Marlin is any of several large, fast-swimming billfish, including blue, white, striped, and black marlin, whose dense, firm, mildly sweet flesh is used in seafood cooking, particularly in coastal and island cuisines. Its texture is often compared to swordfish, and it can be grilled, seared, baked, or served raw in sashimi and poke. Several marlin species are overfished, so sourcing guides commonly recommend choosing marlin from certified sustainable fisheries or substituting mahi-mahi or swordfish.