Skip ... according to the article, the "scientific documentation" was doing the otolith ring count, where they take that "ear bone" out of the fish and measure it to determine age.

I don't know as the amount of Shad in a lake is any indication of fast growth in the first few months ... since those fry/fingerlings don't eat "fish", but subsist on the various forms of plankton critters swimming around in the water.

I have noticed that the studies I've read seem to indicate that Crappie do grow faster in the first two years (several inches per year) and then slow to 1-2" per year by the time they get into their third year and beyond. I just can't seem to find any info on Texas or Fla. growth rates in the first year.
I guess since nobody is interested in catching a 3" Crappie, there just isn't any reason to know how fast they get to that size (except maybe by the biologists publishing papers & articles)

... cp