Istiompax indica, commonly known as the black marlin, inhabits warm oceanic waters of the Indo-Pacific. Known for its incredible speed, reaching up to 82 mph, this species is notable for its large size, distinctive dark blue to black coloration, and elongated bill. It primarily feeds on small fish and squid.

Istiompax indica, commonly known as the black marlin, is native to the tropical and subtropical regions of the Indian and Pacific Oceans. Its geographical distribution includes the waters off the coasts of Southeast Asia, East Africa, the Indian subcontinent, northern Australia, and the islands of the Pacific Ocean.

Black marlins typically inhabit open ocean environments, preferring warm, tropical, and subtropical waters. They are often found in surface waters, usually above the thermocline, where temperatures range between 22°C and 30°C. They are known to inhabit areas with significant water clarity and are often found near coral reefs, islands, and continental shelves where upwelling occurs, providing rich feeding grounds.

The black marlin occupies the ecological niche of a top predator in its habitat. It preys on a variety of fish species, including mackerel, tuna, and smaller pelagic fish, as well as cephalopods like squid. Its role is crucial in maintaining the balance of the marine ecosystem by controlling the population sizes of its prey species.