Adults are most easily identified, as the nape is well-elevated and the pectoral fins are rigid and cannot be pressed back against the sides of the body. There are usually no blotches or dark stripes along the body after death. Black marlin scatter along the same warm 70 to 85 degree currents as do blue marlin, but often can be found closer to shore. As with the blue marlin species, activity around Baja diminishes as the summer fades.
Blacks are solitary feeders and kill their prey in the same way as the other marlins and sailfish.
The male of this species is considerably smaller in size than the female. The black marlin is found in the Indian and the Pacific oceans. Open ocean along continental shelf drop off, ocean mountains and canyons, current and weed lines. Gatherings of bait schools such as tuna, mahi mahi and squid are likely black marlin haunts. Will come within close proximity of land if warm currents and bait schools are present.