Spotted Sucker
Minytrema melanops
Species Description
A medium-sized member of the family Catostomidae (Suckers), reaching an average length of 23cm to 38cm, the Spotted Sucker is a rare sucker species in the waters of southwestern Ontario. They range in colour from brown to green with silver to bronze sides and a light belly. They have large scales that are unique from other species because of the presence of a dark spot on the base of each scale, creating lateral rows of spots across their sides and back.
Spotted Suckers are adapted for feeding on molluscs, aquatic insects, and algae along the river bottom, with their thick fleshy lips located on the underside of the head.
Habitat
This spotted beauty prefers the slow-moving waters of lakes and rivers that provide long deep pools, clear water, and clay, sand, or gravel substrates. The Spotted Sucker has also been detected in a variety of other habitats including oxbows and backwater areas, impoundments, and small turbid creeks.
Distribution in the Sydenham
Spotted Sucker can be found in slow-flowing freshwater bodies in central and eastern North America. In Ontario, this species is restricted to the extreme southwest in the drainages of western Lake Erie, Lake St. Clair, and the St. Clair River. There is evidence that their extent of occurrence has decreased in Ontario, particularly in Lake Erie.
The first Spotted Sucker sighting documented in Canada was by a commercial fisher from Lake St. Clair in 1962. The St. Clair Region Conservation Authority (SCRCA) has 54 records of Spotted Sucker in their fish database from 1964 to 2017 for the Sydenham watershed and immediate surrounding area. This includes observations from Fisheries and Oceans Canada, the Royal Ontario Museum, and SCRCA in Bear Creek, Black Creek, North Sydenham, East Sydenham, and Lake St. Clair and the St. Clair River and their tributaries. The SCRCA’s most recent sightings for Spotted Sucker are from St. Clair River tributaries in 2014 and 2017 and the lower North Sydenham in 2016 and 2017.
Threats to Spotted Sucker
Spotted Sucker may never have been common in Ontario as they are at the northern limit of their range but there are large-scale threats to Spotted Sucker that may threaten their persistence in Canadian waters that are also shared by other species. This species is vulnerable to habitat degradation from siltation, pollution, and instream barriers. Within the Sydenham River, increased erosion and turbidity are considered the greatest threats to the Spotted Sucker.