Cephalaspidomorphi (lampreys) > Petromyzontiformes
(Lampreys) > Petromyzontidae
(Northern lampreys) > Lampetrinae
Etymology: Lampetra: Latin, lambere = lick + Greek,petra = stone, with allusion to the lamprey attaching itself to stones (Ref. 45335); ayresii: Named after W.O. Ayres who first described the species from California.
Environment / Climate / Range
Marine; freshwater; brackish; demersal; anadromous (Ref. 51243). Temperate; 59°N - 37°N
Length at first maturity / Size / Weight / Age
Maturity: Lm 16.2  range ? - ? cm
Max length : 28.1 cm TL male/unsexed; (Ref. 1998); 31.1 cm TL (female); common length : 20.5 cm TL male/unsexed; (Ref. 12193)
Morphology | Morphometrics
Distinguished by 2 large teeth on the supraoral bar, a large middle tooth on the tongue, 3 points (rarely 2) on each central lateral tooth plate, and the absence of posterial teeth (Ref. 27547). Anterior dorsal fin being lower than posterior, the fins separate in nonbreeding individuals but coming into contact at spawning; caudal fin lobes about equal, lower lobe joined to anal fin; anal fin virtually absent in males (Ref. 27547). Dark brown or brownish gray on sides and back; belly yellowish, silvery around head, gill openings and lower sides; caudal fin has a band of dark pigment inside its margins, symmetrical on each lobe (Ref. 27547).
Eastern Pacific: Tee Harbor, Alaska to Sacramento-San Joaquin drainage in California, USA. Freshwater resident population in Morrison Creek, Vancouver Island, British Columbia (Ref. 12269).
Parasitic adults are found in estuaries and the ocean, migrating to clear gravel riffles of streams to spawn (Ref. 5723). Ammocoetes burrow into the mud where they live for an unknown period and migrate to the sea only after transformation (Ref. 1998). Adults feed by ripping flesh from other fishes (Ref. 2850), ammocoetes feed on microscopic plants and animals just like other members of this family (Ref. 1998). Parasitism can take place at a length of 16.2 cm TL (Ref. 1998). Preyed upon by a number of fishes, e.g. lingcod, and birds (Ref. 1998). Because of its small size, it is unlikely to pose a threat to economically important fish (Ref. 1998). Utilized fresh or smoked by some cultures (Ref. 27436).
Page, L.M. and B.M. Burr, 1991. A field guide to freshwater fishes of North America north of Mexico. Houghton Mifflin Company, Boston. 432 p.
IUCN Red List Status (Ref. 90363)
Threat to humans
Fisheries: minor commercial
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
CollaboratorsPicturesStamps, CoinsSoundsCiguateraSpeedSwim. typeGill areaOtolithsBrainsVision
Estimates of some properties based on empirical models
Phylogenetic diversity index (Ref. 82805
= 0.5078 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00126 (-0.19178 - 0.19430), b=2.98 (2.88 - 3.08), based on LWR estimates for this family-BS (Ref. 93245
Trophic Level (Ref. 69278
): 4.5 ±0.80 se; Based on food items.
Resilience (Ref. 69278
): Low, minimum population doubling time 4.5 - 14 years (Fec=11,398).
Vulnerability (Ref. 59153
): Moderate to high vulnerability (52 of 100) .