Lampetra ayresii  (Günther, 1870)

Western river lamprey
Add your observation in Fish Watcher
| Native range | All suitable habitat | PointMap | Year 2100 |
This map was computer-generated and has not yet been reviewed.
Lampetra ayresii   AquaMaps   Data sources: GBIF OBIS
Upload your photos and videos
Pictures | Google image
Image of Lampetra ayresii (Western river lamprey)
Lampetra ayresii
Picture by FAO

Classification / Names Common names | Synonyms | Catalog of Fishes (gen., sp.) | ITIS | CoL | WoRMS | Cloffa

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). Latin, lambendis petris, which means to suck rocks (Ref. 89241);  ayresii: Named after W.O. Ayres who first described the species from California.

Environment / Climate / Range Ecology

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)

Short description 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). Other diagnostic features: Adults: 11.4-31.1 cm TL. Body wet weight in individuals 17.5-23.0 cm TL, 20-24 g. Body proportions, as percentage of TL (based on 68 specimens measuring 11.7-31.1 cm TL): prebranchial length, 10.9-14.1; branchial length, 7.8-11.8; trunk length, 45.9-55.9; tail length, 24.4-29.5; eye length, 2.3-4.3; disc length, 4.7-7.2. The urogenital papilla length, as a percentage of branchial length, in two spawning males measuring 17.4-18.7 cm TL, 10.3-12.5. Trunk myomeres, 60-71. Dentition: supraoral lamina, 2 unicuspid teeth; infraoral lamina, 7-10 teeth, the lateralmost often bicuspid, the others unicuspid; 3 endolaterals on each side; endolateral formula, typically 2-3-2, very rarely 2-2-2; 3 rows of anterials; first row of anterials, 4 unicuspid teeth; exolaterals absent; posterials absent; transverse lingual lamina, 12-17 unicuspid teeth, the median one greatly enlarged; longitudinal lingual laminae each with 9-12 unicuspid teeth. Velar tentacles, 3-5, with tubercles. Body coloration in marine waters (live), lead gray on dorsal and upper lateral aspects, silvery on the lateral aspect, and white on the ventral aspect. Body coloration (preserved), dorsal and lateral aspects brownish gray and ventral aspect whitish. Lateral line neuromasts unpigmented. Extent of caudal fin pigmentation, 25% to more than 75%. Caudal fin shape, spade-like or rounded. Oral fimbriae, 88-117. Oral papillae, 12-18 (Ref. 89241).

Distribution Countries | FAO areas | Ecosystems | Occurrences | Point map | Introductions | Faunafri

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).

Biology     Glossary (e.g. epibenthic)

Anadromous. A permanent freshwater resident population is believed to occur in Morrison Creek, British Columbia. In marine waters, they inhabit surface waters. In fresh waters, they occur in lakes, rivers, and creeks. They leave rivers to enter the sea in late spring or early summer, where they actively feed throughout the summer, and return to the rivers in the fall (Ref. 89241). 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). In the Sacramento River, California, the spawning season is thought to be from late April into May. Fecundity, 11,398-37,288 eggs/female. Egg diameter, 0.6-0.7 mm (Ref. 89241). 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).

Life cycle and mating behavior Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae

Probably spawns in gravel, with an activity similar to Lethenteron japonicum (Ref. 1998).

Main reference Upload your references | References | Coordinator | Collaborators

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. (Ref. 5723)

IUCN Red List Status (Ref. 96402)

CITES (Ref. 94142)

Not Evaluated

Threat to humans

  Harmless




Human uses

Fisheries: minor commercial
FAO(Publication : search) | FisheriesWiki | Sea Around Us

More information

Countries
FAO areas
Ecosystems
Occurrences
Introductions
Stocks
Ecology
Diet
Food items
Food consumption
Ration
Age/Size
Growth
Length-weight
Length-length
Length-frequencies
Morphometrics
Morphology
Larvae
Larval dynamics
Recruitment
Abundance
References
Aquaculture
Aquaculture profile
Strains
Genetics
Allele frequencies
Heritability
Diseases
Processing
Mass conversion
Collaborators
Pictures
Stamps, Coins
Sounds
Ciguatera
Speed
Swim. type
Gill area
Otoliths
Brains
Vision

Tools

Special reports

Download XML

Internet sources

BHL | Cloffa | Websites from users | Check FishWatcher | CISTI | Catalog of Fishes (gen., sp.) | DiscoverLife | Faunafri | Fishtrace | GenBank(genome, nucleotide) | GOBASE | Google Books | Google Scholar | Google | IGFA World Record | iSpecies | PubMed | Scirus | SeaLifeBase | Tree of Life | uBio | Wikipedia(Go, Search) | World Records Freshwater Fishing | Zoological Record

Estimates of some properties based on models

Phylogenetic diversity index (Ref. 82805):  PD50 = 0.5002   [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00123 (0.00052 - 0.00293), b=2.99 (2.78 - 3.20), based on LWR estimates for this Subfamily-body shape (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):  Low vulnerability (17 of 100) .
Price category (Ref. 80766):   Unknown.