It stands to reason that fish have a sense of taste. That is what attracts them to food; just as it does with every other creature.. All have their own food preferences from bacteria to us. "Tastes" vary widely in form depending on the tasters .. the simplest forms are in the bacteria and similar lower forms , becoming more sophisticated as the organism becomes more sophisticated. The lowest forms are drawn to whatever supplies their needed nutrients while as the sophistication increases the "presentation" also comes into play... and remember, tastes vary greatly. At the top, some things that are delicious to your dog are absolutely revolting to you .. LOL.... . Look at fish feeding and the foods you present to them .. some things that look identical will be greedily eaten by your pets , and others rejected or eaten more reluctantly. Taste and "smell" factor in on those choices .