Fish of the Credit
There are 79 fish species in the Credit River Watershed. Different fish species prefer different habitats. The variety of fish habitats in the Credit River Watershed support the needs of many types of fish. Historically Brook Trout and Atlantic Salmon thrived throughout the watershed. Brown trout now make their homes in the middle and upper areas of the Credit River as well as at the mouth of the Credit on Lake Ontario. Rainbow Trout and Chinook Salmon can also be found at the mouth of the river. Fish that prefer small lake habitats can be found in various lakes in the watershed. For example, Smallmouth and Largemouth Bass are found in Lake Aquitaine (Mississauga). Northern Pike, Black Crappie and Pumpkinseed Sunfish are found in Island Lake (Orangeville).
Black Crappie can now be found in both Fairy Lake (Acton) and Island Lake. Black Crappie are silvery-green or yellow with black blotches over their body and fins. They have a strong schooling behaviour. Black Crappie clear out a circular nest in vegetated shallow water and under banks in which to lay their eggs.
The Blacknose Dace is one of the most widespread minnows in the Credit River Watershed. They do not build nests but the males are very territorial and the females may force eggs into gravel to protect them. Blacknose Dace can be distinguished from long nose dace by its snout which barely projects beyond the blacknose dace’s mouth. The blacknose dace hibernates under rocks over winter.
The Credit River boasts one of the healthiest populations of Brook Trout in Southern Ontario. They can be distinguished from other trout by the “worm-like” markings on their backs and red spots outlined in blue on their sides. They also have white edges along their lower fins. They prefer cold water with high oxygen levels and spawn in the fall over groundwater upwelling areas.
Brown Trout can be distinguished from Brook Trout by the black spots on its back. Their bodies are brown with black and red spots on their sides. Brown Trout spawn in the fall and migrate north to the headwaters. They can tolerate warmer water than brook trout with whom they are in direct competition for habitat and food.
The Mottled Sculpin is teardrop shaped. They are wide and flattened with eyes on the top of their heads. Their body shape and pectoral fin (fin located closest to the underside of their head) help them to remain on the bottom of the stream in turbulent currents. Mottled Sculpin are most active at night and prefer riffle areas of cold streams. Their main food source is fly larvae that live in the river. They detect vibrations of their prey with their jawbone.
Northern Redbelly Dace
Northern Redbelly Dace can be found in wetlands and tributaries of the Credit River Watershed. They thrive in acidic bogs and beaver ponds where the bottom is silty. They often breed twice or over a long period of time leaving loose eggs in algae. The Northern Redbelly Dace has a small mouth that ends before a large eye. They have two stripes down their sides, red and yellow, that change colour depending on sex and season.
Pumpkinseed Sunfish are common and widespread in ponds and lakes in the Credit River Watershed. They are also found sporadically throughout the main Credit River and its tributaries. Their most distinguishable marking is a black earflap with red edge. They have blue-green sides and rusty-orange markings on their face and body. Pumpkinseed Sunfish are common and widespread in ponds and lakes in the Credit River Watershed.
The Rainbow Darter is one of our most beautiful native fish. It can be found sporadically throughout the Credit River Watershed. Their presence is a good indicator of a healthy stream, low in silts and chemical pollution. The males are most colourful with green and blue on head. They have between 9 and 14 green and blue bars on their sides. Their fins are coloured red, yellow and blue.
Rock Bass are found sporadically throughout the Credit River Watershed, including Lake Aquitaine. Their aggressive nature provides excellent opportunity for youth and urban angling. Rock bass have red eyes and short black earflaps. Their lower scales have spots that can form eight or more rows.