it's been 4 months but I found this
“Tiger Trout are a sterile cross of a brown and brook trout. The name comes from the wavy stripes along their body. A hatchery can readily produce them by ,Fertilizing eggs of Brown Trout with sperm of a Brook Trout and heat-shocking them to create an extra set of chromosomes. Some claim they grow faster than either of their genetic origins.”swittersb.files.wordpress.com/2009/07/tiger-trout-b.jpg

Sam, Lycoming County North Central PA NAFC Life Member ,Angler Legacy Ambassador