There is some confusions about that species and the way they look like until recently.  In less then half a dozen star system many civilization have the same family root.  Some are more pacific then others, when others are turn toward military life style.  A group of less then fifty individuals found their way into the resistance after an attack on one of their colonies.  Those Ktarians are the ones with bony spikes in the middle of their forehead.  They have a rapid growth rate.  A two years old looks like a three year old human.  It levels off when they are at adolescence.  The name of their planet origins is Katarus.  They don't like the others who called themselves the same way and ovoid their contacts which isn't a problem in our part of the quadrant since they are the only ones.  There's no problem detected in inter species breading.