Species: Lampetra tridentata

The timing of migration to spawning stream varies geographically, and different runs may occur in a single river system. According to Wydoski and Whitney (1979) spawning occurs in June-July in Washington. In southern California, spawning likely begins by late January in most years, and spawning may continue into April (Chase 2001). In the Santa Clara River in southern California, upstream migration began as early as mid-December or as late as mid-March; peak migration occurred in March in most years (Chase 2001). Eggs hatch in 2 or 3 weeks. Ammocoetes remain in stream, metamorphose in 4-6 years (late September-October). Form <i>macrostoma</i> in British Columbia: spawns May-August, probably spends 6 years as larva and 2 years as subadult-adult before reproducing; metamorphosis July-October (Beamish 1987). Oceanic phase apparently may last 3-4 years in British Columbia but may be shorter in more southern areas (Moyle 2002). Generation time is 9 years (Luzier et al. 2011).<br><br>This is the only species of lamprey in which some individuals (from Washington) are known to spawn more than once (Page and Burr 1991).<br><br>See Luzier et al. (2011) for an up-to-date review of Pacific lamprey life history.