I have heard that HSB do not spawn. Then I called my state fisheries biologist and asked why they stocked Pure Striped Bass in a 162 acre lake as opposed to HSB. He told me that in NJ they do not stock HSB in any water that they can escape because even though theya re generaly sterile they have a 1:200,000 chance of spawning with Pure Striped Bass. I thought this was very interesting.

Actually masterbasser, it's even worse than the state biologist told you. Hybrid striped bass are "functionally" sterile. The 1:200,000 probably applies to hybrids spawning with hybrids. However, the males of both species commonly run with either striped bass or white bass, and they certainly can produce a back-crossed generation with either. For example, hybrid males running with striped bass females will produce offspring that are 3/4 striper and 1/4 white bass genes.

The "functional" sterility comes from the difference in egg types for the two parentals. Striped bass have eggs that are nearly neutral buoyancy, and along the east coast they spawn in rivers that carry the eggs while they develop and hatch. If the eggs settle to the bottom, they typically smother and die in the organic/silt layer on the river bottom. Eggs need some oxygen, which crosses the membrane. White bass have heavy, sticky eggs. In rivers, they spawn on gravel riffles. The sticky, heavy eggs attach to the bottom and the current keeps them clean and oxygenated. Hybrid striped bass eggs are halfway in-between. They are too heavy to float with the striped bass eggs, settle to the bottom, and generally die. They are too light and not sticky enough to stay on the gravel if spawned in a riffle. They wash off, into a pool below, settle on the organic mud that usually has low or no dissolved oxygen, and die.