. The Canadian field-naturalist. 92 The Canadian Field-Naturalist Vol. 98. Figure I. Silver Shiner (Notropis photogenis). Courtesy of D. E. McAllister, National Museum of Natural Sciences. Co. (43°08'30"N, 80°17'20"W). In the Conestogo River, this species occurs in the lower stretch of the river below the dam at St. Jacobs, Waterloo Co. (43°32'10"N, 80°34'25"W). Nith River specimens were taken near Ayr, Waterloo Co. (43°i7'40"N, 80°28'i3"W) (Figure 3). In the Lake St. Clair drainage, the Silver Shiner population is apparently centered near the city of London, Midd
. The Canadian field-naturalist. 92 The Canadian Field-Naturalist Vol. 98. Figure I. Silver Shiner (Notropis photogenis). Courtesy of D. E. McAllister, National Museum of Natural Sciences. Co. (43°08'30"N, 80°17'20"W). In the Conestogo River, this species occurs in the lower stretch of the river below the dam at St. Jacobs, Waterloo Co. (43°32'10"N, 80°34'25"W). Nith River specimens were taken near Ayr, Waterloo Co. (43°i7'40"N, 80°28'i3"W) (Figure 3). In the Lake St. Clair drainage, the Silver Shiner population is apparently centered near the city of London, Middlesex Co., in the Thames River watershed. All specimens were collected within an eight km radius of the city centre (42°59'22"N, 81°I4'57"W): from the North Thames River, from Medway Creek, and from the Thames River both upstream and downstream of the North Thames con- fluence (Figure 3). Protection No specific protection for the Silver Shiner now exists in Canada, although the fish habitat section of the Fisheries Act does afford general protection. Population Size and Trend The Silver Shiner was found to be locally abundant in the Grand and Thames River watersheds by Parker and McKee (1980). Their 1979 catches averaged 37 Silver Shiners per 100 m". Densities were not con- stant. While schools of Silver Shiner occurred in areas of moderate current and eddies below dams, several sampling stations in the Grand and Thames River watersheds which seemed to provide suitable habitat provided few or no specimens. The species was rare in, or absent from, smaller tributary streams and slow- flowing sections of the main rivers. The first collections of Silver Shiners in Canada in 1971 and the continuing presence of the species sug- gest an increase in numbers prior to or during the early 1970's. A recent invasion of the Grand River by this species is improbable since large areas of unsuitable habitat separate this Ontario watershed from the nearest populations in t
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