Well i dont think the picture shows it but the bigger one has a blue tint to her and the smaller one has a red tint.
I don't know how old they are.. I just know that the big one was at the pet store for about a month.... The tank was FULL of them and they all looked pretty shabby. I got the clerk to scoop up the blue one and he accidentally scooped the red one up too! I only payed for one
I already have the new tank, its a 3.5... im just waiting to get it cycled. I've got some cultured gravel from my 20 gal in it.