EVERYDAY SCIENCE

Detailed explanation-1: -Lampreys are anadromous species that breed in FW; the resulting larval forms (ammocoetes) metamorphose after a few years into juveniles that migrate downstream and live most of their adult life in the marine environment (see also HAGFISHES AND LAMPREY | Lampreys: Energetics and Development).

Detailed explanation-2: -Juvenile parasitic sea lamprey are 6 to 24 inches in length with smooth, scaleless skin that is mottled grey/blue to black, darker on top and fading to a lighter colored belly. Adult sea lamprey, preparing to spawn, are 14 to 24 inches in length and exhibit mottled dark brown/black pigmentation.

Detailed explanation-3: -Adults spawn in freshwater streams, then the larvae live in sediments. Juveniles then migrate to the ocean. After a life in the ocean they return to streams to spawn and die.

Detailed explanation-4: -Sea lampreys are parasitic pests. They attach to fish with their suction mouth and teeth, and use their tongue to rasp through a fish’s scales and skin so they can feed on its blood and body fluids. A single sea lamprey will destroy up to 18 kgs (40 lbs.) of fish during its adult lifetime.

Detailed explanation-5: -At least 46 genera of parasites, seven genera of bacteria, two genera of fungi and oomycetes, and two viruses belonging to two families have been documented to occur in lamprey, most of which have also been identified in other fish species.