Jacks in Hawaii
Jacks are strong, fast-swimming fish often seen near reef edges, channels, drop-offs and open water close to reefs. They belong to the Carangidae family, which includes trevallies, scads, pompanos, rainbow runners and related fish.
In Hawaii, adult jacks are called ulua, while younger jacks are called papio. These names are familiar in fishing, local food traditions and ocean life conversations. Ulua are especially respected for their speed, strength and hard-fighting nature.
How Jacks Hunt
Jacks are pursuit predators. They use speed and power to chase smaller fish, often moving quickly through open water near reef structure. Their strong tails help them accelerate, turn and overtake prey.
Many jacks have silvery sides and lighter bellies with darker greenish or bluish backs. This coloring helps them blend into open water. From below, the pale belly matches surface light; from above, the darker back blends with deeper water.
Where to See Them
Snorkelers and divers may see jacks cruising along reef edges or passing through schools of smaller fish. Large individuals may appear alone, while younger fish sometimes move in groups. They may pass quickly, so watch the open water around the reef, not only the coral itself.
Jacks are among Hawaii's most powerful reef-edge predators. Related pages include the Hawaii fish guide, barracudas, groupers, lizardfishes and Hawaii beach safety tips.
