Unique Characters: Parasitic. One slightly notched dorsal fin. Oral disc as wide or wider than head. Sharp, well-developed teeth in radiating rows with bicuspid lateral teeth. Lateral line neuromasts on the ventral surface of the branchial region darkly pigmented. Black on lateral line pores. Thick, functional gut in adults. Not know to occur in the Hiwassee basin.
Mountain Brook Lamprey
Mountain Brook Lamprey Ichthyomyzon greeleyi. Nonparasitic. One slightly notched dorsal fin. Oral disc narrower than head. Moderately developed disc teeth. Lateral line neuromasts on the ventral surface of the branchial region unpigmented. No black on pores below gills. The ammocoetes of these two species cannot be differentiated, except in the Hiwassee basin where Ohio Lamprey is not known to occur. Thin, non-functional gut in adults.
American Brook Lamprey
American Brook Lamprey Lethenteron appendix. Nonparasitic. Dorsal fin deeply notched appearing as two contiguous dorsal fins. Oral disc narrower than head and with blunt teeth. No black on lateral pores. Known to only occur in Spring Creek and nearby French Broad River in Hot Springs, Madison County.