Lamprey: Sucker-Fish Pesticide Will Be Based in Alluring Scent of Sex

Those of us who keep track of potentially appalling things in the universe know about lampreys. They're eel-like creatures that really give eels a bad name -- in this case, the animal has a sucker-like mouth with sharp, horny teeth and a tongue with which it can rasp at prey. It's been called vampiric, attaching itself to other fish and sucking the blood from them.

Plus, lampreys are invasive species. Native to the Atlantic Ocean and a vertebrate with an ancient lineage, they've been in the Great Lakes since at least the 1930s and have been considered an ecological disaster there. In recent years they seem to be at a more manageable level, and the Great Lakes Commission declared in 2015 that they are on a decline across those very large bodies of water. But Lakes Erie and Superior still have lamprey populations above target levels. Here's a photo of a lamprey in Minnesota, which has attached itself to a large fish and sucked blood from it. 

So, the government is hoping to take further action against these villains. In one example of that, the U.S. Environmental Protection Agency (EPA) recently registered a biopesticide that works by using vertebrate pheremones, according to a release from the Great Lakes Fishery Commission.

That is, in the biopesticide method, a male mating pheremone known as 3kPZS will serve as "an alluring perfume" to dupe female lamprey into moving upriver in search of spawning opportunities in lake tributaries. The scent will be left behind in spots where lamprey can easily be caught and killed, according to an article on MLive, the digital home of eight Michigan daily newspapers .

"With a large-scale field trial, we demonstrated that pheromone baits can increase trapping efficiencies by up to 53 percent and baited traps can capture up to two times the sea lampreys that unbaited traps can," Michigan State University professor Weiming Li said in the release. 

The scent that was registered is a synthetic version of the pheremone, developed by researchers at Bridge Organics Co. in Michigan. Canadian regulations are working through the process of registering the pheremone for use there, the release confirmed.

"The Great Lakes Fishery Commission is very excited about this accomplishment," commission chair Robert Hecky said in the MLive article. The idea is to use the pheremone to phase-out use of the chemical pesticide TFM, which is effective but expensive and can be lethal to fish species other than the lamprey.

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