by by Matt Surka

Vampire traps
12:17 PM, T-minus seven hours and forty-three minutes to third-date pickup hour, strolling down a mall walkway somewhere between Abercrombie and Auntie Anne's, a young woman--call her "Rosalie"--smells traces of perfume flowing seductively from a nearby pushcart and wanders over. Snap! go the stainless-steel jaws of an enormous floor-mounted cage; Rosalie is trapped, never to make her nine o'clock dinner-and-a-movie, doomed to spend the rest of her days in bleak, nonprocreative bondage.

Over-the-top though it may be, this image is actually a pretty good metaphor--some squinting required, but the parallel is there, I promise--for a new weapon US researchers hope to soon deploy against the dangerously widespread population of a species of parasitic fish in the Great Lakes. Replace Abercrombie-decked mallway with a Great Lakes tributary, Rosalie with a sea lamprey, and the smell of pushcart perfume with male lamprey pheromones, and the analogy hums perfection.
In a preliminary experiment, BBC News reported last week, scientists planted samples of lab-produced pheromones inside riverbed traps; drawn in by the smell, ovulating female lampreys entered the cages looking for what they assumed would be a source male, only to be locked inside and yanked into reproductive oblivion.
Sea lampreys (known as "vampire fish" for the grisly way they latch onto larger fish and suck out blood and body fluids) have posed a constant threat to the billion-dollar US-Canada fishing industry ever since their accidental introduction to the Lakes two centuries ago, when the completion of the Erie Canal opened an avenue from ocean to lake. Decades later, native fish populations hit record lows.
Scientists spend $20 million per year to keep the population of bloodsucking fish at bay, dropping into the water everything from tactical pesticides to sleeper-agent sterile males to--whichever scientist thought of this last one deserves a prize for straightforward thinking--huge, fish-blocking walls. Sea lampreys, though--unlike salmon--feel no need to seek out any specific spawning bed to lay eggs; they'll pick whichever stream looks promisingly unfortified. Should further tests prove successful, scientists should be able to skirt this obstacle by luring lampreys into only the trap-rigged tributaries. But though this scheme may sound Darwinishly cruel, humans--save for poor Rosalie--need not give it a second thought: there are no current plans to cull local mall-lurker populations.
Doin' it in vitro
In other upstream-swimming news, scientists at Edinburgh University in Scotland have developed a means of testing a sperm-cell's mettle before it's used for in vitro fertilization. Lead scientist of the project Dr. Alistair Elfick told BBC News last Monday that their technology can rate each sperm cell's chance of completing the eggward trek "with a DNA-based 'quality score.'" Testing involves subjecting each individual sperm cell to examination by two highly focused lasers; DNA properties are then calculated by a process called Raman spectroscopy.
One can imagine the BBC reporter--with echoes of the words "quality score" reverberating in her head to a montage of scenes from 1997's Gattaca (tagline: There Is No Gene For The Human Spirit)--staring at Dr. Elfick in silence for a full five seconds, horror-struck. But before her trembling lips could utter "eugenics," Elfick quickly added, "This is not about designer babies. We can only tell if the sperm is strong and healthy, not if it will produce a baby with blue eyes."
So no, don't expect to see Liam Neeson leaning over any minutes-old infants saying, "They've finished the gene projection; you're going to look a lot like your dad!" At least, not anytime soon. Pip-Boys, though, are right around the corner.

The lamb fell in love with Matt Surka B'11.