Can a long finned danio live in a 1 gallon tank?

A 1 gallon tank is not large enough to keep any fish in for any reasonable period of time. The basic rules of fish keeping are :- 1 inch of fish needs a MINIMUM of 1 gallon of water. :- Every tank needs a permanently running filter. :- Every tank need to have at least 50% of its water changed every week. Keep the above rules and you can be successfull keeping fish alive. Fail to keep the above rules and I can guarantee you failure. A Zebra Danio grows to about 1.5 inches and so needs a MINIMUM of 1.5 gallons of water. Knowing that tanks are never filled to their maximum capacity ie the brim. You would need a tank that nominally holds 3 gallons to be on the safe side when keeping a Zebra Danio.