Thank you. I love them. By the looks of it we have 1 male and 1 female, but they are too small to tell. The photos from my phone really don't do them any justice, but they are very camera shy, it's near impossible to get a good head on shot.
I really don't mind what they turn out to be, I would just like to know so I can look after them as best as I can. They don't seemed too fussed on algae wafers or cucumber, will try courgette (zucchini) next.