SCIENTIFIC NAME: Fundulus notatus
CHARACTERISTICS: Individuals of this species are characterized by a dark lateral stripe extending from the mouth to the caudal fin base and a dark basicaudal spot that is separated from the lateral stripe. Fundulus notatus can usually be distinguished from the blackspotted topminnow, F. olivaceous, by the absence of small dark dots along the upper sides and back. The back is olive brown above the lateral stripe, and the venter is white. Breeding males have vague to prominent vertical spikes originating from the lateral stripe. The median fins of adult males have black blotching on their proximal halves, becoming translucent near their free margins. The paired fins and anal fin are light yellow near their margins. Adult females lack fin color and have little or only faint spotting in the fins. The blackstripe topminnow, together with F. olivaceous and F. euryzonus (the broadstripe topminnow, located in the Lake Pontchartrain system in Mississippi and Louisiana), are members of the F. notatus species group.
ADULT SIZE: 1.8 to 2.9 in (47 to 74 mm)
DISTRIBUTION: Fundulus notatus occurs along the Gulf Coast from the San Antonio Bay drainage in Texas east to the Tombigbee River drainage in Alabama and north through the Mississippi basin to Indiana and southern Wisconsin. It is also known to inhabit drainages of both Lake Michigan and Lake Erie. In Alabama, blackstripe topminnows are widespread in the upper Tombigbee River and its western tributaries, but they are absent from its eastern tributaries. We have also collected specimens from locations in the Alabama, Mobile, and Tennessee river drainages.
HABITAT AND BIOLOGY: Blackstripe topminnows prefer low-gradient, slow-moving, and slightly turbid streams. Food items include terrestrial insects, crustaceans, and algae. Breeding occurs in late spring and early summer, when individual eggs are laid in vegetation or debris patches. Thomerson and Wooldridge (1970) suggest that aggressive feeding behavior gives F. natatus a competitive advantage when it occurs with F. olivaceous, a rarely encountered circumstance since the two species occupy distinctly different habitats (Braasch and Smith, 1965). Nieman and Wallace (1974) report longevity of three or more years for a population in Michigan. Blackstripe topminnows in the Tombigbee River have a higher chromosome number than do other populations (Howell and Black, 1981).
ORIGINAL DESCRIPTION: Rafinesque described the blackstripe topminnow in 1820.
Fundulus means bottom.
Notatus means spotted.
The copyrighted information above is from Fishes of Alabama and the Mobile Basin.