Thanks everyone, between you and me he was my fav.
I moved all my fish into a white wheely bin sort of thing, its was probably too about 70litres. I left it uncovered until we left. Only filled it about 1/3. Put the lid on and left them in the sun as much as i could have in the car. Stopped off to check on them and he was already gone with his mouth stuck open. Maybe he was gasping?