Bowfin, Amia calva
Identifying characteristics: Long, stout body with rounded tail; long, continuous dorsal fin and large, toothy mouth. Bony plates cover the head and back and side are brownish green with white belly. Males and juveniles have a large "eye" spot at the base of their tails. The "eye" spot is also present on females but it becomes much less prominent with age. The average size is typically from 12 to 24 inches and two to five pounds but fish over 30 inches and 10 pounds have been caught in Michigan.
The bowfin family, or Amiidae, dates back to the Jurassic period and was once distributed across North America, South America, Europe, Asia and Africa. Today the family consists of only one living species, the bowfin. Lost from all other continents, the bowfin's current range is limited to North America from the Mississippi River east through the St. Lawrence drainage, south from Texas to Florida, and it's common throughout the Lower Peninsula of Michigan.
The bowfin is also known as the dogfish, grindle, mudfish, cypress trout, lake lawyer and beaverfish and is common in deep waters associated with weed beds in warm water lakes and rivers. It feeds in shallow weeds, typically on other fish and crayfish.
Bowfins typically reproduce when the water warms to past 61 degrees in the spring. Males remove vegetation on sandy or gravely bottoms and one or more females deposit up to 5,000 eggs into a nest. The males will guard the fertilized eggs until the young reach about four inches in length.
A primitive fish, it retains a lung-like gas bladder and can gulp and breathe air. It is said to be able to live out of water for up to 24 hours. This trait allows the bowfin to survive buried in the mud during drought conditions.
The bowfin is considered a voracious predator as it prowls shallow weedbeds. They were previously thought to be detrimental to game fish populations but they are now considered valuable for controlling rough fish and stunted game fish. Therefore as an important native Michigan species, the bowfin should not be needlessly harassed or killed.
Bowfin graphic courtesy of Joseph R. Tomelleri and copyrighted.