Pacific lampreys Lampetra tridentata are in decline throughout much of their historical range in the Columbia River basin. In support of restoration efforts, we tested whether larval and adult lamprey bile acids serve as migratory and spawning pheromones in adult Pacific lampreys, as they do in sea lampreys Petromyzon marinus. The olfactory sensitivity of adult Pacific lampreys to lamprey bile acids was measured by electro-olfactogram recording from the time of their capture in the spring until their spawning in June of the following year. As controls, we tested L-arginine and a non-lamprey bile acid, taurolithocholic acid 3- sulfate (TLS). Migrating adult Pacific lampreys were highly sensitive to petromyzonol sulfate (a component of the sea lamprey migratory pheromone) and 3-keto petromyzonol sulfate (a component of the sea lamprey sex pheromone) when first captured. This sensitivity persisted throughout their long migratory and overwinter holding period before declining to nearly unmeasurable levels by the time of spawning. The absolute magnitudes of adult Pacific lamprey responses to lamprey bile acids were smaller than those of the sea lamprey, and unlike the sea lamprey, the Pacific lamprey did not appear to detect TLS. No sexual dimorphism was noted in olfactory sensitivity. Thus, Pacific lampreys are broadly similar to sea lampreys in showing sensitivity to the major lamprey bile acids but apparently differ in having a longer period of sensitivity to those acids. The potential utility of bile acid-like pheromones in the restoration of Pacific lampreys warrants their further investigation in this species.
|Original language||English (US)|
|Number of pages||9|
|Journal||Transactions of the American Fisheries Society|
|State||Published - 2009|
Bibliographical noteFunding Information:
We thank Susan Imholt, Rebecca Reiche, and Brian Sharp (U.S. Geological Survey [USGS], Columbia River Research Laboratory) for the hours they spent performing these experiments. We thank Weiming Li and Michael Siefkes (Michigan State University) for their assistance with designing and testing the EOG apparatus. We thank Dena Gadomski, Matthew Mesa, Michael Meeuwig, Alec Maule, and Dennis Rondorf (USGS, Columbia River Research Laboratory) and Keith Tierney (Simon Fraser University) for their editorial reviews. We thank Darren Ogden (NOAA– Fisheries) for specimen capture and collection. We thank David Close (Confederated Tribes of the Umatilla Indian Reservation [CTUIR]) for his collaboration in initiating this project and for contract management. This research was supported by the CTUIR with funding from the Bonneville Power Administration (project 1994-026-00). Mention of trade names does not imply endorsement by the USGS.