Top stories: Crayfish clones, happy lab animals, and the world’s smallest 3D glasses

An aquarium accident may have given this crayfish the DNA to take over the world

It sounds like a bad monster movie plot: a 10-legged mutant creature that reproduces asexually, escapes from confinement in Germany, and quietly begins a global invasion. Within 2 decades, clones of the voracious animal spread through Europe and Africa, bringing devastation to ecosystems and threatening native species. That appears to be the strange-but-true story of the marbled crayfish, an invasive freshwater species suspected to have been created through a reproductive accident in an aquarium around 1995. A new analysis of the crustacean’s genome supports this unlikely origin and may help explain how the animal has subsequently spread and adapted to so many new environments.

Are happy lab animals better for science?

For decades, lab animals such as rodents and fish have lived in barren enclosures: a small plastic box, few—if any—companions, and little else. The smaller the number of variables, the thinking went, the greater the accuracy of the experiment. But a growing number of studies suggests that this approach may have backfired. Only one in nine drugs that works in animals ever succeeds in human clinical trials, and labs often struggle to reproduce one another’s results. Could the environment these creatures live in be part of the problem? A group of advocates think that the answer is yes.

Nasty U.S. flu season continues to intensify

It’s week 11 of a flu season that may only be half over, and a wave of influenza across the entire United States has led to an alarmingly high number of sick people. In the last week of January, 7.1% of all outpatient visits were for what’s classified as influenzalike illness, said Anne Schuchat, acting director of the U.S. Centers for Disease Control and Prevention in Atlanta. That was a jump of 0.5% from the preceding week, indicating that this year’s flu may not have peaked yet.

Major mental illnesses unexpectedly share brain gene activity, raising hope for better diagnostics and therapies

Mental illness affects one in six U.S. adults, but scientists’ sense of the underlying biology of most psychiatric disorders remains nebulous. Now, however, a large-scale analysis of postmortem brains is revealing distinctive molecular traces in people with mental illness. An international team of researchers reports that five major psychiatric disorders have patterns of gene activity that often overlap but also vary in disease-specific—and sometimes counterintuitive—ways. The findings, they say, might someday lead to diagnostic tests and novel therapies. One has already inspired a clinical trial of a new way to treat overactive brain cells in autism.

World’s tiniest 3D glasses reveal how praying mantises see the world

Praying mantises are the only invertebrates known to see in 3D. The predatory insects excel at detecting prey that comes within striking distance, but—unlike us—their depth perception only works when the prey is moving. Scientists figured that out by gluing the world’s tiniest 3D glasses on praying mantises and showing them a series of 3D movies. It’s the first time this kind of 3D vision has been found in nature, and it’s yet another example of evolution coming up with different solutions to the same problem—in this case, when to strike at a passing fly.