Thanks Snipe. Great point about optimal foraging (needing the right size forage at the right time). I suppose in theory GSH can get over 10", but I don't know enough about them to be confident that I could maintain enough larger ones to optimally feed the largest SMB. I wouldn't really want the forage base to be based on just one species, so this little quest is mainly just to wisely choose another pillar in the forage base so that ideally my forage pillars wouldn't be competing directly head-to-head for a limited food resource, rather that each one would have enough of a distinct diet to bring some different/new biomass into the food chain.
Your comment about the YP and SMB preying on each other's fry just made it dawn on me that maybe one reason to have YP in the mix is due to spawn timing. I believe that usually YP will spawn quite early, then SMB a bit later, and probably most of the minnows and shiners a month or so after the SMB; so, is part of the benefit of having YP that they'll produce fry early so that SMB fry/fingerlings have something to eat while they wait for the GSH or other forage species to spawn and produce fry?
I've definitely put lots of thought into this, though that doesn't necessarily mean my millions of thoughts are even remotely meaningful haha. Time will tell...
