Giant Trevally | Hawaiian Marine LIfe
Go back

Giant Trevally

The jacks, or trevally, are a family of strong-swimming predators frequently seen at drop-offs or near reefs. Usually silvery in color, most have streamlined bodies with varying body shapes across genus and forked tails. For most species, the base of the tail is slender and usually reinforced by specially strengthened scales called scutes.

Jacks can grow to over five feet in length, and records have shown them weighing in at close to 200 pounds. Jacks are highly prized as game fish by fishers because of their size and their ability to put on a fight. Jacks are abundant in the Northwestern Hawaiian Islands, where they are protected. Schools are frequently seen near reefs or drop-offs, and they hunt in the early morning or late afternoon hours. Typically feeding on other fishes, they can also be seen foraging on the bottom for crustaceans and other invertebrates.

Did You Know...
There are about 140 species of jacks worldwide, 24 of which are present in Hawaiian waters.

The giant trevally or white ulua is commonly observed in schools or as solitary individuals. They have a distinct steep profile head and a black spot at the base of their pectoral fin that distinguishes this species from others in the same genus. An all-black appearance can distinguish courting males, whereas females are silver in color. One of the largest jacks, they are agile pack hunters who display aggressive behavior and bite anything when curious.

*Due to the constant rotation of animals back to the ocean, we cannot guarantee the presence of any specific animal.

Hawaiian Name:
ulua aukea
Scientific Name:
Caranx ignobilis
Where to See:
Deep Reef, Open Ocean Exhibit*
Next Up
Sea Cucumber
Sea Cucumber
Sea cucumbers (loli) are a common sight on Hawaiʻi’s reefs. This unique and strange animal has a distinct tubular shape which some say resembles sausages. Sea cucumbers use the tube feet that cover...
Read more
Sea Stars
Sea Stars
Sea stars are one of the most recognizable marine species and typically have a five-part body consisting of a central disk and radial symmetry. Size, shape, color, and texture are quite diverse in the...
Read more
Whitetip Reef Shark
Whitetip Reef Shark
The whitetip reef shark is found throughout the Indian and Pacific Oceans and is associated with the coral reef environment. In the Hawaiian Islands, they can be observed resting in caves or under led...
Read more
Discover Maui's Marine Habitat
Exhibits
Open Ocean
Take a stroll through the 35-foot long acrylic tunnel as sharks soar above your head. Watch elegant stingrays turn backflips in our 750,000-gallon Open Ocean tank—a sli...
Read more
Open Ocean
Exhibits
Humpbacks of Hawaiʻi Exhibit & Sphere
Explore the realm of the whales in our virtual sphere experience.
Read more
HUMPBACK WHALES IN MAUI
Exhibits
Turtle Lagoon
Say aloha to the honu, our charismatic Hawaiian green sea turtles!
Read more
Benefits of membership