The trick to controlling invasive blood-sucking sea lampreys—sometimes known as vampire fish—may be a love pheromone, according to a new study. Researchers have designed a synthetic version of the male lamprey pheromone that ovulating female lampreys find irresistible, and could be used to lure them into traps. This would be the first instance of using pheromones to control non-insect pests. “There’s been extensive study of pheromones in animals and even in humans,” said lead researcher Weiming Li… “But most researchers have presumed that as animals get more complex, their behaviour is regulated in a more complex way, not by just one pheromone,” [BBC News].
When Li’s team placed traps laced with the synthetic pheromone in a stream, female lampreys swam eagerly towards the trap. Only a whiff of the pheromone was needed to attract females from hundreds of meters away, the researchers report in the Proceedings of the National Academy of Sciences. “The pheromone is expensive to synthesize… But only a very small amount is needed for it to work successfully. It’s very potent. Only a few hundred grams, less than a pound, would be used each year” [LiveScience] said Li, who discovered the natural lamprey pheromone in 2002. Currently, lampreys are controlled mainly by adding TFN, a compound that kills the larval stage, to freshwater streams where lampreys spawn. But there are environmental concerns about adding the chemical to streams, as well as the possibility that lampreys could develop resistance to TFN [LiveScience].
