Wedgetail Trigger (Rhinecanthus Rectangulus)

Wedgetail Triggerfish (Rhinecanthus rectangulus)

The Wedgetail Triggerfish, also famously known as the Reef Triggerfish or by its iconic Hawaiian name, Humuhumunukunukuāpuaʻa, is a masterclass in geometric evolution. While it’s the state fish of Hawaii, it is widely distributed across the Indo-Pacific, including the coastal reefs of Indonesia. It is essentially a "tank on fins"—incredibly tough, highly intelligent, and occasionally quite "spicy" toward its neighbors.

Key Information

• Common Names: Wedgetail Trigger, Reef Triggerfish, Humu-Humu

• Scientific Name: Rhinecanthus rectangulus

• Origin: Indo-Pacific (Red Sea to Hawaii, abundant in Indonesia)

• Max Size: 25–30 cm (approx. 10–12 inches)

• Lifespan: 10–15+ years

• Temperament: Aggressive / Highly Territorial

• Diet: Omnivore – Will eat almost anything

• Care Level: Easy (Very Hardy)

Appearance & Identification

The Wedgetail is one of the most mathematically beautiful fish in the ocean:

• The "Wedge": Named for the distinct black V-shaped wedge on its rear half, which points toward the tail.

• The Colors: A base of tan and cream with a bold black band running diagonally through the eye. It also features a bright blue-and-yellow "mustache" above the mouth.

• The Trigger: Like all triggerfish, it has a specialized dorsal spine (the "trigger") that it can lock into place to wedge itself into rock crevices at night, making it impossible for predators to pull it out.

• The Teeth: It has powerful, buck-toothed jaws capable of crushing sea urchins, crabs, and even shells.

Behaviour & Tank Compatibility

• The Intelligent Architect: These fish are smart. They will rearrange your sand bed, move small rocks, and even "spit" water at the surface to get your attention for food.

• Aggression Warning: This is not a community fish. As they mature, they become extremely territorial. They may attack other fish, heater cables, and even your fingers during maintenance.

• Reef Safe (No): They are not reef safe. They will eat almost any invertebrate (snails, crabs, shrimp, urchins) and may "sample" corals just to see what they taste like.

• Tank Mates: Best kept with similarly aggressive, large fish like Groupers, large Tangs (like the Sohal), and large Angelfish. It should ideally be the last fish added to the system.

Ideal Tank Setup

• Tank Size: A minimum of 380L (100 Gallons) for an adult, though 475L (125 Gallons) is better to accommodate their active swimming.

• Rockwork: Provide large, stable rock structures with deep caves. Make sure the rocks are secure—they are strong enough to knock over loose aquascaping.

• Filtration: They are messy eaters. You need a powerful protein skimmer and high-turnover filtration to handle the biological load.

• Equipment Safety: They are known to bite at aquarium equipment. It is highly recommended to hide heaters and probe sensors behind a baffle or inside a sump.

Dietary Needs

They have an appetite that is hard to satisfy:

• Diet: A varied diet of chunky meaty foods (shrimp, squid, clams, krill) and algae-based foods.

• Hard Shells: Occasionally providing whole shrimp or clams in the shell is great for their dental health and enrichment.

• Frequency: Feed 1–2 times daily.

Why Choose the Wedgetail Trigger?

The Wedgetail Triggerfish is for the hobbyist who wants a "pet with a personality" and is running a fish-only-with-live-rock (FOWLR) system. Their striking geometric patterns and high intelligence make them one of the most engaging fish to own. If you have the space for a large, aggressive setup and want a fish that will truly "interact" with you, the Wedgetail is an Indo-Pacific classic.