One of the most striking qualities about triggerfish as a group is the obvious intelligence exhibited by these fish. Unlike other fish which seem to move through their environment with no obvious purpose, triggerfish seem to move with deliberation. To top this, in a similar way to freshwater cichlids, triggerfish learn to recognize their keepers.
In addition to their intelligence and their striking colours, triggerfish are some of the hardiest fish out there. They are as forgiving as aquarium fish get, marine or freshwater. Triggerfish are tremendously disease resistant and this quality alone makes them appealing to a wide range of aquarists. They rarely succumb to the common marine parasites. On the rare occasion that a triggerfish does become infected with a parasite such as saltwater ick they recover with nothing more than a bit of TLC on the part or the aquarist.
Finally, it should be noted that triggerfish get their name from the three dorsal spines that comprise the first dorsal fin. They can use this spine, along with the ventral spine to lock themselves into coral heads or rock crevices when threatened, and once they do, they are immovable. You should NEVER attempt to remove a triggerfish which has locked itself into a rock crevice in this way. Instead, wait for the triggerfish to come out of its own accord and then attempt to capture it.
The size of the tank that you will require to house a triggerfish is largely dependent on the species that you plan on keeping and the other fish you plan on keeping it with. Triggerfish are very active fish and as such, tall narrow tanks should be avoided as these do not provide adequate swimming space. A hexagonal tank is also very poor choice for a trigger unless it happens to be a very large one.
Triggerfish are highly resilient fish making shipping a breeze. When selecting a triggerfish make sure there are no concave or sunken regions on its flanks. Sunken flanks indicate that the fish has not been fed properly and lack of proper nourishment. The prospective keeper should also watch for cloudy areas or spots on the eyes, fins and body, as well as poor colour. One of the only exceptions to the stereotype of resilience are Clown triggerfish under 2.5 cm (1 inch). Small specimens under 2.5 cm in length often last only a matter of weeks in captivity. Still, bear in mind that the trigger should be the smallest fish in the tank; for those species where cohabitation is a reasonable option. Of course, the trigger must be of sufficient size to prevent it from being consumed by larger piscivore’s that might already be present in the system.
Some Triggers always end up alone, or traded back to the fish store, regardless of the extent to which they tolerate tank mates when young, so the aspiring trigger keeper needs to keep this in mind when selecting the species to be kept. Others will live out their lives in a community setting with few problems provided enough space is provided, some stocking order rules are honoured, and tank mates are chosen with some care. A few will even live in a reef setting.
Fortunately, there are species that usually do quite well when mixed with other tough marine species in large quarters. Among the most commonly seen species that fit this description are those of the Rhinecanthus genus, which includes the Picasso trigger (R. aculeatus), Arabian Picasso trigger (R. assasi) and Reef trigger (R. rectangulus). More than one Triggerfish from this genus can even be kept in the same tank, but they should be introduced at the same time to avoid serious territorial aggression. Also, despite it being a larger species, Odonus niger does quite well in a mixed species setting provided the tank is large enough to accommodate its considerable adult size, in the 20” range.
Certain species of triggerfish are more appropriate than others for long-term cohabitation with other fish species. Some are just too large or aggressive to live successfully in a community setting for more than a short time. While these species can certainly be kept with other species when small, attempting to keep them in a community setting once they begin to put on some size usually ends badly.
Among the best tank mates for triggerfish are fish of the genus Cephalopholis. These fish are beautiful, hardy, intelligent and contrary to common perception generally unaggressive toward members of other families. However, their large size and robust nature means that they can hold their own in the presence of most triggerfish. Members of the genus Epinephelus also make great tank mates as long as you obtain one the few species that remain small enough to be kept in a large home aquarium. Within this genus, a few of the better choices are E. ongus, E. hexagonatus, E.merra. Just ensure that the sizes and growth rates of the fish are taken into account so that the trigger doesn’t end up being a late night snack for the Grouper or Hind in question.
The larger, hardier angelfish species do well with triggerfish, as do many wrasse, surgeonfish, and damselfish species, as well as various moray eel species.
Although lionfish are often falsely lumped into the “aggressive fish” category, it would be unwise to place them in the same tank as triggerfish. Some of the more boisterous triggers may harass the lionfish and even nip spines off. (See: Fu Manchu Lionfish)
A warning note here. As with all fish in the aquarium hobby there are exceptions to the rule. However, when it comes to triggerfish these exceptions should in no way inform your decisions. Just because someone has gotten away with keeping an Orange-lined triggerfish in a community aquarium doesn’t mean that you should attempt the same. Most of the time these people have added a triggerfish to a community ignorant of the risks. The fact that that person got away with it is a miracle rather than a result of method.
The Rhinecanthus genus comprises a few very popular species, including the Picasso triggerfish (R. aculeatus) and the Reef triggerfish (R. rectangulus). This genus arguably comprises some of the most easily kept and sociable of all trigger species. However, they are also very slow growers. For this reason, a young specimen can be purchased and comfortably housed alone in a 150 litre (40-gallon) tank for at least 12 to 18 months before larger quarters are needed. After that a 260 litre (70-gallon) tank will be suitable, as after 12cm growth slows even more. These generalisations can also be applied to the Orange Line triggerfish (Balistapus undulates). The primary difference here is that B. undulatus MUST be kept alone, for they are without a doubt the most aggressive aquarium species available, either freshwater or marine!
A few commonly seen species get quite large, and grow at a much faster rate than those of the Rhinecanthus genus. Among these are Odonus niger, Balistes vetula, Balistoides conspicillim and Psuedobalistes fuscus. All four are relatively fast growers and require very large tanks as adults. A 2000 litre (500-gallon) aquarium should be considered the minimum for Balistes vetula and at least a 750 litre (200-gallon) tank for the remaining 3 species. Of the four, only O. niger generally makes a good tank mate over the long term when kept with other fish.
The enormous size and aggression displayed by the Queen trigger (Balistes vetula) makes long term cohabitation with other fish all but impossible. The Queen trigger grows much too quickly to consider anything but a very large tank from the get go
Balistoides conspicillim and Psuedobalistes fuscus while still quite aggressive are still a bit more social than B. vetula, and if acquired small can live quite comfortably in a 210 litre (55-gallon) or 260 litre (70-gallon) tank for some time before a larger tank becomes necessary. Both species are able to coexist with other species for a time if enough space is provided. However, this almost always changes at some point though. Having said all this, a tank of at least 70 to 80 gallons will provide sufficient space on a long term basis for the vast majority of triggers that you’re likely to encounter at your local fish store if kept alone. Even with the more sociable species, you will be very limited as far as suitable companions unless even more space is afforded.
The Half-moon (Sufflamen chrysopterus), Bursa (Sufflamen Bursa), Pinktail Triggerfish (Melichthys vidua), Bluechin (Xanthichthys auromarginatus), Crosshatch (Xanthichthys mento) and the Sargassum Triggerfish (Xanthichthys ringens) are all suitable for the community aquarium. The latter 4 species, as well as Odonus niger, have the distinction of being generally safe in reef settings, with the stipulation that small shrimp should be added before the triggerfish, and the triggers themselves should generally be added last, and be the smallest fish in the tank.
In all cases the triggerfish should be the last and smallest fish added to the community. The reason for this is that even relatively peaceable species like Picasso (R. aculeatus) are only peaceable in relative terms! They are still somewhat aggressive fish, and can do a fair amount of damage in an altercation. By ensuring that the trigger is the smallest fish in the tank you minimise the damage that it is capable of and allows the Trigger to become conditioned to the presence of their tank mates. Simply following these two rules generally assures that the Trigger does not establish itself as the dominant fish in the community, and allows the other inhabitants to adapt to the presence of the triggerfish.
Both O. niger and M. vidua can be kept in reef setups and will even leave your shrimp alone if the shrimp are introduced before the trigger.
Keeping a single fish alone in a species tank is the only viable option for certain species, including the Orange-lined triggerfish (B. undulates) and the Queen triggerfish (V. vetula). For the Queen Triggerfish, which can attain a length of 50cm, the tank will have to be in the 2000 litre (500-gallon range). The other consideration to keep in mind is the highly destructive capabilities of these fishes. Nothing is out of bounds with this fish. That means filters, powerheads, power cords and heaters are all potential targets. For this reason, it is best to house most or all of your equipment in the sump. They are also capable of overturning and moving rocks and other pieces of décor. This tendency should be taken into account when aqua-scaping a tank that will eventually house an adult triggerfish.
It would also be wise to remember that a triggerfish’s aggression may extend to its owner. Therefore, it is advisable to keep your hands out of the tank as much as possible. Triggerfish have a nasty bite and can even remove fingers, so be warned!
Feeding a triggerfish is the easiest thing you can imagine. Triggerfish will accept a wide range of fresh and prepared fish foods. Although you will be able to find a range of appropriate foods at your local fish store, your triggerfish will appreciate a range of fresh foods as well. As with any fish, a varied diet will ensure that your triggerfish remains in optimum health. A fresh food items to consider are fresh squid, octopus, scallops, fish, shrimp and crab. These foods can be cut into bite sized morsels and offered to the Trigger 2 or 3 times a day. Whole crayfish can even be offered, shell and all, and this will allow you to witness the business end of a Triggerfish doing what it was meant to do. Even the few available species that are planktivores in the wild readily accept and thrive on all the options mentioned above with the exception of large, whole invertebrates.
The importance of vitamin supplements is vitally important when keeping triggers. As triggers are natural predators it is nearly impossible to completely replicate their natural diet. When a Trigger consumes a crab in the wild, it not only ingests the meat, but all the blood, organs and other matter that makes up the animal. This provides a complete nutrition package. Feeding a combination of whole food items and vitamin supplements mitigates any problems that may occur down the road due to improper nutrition.
This article was sponsored by Nature at Work.