Lei (Boomerang) Triggerfish

The Lei (Boomerang) Triggerfish (Sufflamen bursa), also called the Scythe Triggerfish, has a gray to tan body, a pale chin and chest, and a curved marking that crosses the base of the pectoral fin. That shoulder marking is often yellowish tan to green in juveniles and subadults, while older fish can show a darker, more subdued pattern. A pale diagonal line behind the mouth adds contrast. The curved shoulder marking distinguishes this species from the Bursa Triggerfish (Rhinecanthus verrucosus), which has a large dark patch on the lower rear flank.

The Lei Triggerfish ranges from East Africa through the tropical Indo-Pacific to Hawaiʻi, the Marquesas, and Pitcairn, extending north to southern Japan. It occurs on clear inner and outer reefs, from shallow algal flats to seaward drop-offs. Much of its foraging takes place around the bottom, where it investigates rubble, shells, and crevices for crabs, mollusks, worms, and other invertebrates. Algae is also part of its natural diet.

In an aquarium, the Lei Triggerfish is an active fish that spends time inspecting the rockwork and may quickly learn where food is offered. Its manageable adult size relative to some larger triggers still calls for substantial swimming space and a mature fish-only system. Aquarists should plan around the adult’s strong jaws, digging and foraging habits, and ability to defend shelter or food from tankmates.

Quick Care Guide

Care Level: Moderate
Minimum Tank Size: 125 gallons
Adult Size: Up to 9.8 inches (25 cm)
Temperament: Aggressive
Diet: Omnivore
Reef Safe: No
Region: Indo-Pacific
Scientific Name: Sufflamen bursa

Tank Requirements

Provide a mature aquarium of at least 125 gallons for long-term housing, even when starting with a juvenile. Adults can reach 9.8 inches (25 cm) in total length. Choose a footprint with a long open swimming lane and enough width for the adult to turn freely around the rockwork. A larger system gives tankmates more room to avoid one another and is preferable for a mixed predator display.

Build several secure caves or overhangs and leave clear paths between them. Like other triggerfish, a Lei can raise its first dorsal spine to brace itself in a crevice while resting or hiding. Give it a refuge it can enter and leave easily as it grows, along with alternative shelters that tankmates can use without passing directly through its territory.

Stabilize the aquascape before adding sand. This triggerfish may lift loose shells, turn rubble, and excavate around the base of rocks. Support heavy structures on a stable foundation and keep large pieces from shifting when sand is moved. A small area of sand and manageable rubble gives the fish somewhere to forage without undermining the main rockwork.

Use dependable biological and mechanical filtration, good surface agitation, and enough circulation to prevent food and debris from settling behind rocks. A protein skimmer can help manage the waste from regular seafood feeding. Arrange the rockwork so you can siphon around it and reach areas where the fish tends to drop bits of food.

Fit a secure lid around plumbing and cables and protect accessible pump intakes. Place heaters and fragile probes in a sump or behind guards where practical. Keep maintenance access clear near the front of the tank, since a fish defending its shelter can make it difficult to reach equipment behind the rocks.

Diet and Feeding

The Lei Triggerfish is a meat-forward omnivore. In the wild it eats crabs, snails, bivalves, sea urchins, worms, and other bottom-dwelling prey, along with algae and other material encountered during foraging. In captivity, make varied marine seafood and balanced prepared foods the core of the diet, with a modest algae-based component such as a spirulina-enriched marine food.

Rotate foods from the following options.

• Mysis or finely chopped shrimp for smaller fish
• Shrimp and prawns, including some shell-on pieces
• Clams and mussels, including portions on the half shell
• Chopped squid and other marine seafood
• Balanced frozen marine blends or marine pellets
• Spirulina-enriched marine food as part of the rotation

Feed once or twice daily as a starting point and adjust portions based on the fish’s size, body condition, and how much food remains after each feeding. Smaller specimens can be offered more frequent, smaller portions. Distribute food in more than one area in a mixed tank so tankmates can eat without approaching the triggerfish’s feeding station.

Include appropriately sized shell-on foods. Shrimp in the shell and clams or mussels on the half shell give the fish a chance to pick and crush food as it would while foraging. Offer pieces it can handle and take out shells with leftover flesh before they decay. Rotate hard and soft foods for variety.

Use long feeding tongs for larger pieces and keep hands away from the fish during feeding and maintenance. The Lei Triggerfish can move quickly when food enters the water. Watching the fish bite and swallow also helps you catch changes in appetite early, especially after a move or the addition of a tankmate.

Temperament and Tankmates

The Lei Triggerfish is aggressive and may become more territorial as it matures. It can defend a favored cave, chase fish that cross its path, or monopolize food. A juvenile that readily shares space may behave differently once it has settled and grown. Repeated pursuit, torn fins, and a tankmate missing meals are signs that the arrangement needs to change.

Keeping a single triggerfish is the most predictable approach. In a larger fish-only system, sturdy, similarly sized fish with confident swimming and feeding behavior may be suitable. Robust tangs or other assertive fish can be considered when their adult size, shelter needs, and feeding behavior fit the aquarium. Give each fish several routes around the rockwork and observe how the group behaves at feeding time.

Small gobies, timid fish, slow swimmers, and long-finned species are especially vulnerable. Other triggerfish may compete for the same caves and feeding areas, and larger tankmates can still be injured during repeated territorial encounters. Account for how the whole group will use the tank after the fish reach adult size.

Where practical, add the Lei after compatible tankmates have settled. Use separate rock islands or breaks in the line of sight, spread food across the aquarium, and keep a divider or separate housing available. Intervene if a tankmate is repeatedly driven from food or cover, since rearranging rockwork alone may provide only short-term relief.

Reef Compatibility

The Lei Triggerfish is Non Reef Safe. Ornamental shrimp, hermit crabs, snails, clams, and urchins are vulnerable to its normal foraging and powerful bite. A well-fed triggerfish may continue inspecting and sampling animals it encounters around the rockwork.

Reef risk also comes from digging and moving objects. The fish can shift shells and rubble, knock loose coral fragments, and expose coral bases while searching for food. A mature reef with stable rockwork still leaves ornamental invertebrates exposed to predation or disturbance.

A fish-only or fish-only-with-live-rock system gives this triggerfish room to explore while allowing the aquarist to clean areas where debris settles. Choose sturdy décor and plan for manual substrate and algae maintenance where snails or other invertebrate cleaners would be vulnerable.

Water Parameters

Temperature: 75–78°F
Specific Gravity: 1.024–1.025
pH: 8.1–8.4
Alkalinity: 8–12 dKH

Use a fully cycled, well-aerated marine system. Maintain undetectable ammonia and nitrite, monitor nitrate trends, and check water quality after changes in feeding or stocking. Replace evaporated water with fresh water and match the temperature and salinity of new saltwater during routine water changes.

Remove seafood scraps promptly and service mechanical filtration before trapped food breaks down. Observe breathing, appetite, and normal use of shelter during the first weeks and after aquascape changes. Keep temperature and salinity steady and allow a new fish time to establish a regular feeding routine.

Common Considerations

• Adult Housing: Allow at least 125 gallons for an adult up to 9.8 inches (25 cm), with an open swim lane and secure shelters.
• Species Identification: Look for a curved shoulder mark at the pectoral base. The black patch on the lower rear flank identifies the separate Bursa Triggerfish listing.
• Territorial Behavior: Monitor for chasing, fin damage, and missed meals as the fish matures. Provide distinct shelters and separate incompatible fish.
• Rockwork and Foraging: Support heavy rock independently of loose substrate and use small rubble or shells where they cannot destabilize the structure.
• Varied Diet: Offer marine seafood, shell-on items, balanced preparations, and a modest algae-based component.
• Reef Compatibility: House in a fish-only system. Keep ornamental crustaceans, mollusks, urchins, and corals in separate displays.
• Safe Maintenance: Use long feeding tools and give the fish space to leave its shelter before attempting to move it.