What Fish Are Reef Safe?

One hobbyist tries to answer the question by testing five marine fish to determine whether or not each is compatible in a community reef setting.

Niger triggerfish (). Photo by Al Castro

What is reef safe? This is perhaps one of the more vexing questions plaguing marine aquarists today. Some reefkeepers argue that any species of triggerfish is a terror in the reef aquarium. Others claim that some triggerfish — such as the crosshatch (Xanthichthys mento), pinktail (Melichthys vidua) and blue throat (X. auromarginatus) — are perfectly safe in reef settings. Then there are those aquarists who have blacklisted all species of marine angelfish from their reefs, even the dwarf angels.

Why are these animals so unsafe in our home reefs? Perhaps their unique love of corals, crabs and other crustaceans and invertebrates as menu items is one answer. Though, is there really any “reef-safe” fish at all? Fish possess individual personalities, and the actions of an individual fish do not necessarily establish a precedent for a species.
Through the years I have tried to break through the reef-safe mold several times. I have kept fish that were considered totally not reef safe in my 120-gallon — just to see if I could be successful. Some of these experiments (if that is what you would call them) were total successes while others were total failures.
While I encourage reef aquarists to try to maintain fish that are not destructive in a reef setting, I feel strongly that with a little technique and intelligent planning the traditional reef-safe-fish list can be expanded as new opportunities open up for aquarists.

Blueface Angelfish (Pomacanthus xanthometopon)

Keeping a blueface angelfish in my reef aquarium is perhaps my greatest success story of all. Nearly everyone I spoke with about the prospect claimed it was destined for failure. Because large polyp stony corals dominate my aquarium and bluefaces are known coral eaters, not one aquarist thought it was even worth trying.
As I stared into a fish tank on display at my local fish store (LFS), the vibrant blue face of one of these angels captured my attention, and I decided to give keeping one a try.

So has the blueface angelfish been an angel in my reef aquarium? Overall, I would have to say yes. Shortly after the fish was introduced into the tank, it did manage to pick an open brain coral to the point of no return. And I assumed after finishing off the open brain that it would move onto my tank’s two maze brain corals. But to my surprise, after keeping a watchful eye on the fish, it did not.

In fact, I found that when fed a frozen angelfish formula and Mysis shrimp preparation in the morning that the blueface was a model tenant. In fact, its behavior was far more exemplary than that of my dwarf flame angelfish (Centropyge loriculus). Of all the various corals within my reef aquarium (e.g., zoo polyps, frogspawn, torch coral, etc.), the only thing the blueface angelfish has ever attacked was the open brain coral.

As time went on, however, I was concerned that as the angel aged its tastes would change and soon other coral species would be on the menu. For about two years the fish has made its home in my reef aquarium and nothing else has been damaged — at least in the way of corals — by its menacing jaws. I found blueface angelfish to be reef-safe fish.

Picasso Triggerfish (Rhinecanthus aculeatus)

After my success with the blueface angelfish, I started to think that anything was possible. So, against the advice of nearly every reefkeeper I know, I purchased a small 2 1/2-inch-long Picasso triggerfish. This fish only did well for about one week.
Soon skunk cleaner shrimp, snails, hermit crabs and nearly every mobile invertebrate in my tank was on the menu. The cute little Picasso was literally eating me out of house and home. And removing this tiny triggerfish from a large aquarium packed with more than 100 pounds of live rock was going to be a daunting task.
After several hours of removing rock, water and half of the tank’s coral occupants, I was finally able to safely extract the trigger, which I gave away to a fellow aquarist, one with a fish-only aquarium. I found this species to be a reef-safe failure.

Bluejaw Triggerfish (Xanthichthys auromarginatus)

The bluejaw triggerfish, like the crosshatch and pink-tailed triggers, is a midwater plankton feeder. Its feeding habits and better disposition in the aquarium make it an ideal candidate for reef aquaria. After the Picasso triggerfish episode I was scared to death of trying another triggerfish in my reef system, although when I saw a nice male bluejaw trigger for sale at my LFS I couldn’t pass up the opportunity to keep one in my system.
The bluejaw triggerfish has been a model citizen in my reef aquarium. It shows no interest in shrimp, crabs or snails, and it is an active and gorgeous fish. In fact, if I were judging from my experience alone, I would imagine the bluejaw trigger is the ultimate poster fish for the reef aquarium.
I have not done anything special to keep my bluejaw, and it eats the same food as the tank’s other tenants and hasn’t had any aggression problems with other fish species.
The only foreseeable problem bluejaws may cause in reef aquaria are raised levels of dissolved organics. And this only occurs if water changes are not administered properly. Proper protein skimming and water changes can prevent this.
The bluejaw trigger was another reef-safe success.

Miniatus Grouper (Cephalopholis miniata)

When I start thinking about my experience keeping a miniatus grouper in my reef aquarium, my hands start trembling. What a horrible mistake! Those who have seen a miniatus would probably agree; of the grouper clan they are one of the most beautiful. I was struck by the vibrant coloration of a 4-inch-long miniatus grouper and just had to have it.
For several weeks this fish was an exciting model tenant in my reef aquarium. It allowed the cleaner shrimp to work away and didn’t seem to bother any of the other fish, even those I suspected could become its dinner. I was sure to keep it well fed so as to lessen any urges it might have to eat its tankmates.

Then one evening as I was watching the tranquility of my reef aquarium unfold, I was shocked to see the miniatus grouper ingest a Bartlett’s Anthias of nearly equal size. I was awestruck. After a week of lying at the bottom of the tank and digesting my gorgeous female Anthias, the grouper’s head reappeared at its normal spot. It was removed shortly after and donated to a local fish store.

While I was shocked the grouper could ingest the Anthias, I will say it never did bother any corals or invertebrates. I would hazard to guess that if kept with other large fish that the grouper might make an agreeable reef tenant.
A reef-safe failure in my book, this fish could probably be successfully kept with larger marine fish in a reef setup.

Niger Triggerfish (Odonus niger)

The Niger triggerfish is arguably the most popular triggerfish among marine aquarists and with good reason. This fish is very pretty and often commands only a moderate price at fish stores. While it is not a midwater plankton feeder like the bluejaw triggerfish, most aquarists would agree that the Niger triggerfish has a more passive personality as compared to many other triggerfish.

Given this, I thought it would be a good idea to try keeping one in my reef aquarium. Overall, the Niger triggerfish was a joy to keep. In fact, the only problem I had with this fish was a powder blue tang that picked on it!
The Niger triggerfish accepted the same foods as all the other wards in the tank, and it wasn’t too aggressive at feeding time and eventually grew into a beautiful fish that had a great “pro-reef” disposition. The only reason I eventually got rid of it was that it grew too large for the tank. I found this fish to be an excellent species to include in a reef tank.


The truth is simple; every fish is an individual and there is really no “reef-safe” genus or species of fish. What the aquarist can do is attempt to use creative means that try to get a desired behavior from a particular animal. Feeding that animal a food it eats more aggressively or arranging rockwork in a manner that doesn’t promote certain behaviors are examples of ways that we can work with our fish to produce the desired results.
As you can see here, after attempting to keep five different marine fish in a reef environment, I was able to enjoy success with three of the five I tried. Personally, I feel that with more suitable tankmates that the miniatus grouper would have been a great reef fish.

I would never encourage aquarists to do anything that would harm their reef systems as well as their pocketbooks. However, I would encourage them to be creative and willing to try something different. In that vein, anyone bringing a new, unfamiliar fish into their reef tank should thoroughly read up on it before doing so. I still attempt to keep non-reef-safe fish in my aquarium, and as time goes on I have found that the ones I have been successful with become some of my favorite captive reef fish.

Jeremy Gosnell fell in love with aquatic animals at a young age. He currently keeps both freshwater and saltwater aquariums, which enables him to study a variety of creatures in captivity. He is interested in the ethical aspects of keeping aquariums and is active in coral reef preservation efforts. He is also an avid scuba diver.

Article Categories:
Fish · Reef Tanks