Keeping Tangs From Being School Bullies

Know Your Genera

Best practice is not to add two tangs from the same Genus. Genus is the scientific classification for tangs. Kingdom, Phylum, Class, Order, Family, Genus, Species. All tangs are in the same Family, but they have different Genera and species. You can keep multiple tangs of the same genus and species, but you will have more success if you mix genera. Tangs see anything like them as a competitor, which triggers their aggressive instinct.

In addition to not mixing Genera, some Genera are more aggressive than others. While it is true that each species and even each fish behaves differently, knowing how the Genera generally behave will help inform your species selection. There are over 80 species of tang, and grouping them into genera will help you learn a little about each one. Below is a list of the tang Genera you commonly see in the aquarium hobby, along with basic information about each genus.

Add A lot

If you add only 2 tangs to an aquarium, they tend to fixate on one another, which can lead to problems. We recommend adding at least 3 tangs to a tank if you are going to keep more than one. 6-10 is even better. Obviously, you will need a very large tank to keep this many tangs. Keeping a single small tang in a 4ft long 55-gallon aquarium is perfectly fine, but if you want to keep multiple tangs, your tank should be at least 6 feet long; 8- and 10-foot tanks are better. For tangs, tank length matters more than volume. The length will allow for long swimming paths and room for individual fish to establish their own territory.

Add At Once

If you add one tang and then wait a few months, or even a year, before adding your next tang, the first fish may have claimed the whole tank as its territory and will viciously defend it against any new tangs. Adding the fish as close together as possible will help to mitigate this issue. You don’t need to add the fish on the same day, but weeks or months apart is far better than years apart.

Another helpful tool when adding a tang to a tank that already has an established tang is an acclimation box. An acclimation box is an acrylic box that sits inside your aquarium where you can add new fish. You add the new fish to the box so it can see the current tank inhabitants, but the established fish can’t terrorize the new arrival. After a week, or up to a month, let the new fish out of the box. This social acclimation can dramatically reduce the aggression towards new arrivals. The IceCap Isolation Boxes are a good option for an acclimation box.

Feed Plenty and Often

Fish get Hangry. If fish feel limited in their food supply, they will fight aggressively for food. As grazing animals, tangs link territory to available food resources in that territory. If they are constantly hungry, they will try to secure more grazing space. Feeding large amounts often will greatly reduce the aggression between fish. We recommend using an automatic feeder to feed 4 or more times per day. Some public aquariums will feed every hour. The fish should never want for food, which will greatly reduce their urge to compete with their fellow fish. You can feed this often by hand, but most of us aren’t going to, which is where the auto feeder comes in.