Tuna:

Tuna meat differs from that of many other fish because it is pink or red rather than white, and tuna is one of the most widely consumed types of fish. High levels of mercury in some kinds of tuna is a health concern, particularly for children and pregnant or nursing women. Unlike most fish species, which have white flesh, tuna have flesh that is pink to dark red. The red coloring comes from tuna muscle tissue's greater quantities of myoglobin, an oxygen-binding molecule. Usually severed in steaks.

Grilled Tuna with Teriyaki Sauce and Sliced Papaya

Grilled Bourbon Tuna Steaks

Tuna Grilled Korean Style