i am also a student and have a baby biorb on my desk!
i understand what the others saying about such a small space, but in my experience if you are committed to frequent water changes it can be fine with fish! i know it doesnt come with a heater, so unless you buy a small heater sepatarely, i would look into white cloud mountain minnows. you could probably keep 2 or 3, and they have pretty red tails.
let me know what you decide!