"Although common names for marlin generally focus on color (e.g., black marlin, blue marlin, white marlin, etc.) color is typically not the best feature to use in identifying billfish. Especially in this case! The shape and size of this marlin’s dorsal and pectoral fins clearly indicate that it’s a blue marlin even though it’s not blue at all. The eye color - black, rather than red or pink - also indicates that this marlin is leucistic (which is a reduction in pigmentation) rather than albino."