About Fundulus notatus (Rafinesque, 1820)
The blackstripe topminnow, scientifically Fundulus notatus (Rafinesque, 1820), gets its name from a horizontal black stripe that runs the full length of its body along both sides. It has a small mouth that tilts slightly upward, a flat-topped head, and a multi-coloured spot on its head. This fish typically reaches an average length between 5 and 7 centimetres, or 2.0 and 2.8 inches. Males and females of this species have distinct appearances. Males have dark vertical bars located above and below their black stripe, yellow-toned fins, and longer, more pointed dorsal and anal fins. Females lack these vertical bars, have white fins, and have shorter, more rounded dorsal and anal fins. In the United States, this species is found in portions of the southern drainage of Lakes Erie and Michigan, and in the Mississippi drainage basin between Illinois and the Gulf of Mexico. The entire Canadian population of this small freshwater fish lives along a roughly 60 kilometre stretch of the Sydenham River in southwestern Ontario, and its presence in this area was only discovered in 1972. The blackstripe topminnow is a fairly hardy fish, but the greatest threats it faces come from human-caused changes to its habitat.