Its a strange one, i would say it is mostly roach, as it has the classic shape, but it has an upturned mouth which made me think that it has some rudd in it, although the photos dont do it justice it also had really blood red fins.
This pond isnt stocked by any club and hardly anyone fishes it.
The predominant species is roach.
I've also has various goldfish from there.
Plus it has the crucian thingy fish you know looks like a crucian but has probably cross bred with the brown goldfish.
I know someone let 5 or 6 rudd free from their tank into there so you never know.