The Rams in question here are Bolivian rams (altispinosa)
the most reliable method to use to sex bolivians is a procedure referred to as Venting..
basically you look at the ovipositors and can determine the sex with visual inspection..
males long, thin pointed.
females short , blunt and rounded at tip.
it is a bit different with ramirezi aka blue rams.. the female will generally have a pink/orange hue to her belly