STREAMLINE CHUB
SCIENTIFIC NAME: Erimystax dissimilis
CHARACTERISTICS: Has a slender, terete body that is slightly depressed in cross section. Its blunt, rounded snout extends beyond the upper lip, and its eye is smaller than the snout. The mouth is small, horizontal, and inferior, containing a small barbel in each corner. The sides are typically marked with nine or 10 dark, horizontally elongate blotches that are about the same size as the pupil of the eye, while lateral line scales usually number more than 46. This species is distinct from the similar blotched chub, E. insignis, which is shorter and more robust, has vertically elongate blotches, and usually has 43 or fewer lateral line scales.
ADULT SIZE: 2.6 to 4.5 in (65 to 115 mm)
DISTRIBUTION: Streamline chubs occur throughout the Ohio River basin from New York to the Tennessee River drainage. Their distribution in Alabama is limited to the Tennessee River drainage, where records are from only two systems—the Paint Rock River in Jackson County and Shoal Creek in Lauderdale County. Streamline chubs are uncommon and, when encountered, occur in low numbers. This species occurs sympatrically with E. insignis, with which it can be confused.
HABITAT AND BIOLOGY: Erimystax dissimilis prefers medium to large clear streams with moderate flow over clean gravel and cobble substrates. Individuals have been observed on the bottom in chutes below riffles. Harris (1986) reports a diet consisting of aquatic insects, particularly midges, mayflies, caddisflies, and organisms that live attached to underwater surfaces, suggesting a benthic life for this species. The streamline chub’s reproductive cycle in Alabama is not known; however, spawning is reported to occur from mid-April through May in Tennessee (Harris, 1986), and it may run as late as early June in Alabama.
REMARKS: On 7 September 1995, after the creation of the distribution map on the facing page, we collected a series of 10 individuals in the Paint Rock River, at the community of Paint Rock. In only one net haul made in a pool about 3 feet deep, we captured five of these individuals over a sandy-silty bottom near a large, submerged log. We found the other five individuals in a plunge pool that also had a sandy bottom and that was located at the food of a long riffle. This single collection has encouraged our hope that streamline chubs are retaining a foothold in Alabama.
ORIGINAL DESCRIPTION: Kirtland described the streamline chub in 1840.
ETYMOLOGY:
Erimystax means loosely interpreted, large lip or mustache.
Dissimilis means dissimilar.
The copyrighted information above is from Fishes of Alabama and the Mobile Basin.
