I have noticed that my Albino Corrys every so often will swim super fast to the top of the surface then dart back down again like their life depended on it. Is this normal.
Yes it is, mine do it all the time, its like a race to the top, they hit the surface then go back down as quickly as they went up All cories do it sometimes, some more than others, providing of course your water stats are all spot then, there is nothing to worry about.
This is one of those wierd adaptations some fish have made over millions of years of existance.
These fish are able to survive in low oxygen waters due to being able to "breathe" through their intestines.. Yes, you read that right!
They gasp a gulp of air and swallow it. The air then passes through their intestines where the oxygen is absorbed through the gut wall. Left-over air is released through the vent... A fishy fart if you will.
Mine do it every now and again, I thought exactly the same and had a quick look around.... apparently you only have to get worried if they're doing it frequently (which as mentioned by Minxfishy, suggests poor water quality).