SOUTHERN BROOK LAMPREY
SCIENTIFIC NAME: Ichthyomyzon gagei
CHARACTERISTICS: The dorsal fin is slightly notched but is not divided into two distinct fins. On live individuals, the oral disc is narrower than the head. The teeth-two or three supraorals teeth and three or four bicuspid teeth on each side of the oral opening-are blunt and poorly developed. On most individuals, myomeres between the last gill opening and the anus number from 49 to 59. Lateral line organs on the back and venter are black. The body is olive to yellow on the back, grading to light tan or white on the venter. The fins are light tan to white.
ADULT SIZE: 3.9 to 7.9 in (100 to 200 mm)
DISTRIBUTION: Although collected in every major river system in the Mobile basin, this nonparasitic species is rare in the Tennessee River drainage. We collected single specimens in Lauderdale County at Bumpass Creek and Little Butler Creek. Individuals avoid the unfavorable habitats and poor water conditions of streams draining the Black Belt and Southern Pine Hills.
HABITAT AND BIOLOGY: Southern brook lampreys inhabit small or medium streams having moderate to swift currents over sand and gravel substrates. Dendy and Scott (1953) report that, in Alabama, spawning occurs from March through July. We observed spawning in the Cahaba and upper Tallapoosa river systems in March. We also observed nest building in a Cahaba River tributary in late May: Two males and a female moved gravel to the upper end of a riffle, building a nest about 8 inches in diameter, 2 or 3 inches deep, and in about 4 inches of water. Ammocoetes metamorphose into adults in about three years. Spawning usually occurs in the spring following metamorphosis.
ORIGINAL DESCRIPTION: Hubbs and Trautman described the southern brook lamprey in 1937.
Ichthy means fish.
Myzon means sucking.
Gagei is in honor of S. H. Gage, who studied lampreys.
The copyrighted information above is from Fishes of Alabama and the Mobile Basin.