RAH - I only know that healthy HSB will develop eggs as seen by Cecil Baird and myself. I have a pond near me that has several small HSB that have not been stocked with the original larger ones. Apparently from the information in the links below it takes special conditions of moving water and water quality for the eggs to survive and hatch. The people that own and manage Stubby Steve baits have HSB spawning and recruiting hybrids in their pond which is not supposed to happen. I think I have the name of the pond owners correct as posted on the Pond Boss forum.
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=177718&page=1

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Main=14608&Number=177647#Post177647

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Main=26165&Number=335069#Post335069

Last edited by Bill Cody; 07/07/17 08:26 PM.
aka Pond Doctor & Dr. Perca Read Pond Boss Magazine -
America's Journal of Pond Management