While out collecting his monthly baseline water monitoring data near Spooner, WI, WAV volunteer Phil Sylla observed a surprise guest in the Yellow River: a southern brook lamprey. Before you get spooked by this unique critter, we wanted to share a few fun facts about why they're actually pretty cool...
The southern brook lamprey is a jawless, eel-like species that spends most of its life hidden beneath stream sediments. Unlike its infamous cousin, the invasive sea lamprey, the southern brook lamprey is native, harmless, and never feeds on other fish. After spending three to four years as a tiny, worm-like larva filtering algae and organic matter from the stream, southern brook lampreys grow into an adult that lives only a few months, surviving entirely on energy stored from its larval stage.
Adults emerge in spring to build pebble nests, spawn once, and then die. They spawn in groups of up to 40 individuals - which is exactly what Phil observed while out sampling. The southern brook lamprey reminds us that healthy streams support not only familiar fish and wildlife, but also remarkable species that spend most of their lives hidden from view.