Meet ‘ulua aukea the giant trevally

This big fish in the jack family is very famous here in Hawai‘i because you see stickers of the fish on the back window of the fishermen’s trucks or on their T-shirts.

Almost all Hawaiian natives know what an ‘ulua is, as it has been a prized fish to catch for over 1,000 years, but very few people have ever seen a giant trevally underwater.

This five-foot-long fish can grow up to 200 pounds, and the large ones usually live in underwater caves. They are huge, but also quite shy.

The younger ‘ulua are almost pure white in color, and the name “‘ulua” means “white” or “light-colored.” As they grow older they turn a silver-gray color, and blend into the darkness of a cave.

The large adults just hang out and move very slowly through the caves and gulp down any smaller fish, crab or lobster that may get too close. The younger ‘ulua aukea form large schools, are more mid-ocean swimmers and feed on schools of bait fish.

After doing 3,000 scuba dives in Hawai‘i I have only seen a dozen or so 150-pound-plus giant trevally, but I finally figured out where they like to live.

Here on the remote North Shore of Kaua‘i they tend to be more common, as they are not fished out like in other more-populated parts of the islands. There are outer reefs here off Kaua‘i with large lava-tube caves, and I often see them there. The same giant ‘ulua will stay in the same cave, and can be visited on a regular basis.

I was recently doing a scuba dive along the North Shore of Kaua‘i, near shore in a series of large caves visiting my white-tipped reef shark friends, and I saw a large shadow back in one of the caves that was so big around I thought it may be a tiger shark.

As I slowly approached, it was a huge ‘ulua aukea that had to have weighed over 150 pounds. This was the first really big one I have seen close to shore, and I think that, due to the lack of tourists in the water, these big fish are coming back near shore to feed.

One should never spear or catch one of the large, adult ‘ulua, because they are the successful breeders and can live a very long time to produce millions of offspring. It is always best to let the truly-large fish stay in the sea to ensure there will be a good, healthy population in the future.

Catching the young adult fish that are more common will help the stronger, more-wary fish survive. This is how the sharks help keep the fish populations healthy, as they only can catch the slower, weaker fish, and the faster, stronger fish make it to their full size and become the breeders to pass down the best genetics possible.

You can see ‘ulua aukea in action in the underwater educational video “The World’s Guide to Hawaiian Reef Fish” at underwater2web.com, and also follow the marine-life educational Intagram post at terry.lilley.

Aloha from under the waves.

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Terry Lilley, a marine biologist, lives in Hanalei. His websites include underwater2web.com and www.gofundme.com/5urrm4zw.