For the HSB/Crappie pond, we're thinking fatheads (or rosies) along with t-shad. I figure that t-shad school up in the open water, and the HSB should be right there waiting for them. Gambusias are always good to have around in the summer in Texas, but I won't hold my breath for them to last too long.
BG- there is a species that I love and, like Dave Davidson, that I think are the backbone of a good forage base. I just don't see them being helpful or necessary in an HSB/Crappie pond, however. At least not with the other mentioned forage. Any other suggestions for forage? We're thinking GSH as well.
Steve- We have crappie in the pond at Waelder, and I have no idea how they got there either. I'm guessing they may have been introduced with original stockers or, more likely, arrived from upstream or downstream, as Todd mentioned. Since I don't know how they got there, all I can do is get them out as best I can. If you are managing for LMB/BG, I would suggest the same.