Lepomis suggested best at 16% lipid. Interestingly, they cite Hoagland who says that in a closed system with no other food sources, Lepomis got best growth with 44% protein and 8% lipid.
Interesting. This suggests to me that when natural forage is available for Lepomis, it is naturally relatively low in lipids so a higer 16% lipids in the supplemental feeding of pellets balances the diet to around 8% overall.
But then again the circle comes back to what is "best growth?" They do not define what parameters they are using to rate/measure growth. Big and fat ASAP?