Don't know if this helps, but back in the NY Finger Lakes, my fishing partner and I discovered that, when still fishing with live rainbow smelt, at spawning time, the Lake Trout preferred female smelt filled with roe over males or spawned out females in an overwhelming majority of cases.

We got to the point where we fished with females and fried the males and spawned out females and ate them ourselves! I guess it's a little like brown bears preferring salmon with roe as well toward the end of the run.