Thanks for the reply.. Mine also.same colours..male is dark n female is lighter...they have being in thank for 2 months now.. I seen there head shapes are different small one is male but female is larger with rounded head.male has a narrow shaped head..but my next question is whether they will mate or not.cz of this size matter..i seen in the net.males are larger than female.. N i have setuped this tank as a cold water tank.. Provided freeze water bottle n two coolin fans..