and even the 10-gallon tank you see in every pet store won't cut it. A single adult goldfish needs at least twice that much water to thrive. That's almost 40 kilograms of water, 2000 times heavier ...

Basically, the platform works by moving in a direction based on where the fish is in the tank. Once they had it set up, researchers used color-coded environments to teach the goldfish how to ...