Spawning season varies longitudinally within the range of the lamprey, but in Maine, spawning occurs from late May through early summer. Spawning peaks when water temperatures are about 17 to 19 0C (Applegate 1950; Beamish 1980).

Are lampreys nocturnal?

Environmental cues such as flow conditions and water temperature influence the onset of outmigration for lamprey [12, 24–25]. ... Additionally, sea lamprey exhibit a negative phototactic response at multiple life stages [30] and are mostly nocturnal as both ammocoetes [31] and migratory adults [32].

What time of year do lampreys spawn?

Pacific lampreys spawn between March and July. Males and females both construct nests--known as redds-- by moving stones with their mouths. Adults typically die within 3-36 days after spawning.