Adult sea lampreys locate spawning streams in the Great Lakes by using a migratory pheromone that is released by stream-resident larval conspecifics. Behavioral, electrophysiological, and biochemical analyses of larval release water have suggested that this pheromone is composed of several components, one of which is petromyzonol sulfate (PS), a known lamprey-specific bile acid. Its precursor, allocholic acid (ACA), has also been implicated. In this study, we employed high-performance liquid chromatography and mass spectrometry to look for both bile acids in various stream waters, thereby testing whether they might have a role in natural pheromone function. Although PS was measured at picomolar concentrations in streams known to contain larval lampreys and attract migratory adults, ACA was not. Neither compound was measured in streams lacking larvae. This finding indicates that PS is a component of the natural pheromone, and it suggests that ACA has little relevance.
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AcknowledgmentsVLance Vrieze (University of Minnesota), Roger Bergstedt and Jeff Locke (United States Geological Survey), and Doug Cuddy (Fisheries and Oceans Canada) collected river waters. Jeff Slade (United States Fish and Wildlife Service) provided estimates of larval abundance for some of the rivers. Thanks also to Thomas Krick and Leeann Higgins of the Mass Spectrometry Consortium for the Life Sciences at the University of Minnesota. Funding was provided by the Great Lakes Fishery Commission.
- Allocholic acid
- Bile acid
- Petromyzon marinus
- Petromyzonol sulfate
- Sea lamprey