The snake mackerel (Gempylus serpens) is a species of fish in the monotypic genus Gempylus, belonging to the family Gempylidae (which is also referred to generally as "snake mackerels"). It is found worldwide in tropical and subtropical oceans between the latitudes of 42° N and 40° S; adults are known to stray into temperate waters. It is found to a depth of 600 meters (2,000 feet). Populations of the snake mackerel from the Atlantic and the Indo-Pacific differ in vertebral count (51–55 versus 48–50) and number of first dorsal fin spines (30–32 versus 26–30), and so may represent separate species.