1, Appearance: there is a clear difference between the shape and color of marlin and tuna. Marlin is usually smaller in size, longer in body, thinner in tail, larger in head and dark blue or dark green in skin color. Tuna, on the other hand, is relatively larger, has a thicker body, a wider tail, a relatively smaller head, and a red or orange skin color.

2, distribution: marlin mainly live in tropical and subtropical waters, including the Atlantic Ocean, the Pacific Ocean and the Indian Ocean warm waters. Tuna, on the other hand, has a global distribution, from the Pacific Ocean to the Indian Ocean, from the Atlantic Ocean to the Mediterranean Sea, you can find them.

3, food: marlin is a carnivorous fish, mainly to small fish, crustaceans and other marine life for food. Tuna, on the other hand, is an omnivorous fish with a wide range of food, including plankton, crustaceans, fish and other small marine life.