Acanthuridae (Surgeonfishes/Tangs)

Surgeonfish (Acanthuridae) live primarily of different types of algae, making it a popular choice for coral aquariums, as they help to keep the aquarium algae free.

Most Surgeonfish have a scalpel by the caudal fin, used to defend themselves. It can cause some deep lacerations, so pay attention if the fish start to fight and when handling the fish.

When in the aquarium, they will spend most of their time swimming around and nibbling the algae from the stones. Surgeonfish will rarely irritate corals or invertebrates. Large Palettes/Blue tangs can be an exception.

The Surgeonfish are not typically aggressive towards other types of fish. If more Surgeonfish are added to the aquarium, they will establish a hierarchy. It is best to add the most aggressive species last and to ensure that there are sufficient hiding places, as they prefer to have their own individual sleeping area.

If multiple aggressive species are added to the same aquarium, one runs the risk of one of them dying due to stress. One must therefore be cautious about adding multiple Acanthurus species or Zebrasoma xanthurum into the same aquarium. A combination of the different genera will normally get along well, although the more aggressive species can still be challenging.

Some species in the Acanthurus genus mimic various Angelfish as juvenile, since predatory fish know that small Angelfish are hard to catch. They are therefore difficult to identify from a picture of adult fish.

Acanthurus species often place higher demands on: tank size, surroundings and water quality, than fish in the genus Zebrasoma.

The genus Bristletooth Tang (Ctenochaetus) contains a range of species, which are characterized by special teeth.
Like other Surgeonfish the Bristletooth Tang eats algae but with their specialized teeth they also scrape other organic material from rocks and stones. Ample sand and rocks are therefore imperative.

Overall the Ctenochaetus are peaceful and not quite as active, as many of the other surgeonfish. It is therefore suited to smaller aquaria.

Because of these their mild behaviour they are not a good combination with some of the more aggressive Surgeonfish.

Ctenochaetus are not so colourful as many other Surgeonfish. Some species are more vibrant in colour but this changes when they get to around 3 inch (7-8 cm).

To thrive, species in the Naso genus, normally demand large aquaria, both because of their size, but also to fulfil their need for swimming space.

Like other Surgeonfish, Naso, or Unicornfish, eats a great amount of algae, which should reflect in their food. They need more algae based food then other species of Surgeonfish, this one must be aware of so as not to create nutrition problems.

When newly introduced Naso can be in the aquarium without eating for some time, but they normally begin to eat within a week.

They are, on the whole a peaceful species in relation to other Surgeonfish.

It is important that one chooses a healthy individual at the petshop, i.o.w. a fish that is active, shows normal behaviour and does not look too thin. If it looks poorly one has a challenge on ones hand, especially when the fish takes its time to start eating.

Some sources report, that large Naso Surgeonfish can in some cases scratch acrylic and glass, since their scalpel grows larger then others of the species.

This genus only has one species, but it is unique in relation to other Surgeonfish.

They are generally peaceful and ignored by many other species of Surgeonfish, since they do not resemble them. They are however delicate, especially during transportation. They should be placed in a peaceful environment with plenty to eat during acclimatization.

This surgeonfish has a charming way of swimming and can act almost playful when it is observed.

Because of this behaviour it is absolutely not, suited to small aquaria. It matures quickly and even though it seems that immature ones fit in the tank, it is not recommended.

One almost always sees this genus of Surgeonfish in a coral aquarium, since they are beautifully coloured, relatively easy to keep and useful.

The Zebrasoma genus is distinguished in that all the species have a larger or smaller, sail-like fin, which is folded out when threatened by other fish.

Z. xanthurum are the only fish in this genus which are decidedly aggresive, the others typically do not present problems, when the aquarium has space enough.
Some specimens of Z. flavescens can act aggressively towards other Zebrasoma tangs.