Dwarf livebearer fish for sale
 

I have few pairs up for sale now. Wikipedia article on them http://en.wikipedia.org/wiki/Heterandria_formosa
Very rare in hobby. For setup you will need a sponge filter or undergravel filter.
Sexed juvenile pairs , 1:1 £5 a pair, around 1cm.
7th smallest fish in the world. If you want to liven your nano setup they are the best candidates. But can be seen as prey to other larger fish due to their small size. Eating well crushed flakes and daphnias. Best to keep on their own or in well planted tank with other small fish.
Collection from Oxford, PM me for more details.