Explain which phenotype is not a favorable adaptation to the fish. Why?

Gold is the phenotype that is not favorable to the fish.

Explanation:

Note that, the fish come only in two phenotypes, which are brown and gold. These phenotypes are controlled by a gene with two different alleles.

The fish with gold phenotype are vulnerable than those with brown phenotype because they are easy to catch and taste good, while the other have bitter taste, and are hard to catch because they are sneaky.