(See Fish Gallery Below) These are small often brightly colored fishes with a flattened head and back, upturned mouth, large eyes, and one dorsal fin located far back on the body. As their name implies, topminnows spend most of their lives swimming at or near the water surface. About 40 species are found in fresh, salt, and brackish water in North America; 4 species are found in Virginia. Most species are sexually dimorphic. Males have larger dorsal and anal fins, and are much more highly colored in the breeding season than females. Some of these schooling species are readily caught by nets and used as fish bait by anglers. Some species are important for mosquito control and are favored by aquarium owners. These small stream fishes add to the aquatic diversity and serve as links in the food chain and indicators of water quality.