Augie, I know that to be the case. Question then is what do flathead of that size most commonly eat. There is a lot of data that supports that predators most commonly eat prey at about 18.8% their own length. Across a broad range of predators, albeit I haven't seen data on flat head, this holds true and across many different age classes. Where there is exception it goes the way of smaller prey, for example, Muskellenge which tend to eat prey that is a smaller percentage of their length as they grow bigger. Now they eat larger prey for sure, but the relative size does tend to decrease as they get larger.
The way to look at this is that there is a distribution of prey size and when you look at a frequency plot, the curve is consistent with a probability function. 70% of the prey will fall within .75% and 1.33% the weight of the predator. Some do fall outside this range and when they are attached to a hook, there is little the prey can do to avoid being eaten.
I admit that I can not fully explain this but if I had to venture a hypothesis it would be this. Fish growth tends to be allometric. This means that they tend to grow proportionately in 3 dimensions. What this means is that fish's mouth volume and the volume of water it can engulf when launching an attack is proportionate to its weight. The 1% prey size might represent the optimum prey where the failure of capture and energy gained strike the optimum balance. The lower limit is around .1% or around 10% the length of the predator the upper limit seems to be the limit determined by gape.
From a management perspective, one should plan for the most probable outcomes. If one desires the diet to be primarily 6" prey, then one wants to be sure the predator is large enough to predominately prey on prey that large.
Last edited by jpsdad; 08/26/19 04:07 PM.
