The American brook lamprey is nonparasitic, with the dorsal fin divided by a deep notch. It has degenerate teeth in the adult buccal cavity. It has a naked eel-like body with externally obvious muscle segmentation and seven pairs of gill openings. The adults and ammocoetes are uniformly gray above and paler ventrally. The American brook lamprey is uncommon to rare in the larger portions of Little River and Tab Cat Creek.

Size: maximum total length reported at 200 mm (7.8 in.) (Tennessee specimens)
Trunk myomeres: 63-73 (usually 66-70)
Dorsal fin: elevated and divided by deep notch in adults; fin lower but still separated in larvae
Teeth: degenerate; present in posterior field of disc
Color: pigmentation of adults and larvae uniformly gray above and paler ventrally

Similar species:
Differs from Ichthyomyzon greeleyi in lacking well developed teeth and in having a deep cleft separating the dorsal fin. Myomere count in larvae of Lampetra appendix is higher (more than 63) than in other southeastern lampreys.

Lampetra appendix is a nonparasitic lamprey that chiefly inhabits upland creeks and small rivers; larval and adult habitats contain some sand and gravel substrate. Ammocoetes occur in areas with sluggish current with silty detrital accumulations. Spawning occurs in Tennessee in March-April with females producing an average of 2,833 eggs (860 to over 3,000 in their entire range). The adults die following spawning. Eggs hatch within a few weeks with the larval stage lasting 5-6 years. Larva feed primarily on small algae and organic detritus.

Lampetra appendix is widespread in the uplands of the Mississippi River basin, Great Lakes tributaries, and Atlantic Coast drainages from New England to the Roanoke drainage of Virginia. It is fairly common in the uplands of Tennessee, but not known from elsewhere in the state except for a few collections in middle Tennessee.

Lampetra appendix is uncommon to rare in the larger portions of Little River and Tab Cat Creek. It was collected in Abrams Creek before the reclamation project on Abrams Creek in 1957 (Simbeck 1990).

References:

Etnier, David A. and Wayne C. Starnes. 1993. The Fishes of Tennessee. University of Tennessee Press. Knoxville, Tennessee.

Simbeck, Damien J. 1990. Distribution of the Fishes of the Great Smoky Mountains National Park. Master of Science Thesis, University of Tennessee.