is supported by our readers. When you buy through links on our site, we may earn a commission. Learn more.

Picasso Triggerfish – Housing, Feeding, and Tank Mates 

Picasso triggerfish are one of the few large marine fish that even a well-informed beginner could keep. They eat well, are not sensitive to poor water conditions, and are affordable. Their main downsides are their size, temperament, and ability to create enormous amounts of ammonia.

Housing, Feeding, and Tank Mates for the Picasso Triggerfish 

What is the Picasso Triggerfish?

The picasso triggerfish is a medium-sized species found in the Indo-Pacific Ocean. The Hawaiian archipelago is the eastern part of their range. These fish also live further west, around the Philippines and Polynesia.

Picasso trigger fish are very hardy, for saltwater fish, and don’t have demanding water quality needs. They do create a lot of ammonia though. Both by excreting it as waste and by being messy eaters.

Like all triggerfish, the picasso triggerfish is an aggressive predator. Some species of triggerfish specialize in eating sea urchins and other animals that have few predators. 

Picasso triggerfish prefer crabs, shrimp, snails, and other “juicier” invertebrates. They are also prone to taking chunks out of their tank mate if they are too hungry.

Triggerfish are related to puffer fish and belong to the same order of Tetraodontiformes. Several species are an important part of the diets for people living in the tropics. But a few species pick up ciguatera poison from single-celled algae that sometimes form huge blooms on reefs.

The clown triggerfish (Balistoides conspicillum) is an aquarium favorite that happens to be the most toxic. The levels of ciguatera toxin in their flesh can cause severe illness for days.

Picasso Triggerfish in Hawaii

The picasso triggerfish is one of the better-known marine fish from the Aloha State. The indigenous Hawaiians called it huma huma nuka nuka apua’a: meaning “the fish that snorts like a pig.”

Humu humu triggers will blow water out of their mouths to uncover hidden invertebrates in the sand. And when they are out of the water, they do this while grinding their teeth. 

The grunt is meant to startle a predator holding them. Which increases the chances of the triggerfish dropping back into the water.

The huma huma nuka nuka apua’a is Hawaii’s state fish. The name (and designation as state fish) are also shared with the reef triggerfish (Rhinecanthus rectangulus). 

  • Common Names: Picasso Triggerfish, Lagoon Triggerfish, Humu Humu Triggerfish, huma huma nuka nuka apua’a
  • Scientific Name: Rhinecanthus aculeatus
  • Origin: South Pacific Ocean
  • Length: 9 to 12 inches
  • Aquarium Size: 120+ Gallons
  • Temperament: Aggressive
  • Ease of Care: Easy

Caring for the Humu Humu Trigger

Caring for the Humu Humu Trigger
Deep Sea World

Hardy and inquisitive, picasso triggerfish are an excellent choice, even for beginners. Just make sure their tank mates are also aggressive and the tank is spacious enough for everyone.

Humu Humu Triggerfish Tank Size

As far as these fish go, lagoon triggerfish are a medium sized species. Still, at 9 to 12 inches they are sizable enough for a large aquarium. Triggerfish are also very active swimmers. 120 gallons is the minimum for a full grown adult, with 150 gallons being more comfortable. 

Don’t keep picasso triggers in a tank smaller than 150 gallons with other fish. All triggerfish are territorial. And since they have such large teeth, they will win fights with their tank mates. If a rival tank mate can’t leave the claimed territory of a triggerfish, it will end up dead.

Triggerfish Water Conditions

Triggerfish are undemanding marine aquarium inhabitants. Standard temperatures of (72-78℉) are ideal for them. The pH should be alkaline and high in dissolved minerals. A pH of 8.1 to 8.4 is best, furthered buffered by a crushed coral substrate for alkalinity.

1.020-1.025 is the desired specific gravity (salinity) for huma huma fish. You will need to track ammonia levels with care. 

Triggerfish are not as sensitive as tangs and other more delicate marine species. The problem is that they make a lot of nitrogenous waste. They eat a lot of meat, just like their pufferfish cousins. Which means a lot of poop. And a lot of food crumbs that will decay into ammonia.

Large, carnivorous fish should have a tank with a powerful and fully cycled canister filter. Without a large canister filter, ammonia will continue to rise unless you do water changes twice per week.

Be careful when reaching into the tank during water changes or other maintenance. Triggerfish are intelligent and inquisitive fish. And since they explore the world with their mouths they may try to bite you.

A triggerfish that bites is either interested in you or is territorial. Most fish bites are just cute. But a triggerfish has teeth designed for cracking shells. They will break the skin and may even require a doctor visit if they remove enough flesh.

What do Picasso Triggerfish Eat?

Triggerfish are carnivorous and eat a wide range of prey items. They can also be trained to eat prepared pellet blends. But wild-caught fish may be reluctant at first. Which may lead to the fish starving once you get it home. 

Since they are all wild-caught, ask to see a triggerfish eat if you are thinking about taking it home. If it won’t eat, ask to put a deposit down while the pet store acclimates it to a captive diet.

It is very important to feed invertebrates to your huma huma nuka nuka apua’a. All triggerfish have large teeth that grow all the time. Invertebrate shells wear those teeth down. Triggerfish do eat soft prey and prepared foods. 

Without shells in their diet, their teeth will grow so long that they make it hard for the triggerfish to open its mouth. You will then have to either take it to the vet for a trim. Or do the trimming yourself, the same way you would a puffer’s teeth:

You should stock up on small snails, crabs, clams, mussels and whole shrimp. Fresh or thawed frozen invertebrates are both excellent. Also feed them small pieces of raw fish, 

When young, humu humu triggers enjoy live and frozen foods like brine shrimp and bloodworms. But they still need whole baby snails to keep their teeth short.

Any prepared foods should be as rich in meat as possible. Stay away from blends that have any vegetables in the first three ingredients. Especially plant starches from potato, soy, or wheat. These are just fillers that won’t give your picasso fish the protein it needs. 

Picasso Triggerfish Tank Mates

Picasso Triggerfish Tank Mates

Picaso trigger fish need space not just for them to have swimming space. But also for the comfort of any tank mates you wish to add. All triggerfish are aggressive and bitey. You should keep them with other large and aggressive fish. 

Picasso triggerfish don’t usually eat small fish. But the hungrier they are, the less picky they become. And triggerfish are always hungry.

Large tangs like the powder blue and hippo tang will coexist with a humu humu fish. Larger marine angelfish and wrasses are aggressive enough to hold their own. Predators like lionfish and marine bettas are also ideal tank mates. 

If you want some active and colorful dither fish, try damselfish. The three striped and domino damselfish (Dascyllus sp.) are excellent species for an aggressive community tank.

As you might expect from a specialist invertebrate-eater, the picasso trigger is not a reef-safe fish. They don’t eat corals but they will eat clams, feather duster worms, and other sessile organisms. 

Humu humu triggers aren’t known to eat sea urchins or starfish but other species do. So it may decide to try if bored or hungry. Any crabs, snails, or shrimp of any size category will be picked apart by a triggerfish.

Breeding the Huma Trigger

Triggerfish have not been bred in captivity as of yet. They are too aggressive towards each other. Sexing them is also complicated since they are not seuxally dimorphic animals. Meaning you can’t tell a male from female by looking at their colors, size, etc.

Triggerfish of all species are excellent parents for fish. They are substrate spawners, similar to cichlids. Right after laying their eggs the female humu humu triggerfish will guard them for a few days until they hatch.

Until then the triggerfish will attack any animal that comes too close. Even divers can be attacked at times. A picasso triggerfish won’t cause too much damage. But larger titan triggerfish (Balistoides viridescens) sometimes give serious bites to divers.


Picasso triggerfish are a great species to keep if you are aware of their adult size and dietary requirements. They are hardy and intelligent enough to recognize their owners. Just be sure you have a steady source of crunchy invertebrates for them.

More FAQs About Picasso Triggerfish

What Does a Triggerfish Look Like?

Triggerfish are triangular in appearance. They look like a laterally compressed puffer fish. Their skin is tougher, however. And they don’t inflate with water the way puffer fish will. 

Why is it Called Picasso Triggerfish?

The pattern of stripes along their face further confuses the already distorted face these fish have. Its appearance is reminiscent of several Pablo Picasso paintings

Jason Roberts
About Jason Roberts
Jason is an aquarium fanatic that has been a fish hobbyist for almost three decades.