Niger Triggerfish Care: Odonus niger

Notice the different range of common names for the Niger triggerfish? This is because no one can agree on the color of this trigger. Are they black? Blue? Purple? Teal? A combination of all of those shades? Yes, to all of the above. Niger triggerfish CHANGE color. You’ll never catch the same look two days running. It’s one of the biggest draws for the species.

You can even play up the habit by adjusting the lighting in your tank. Cooler temperatures will bring out darker shades, while warmer lights will “trigger” the greener side of the spectrum. Of course, the ultimate decision resides with the triggerfish itself.

And then there are those famous front teeth. Adult Niger triggerfish develop two prominent “fangs.” Most will turn a vibrant red color – though it’s not a guarantee. The teeth constantly grow throughout the fish’s life, and you’ll see them chewing on sponges, coral rubble, and hard-shelled crustaceans to keep those fangs trimmed. Against the teal highlighting, the red pops and gives them a sinister grin.

Triggerfish get their name from a dorsal spine on either side of the tail. When extended, the spines allow the fish to “lock” into crevices in rocks or coral. And it gives them the appearance of a cocked gun. (Hence – trigger) The behavior’s key for juvenile Niger triggerfish, but even adults will resort to hiding out when they feel threatened. And they use the behavior to rest in caves during the evening hours.

Niger Triggerfish Lifespan

Considering no one agrees on the precise color of the Niger triggerfish, deciding on the boundaries of their range gets tricky. You’ll find those unmistakable red fangs throughout the Indo-Pacific and the Red Sea, though. They congregate in schools at the edge of coral slopes, allowing the strong current to buoy their less-than-graceful swimming style.

Identifying individual triggers isn’t the easiest. Add in the fact that the Niger triggerfish get along in shoals, and the process gets trickier. It’s assumed they live for around a minimum of ten years, though – possibly longer.

Pairing the prominent, upturned teeth (red or white) with a teal to black coloration, divers spot Niger triggerfish from South Africa, throughout the Great Barrier Reef, New Caledonia, and even up to Fiji and Indonesia. The schools duck through reef channels and down along the slopes into the ocean current. The “lock” of their dorsal spine and tail prevents them from getting swept out to sea. And that current? It brings plenty of delicious morsels straight to those waiting teeth.

You don’t need to duplicate a rocky drop-off, but you DO want to provide room for your Niger triggerfish to swim and explore. They’re active fish that spend most of the day investigating the sand and rocks for signs of food. And you’ll want to ensure your trigger can find room to hide out whenever they feel uncomfortable (not to mention somewhere to rest at the end of the day).

Don’t get too attached to all of your careful work, either. Niger triggerfish LOVE to rearrange the “furniture.” It’s not uncommon to walk by and find them moving rocks, corals, and other décor. They also “swirl” sand to check for buried food – creating new patterns in your substrate. It’s part of the fun of owning Niger triggerfish, but it’s also EXHAUSTING setting things right again.

You also need to set up a current. Niger triggerfish are used to a strong ocean swell on their reef channels. You’ll want to use a powerhead on one side of the aquarium. This will give your trigger a chance to exercise those fins. No need to go overboard (you don’t want to plaster your other fish against the glass). Angle the flow through the water column, and your Niger triggerfish can duck in and out as they please.

Niger Triggerfish Tank Size

In the wild, Niger triggerfish can grow up to 18 inches (45.7cm). You probably won’t see that kind of growth in your home aquarium. But you CAN still expect an adult size of 12 inches (30.5cm). Add in the fact that your trigger needs to swim, explore, AND fit into nooks and crannies in the live rock, and you’re looking at an incredible need for space.

You don’t want to go any smaller than 180 gallons (681L). And that’s for ONE Niger triggerfish. If you have designs on a school, you’re going to need to double (or TRIPLE) that size. This is why most hobbyists don’t keep more than one trigger at a time. It’s certainly possible – they’re agreeable with one another – but you’re looking at a demand on resources. Think through your budget carefully.

And that goes for your tank accessories, too. Niger triggerfish produce TONS of waste. You’ll need a strong filter to help keep up with the mess. (This is NOT where you want to pinch pennies) But you need to protect the hoses and housing from your trigger. They like to chew – say the cord. You don’t want to invest in a high-quality filter to have your triggerfish chew through the valves.

You also want a sturdy lid for your aquarium. Not because Niger triggerfish jump or pose a flight risk (they’re not carpet surfers). Nope, these guys like to SPRAY. It’s a way of gaining attention, but it can pose an electrocution hazard if you have plugs nearby. Keep your tank covered to prevent accidental mischief.

Are Niger Triggerfish Reef-Safe?

You don’t want to bring a Niger triggerfish home if you have a reef tank. They don’t feed on corals, but those bright red fangs? They need regular “trimming.” And Niger triggerfish will use sponges, tunicates, snails, and crustaceans to get the job done. They’ll also use coral rubble to prevent unwanted tooth growth. It’s not a situation you want to have in a reef tank.

Add in the complication of that “redecorating” habit, and your corals are in trouble. Triggers don’t check for delicate polyps before they knock over rocks or uproot a decoration. All they care about is making a new cave for the night – or chasing after a potential meal.

You guessed it – that means you need to think carefully about adding crustaceans. In THEORY, cleaner shrimp can share a tank with Niger triggerfish. But ONLY if the shrimp go into the aquarium FIRST. If you attempt to add cleaner shrimp after a trigger, they’ll assume you’re offering a snack. (Not a pretty situation)

Niger Triggerfish Diet

Niger triggerfish look fearsome with those red fangs poking out. However, they’re calm omnivores. That makes them easy to feed (in theory). A varied diet works best. It’ll also prevent your trigger from hunting down tank mates.

You can also offer brine shrimp, small fish, or squid. They won’t wear down those teeth, though, so make these protein offerings less frequent. Put them in the same category of occasional “treat” as nori or sea veggies.

Niger triggerfish need food 2-3 times a day. Otherwise, you’ll see your fish drop weight. Remember, they’re active fish. You need to support that metabolism.

Unfortunately, Niger triggerfish are notorious for spontaneous hunger strikes. And you may not figure out what set off the protest. That’s when you’ll need to pull out your tastiest offerings to stimulate the appetite again.

Niger Triggerfish Behavior and Tank Mates

In the wild, Niger triggerfish form schools on the ocean drop-offs. There, they feed on zooplankton washed in on the ocean currents. You’ll also see them gnawing on sponges to trim those red teeth. They’re easy-going fish, coming in low on the triggerfish scale of aggression. That peaceful temperament is another of the reasons hobbyists love the species so much.

There’s also the personality that comes with a Niger triggerfish. Hang around a tank with one of these blue/teal/purple fish long enough, and you’ll pick up on a soft “grunting” sound. The fish communicate via the noise, and it’s audible to human ears. Even if you don’t keep a school, you’ll probably hear a grumble or two coming from your aquarium.

This is because Niger triggerfish are downright personable. They learn to recognize the people in the home, adopting puppy-like characteristics. You’ll see that tail “wag” as you come close, especially if it’s close to mealtime. Some people even decide to teach their triggers to hand-feed. (Please DON’T do this – those red fangs are SHARP!) In no time, you can train your Niger triggerfish to take food from tongs. (This is the better way to go)

Colorful, packed with personality, and a delight to have, does the Niger triggerfish even HAVE a downside? As a matter of fact, yes. Every fish is different, and you roll the dice when you bring one of these triggers home. As they age, the risk for aggression goes up. Some aquarists have ended up with a “rogue” Niger triggerfish wreaking havoc throughout the tank. (And, yes, it can happen out of the blue – sort of like those hunger strikes)

For the most part, though, you’re in the clear in choosing your tank mates. Niger triggerfish usually come out on the peaceful side – with fish of similar size. This means:

On the flip side, you want to avoid smaller fish or species with a higher level of aggression. Triggerfish DO appear on the menus for other species, and you don’t want to encourage terror in your tank:

• Anglers
• Basslets
• Batfish
• Cardinalfish
• Filefish
• Frogfish
• Pseudochromis
• Pipefish
• Seahorses
• Rays
• Sharks

Attempting to sort a male Niger triggerfish from a female is next to impossible. They look identical. This is why captive breeding hasn’t worked out very well thus far. (Not to mention the fact that most home aquariums aren’t large enough to accommodate a school)

In the wild, the Niger triggerfish have mating grounds they head to. The male sets up a territory in which to build his nest and attract a female. Then he’ll (you guessed it) change colors to gain her attention. The two spawn, and the male guards the eggs. The female sets up patrol around the area to watch over him. (Not the most manageable situation to replicate in a home aquarium)

With all of the flash and pop Niger triggerfish bring to the hobby, it’s easy to see why people want to bring them home. But they also have some quirks you can find yourself battling. You need to decide where your balance point comes out.

Pros

• Niger triggerfish change color depending on their mood, the day, and the color of the lighting you use for your tank. This makes them an exciting addition to a marine aquarium.
• As one of the least aggressive members of the triggerfish group, these fish get along well with most other fish their size.
• You don’t need to worry about a special diet for Niger triggerfish, so long as you keep things high-quality and varied.

Cons

• Niger triggerfish are notorious for rearranging the rockwork and decorations within a tank, especially when creating a cave to sleep in at night.
• To check the growth of their prominent front teeth, triggerfish chew on sponges, tunicates, coral rubble, and crustaceans – including your cleaner shrimp. This makes them poor choices for reef tanks.
• Some Niger triggerfish WILL “go rogue” and start to terrorize their tank maters without provocation. You should continuously monitor behavior as your fish age.

How can you NOT want to learn more about Niger triggerfish? They change colors! And they have bright red fangs (well, some of them do, anyway). Not to mention they learn to recognize you and come up to the front of the glass, tail “wagging.” If you can’t get enough Niger triggerfish, here are some more tidbits.

This YouTube video will cover even more on the personable Niger triggerfish:

Want to know about some of the best Niger triggerfish tank mates?

Maybe you’re intrigued by the triggerfish family. How about investigating another trigger favorite?

Conclusions

Niger triggerfish present some challenges to the average hobbyist. You might encounter an occasional hunger strike. And you always run the risk of a spontaneous personality change. But, overall, they’re delights – for triggers.

And how do you beat a color-changing fish with fangs? One that greets you “at the door” whenever you come over? Really, that makes the Niger triggerfish worth all the risk. Just don’t put your hand in the tank. You know, just in case.

References

• Froese, R. and Pauly, D. 2005. “Odonus Niger.” FishBase.
• Lieske, E. and Myers, R.F. 2004. Coral Reef Guide: Red Sea to Gulf of Aden, South Oman.
• Michael, S.W. 2001. Marine Fishes: 500+ Essential to Know Aquarium Species.
• Myers, R.F. 1999. Micronesian Reef Fishes: A Guide for Divers and Aquarists.