LAMPREY FAMILY Petromyzontidae

AMERICAN BROOK LAMPREY Lampetra appendix (DeKay, 1842)

DISTRIBUTION AND ABUNDANCE: Native - State Threatened. Known only from the eastern Blackstone River drainage, the Mashpee River on Cape Cod, and the Mill and Tiasquam rivers on Martha's Vineyard. American brook lamprey are not common, the first specimens were not collected until the 1960s. The Martha's Vineyard population, which appears very stable, went unnoticed until our surveys in 1988.

SEA LAMPREY Petromyzon marinus Linnaeus, 1758

DISTRIBUTION AND ABUNDANCE: Native. Prior to the 1800s, sea lamprey entered virtually every Massachusetts stream and river which allowed them access to breeding sites. By the mid-1800s newly constructed dams blocked their migration routes and industrial pollution altered their habitat. Recently, new fishways constructed for anadromous fish runs have allowed them to return to many areas. They are now common in the Connecticut River (up to 53,000 per year at the Holyoke fishway ) and migrate well into New Hampshire. The first recent records from the Millers drainage date from the late 1980, shortly after the opening of the Turners Falls Fishway. Sea lamprey are also locally common in portions of the Merrimack and Parker rivers. They are much less frequently encountered in the South Shore, Cape Cod, and Buzzard Bay drainage systems. Counts of fishes currently passing Massachusetts fishways are available.