A lone Pacific lamprey in a viewing tank at the Nez Perce Tribal Hatchery, Lenore, ID. These fish go back more than 400 million years in the fossil record. Photo: Ben Herndon

At first glance, Steve Otto thought it was a snake. Two feet long, brown and slender, it had begun decomposing in the early July sun in 2015. He soon realized it wasn’t a snake but the remains of a Pacific lamprey. The surprise of finding a lamprey at all was soon eclipsed by the location where it was found—floating near the shore of an aqua-green alpine lake whose outlet plunges nearly 7,000 vertical feet over 11 miles to Idaho’s Snake River.

That’s a technical hike for a human and an impressive feat for a slinky suction-mouthed fish that moves by coordinated, coiled leaps.

Did a lamprey really climb a stream the height of the Grand Canyon? The fish was at the right place at the right time of year to have spawned and died, according to Dr. Chris Caudill, associate professor in the Department of Fish and Wildlife Sciences at the University of Idaho. Still, Caudill maintained a healthy skepticism that the lamprey made the climb.

Many people have never heard of, let alone seen, a Pacific lamprey, but “they are older than dinosaurs, than trees, than grasses,” said Ralph Lampman, Pacific Lamprey Project lead for the Yakama Nation in Washington state.  “They’re as native as can be.”

The ancient fish looks and swims a bit like an eel, but it’s not one. A better descriptor is a “vampire-ninja-snake-fish,” Caudill said. They can climb nearly vertical surfaces in just 5 millimeters of water using their powerful jawless suction mouths to grab, coil and jump. Gill pouches, an ancient adaptation, allow them to breathe in trace amounts of water. This gives them access to some pretty obscure places for fish. After hatching, lamprey larvae burrow into river sediment and act as filter and deposit feeders for up to 11 years before heading out to the ocean. In the ocean they are ectoparasites—they latch onto and suck nutrients from larger host fishes for up to seven years before returning to freshwater streams to overwinter and spawn.

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