blue tang in the water

Blue tang fish are small marine aquarium fish that are not only abundant but also popular worldwide. The former stems from the fact that they are relatively easy to located in water.

This stems from the fact that they come in vibrant colors such as canary yellow and royal blue. Interestingly, when blue tang fish mature, they can turn a shade of violet to reflect stress. This type of fish is native to the Indo-Pacific, where it initially found shelter across multiple coral reefs.

Despite boasting a relatively harmless demeanor, the blue tang can become aggressive in the face of danger. These fish are known to draw poisonous and sharp spines that spring up on both sides of their tails. Here are a few more interesting facts about the blue tang fish.

Description and Size.

Besides having a blue frame, the Blue tang additionally has a black pattern across its body that looks like a painter’s palette and a yellow-tail. A good way to describe the blue tang would be to say that it is shaped like a pancake, owing to its rounded and flat surface.

blue tang fish in the wild
(Image source:

This fish has some other fascinating features, including tiny scales, an average of 27 dorsal soft rays, a nose that is shaped like a snout, and a scalpel-like spine that runs on the side of its body. Interestingly, this spine is where the blue tang derives its name from.

Being a small fish, it comes as no surprise that this fish can only grow up to 12 inches/30cm at full maturity. As far as its weight is concerned, research has shown that adult blue tang fish can weigh up to 600 g. One other interesting fact we uncovered about their size is that male fish in this species are typically larger than their female counterparts.

Diet and Eating Habits.

Judging by their eating habits, the blue tang is primarily an omnivorous fish. In their youth, they heavily depend on a diet of smaller aquatic life such as plankton. As they mature, the majority of their diet will switch to algae.

algae growing along the reef
Blue tang fish help to keep algae in check. (Image source:

Adult blue tang fish rely on their sharp teeth to scrape the algae off the coral it grows along. Scientists say that the blue tang’s reliance on algae makes it an essential part of the eco-system. These fish help minimize the suffocation and degradation of coral by feasting on algae, which would harm the food chain.

Can you eat a blue tang fish?

Right off the bat, you would be ill-advised to consume a blue tang fish. This is because people who eat said fish have gone on to be diagnosed with ciguatera poisoning, a food-borne illness that results in diarrhea, vomiting, and in some cases, faintness. So why does the consumption of the blue tang fish expose one to ciguatera poisoning?

To answer this, we must first take a closer look at the fish’s diet. Studies have shown that blue tang fish can consume large amounts of dinoflagellates. These are marine plankton that can be classified as algae; they are also scattered across various freshwater habitats. Consuming these particular algae leads to a build of toxins in the blue tang fish’s body.


Studies have shown that the blue tang fish can live for approximately 20 years when held in captivity. This lifespan increases drastically if the blue tang is in the wild.

Here, it is believed that they can live for as long as 30 or more years. These fish attain sexual maturity anywhere between 9 to 12 months. When it comes to courtship, their mating habits can often be described as aggressive. Once the eggs are fertilized, they hatch after 24 hours.

Location and Habitat.

As mentioned before, the blue tang fish originally comes from the Pacific and the Indian oceans. This encompasses areas stretching from the East coast of Africa to Samoa.

They inhabit reefs scattered across Sri Lanka, the Philippines, Japan, New Caledonia, Indonesia, and even the Great Barrier Reef located in Australia.

great barrier reef in Australia
One of the many locations that the blue tang inhabits. (Image source:

Additionally, these fish can be located close to cauliflower corals. Interestingly, research has found that the blue tang prefers to live in pairs or small groups made up of about 10 individuals.

Blue tang fish care.

The blue tang fish remains a popular choice for most marine aquatics. However, we should stress that this is not a recommended fish species for beginners, as they tend to fair with more experienced care. This is down to the fact that this particular type of fish requires a lot of commitment and attention.

The blue tang fish has a higher chance of developing diseases such as ich, fin erosion, and several skin parasites. To avoid this, you should always make sure that the aquarium’s water is of the best quality.

Besides this, you also have to provide the fish with a diet with sufficient nutritious marine-based algae and seaweed that promote good health. You can additionally offer the fish live brine shrimp and clams.

Most people typically like to feed their blue tang using veggie clips. You could also fasten dried seaweed on a rock and lower it into the aquarium in the absence of one. It is recommended that you feed your blue tang at least three times every week.

Being at optimal health will not only improve the fish’s immune system but also reduce its aggression. You should also know that blue tang fish are best cared for in aquariums that stretch at least 6 feet in length. This will ensure that it has enough space to swim around as the blue tang is a very active fish.

A spacious tank at the rainbow reef
“Overall view of one of the tanks in the Rainbow Reef” by Shankar S. is licensed under CC BY 2.0

The last thing you should consider is that while it will rarely display any aggression towards other fish in your aquarium, the blue tang can often turn nasty in the presence of fish in its own species. So be very careful when selecting your fish’s tankmates.

Most people agree that the blue tang will get on well with fish like the Percula Clownfish, Butterflyfish, and the Ocellaris. Additionally, experts advise that if you wish to keep several blue tangs in the same tank, you will be better served to simultaneously integrate them into their habitat.

Threats to their survival and conservation.

Right off the bat, we should begin by confirming that the Blue tang fish faces no immediate threat of extinction. In fact, the IUCN (International Union for Conservation of Nature) classifies it under the least concern category. However, there is an emerging worrying trend, particularly regarding the aquarium trade.

As we have mentioned, this fish is quite popular amongst most aquatic life enthusiasts. One fact that you may not be aware of is that right up until 2016, breeding these fish in captivity was not possible. It meant that all the blue tangs peddled in the markets were found in the wild.

A worrying estimation revealed that at least 250,000 blue tang fish were being pulled out of their natural habitats every year. The coral reefs they call home also presently face the threat of coral bleaching and acidification in the ocean. This will inevitably lead to the loss of their natural habitat if the matter is not addressed.

Facts about the blue tang fish.

  • The blue tang goes by a host of different names, ranging from hippo tang, palette surgeonfish, royal blue tang, regal blue tang, blue surgeonfish to flagtail surgeonfish.
  • Its scientific name of the blue tang fish is Paracanthurus hepatus.
  • The blue tang fish’s popularity increased after the popular Pixar animated film ‘Finding Dory’ was released. This is because the title character, Dory, was a blue tang fish.
Finding Dory cover
A poster from the Pixar film, Finding Dory. (Image source:
  • The blue tang fish is the sole member of the genus ‘Paracanthurus.’
  • Owing to several similarities the blue tang shares with the Acanthurus coeruleus, an Atlantic fish species, it is quite easy to confuse either of them for each other.
  • Their temperament can be described as ‘semi-aggressive.’
  • When faced with the threat of imminent danger, blue tang fish will aggressively whip their bodies sideways in an attempt to deter would-be predators with their venomous spines.

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