish and aquatic invertebrates.
  • Young bowfins primarily feed on small crustaceans, while adults are mostly piscivorous (fish-eating) but are also opportunistic.
  • Their preferred habitats include vegetated sloughs, lowland rivers, lakes, swamps, and backwater areas. Occasionally, they are found in brackish water.


Bowfins are long-lived freshwater fish. According to the University of Minnesota’s study, by Lackmann et al., of Amia calva’s size-at-age data from their otoliths (ear stones), some individuals reached an impressive age of 33 years in the wild, “15 years longer than previously estimated […]”. This aligns with other studies of Amia calva that lived in captivity for 30 years.

Longnose Gar

Longnose Gar (Lepisosteus osseus) is the most abundant member of the Gar family. They are sometimes referred to as “Gar Pike” because of their resemblance to Northern Pike (Esox lucius), but as discussed in a previous article they hail from very different families of fish.

So, what’s special about Gar? Let’s find out below!

Gar’s Ancient Origins:

Gars have been native to North America for the past 100 million years or around the time the T. Rex roamed the Earth. Gars comprise of seven living species of fish in two genera of ray-finned fish with distant relations to Bowfin. The largest member of the Gar family is the Alligator Gar (Atractosteus spatula). However, Ontario is only home to two, the Longnose Gar and the Spotted Gar. The latter of which is an endangered species residing only in Southern Ontario.

Longnose Gar on the French River Delta, French River Provincial Park, Northeastern Ontario.
Image of a French River, Ontario Longnose Gar of a fisherman in a Bear’s Den rental boat.

While this late Cretaceous era fish could have appeared in Jurassic Park, in Ontario you can find Longnose Gar as far North as Sault St. Marie to Lake Temiskaming. They also reside in many other water bodies in Ontario connected to Lake Huron including but not limited to:

  • French River
  • Georgian Bay
  • Pickerel River
  • Lake Nipissing

They can even be found in other places like:

  • Lake Erie
  • Lake Simcoe
  • Lake Ontario
  • Ottawa River

Longnose Gar’s Physical Features:

Like Bowfin and Sturgeon, Longnose Gars have ganoid scales. Their scales give them a glossy appearance that is tough like tooth enamel, making their scales function like plate armour. They have long tube-like shaped bodies that are coloured olive to brown starting from their back before fading to white on their belly. Longnose Gars also have black spots on their head, fins and body to help break their pattern, but they are not as heavily spotted or dark as the Spotted Gar.

Infographic displaying the differences between the species of Gar's and their snout's shapes. Photo credit to Matthew R. Thomas and the Government of Kentucky.
Photo Credit: Matthew R. Thomas & Kentucky Department of Fish & Wildlife Resources

Now, the most notable part of all Gars are their long narrow mouths. Longnose Gar, as its namesake suggests, has the longest snout out of the Gar family. Their snout’s length measures up to 20 times its width. In comparison, the Alligator Gar which is also the largest member of the Gar family has a wide and stocky snout – measuring 4.5 times its width. As for the Spotted Gar, they too have shorter and wider snouts like the Alligator Gar.

Another unique feature of Bowfins, Gars, and Sturgeons internally is their ancient digestive system.

Infographic sketch showing 4 different types of Spiral Valves in various fish species including sharks.
4 different types of Spiral Valve structures found in nature. Original infographic credit to Leigh et al. 2021 via The Royal Society Publishing. Edited image found on Malcom Peaker’s BlogSpot.

They have an organ called a “Spiral Valve” or “Scroll Valve” – a type of corkscrew-shaped portion of their intestine that internally twists or coils to increase the surface area the intestines can extract nutrients from their food. Because of its shape, it allows these fish to maintain smaller digestive organs and act partially as a second stomach while their food slowly passes.

In short, Bowfins, Gars, and Sturgeons do not need to eat as frequently as some other types of freshwater fish and their bodies can prioritize growing other larger organs such as swim bladders or hearts. Yet, the trade-off to their ancient digestive tract is their difficulty in passing large hard objects (like bones and stones) and they either need additional time in their stomach to soften or be regurgitated.

Gar’s Ecological Role:

Traditionally, anglers viewed Gars to be a pest, but there has been growing interest. Currently, few actively fish for Gars in Ontario, but let’s discuss their impertinence and ecological role. ​

  1. Biodiversity Enhancement:
  • The Longnose and Spotted Gar contribute to the overall biodiversity of the aquatic ecosystem they inhabit.
  • Their presence helps control the population of smaller fish species, crustaceans, small mammals, and insects allowing for a more balanced ecosystem.
  1. Movement Patterns and Spatial Ecology:
  • Longnose Gars were traditionally thought to be highly resident, with limited large-scale movements. However, in 2023, Environmental Biology of Fishes published research from Melanie Croft-White et al. using acoustic telemetry and tagging in Lake Ontario. Their study revealed Longnose Gars have a more dynamic behaviour.
  • Three distinct movement patterns were observed:
    • Migrants: These individuals moved throughout much of Western Lake Ontario, covering a maximum displacement of 184 km (linear distance).
    • Residents: Some remained near their original tagging location.
    • Sporadic Migrants: These fish exhibited both migratory and resident behavioural patterns in different years.
  • Seasonally, Gars were most active during summer and fall, with more restricted home ranges during winter, suggesting quiescent behaviour.
  1. Reframing Assumptions:
  • The study challenges the presumption that Gars are primarily resident fishes with restricted space use. Instead, it confirms that a majority of tracked Longnose Gar make large-scale movements in Lake Ontario and presumably in other water bodies of Ontario.

In summary, the Longnose Gar’s ecological role extends beyond mere residency, contributing to the health and balance of Ontario’s aquatic ecosystems.


The Lake Sturgeon (Acipenser fulvescens) is a fascinating species. They’re ancient, culturally important, enormous, and a species at risk. Sturgeons are one of the oldest surviving freshwater species in North America and are the oldest species of fish to inhabit the Great Lakes reaching into the French River.

Harry with his French River Sturgeon for a quick photo before release. Read the full story of this amazing catch!

Sturgeon’s Ancient Origins:

Lake Sturgeon belong to the Acipenseridae family consisting of 28 species of fish. We can trace Sturgeon’s origins to the Late Cretaceous – Early Jurassic period approximately 200 million years ago. The family is grouped into four genera: Acipenser, Huso, Scaphirhynchus, and Pseudoscaphirhynchus.

All Sturgeons are slow-growing fish, seldom maturing before age 12 depending on the specific species and gender. All are long-lived and most Sturgeon attaining 75 years or more in the wild.

Specifically, Lake Sturgeon do not reach sexual maturity until they are 10 – 30 years old according to U.S. Fish & Wildlife and spawn in intervals. Female Lake Sturgeon spawn once every 4 to 9 years whereas males spawn every 2 to 7 years. The Government of Canada’s research indicates Lake Sturgeons:

[…] Ranges from 18-20 years for males and 20-28 years for females. On average, males spawn every second year, and females every fourth to sixth year, in the spring when water temperatures reach 10-18˚ C. Fecundity depends on size of the female; the number of eggs laid ranging from 50,000 to [more than] 1,000,000. The eggs hatch in 7-10 days and the larvae are negatively buoyant until the formation of the swim bladder, about 60 days post-hatch. Larval drift occurs at night and begins about 2 weeks after the first spawning activities.


Larval and juvenile mortalities are high and few survive to adulthood. Adult mortality is low in areas not impacted by human influences such as hydro-dams, agricultural runoff, and land development.

Lake Sturgeon’s Physical Features:

  • The Lake Sturgeon is Canada’s largest freshwater fish. In North America, they can weigh over 240 lbs (108.862 kgs) and reach over 87.5 inches long (222.25 cm) in length.
  • It boasts an extended snout with four barbels (whisker-like) organs near its mouth. Interestingly, its tastebuds are located on and around its barbels and rubbery prehensile lips used to vacuum in soft foods similar to Suckerfish and lack teeth.
  • Its body is covered with large bony plates called scutes, a bony plate overlaid with scales like on the shells of turtles and birds’ feet. The scutes are more pronounced in juvenile Sturgeon and less so in larger fish.
  • The colouration ranges from dark to light brown or grey on the back and sides, with a lighter belly.
  • Unlike most fish found in Ontario, the Lake Sturgeon and Bowfin have a cartilage-based skeleton instead of bones.
  • These ancient fish can live up to 150 years.

Sturgeon’s Habitat:

  • Lake Sturgeons thrive almost exclusively in freshwater lakes and rivers with soft bottoms of mud, sand, or gravel.
  • They prefer depths ranging from five to 20 meters.
  • During spawning, they seek out relatively shallow, fast-flowing water with gravel and boulders at the bottom. This often occurs below waterfalls, rapids, or dams.
  • However, they are adaptable and will spawn in deeper water if suitable habitat is available.
  • Interestingly, they also spawn on open shoals in large rivers with strong currents.

Lake Sturgeon’s Distribution in Ontario:

Lake Sturgeons can be found across North America, from Alberta to the St. Lawrence drainage in Quebec and from Southern Hudson Bay to the lower Mississippi.

In Ontario, they inhabit rivers within the Hudson Bay basin, the Great Lakes basin, and their major connecting waterways, including the St. Lawrence River.

There are three distinct populations in Ontario:

  • Great Lakes – Upper St. Lawrence
  • Saskatchewan – Nelson River
  • Southern Hudson Bay – James Bay

Conservation Status:

Lake Sturgeons were listed as “Special Concern” when the Endangered Species Act became enforced in 2008 before reclassifying them into three distinct conservation populations:

  • Endangered (Great Lakes – Upper St. Lawrence populations): Imminent risk of extinction or extirpation. Sturgeon fishing in the French River was closed in 2012.
  • Threatened (Saskatchewan – Nelson River populations): Likely to become endangered if not addressed.
  • Special Concern (Southern Hudson Bay – James Bay populations): Not endangered or threatened but may become so due to specific factors.

Final Thoughts

As discussed, Bowfin, Longnose Gar and Lake Sturgeon are amazing creatures that have prevailed through some of the harshest conditions over millions of years with little change in their morphology. A true testament to their nicknames as “living fossils”

These ancient fish, with their storied history and unique adaptations, continue to capture our imaginations and remind us of the rich biodiversity in our freshwater ecosystems in Ontario. Without Bowfin, Longnose Gar, and Sturgeon helping to maintain balance, other animals and plants within the ecosystem would be impacted before we noticed the changes.

Protecting Ontario’s fishery is just one small part of helping protect our Planet’s resources like nutrient recycling, food security, medical discoveries, disease resistance, and much more. Taking care of our environment in essence helps us take care of ourselves, otherwise, who will build a “Jurassic Park” for us?


Article by Joe Barefoot, M.B., Outdoor Writer and Nationally Published Author & Photographer. A member of the Professional Outdoor Media Association of Canada



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