Occurrence, Detection, Habitat Use of Larval Lamprey in Columbia River Mainstem Environments: Bonneville Reservoir and Tailwater. 2010 Annual Report

摘要

Pacific lamprey Entosphenus tridentatus have experienced a great decline in abundance, specifically in the Columbia River Basin (CRB) and have been given protected status within Oregon. Lamprey are culturally important to Native American tribes, are ecologically important within the food web, and are an indicator species whose decline provides further insight into the impact of human actions on ecological function. Information is lacking on basic biology, ecology, and population dynamics required for effective conservation and management. Pacific lampreys have a complex life history that includes a three to seven year larval (ammocoete), migratory juvenile (macrophthalmia) and adult marine phase. Ammocoetes and macrophthalmia are strongly associated with stream and river sediments. Ammocoetes live burrowed in stream and river sediments for periods up to seven years after hatching, where they filter feed detritus and organic material. Ammocoetes metamorphose into macrophthalmia from July to December and migrate downstream to the Pacific Ocean.