In observing surgeonfish, Acanthuridae, as they are known among researchers, are species that can commonly be spotted in the warmer waters of tropical islands and coastlines, particularly near coral reefs. They are oval-shaped, brightly colored fish that can grow to quite a significant size, considering the fact that they are mainly herbivores. Members of the species have been around in one form or another for more than 50 million years. Also known as tangs, saltwater surgeonfish are extremely resilient, a trait that benefits them even more due to their remarkable speed, as well as the fact that they’re very collaborative when found in the vicinity of other species of fish.
Surgeonfish have the particular feature of possessing very sharp spines that can be erected at short notice when needed for self-defense. This is the main reason why they are called surgeonfish in the first place. Their spines are located near their tail fins, being extremely handy when danger arises. With a simple flick of their tail, they can turn their spines into exceptionally practical weapons, and their remarkable acceleration and natural colors allow them to hide in plain sight or sprint away with ease when spotted by predators. Despite their size, which can reach up to 1 meter in length, tangs are laterally compressed to a great extent. Finally, their tiny mouths have evolved to allow them to easily access small spaces in crevices or between algae in order to forage for food.
For surgeonfish, Acanthuridae behavior traits are found to be similar in virtually all the seas and oceans of the world, except for the Mediterranean, where tangs are not present at all. They live in coastal waters, estuaries and even harbors, as well as anywhere else where shallow waters expose rock and coral formations to sunlight, allowing for ripe algae growth. Tangs generally live in schools, and they stick to coastal regions. They are very seldom found out in the open ocean, and their sleep areas are small crevices and caves in the reef, where they can keep themselves protected from predators.
Acanthuridae normally feed in schools, although their feeding patterns are quite flexible. They can also be individual, and may even travel long distances in order to find food. They mainly feed on plant matter, however, there are a few species that have also been found to consume zooplankton. When taking a closer look at surgeonfish, Acanthuridae researchers pointed out that the fact that these fish feed in schools could be a counteraction to the defense responses of territorial damselfish, which are known to actively guard their small patches of algae on the reef.