I wonder if it works both ways.... Strangely, I don't ever recall getting any unwanted fish in with any of my HBG.
![whistle whistle](/images/graemlins/default/whistle.gif)
Two weeks ago I picked up another 100 HBG and placed them in a cage. I purposefully didn't get these from my usual hatchery, but right off the local fish truck, just to satisfy my own curiosity. I counted 115 when I put them in the cage, all met the stated size, No BG or GSF. I have since lost 3. Tonight, I sampled the cage and was pleased with what I saw.
So far, so good.
This Saturday, I will try yet another unfamiliar hatchery to pick up my HSB. Hopefully, it too will go well.