If you are looking for a fish that will make your saltwater aquarium stand out, you might be tempted by the Achilles tang. This fish has a striking appearance, with a black body, orange spots, and a white patch near the tail. It also has a bright white spot on its gill cover, said to resemble the Achilles heel of the Greek hero.
The Achilles tang is one of the most sought-after fish in the aquarium hobby, but it is also one of the most difficult to keep. This fish requires a lot of space, a varied diet, and a stable environment. It is also prone to diseases and aggression, especially towards other tangs.
This article will tell you everything you need to know about the Achilles tang, including its natural habitat, behavior, tank requirements, feeding, compatibility, and health issues. We will also give you some tips on how to acclimate and care for this fish. By the end of this article, you will be able to decide if the Achilles tang is the right fish for you.
What is an Achilles Tang?
The Achilles tang (Acanthurus achilles) is a species of marine fish belonging to the family Acanthuridae, also known as surgeonfishes or tangs. These fish have a characteristic spine or scalpel on each side of their tail base, which they use for defense or aggression.
The Achilles tang is native to the Pacific Ocean, where it inhabits coral reefs and rocky areas. They can be found anywhere from Hawaii to Japan and from Australia to French Polynesia. They usually live in shallow waters, between 3 and 40 meters deep.
The Achilles tang is an herbivorous fish that feeds mainly on algae and other plant matter. It uses its sharp teeth to scrape off algae from rocks and corals. It also consumes some animal matter, such as copepods and amphipods.
Achilles tangs are social fish that form large schools in the wild. It can be seen swimming in groups of hundreds or thousands of individuals, often mixed with other tang species. The are highly territorial and will defend their feeding area from intruders.
An Achilles tang can grow up to 10 inches in length and can live up to 20 years in captivity. It has a beautiful coloration that varies depending on its mood and environment. It can change from dark black to light brown, with different shades of orange and yellow on its body and fins. The white patch near its tail can also expand or contract depending on its stress level.
Scientific Name |
Acanthurus achilles |
Common Names |
Achilles tang, Achilles surgeonfish, red spot surgeonfish, redtail surgeonfish |
Family |
Acanthuridae |
Origin |
Pacific Ocean, from Hawaii to Japan, and from Australia to French Polynesia |
Adult Size |
Up to 10 inches in length |
Life Expectancy |
Up to 20 years in captivity |
Aggression |
Semi-aggressive, territorial and aggressive towards other tangs or similar-looking fish |
Difficulty |
Expert |
Minimum Tank Size |
180 Gallons |
Captive Breedable |
No |
Why is the Achilles Tang so Popular?
A quick look on reddit, facebook groups, and reef forums all point to the same inescapable fact. The Achilles tang is one of the most popular saltwater fish among aquarists, likely due to its stunning appearance and personality. These tangs have a sleek and elegant body shape, with a long snout and a forked tail. But the coloration is the biggest draw, vibrant and eye-catching, with contrasting patterns and spots that make it stand out in any aquarium.
The are also very active and curious fish that likes to explore their surroundings and interact with their tank mates. Watching it swim around the tank, grazing on algae, and darting away from potential threats can be very entertaining. It can also show different expressions and behaviors depending on its mood and situation.
Their beautiful appearance isn’t the only thing an Achilles Tang is capable of providing. They are extremely beneficial fish for your aquarium. You’ll notice them controlling algae growth by eating it regularly. They’ll also help aerate the water by creating currents with their quick movements. Keeping a close eye on an Achilles can even indicate water quality since they change color or show signs of stress when something is wrong. Let’s be real though, there are much better ways of watching for water quality issues.
What are the Challenges of Keeping an Achilles Tang?
Despite its massive popularity, the Achilles tang is not a fish for beginners or casual aquarists. This fish has very specific needs and demands to be met to thrive in captivity. Some of the challenges of keeping an Achilles Tang are:
- Space: The Achilles tang is a large and active fish that needs plenty of room to swim and graze. It should be kept in a tank of at least 180 gallons. The tank should also have ample rockwork and hiding places for the fish to feel secure and comfortable.
- Diet: The Achilles tang is a herbivore that needs a varied and nutritious diet to stay healthy and colorful. It should be fed several times daily with high-quality aquarium foods containing algae, spirulina, nori, or other plant-based ingredients. It should also be offered fresh or frozen food products such as mysis shrimp, krill, brine shrimp, or other meaty foods once or twice a week. These foods provide protein and other nutrients that the fish needs for growth and health. Additionally, the fish should have access to live or dried algae in the tank, either on an algae clip or on the rocks. Algae is the main source of food for the Achilles tang in the wild, and it helps prevent digestive problems and malnutrition.
- Water quality: The Achilles tang is very sensitive to water quality and can easily get sick or stressed if the water parameters are not optimal. The tank should have a good filtration system, a protein skimmer, and regular water changes to maintain the water clean and clear. The water temperature should be between 24 and 27°C (75 and 81°F), the pH should be between 8.1 and 8.4, the salinity should be between 1.020 and 1.025, and the ammonia, nitrite, and nitrate levels should be as close to zero as possible.
- Acclimation: The Achilles tang is one of the most delicate tangs to acclimate to a new tank. This fish can suffer from shock, stress, or disease during the transport or quarantine process. It is very important to acclimate the fish slowly and carefully to avoid any sudden changes in water temperature, salinity, pH, or other factors. The best method to acclimate the Achilles tang is to use a drip line that gradually mixes the water from the bag with the water from the tank over several hours. Keep them in a dark, quiet place during acclimation to reduce stress.
- Disease: The Achilles tang is prone to several diseases that can affect its health and appearance. Some of the most common diseases are:
- Ich
- Lateral line erosion
- Fin rot
- Head and lateral line erosion (HLLE)
How to Choose a Healthy Achilles Tang?
The Achilles tang is not a cheap fish to buy or maintain. A quick search shows average prices between $300 and $700, depending on size, coloration, and availability. Therefore, choosing a healthy specimen that will have a better chance of surviving and thriving in your tank is important.
Here are some tips on how to choose a healthy Achilles tang:
- Bright and vivid coloration without signs of fading or dullness.
- Clear and alert eyes with no signs of cloudiness or injury.
- Intact and smooth scales and fins with no signs of damage or disease.
- Plump and rounded body shape with no signs of emaciation or bloating.
- Swims actively and confidently around the tank with no signs of lethargy or hiding.
- Breathes normally and regularly, with no signs of rapid or labored breathing.
- Eats eagerly when offered food, with no signs of loss of appetite or pickiness.
- Find out what it has been fed (preferably a variety of aquarium foods and food products that contain algae and meaty foods).
- Find out how it has been treated (preferably with no medications or chemicals that could harm its health or coloration).
- Find out how it has been handled (preferably with minimal stress and damage).
If you are buying fish online, make sure to check the seller’s reputation, reviews, and policies. Ask for clear and recent photos or videos of the fish, and request a guarantee or refund in case the fish arrives dead or unhealthy.
Caring for an Achilles Tang
Once you have chosen a healthy Achilles tang, you need to acclimate and care for it properly to ensure its survival and well-being in your tank. Here are some steps to follow:
Prepare your tank
Before introducing the Achilles tang to your tank, make sure that your tank is fully cycled, stable, and ready to accommodate the fish. The tank should have a large size, a good filtration system, a protein skimmer, and regular water changes. The tank should also have plenty of rockwork and hiding places for the fish to feel secure and comfortable. As mentioned above, the water parameters should be within the optimal range for the fish.
Quarantine your fish
It is highly recommended to quarantine your Achilles tang for at least two weeks before adding it to your main tank. This will help prevent the spread of diseases or parasites the fish may have contracted during transport or captivity. It will also help the fish adjust to its new environment and diet without any competition or stress from other tank mates. The quarantine tank should have a similar size, water quality, and temperature as the main tank. It should also have some rockwork and hiding places for the fish. The quarantine tank should be monitored closely for any signs of illness or abnormal behavior.
Acclimate your fish
As mentioned above, the Achilles tang is very sensitive to changes in water conditions and needs to be acclimated slowly and carefully to avoid shock or stress. The best method to acclimate the fish is to use a drip line that gradually mixes the water from the bag with the water from the quarantine tank over several hours.
Feed your fish
The Achilles tang needs a varied and nutritious diet to stay healthy and colorful. It should be fed several times daily with high-quality aquarium foods containing algae, spirulina, nori, or other plant-based ingredients. It should also be offered fresh or frozen food products such as mysis shrimp, krill, brine shrimp, or other meaty foods once or twice a week. These foods provide protein and other nutrients that the fish needs for growth and health. Additionally, the fish should have access to live or dried algae in the tank, either on an algae clip or on the rocks. Algae is the main source of food for the Achilles tang in the wild, and it helps prevent digestive problems and malnutrition.
Monitor your fish
The Achilles tang is a delicate fish that can easily get sick or stressed if something is wrong in its environment or diet. Monitoring your fish regularly for any signs of illness or abnormal behavior is important. Some of the signs to look out for are:
- Loss of color or appetite
- Lethargy or hiding
- Rapid or labored breathing
- White spots or patches on the skin, fins, or gills
- Inflammation or decay of the fins
- Ulcers, lesions, or scars on the face or body
- Scratching or rubbing against objects
If you notice any of these signs, you should take action immediately to diagnose and treat the problem. You may need to isolate your fish in a hospital tank and administer medications or therapies as needed.
Compatible Tankmates for an Achilles Tang
Achilles tangs are reef safe and quite sociable, getting along with many other saltwater fish in a large and well-stocked tank. But they are often territorial and aggressive towards other tangs or similar-looking fish. Therefore, choosing compatible tankmates for your Achilles tang is important.
Here are some tips on how to choose compatible tankmates for your Achilles tang:
- Avoid keeping more than one Achilles tang in the same tank unless you have a very large tank (over 200 gallons) and plenty of rockwork and hiding places. Even then, there is no guarantee that they will not fight with each other.
- Avoid keeping other tangs of similar appearance or behavior with your Achilles tang, such as clown tangs, whitecheek tangs, yellow tangs, or sailfin tangs. These fish may compete with your Achilles tang for food and space, triggering aggression or stress. If you want to keep other tangs with your Achilles tang, you should choose different Zebrasoma species, such as the purple tang, the scopas tang, or the gem tang. These types of tangs have different body shapes and coloration and are less likely to cause conflicts with your Achilles tang.
- Avoid keeping fish that are too small, slow, or timid with your Achilles tang, such as seahorses, pipefish, mandarins, or gobies. These fish may be harassed or outcompeted by your Achilles tang, and may not get enough food or shelter. If you want to keep these fish with your Achilles tang, you should provide them with plenty of hiding places and feed them separately.
- Avoid keeping large, fast, or aggressive fish with your Achilles tang, such as triggers, groupers, lionfish, or eels. These fish may prey on or intimidate your Achilles tang, and may cause injuries or stress. If you want to keep these fish with your Achilles tang, you should make sure that they are well-fed and have enough space to coexist peacefully.
- Choose fish that are compatible in size, temperament, and water requirements with your Achilles tang, such as angelfish, butterflyfish, wrasses, anthias, clownfish, or damsels. These fish can form a colorful and lively community with your Achilles tang, enhancing your tank’s beauty and diversity. However, you should monitor their interactions and behavior to ensure they get along well.
Final Thoughts
The Achilles tang is a stunning but challenging saltwater fish that requires a lot of care and attention from its owner. This fish has a striking appearance, a lively personality, and a beneficial role in the aquarium ecosystem. However, they also have very specific needs and demands to be met to thrive in captivity.
If you are willing and able to provide the Achilles tang with the proper care and environment, you will be rewarded with a stunning and lively fish that will enhance the beauty and diversity of your aquarium. However, if you are not ready or able to meet the challenges of keeping this fish, you may want to consider other options that are more suitable for your level of experience and budget.
We hope this article has helped you learn more about the Achilles tang and decide if it is the right fish for you. If you have any questions or feedback, please let us know. Thank you for reading, and happy fishkeeping!
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