I think it's a female. It looks very much like my female, the same bodyshape, the same line of spots and so on... But then again, I could be wrong...
Anyway, here are some things that I've noticed in the very short time that I've had my jags...
1. Males have spots on all their fins, females also has spots but they are much lighter in colour. The males also has a tint of blue at the very end of their fins.
2. Females has a plumper bodyshape, males are slender.
3. Males has a lot of spots on their belly and the lower part of their face. In fact they have spots pretty much all over their body.
4. Males usually rule the tank and pretty much harass the females all day long...
5. Females has a very dark line of spots down their lateral spine, males has those spots too but they break up i a bunch of other spots all over their body.
Some pictures:
Male
http://hem.bredband.net/freisa/akvariesidan/bilder/jaguar03.jpg
Female
http://hem.bredband.net/freisa/akvariesidan/bilder/jaguar01.jpg
I'm sorry for my bad english, I'm from sweden...
/FI76