|Least Brook Lamprey
Unique Characters: Nonparasitic. Dorsal fin deeply notched appearing as two contiguous dorsal fins. Oral disc narrower than head and with extremely degenerate teeth. No black on lateral pores. Restricted to Tar and Neuse basins.
Sea Lamprey Petromyzon marinus. The adult is readily distinguished from the Least Brook Lamprey by a number of characters, but the ammocoetes are more difficult to differentiate. The Sea Lamprey has 66-75 trunk myomeres versus 52-59 in the Least Brook Lamprey. Additionally, there is a lot of black pigment in the tail of the Sea Lamprey ammocoete versus none in the Least Brook Lamprey ammocoete.