And the answer is:  LAMPREY 

This individual was collected from Birdsong Creek in December of 2005.  It is a Southern Brook Lamprey (Ichthyomyzon gagei), a nonparasitic lamprey that lacks teeth on its oral disk.  Parasitic lamprey have horny 'teeth' on their oral disk which they use to attach to unlucky fish hosts and then feed on the fish's body tissue. 

The Southern Brook Lamprey spends a good bit of its life buried in the streambed sediments as an immature laval form, a filter feeder consuming small particulate matter. After metamorphosis into an adult, the lamprey lives long enough to reproduce and then soon dies.

This fish species occurs in Alabama throughout the Mobile River Basin, coastal drainages, and in tributaries of the Tennessee River in Lauderdale and Franklin counties.