Aquarium blue-throat trigger fish. Courtesy of reefkeeping.comThe Wild Trigger Fish

The trigger fish is a carnivorous, bottom-dwelling fish that gravitates toward tropical waters. They are part of the Balistidae family and have the scientific name of rhinecanthus. These fish can be primarily found in shallow waters on the edge of reef habitats. Similar to many other tropical fish, the Hawaiian trigger fish (also named the reef trigger fish or the rectangular trigger fish) has splashes of vibrant orange and blue that stand out in the clear waters. It has small eyes that are positioned high on either side of its head, while the rest of its body is narrow and arrow-shaped. While relatively small, the jaws of the trigger fish are strong and house sharp teeth that can break through shells without difficulty. Due to their unique body shape and strong fins, trigger fish can maneuver the waters and reefs quickly and easily. These fish can grow from ten inches to upwards of twenty inches in the wild depending on the type.


While they tend to swim alone, trigger fish will meet at mating grounds where the males prepare nests on the seafloor. After mating, a female can lay thousands of eggs and guards them from predators until they hatch. They have tough scales for protection and their beak-like mouths make them more dangerous than most fish. Trigger fish get their name from a spine appendage that helps them anchor at night to rest and help ward off potential predators. Crabs, urchins, and algae make up the majority of their preferred diet. While beautiful, the trigger fish can be harmful to humans and neighboring fish. They have been documented to make grunting sounds when threatened or irritated, especially around their nests, and can charge or bite an intruder. For this reason, they are considered highly territorial and most divers are advised to keep their distance.

Trigger Fish in Tanks

For the experienced salt-water aquarium enthusiast, a trigger fish would bring beauty and personality to a large tank. While there are over forty different types of trigger fish, only a select few can survive in a home aquarium such as the clown trigger and the blue-throat trigger. They need a minimum of seventy-five gallons, but many experts recommend one hundred and eighty gallons to make sure the fish has enough room to create a comfortable “territory.” A healthy diet would consist of shrimps, crabs, urchins, and/or small fish, supplemented with algae to mirror their wild diet. A trigger fish’s vibrant coloring has been known to dull due to a lack of proper nutrition, although this has been noted to occur in the evenings regardless of diet for some aquarium trigger fish. To feel safe, they need equal open water to swim freely and hiding places. Since trigger fish are territorial and aggressive fish, there should only be one trigger fish per tank. Steer clear of adding invertebrates to the tank, as the trigger fish will see them as food. There has been mostly positive experiences with keeping large adult eels, snappers, angel fish, and lion fish in the same tank.


Hawaiian reef trigger fish. Photo courtesy of Symbol of Hawaii

Known to native Hawaiians as the humuhumunukunukuāpuaʻa, the reef trigger fish is the official state fish of Hawaii. “Humuhumu” is the Hawaiian term for trigger fish while “nukunukuāpuaʻa” refers to a pig’s snout. While it is not considered a normal food in modern culture, early Hawaiians consumed the fish or dried it as a fuel source. They were also used in traditional ceremonies in place of swine. The Hawaiian trigger fish was elected as the state’s fish in 1984, but after the necessary five years it did not have a reelection campaign. The laps was noted and in 2006 Governor Linda Lingle made the humuhumunukunukuāpuaʻa the permanent state fish of Hawaii. It is a well-recognized symbol of the state and many tourists plan snorkeling trips with the hope of glimpsing the colorful fish.