Miller Lake Lamprey Identification Guide

Key identification features

• Very small, dwarf-sized lamprey, typically under about 15 cm at maturity
• Reduced oral disc with weak, blunt teeth since adults do not feed after transforming
• Dark, mostly uniform brown to grey body coloration
• Slender, scaleless, eel-like build with two low dorsal fins toward the rear
• Eyes present but modest in size compared with larger migratory relatives
• Larvae are blind and toothless, living buried in fine stream sediment for an extended period

Common look-alikes

• Pacific lamprey is its closest large relative but grows far bigger, migrates to the ocean, and keeps strong, well-developed feeding teeth this dwarf form lacks.
• Other small non-parasitic lampreys can look similar at a glance, so confirming the exact watershed is important since this species has an extremely limited range.
• Ammocoete larvae of nearby lamprey species are difficult to separate visually and usually require examining a transformed adult.

Where you'll see one

This dwarf lamprey is historically tied to Miller Lake in the Klamath Basin of southern Oregon, USA, and though eliminated from the lake itself decades ago, it persists in a few small nearby tributary streams.