Originally Posted by FishinRod
Originally Posted by Snipe
"X" acres of water will support about 25-30% more lbs of SMB per acre than LMB.

Snipe (and everyone),

That is not one that I had heard before. (But that is true of LOTS of things!)

I like "rules of thumb" for complicated issues, as they typically provide good starting points for more thorough investigations.

What is the reason for the ability to support more biomass of SMB?

Does that rule generally apply from north to south, or does the SMB advantage become smaller for warmer ponds at more southerly latitudes?

FishingRod,

The main thing that determines the ... is the breadth of trophic exploitation. So one of the ways this can be determined is to raise fish in monoculture. The link is a reference to such tests that were conducted in Illinois by Buck and Thoits. Essentially, the LMB are more dependent on prey that is further up the food chain which is why they don't achieve as great a standing weight in otherwise equal water. The SMB are able to consume more because they are inclined to consume things that the LMB may not. Buck and Thoits thought pond invertebrates where under utilized by LMB. So the food chain is a pyramid where the greatest biomass is at the base. Usually fish that have the broadest (and lowest) trophic exploitation achieve the greatest standing weights.

Buck and Thoits remarked that SMB were hardy fish that handled well. There is probably a limit to how far south one should try them but where conditions are not adverse to SMB ... they should attain higher standing weights than LMB. Exceptions could occur where community interactions prevent them shining. For example the combination of LMB and BG is not conducive to high standing weights of SMB and the pressures of both species through competition (and predation) will in most cases eliminate the SMB overtime. So other members of the community are important.