How goldfish use booze to get through a hard winter
Who needs oxygen when you can make ethanol?
By Rachel Feltman
No matter how many goldfish we’ve all buried at sea, the creatures are clearly pretty resilient. Pop ’em in a bowl on your desk and they might last longer than your job. Drop ’em in a local pond and they might grow to monstrous sizes and consume everything in sight, destroying native ecosystems. Stick ’em under ice all winter, and they’ll somehow still be swimming come spring.
Consider for a moment just what a feat that is: sure, it’s cold, and that slows down a fish’s metabolic processes — the chemical reactions conducted in each cell that keep all animals alive. The sheet of ice over a frozen body of water actually helps to trap heat within, so down at the bottom — warm, fresh water stays near the bottom in cold weather — fish can head towards relatively warm sediment and basically chill for a few months. But it’s hard to breathe down in those cozy pockets, even with gills. The ice at the top of the lake keeps new oxygen from entering the system, while the microbes that live at the bottom use up the gas when they eat. Where it’s warmest, it’s also the most anaerobic — and it’s not like anywhere has much oxygen to spare until the ice melts. Without oxygen, the chemical reactions that keep cells running can’t…
