NORTHERN STARHEAD TOPMINNOW
SCIENTIFIC NAME: Fundulus dispar
CHARACTERISTICS: Adult males have 3 to 13 thin vertical bars, with the anterior bars restricted to the flanks and not extending onto the venter. Single spots on upper areas along the sides join along the lower areas to form generalized stripes. Adult females have longitudinal stripes, no vertical bars, and no spots along their sides. Paired fins of adult males are light yellow, while the median fins are speckled with light brown blotches. Male pigment spots are generally brown to rusty red, and the back is yellow-green, fading to white on the venter. Adult females are olive green to light brown on the back, fading to white on the venter, and all fins are translucent. Genetic data presented by Cashner et al. (1992) indicates that Fundulus dispar most resembles the lined topminnow, F. lineolatus (not occurring in Alabama), in the F. notti species group. “Starhead” refers to the star-shaped patch of light pigment on the top of the head.
ADULT SIZE: 1.2 to 3.2 in (30 to 81 mm)
DISTRIBUTION: The northern starhead topminnow is distributed from the Tombigbee River drainage of the Mobile basin westward to the Ouachita River drainage in Louisiana and northward through the Mississippi basin to Michigan. In Alabama it is generally found in northern counties, while the southern starhead topminnow, F. blairae, is found in southern counties.
HABITAT AND BIOLOGY: Fundulus dispar inhabits small streams and shallow, often vegetate backwaters of swamps and large streams. When encountered, individuals can usually be seen swimming at the water surface. The diet consists of terrestrial insects, snails, small crustaceans, and occasionally algae (Gunning and Lewis, 1955). Although little is known of this species’ reproductive biology, Smith (1979) indicates spawning from late spring through early summer in dense beds of aquatic vegetation.
ORIGINAL DESCRIPTION: Agassiz described the northern starhead in 1854.
Fundulus means bottom.
Dispar means dissimilar.
The copyrighted information above is from Fishes of Alabama and the Mobile Basin.