Bowfin or faux-fin? Reeling in the truth about these look-alike fish
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EmailLearn how to ID between bowfin, burbot, and the invasive northern snakehead by spotting key differences in body shape, coloration, and fins.
A case of a “fishy” misidentification
From the Great Lakes to lesser-known inland gems, our state is home to some of the most diverse lakes and waterways. Whether you're a seasoned local casting for walleye or a visiting angler chasing your first northern pike, Michigan's waterbodies are teeming with life all year long. With a wide range of species living in our waters from catfish and bass to muskellunge, there’s a catch waiting for everyone, but do you know what you’re catching?
While out on the water, anglers may often come across a fish or plant species that can often be mistaken for an invasive species look-alike. For example, native northern watermilfoil can often be confused with the highly invasive Eurasian watermilfoil, and with only a few key differences between species, identification can be difficult.
Another example of an invasive species' mix-up is one involving two native Michigan fish, burbot and bowfin (dogfish), for another notorious invader: the northern snakehead. These three fish all share a similar appearance that can lead to misidentification of our native species. Misidentification of native species can lead to issues such as false positive sightings of invasive species or accidental harm to the native species caught.
Positive identification of invasive species, such as snakeheads, is critical to ensure early sightings are caught and reported (see below for reporting procedures) before an established invasion. The northern snakehead is highly adaptable and can cause much trouble for our native fish and ecosystems. Northern snakehead can survive in a wide variety of freshwater habitat systems due to their ability to breathe air while out of the water and has been spotted in both the eastern and southern U.S. already.
These voracious predators were likely introduced to the U.S. by people who purchased live snakehead from either fish markets or pet shops, and later released these fish into our lakes, rivers, or ponds. In their native freshwater habitats, northern snakeheads are preyed upon by fish-eating predators, such as larger fish, birds or crocodilians, to help keep their population in check.
Since there are no natural predators for snakehead in Michigan, their introduction could cause harmful competition with our native fish for food and habitat, and feed upon smaller freshwater species.
While no positive sightings of the northern snakehead have been verified in Michigan yet, it is critical that anglers are aware of different identification markers for our native look-alikes to avoid future misidentifications.
Bowfin vs. northern snakehead
Bowfin, also known as dogfish, are one of the ancient fish species that we can find both in Michigan and North America. Even with this claim to fame, bowfin are often identified as northern snakehead due to their similar cylindrical body shape and long running dorsal fin. Luckily, as a “living fossil,” the bowfin has several different anatomical traits from the northern snakehead that you can use for a positive ID.
First, let’s compare the difference in the fins between both fish. Bowfin have pelvic fins that are located further back, compared to the northern snakehead’s pelvic fins that are right below its pectoral fins. Further, the bowfin has one small, short anal fin after its pelvic fin, but the northern snakehead exhibits a long running anal fin down the rest of the fish.
Next, while color does help with some identification of species look-alikes, fish are known for color variation within a species, so it can’t be relied on solely. To assist with this barrier, anglers can look for a large black and yellow eye spot on juvenile and adult male bowfin tails (rarely present if at all on females).
If there are no dots, it is recommended to go back to the anal fin size comparison. A bowfin’s head is typically more round with smoother heads compared to the northern snakehead that has scales uniformly across its head. See more ID tricks here in this helpful video from the Michigan Department of Natural Resources (DNR).
Burbot vs. northern snakehead
To add more murkiness to the issue, another Michigan native species looks awfully similar to the northern snakehead as well. Burbot, also known as a freshwater cod, lives in the colder waters of our Great Lakes and deeper inland lakes. Similar to the bowfin identification, you can start your ID by comparing fin shape. Burbot have a long dorsal fin similar to the northern snakehead, except the burbot dorsal fin is split into two.
Burbot may get confused with snakehead due to their pelvic fin location and anal fin size being comparable to the snakehead. Like bowfin, color cannot be solely relied on for identification. Additional tactics that can be used for a positive ID on burbot include noticing if a long chin barbel is present and if its scales are smoother than a snakehead.
How to submit an identification
To help protect Michigan’s waterways, state agencies rely on the eyes and ears of anglers to report early sightings of invasive species. Having the knowledge to identify invasive snakeheads from our native species is key to preventing invasive species being established in Michigan.
If a fish is suspected of being a northern snakehead, take multiple photos and note the location, date, and time. Potential sightings can be reported to Justin Bopp, DNR Fisheries Division by email (boppj@michigan.gov), phone (517-420-9110), or online at through the Midwest Invasive Species Information Network (MISIN).
More information on aquatic invasive species and ways to prevent their spread can be found on the Michigan State University Extension Clean Boats, Clean Waters (CBCW) website, or by visiting the CBCW profiles on Facebook (@MichiganCBCW) and Instagram (@michigan_cbcw).
