thanks for all the comments!
sarahfish, i had bought the angel fish about 2 months before the picture was taken but do not know how old it was at the time. it was the size of a fifty pence (hope your english or that will mean nothing too you!!) and came as a pair. i have never had any luck keeping angles alive before these two but they seem to be doing fine after about 10 months. here's it's partner! (i call them it as i have no idea how to sex them!