Creatures that live in the dark may lose their sight over evolutionary time. They may even lose their eyes entirely. Now it appears that they also lose sleep. Because a new study shows that cave-dwelling fish spend more time awake than their counterparts at the sunny surface. The finding is in the journal Current Biology. [Erik Duboué, Alex Keene and Richard Borowsky, "Evolutionary Convergence on Sleep Loss in Cavefish Populations"]
生活在完全黑暗环境中，丧失了视力的鱼类保持清醒的时间多于那些没有失去视力的鱼，这可能是因为盲鱼需要花费更多的时间觅食。--凯伦·霍普金报道。生活在黑暗环境下的生物可能在演化过程中视力逐渐下降。它们甚至会完全失明。现在看来它们同样减少了睡眠。最新研究显示相比生活在阳光下的鱼类来说，洞穴鱼类保持清醒的时间更长。这项成果发表在《当代生物学》上。[Erik Duboué, Alex Keene and Richard Borowsky"Evolutionary Convergence on Sleep Loss in Cavefish Populations"]
Researchers studied three populations of Mexican tetra in the lab. Fish that live in creeks or rivers have two eyes and see just fine. But those that have adapted to living in caves lack eyes. What they do have is insomnia. The scientists observed that the tetras that normally spend time in the light do sleep soundly at night, resting on the bottom of their tanks. The cave fish, on the other hand, remain on high alert, patrolling their habitats even after hours.
The researchers are working to identify the genes responsible for this fishy restlessness. Not that they’ll reveal how you can get by on minimal shut-eye. Because the cave fish may not need less sleep—they may need to stay awake to forage more in an environment where food can be scarce and appear unpredictably. And even a blind fish can see: you snooze, you lose.