Description

Adults: 9.8-17.5 cm TL. Body proportions, as percentage of TL (based on 39 specimens measuring 9.8-17.3 cm TL): prebranchial length, 8.9-12.8; branchial length, 8.9-11.3; trunk length, 44.7-53.5; tail length, 24.3-35.0; eye length, 1.4-3.0; disc length, 4.1-7.2. Urogenital papilla length, as a percentage of branchial length, in ten spawning males measuring 11.2-13.3 cm TL, 17.8-36.4. Trunk myomeres, 53-58. Dentition: supraoral lamina, 2 unicuspid teeth; infraoral lamina, 6-9 unicuspid teeth, usually 8; usually 3 endolaterals on each side, occasionally 2 on one side; endolateral formulae highly variable with the first two teeth 1-3 and the third 1-2; 1-2 rows of anterials; first row of anterials, 6 unicuspid teeth (in spawning specimens, the teeth in the anterior field may be lost); exolaterals absent; posterials absent; transverse lingual lamina, undetermined number of minute unicuspid teeth on either side of an enlarged median one; longitudinal lingual laminae cusps too small to count. Velar tentacles, 3-6, with tubercles. Body coloration (preserved), dark gray on dorsal and lateral aspects, whitish on ventral aspect. Lateral line neuromasts unpigmented. Extent of caudal fin pigmentation, 1% to <25% (in prespawning individuals) or, 75% or more (in spawning individuals). Fleshy tissues around the lingual laminae darkly pigmented. Caudal fin shape, rounded. Oral fimbriae, 83 (holotype).

Common Names

Taxonomic Hierarchy

Kingdom: Animalia

Phylum: Chordata

Class: Petromyzonti

Order: Petromyzontiformes

Family: Petromyzontidae

Genus: Lampetra

Species: Lampetra pacifica Vladykov, 1973

Climate Zone

Biology

Freshwater; creeks and rivers. Metamorphosis occurs in October in Oregon and California. Adults nonparasitic. Based on the dates of collection of spawning individuals in the original description, the spawning period probably occurs between mid-April and August in Oregon, while in California spawning probably occurs between the end of April and the beginning of May (Ref. 89241).

Habitat

demersal

Conservation Status

Not Evaluated

Threat to Humans

Harmless