One must also keep in mind that protein requirements are not just species specific, but even more so are dependent on the life stage of the fish. Juvenile fish require more protein than adult fish due to their higher metabolic rates. Most flowerhorn will show good healthy growth with 50% protein at fry stage, and can later easily be reduced to a maintenance diet as low as 30-35% when adult if quality protein is being used. Also, too much protein can sometimes have a negative effect on the growth of a fish because it also requires energy to deaminate the excess amino acids and then excrete them. If too much energy is utilized to break down and excrete excess protein, that too can affect overall growth. There are studies involving tropical fish where this has been discussed by researchers.
