Scientists Trick Eels With Phenomenal Pheromone

The introduction of the sea lamprey in the Great Lakes has been decimating the recreational fishing industry on the Great Lakes for over 100 years. But now US researchers are using the chemicals in the male lamprey to lure ovulating females into traps.
The trickery being performed is seen as a breakthrough technique for controlling the non-native lamprey.
"There's been extensive study of pheromones in animals and even in humans," said lead researcher Weiming Li from Michigan State University in East Lansing, US. It was one of the worst things to hit the Great Lakes in the history of European settlement
"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," he told BBC News.
The researchers, let by Professor Li, released the synthetic version of a lamprey hormone from a trap placed in a stream where lampreys come to breed.
Females scenting it would swim vigorously upstream until they found the source, some becoming trapped in the process.
The sea lamprey's natural life cycle takes it from birth in a stream to adulthood in the ocean, where it gains its vampirical appellation. Circular jaws lock on to another, larger fish, and a sharp tongue carves through its scales. From then on the lamprey feeds on the blood and body fluids of its temporary host, often killing it in the process. Eventually, the satiated lampreys - both males and females - find a suitable stream to swim up, breed and die.
In their native Atlantic Ocean, their numbers are controlled by predation; but in the Great Lakes they have no predators.
They first appeared in the 1800s after completion of the Erie Canal linking the lakes to New York. Colonization was completed a century later when other canals provided unfettered access to the upper lakes.
"It was one of the worst things to hit the Great Lakes in the history of European settlement," said Marc Gaden from the Great Lakes Fishery Commission (GLFC), the body responsible for controlling the lamprey problem.
"Before it, we had a thriving fishery largely dependent on native fish such as the lake trout... but by 1940 they had colonized thousands of streams and fishermen were beginning to see the devastation."
The techique will be expanded to streams and tributaries over the next three years