Smallmouth Bass
Micropterus dolomieu
This robust fish is the second largest member of the sunfish family in Ontario. The only larger species is the largemouth bass. The average size is from 203mm to 381mm with the Ontario record being a 584mm individual weighing over 9 lbs. Colour varies greatly depending on habitat but generally adults tend to be golden brown to olive green with 8 to 15 vertical bars (sometimes faint) along their side. The most consistent distinguishing features between smallmouth bass and largemouth bass is the position of the mouth in relation to the eye. If the back edge of the mouth only extends to the middle of the eye, it’s a smallmouth bass. If the back edge of the mouth extends past the back edge of the eye, it’s a largemouth bass.
Smallmouth bass are distributed throughout Ontario and inhabit a wide variety of water bodies. Young smallmouth bass prey on a range of aquatic insects, invertebrates and other smaller fish. Adults prey heavily on crayfish, fish and frogs. Sexual maturity is usually reached by their 3rd to 5th in males and 4th to 6th year in females. The maximum lifespan in Canada is about 15 years.
Spawning takes place in the late spring over a 6 to 10 day period when water temperatures have reached 16 to 18 degrees C. Males build a nest on a sandy or gravelly bottom in 1 to 6 metres of water. Females pair up with the males and after considerable pre-spawn courtship, eggs are laid in the nest. Females’ average up to 7000 eggs per pound of body weight and may spawn with more than one male. Males aggressively guard the nest until the eggs hatch (4 to 10 days) and continue to guard the young fry for about 3 weeks. Growth of the young bass is rapid with some bass in Lake Erie documented at growing almost 1 mm a day.
Smallmouth bass will readily adapt to pond environments and can become quite large if there is sufficient forage. They are an excellent alternative to stocking trout, especially when higher water temperatures are expected. They provide great sport and are also excellent on the table.