I liked the answer on the wiseGEEK site. They tell about the differences in species, and where they live, diet, taste and texture. Cod tends to be softer, and the haddock is drier and flakier but sweeter in taste. read more
Haddock is a large fish, ranging in length from 15 to 27 inches (38–69 cm). The meat has thick flakes or layers which makes it ideal for restaurant dishes like the British fish and chips and American fish sandwiches. It has a mild taste, that is e... read more
Tilapia is a pan fish, small, with the fillet about the size of an adult male hand. Taste is a little stronger than Haddock, but still mild. It’s a very delicate flesh which cooks very quickly. read more
Both tilapia and haddock are rich sources of protein. If you want to up your protein intake, however, consider choosing tilapia more often. A standard fillet of tilapia provides nearly 23 grams of protein, compared to about 17 grams in a haddock fillet. read more