Photo courtesy of Konrad Schmidt
Banded Killifish - Common name
Fundulus diaphanus - Scientific name
Family - Fundulidae (topminnows)
Status :SE, S1, G5
IDENTIFICATION: The banded killifish is a small (2-3 inches, 50-75 mm) fish with a brown to olive green back, silver or yellow silver sides, and a yellowish belly. Its sides have 12-20 green-brown vertical bars. It has a protruding lower jaw and a mouth that is well-developed for surface feeding. Its tail fin is rounded and not forked.
SIMILAR SPECIES FOUND IN SOUTH DAKOTA: The central mudminnow and plains topminnow are similar species found in eastern South Dakota. The central mudminnow is a darker color (olive-brown to brownish-black) and does not have an upward protruding lower jaw. The vertical bars of the mudminnow are irregular. The plains topminnow typically has a bluish-green color and does not have vertical stripes along its side or at the base of its tail.
HABITS AND HABITAT: Habitat for the banded killifish ranges from quiet waters of lakes and ponds with abundant vegetation to muddy streams without vegetation. It is often found in small schools in shallow water over a sandy, gravelly or detritus-covered bottom with patches of aquatic plants. This species spawns in late spring and summer. A male releases sperm at the same time as the female releases 5-10 eggs. Egg clusters attach to plants by adhesive filaments. Spawning continues until the female has laid 50 or more eggs which hatch in 10-12 days. Banded killifish eat small invertebrates (crustaceans, insect larvae) and some plant material, feeding in all levels of the water column. Where abundant, the banded killifish may be an important prey item for northern pike and fish-eating birds such as kingfishers. Most individuals live for two years at most.
DISTRIBUTION: Distribution Map This species occurs from South Carolina north to the Maritime Provinces and Newfoundland, west through New York, Pennsylvania, and southern Canada in the Great Lakes Basin. In eastern South Dakota the banded killifish has been found in Waubay and Blue Dog Lakes in Day County on the Big Sioux Cotteaux, and from Lake Cochrane in the Minnesota River Basin in Deuel County.
CAUSES OF CONCERN AND CONSERVATION MEASURES: The banded killifish occurs only at a few sites in northeastern South Dakota, which is along the western-most edge of the species' range. The banded killifish is also found in Lake Andes west of the Missouri River, however it is not certain whether these fish were stocked into this lake or occur naturally. The banded killifish has experienced reduced habitat due to wetland drainage.