im going to go against what everyone else is saying and say thats a female. just in my experience ive had 3 breeding pair of jags and the females tail fin always had much less speckling then the males. yours looks just like all my females did. my males had double triple the amount of speckling on the tail fin. also i noticed on this thread that most males show much more speckling then the members who show there female jags. lots of pics to look at. http://www.monsterfishkeepers.com/forums/showthread.php?t=90820&highlight=female+jag