RIFFLE MINNOW
SCIENTIFIC NAME: Phenacobius catostomus
CHARACTERISTICS: The riffle minnow has a cigar shaped body tapering to a slight peduncle toward the tail. The head is large, the snout blunt and rounded, and the mouth small, with thick lips expanded into corner lobes. The eye is small (about half the snout length), and the wide lateral band extends from the snout to the caudal fin. All the fins have rounded edges and lobes. In life, the snout and paired fins have some orange color. Scales are small all over the body, and life color is olive brown along the back, grading to white on the venter. See Jordan (1877a) for original description.
ADULT SIZE: 2.4 to 3.9 in (60 to 100 mm)
DISTRIBUTION: Although most collections of this Mobile basin endemic are from above the Fall Line, its range extends some distance downstream in the Cahaba River drainage. Another isolated population occurs in the lower Alabama River drainage, where it flows through the rugged Lime Hills physiographic district.
HABITAT AND BIOLOGY: Phenacobius catostomus is commonly found in swift riffles and runs of large rivers and tributaries with cobble and gravel bottoms. It often occurs in swift pools, runs, or deep erosional pools at the base of shallow riffles. The riffle minnow is adapted to life on the stream bottom. Its spindled body form and the placement of its fins are adapted to gathering insect immatures by foraging through the bottom gravel and sediments. While little is known about the reproductive behavior of this species, spawning occurs in gravel riffles and nearby swift, sandy shoals from April to June. Although the riffle minnow is typically considered a clean-water inhabitant, recent surveys in the Cahaba River reveal abundant populations in parts of the river receiving treated domestic wastes and nonprofit runoff of sediments.
REMARKS: The type locality of the riffle minnow is Silver Creek, a tributary of the Etowah River, Floyd County, Georgia.
ORIGINAL DESCRIPTION: The riffle minnow was described by Jordan in 1877.
ETYMOLOGY:
Phenacobius means deceptive life, because this species" bottom feeding habits suggest that it, like the stoneroller is herbivorous.
Catostomus means inferior mouth.
The copyrighted information above is from Fishes of Alabama and the Mobile Basin.
