Silver lamprey

Ichthyomyzon unicuspis

FAMILY

Petromyzonidae

TAXONOMY

Ichthiomyzon unicuspis Hubbs and Trautman, 1937.

OTHER COMMON NAMES

None known.

PHYSICAL CHARACTERISTICS

Total length 15.3 in (39 cm). Eel-like, scaleless, lack jaws, have funnel-like mouths and cartilaginous skeletons. Body grayish brown in color. Gonad in both sexes is unpaired and median, and is suspended from the dorsal wall of the body cavity by a mesentery containing connective tissue. Considered the most primitive Ichthyomyzon species.

DISTRIBUTION

Hudson Bay and Great Lakes regions, as well as the St. Lawrence river system.

HABITAT

Heads of freshwater streams around the Great Lakes and Hudson Bay regions, as well as the St. Lawrence.

BEHAVIOR

Anadromous; returns to fresh waters to reproduce, during which time it carries out spawning behaviors, including nest building and fanning behavior.

FEEDING ECOLOGY AND DIET

Larvae feed on microscopic plankton, algae, and detritus filtered from mud. During the parasitic phase, adult attaches to a host fish and extracts blood and/or muscle tissue. Does not feed after migrating upstream to spawn in fresh water.

REPRODUCTIVE BIOLOGY

Female releases her eggs, which are fertilized by released sperm from the male. The adults die shortly after spawning.

CONSERVATION STATUS

Not listed by the IUCN.

SIGNIFICANCE TO HUMANS

Research on the species can provide insight into human biology and perhaps yield medicinal applications.