Mountain Brook Lamprey
(Ichthyomyzon greeleyi)
The mountain brook lamprey is one of the seven lamprey species found in Ohio. This species is non-parasitic, so they do not attach them selves to larger species of fish. Six of the seven species of lampreys are native to Ohio and pose no threat to sport fish. Only the sea lamprey is not native and a potential threat.
Description
All lampreys have a long eel-like body and no scales. They have segments of muscles that are visible along their body called myomeres, and a jawless mouth. In larval lampreys, called ammocoetes, their mouth is not fully developed, very small, and hidden between folds of skin. Adults have a disk shaped mouth with varying amounts of teeth depending on the species. The mountain brook lamprey has a single continuous dorsal fin, not separated into two distinct parts. They have 53-62 myomeres (muscle segments) between the last gill opening and the anus. The disc like mouth of the adults contains bicuspid or double pointed teeth around the mouth. Teeth on the outer portion of the disc are very small and difficult to see. Adults are a light tan or silvery tan in coloration and often strongly bicolored (darker on top and lighter on belly) prior to spawning. During spawning, adults become blue-black in color. The mountain brook lamprey differs from the northern brook lamprey by having bicuspid teeth (rather than single pointed) and a higher average myomere count. Silver and Ohio lampreys are larger and parasitic on larger fish as adults. All other Ohio lamprey species have 2 separate dorsal fins.
Habitat and Habits
All non-parasitic lampreys required two distinctly different habitats that are connected by free flowing (free of dams) stretches of streams. Adults are found in clear brooks with fast flowing water and either sand or gravel bottoms. Juveniles or ammoccoetes are found in slow moving water buried in soft substrate of medium to large streams. Mountain brook lampreys are only found in the Mahoning river drainage in Ohio. The only known existing populations are in Eagle Creek and the West Branch of the Mahoning River.
Reproduction and Care of the Young
Mountain brook lampreys spawn in early May in shallow pits that are excavated near the upper ends of gravel riffles. These pits are created communally by several individuals constructing one pit. They use their suction cup like mouth to move stones away to form the pit. Females then deposit many eggs in these pits. After hatching, the ammocoetes (larval stage of lampreys) drift down stream to larger slower moving streams and burrow into the sediment. During this phase, they eat organic particles strained from bottom sediments and the water, as well as microscopic organisms. After several years, the ammocoetes transform into a non-parasitic adult in the late summer or fall. Adults migrate into smaller streams and do not feed. The following spring they spawn and then die shortly after.