Black Jacks are fish of the open ocean. Their silver color gives them fairly good camouflage in open water. Many fish of the open ocean are silver colored, unlike the brightly colored fish that live near the reef. Black Jacks can be found over 1200 feet deep. Black Jacks can be identified by their size, the color of their tail fins, and the size of their dorsal and anal fins. Black Jacks can be up to 3 feet long. All jacks have a similar shape. But the Black Jack has a two color (black and white) tail fin, and has long dorsal and anal fins. The dorsal fin is the fin on top, and the anal fin is the fin on the bottom near the tail. The tail fin is also called the caudal fin. Although often a silvery gray color, Black Jacks can change their color to a dark brown or black. Black Jacks are built for speed. They have a steeply sloping forehead and a body that tapers down to a narrow tail. The Black Jack's tail is deeply forked and swept back from its body. The Black Jack's shape reduces drag, and its tail is shaped for propulsion. The Black Jack is a hunter that catches other fish. It uses its speed to chase and catch its prey. They often swim alone, but may also hunt in small groups. Black Jacks are found all around the world in tropical waters. While some places do serve it as food, there have been poising cases attributed to the black jack, with laboratory tests confirming the presence of toxins in the flesh. Nevertheless, they are not considered an aggressive fish towards humans.