Distribution: Swamp darters have a patchy distribution along the Atlantic coastal plain from southern Maine to the gulf coast and the Lower Mississippi drainages. In New Hampshire, swamp darters are restricted to the coastal and lower Merrimack River watersheds.
Description: A very small fish with grayish to olive colored markings. Swamp darters may be distinguished from tessellated darters by a lateral line that arches upward and the absence of a distinct groove that separates the snout and the upper lip. There is a dark vertical bar below the eye of the swamp darter.
Species commonly confused with: Tesselated darter
Habitat: Swamp darters are usually found in vegetated backwaters and pond shorelines, but they may also inhabit gravel or sandy sections of river and streams. Swamp darters seem equally at home in large rivers, like the Merrimack River in Concord, or small streams, such as Brown’s Brook in Hooksett.
Life History: With a maximum length of 2 inches and a life span of less than two years, the swamp darter is New Hampshire’s smallest and shortest-lived species. Little is known about swamp darter life history. They are thought to spawn in the spring among aquatic vegetation and their diet consists of small insect larvae.
Conservation/Management: Swamp darters are difficult to capture, and as a result they may be more widely distributed than records indicate. However, due to their short life span, swamp darters may be susceptible to extirpation as their habitat becomes degraded. Removal of aquatic vegetation and draining or filling of wetlands may extirpate local populations. The swamp darter is a species of conservation concern in New Hampshire because its range is limited to the southeastern corner of the state, where aquatic habitats are increasingly degraded by expanding development. It is considered imperiled, critically imperiled, or vulnerable in the majority of states within its range. The swamp darter is a state threatened species in Maine and is presumed extirpated from the state of Pennsylvania.