Blackstripe Topminnow
Fundulus notatus
Species Description
Blackstripe Topminnow is a member of the family known as Fundulidae (Topminnows). With a prominent black lateral stripe, flattened head, and upturned mouth, the Blackstripe Topminnow is one of the easier SAR fish to identify in the Sydenham River. It is a small fish that grows up to 7.4cm in length and has a lifespan of about 2-3 years.
Feeding and Habitat
Blackstripe Topminnow prefer the warm, slow-moving surface waters of rivers and streams where riparian and in-stream vegetation provide spawning habitat and plenty of cover from predators like Belted Kingfishers and herons. From spring to fall, Blackstripe Topminnow spend significant time foraging along the surface of the water. Approximately half of their diet consists of terrestrial invertebrates, the rest is made up of a combination of aquatic insects, crustaceans, snails, and algae.
Distribution in the Sydenham
The Blackstripe Topminnow occurs in tributaries of lakes Erie and Michigan as well as the Mississippi River basin.
The entire Canadian population of this small freshwater fish is found in the Sydenham watershed in southwestern Ontario. It was first recorded in the watershed in 1972 on the North Branch in Black Creek. It has since been documented on the East Sydenham River, North Sydenham River, Little Bear Creek, Bear Creek, Black Creek, Maxwell Creek, and Whitebread Drain.
Threats to Blackstripe Topminnow
Blackstripe Topminnow depend on healthy plant life, both in-stream and along the banks for food, spawning sites, and protection from aerial predators. Riparian vegetation also shades waters keeping them cooler and captures pollution preventing it from entering the aquatic environment. Activities and practices that remove streamside plant life and change flow regimes pose the most significant threats to the persistence of this surface dweller. These threats include development, the trampling of banks by livestock, lowered water levels from irrigation, and the draining of wetlands. The combined impact of each threat can alter the size and health of Blackstripe Topminnow populations especially during low-flow conditions. Additional threats include the channelization of watercourses, oil seepage from oil wells, sedimentation, nutrient enrichment, invasive species, and pesticides.