Plants and Animals

Bowfin

This Mississippi River fish has a fascinating list of traits and an amusing list of nicknames.

While they have to compete against some bona fide oddballs like the paddlefish and gar, bowfin still make a strong case for the title of strangest fish in Missouri. Bowfin have often been described as living fossils. They are the only surviving species of a once widespread group of primitive fishes called Amiiformes. Armed with a set of unusual adaptations and behaviors, bowfins have survived for more than 150 million years, through periods of untold change and turbulence.

Bowfin (Amia calva) are stout, cylindrical fish. The largest bowfin ever caught in Missouri was 19 pounds, although 1 to 5 pounds is a normal adult weight. Like most other Missouri fish, bowfin propel themselves through the water with their tail fin, but they can also swim by moving their extra-long dorsal fin in an undulating motion. Using this method, bowfin can stop on a dime and swim backward as easily as they can forward. They have a primitive skeleton with a double skull (a cartilage one inside a bony one) and their wide mouth, full of teeth, has earned them the nickname “grinner.” Perhaps this fish’s most unusual adaptation is its ability to breathe air. Bowfin have a swim bladder that functions as a primitive lung, which they use to survive in low oxygen waters. This ability has led to some speculation that bowfin estivate (become dormant underground during a drought). Several studies have shown that, while bowfin are probably not capable of long-term estivation, they can survive up to five days out of water.

Bowfin live in the sluggish backwaters and tributaries of the Mississippi River. They prefer clear water with lots of vegetation. When ready to spawn, the male bowfin builds a nest in the weeds. At this time his mouth, tongue and fins turn vivid green. The male cares for the eggs and protects the school of young for several weeks. Males have even been known to try to run off anglers if they wade too close to their nests.

Despite their impressive traits, bowfin have an image problem. For decades they have been persecuted as ugly, voracious predators. They do eat much of the same prey as most game fish, but have never been shown to be a cause of sport fish decline. Bowfin also suffer from a new phenomenon: snakehead-phobia (for more information on the invasive northern snakehead fish, visit www.invasivespeciesinfo.gov/aquatics/snakehead.shtml). While the thought of snakehead fish in our waters is a scary one, bowfin should not be punished for the offense. Though similar in appearance, the two fish can be easily distinguished by a quick look at the anal fin. The snakehead’s is very long and the bowfin’s is very short.

There is probably no other fish that has quite the collection of colorful local names that the bowfin does. Besides “grinner,” as mentioned above, beaver fish, dog fish, cabbage pike, choupique, bugle mouth, cypress trout, grindle, cotton fish and lawyer are just a few of its other aliases. Call it what you want, the bowfin is a strange and magnificent part of Missouri’s aquatic community.

—by Sarah Peper, photos by Noppadol Paothong