Yellow Tang

   The Yellow Tang brings a bit of bright sunshine to any level aquarist’s tank, providing hours of viewing pleasure each day!

   The Yellow Tang is a bright sunshine yellow on a deep disc shaped body.  Laterally compressed, they sort of look like a little sun floating around in the tank!  They have an extended snout that helps them to pick algae out of hard to reach crevices that allude other tangs.  Like all seven of the sailfin tang species, when the fins of the Yellow Tang are fully extended its height is about the same as its length, giving it a disk-shaped appearance.  They have a white “scalpel” at the base of their tail fin in the caudal area.  This fact also necessitates the need to capture them in a container and not a net, as their spine can get tangled, torn and infected.  Males are larger and can reach 8″ with females being smaller.  Males will reach about 6.5″ within their first 4 to 5 years of life and Zebrasoma tangs are known to live 30 to 45 years.  (Choat and Axe, 1996)

   By far the most popular tang available, the Yellow Tang is also one of the ten most popular marine aquarium species.  Around the island of Hawaii (Big Island), almost 350,000 juvenile Yellow Tangs a year are exported for the marine hobby.  Since hobbyists prefer juveniles and not full grown adults, this has not affected the population.  In fact, reports are showing that the Yellow Tang has increased in number by 35% in 2011.  This is probably because in the wild, most juveniles probably would have been victims of predation before they reach adulthood, as is true with all marine fish and since the spawning population isn’t collected, they are not being reduced in number.   It is a very close relative to the Scopas or Twotone Tang, (Zebrasoma Scopas), which also has a known color form that is yellow with a white peduncle spine. These two species co-occur and interbreed in Micronesia and southern Japan. As they co-habitat in many areas and behave the same, it has not been ruled out that this tang may actually be a xanthic form of the Scopas or Twotone Tang, or possibly a geographic variant.

   Yellow Tangs are one of the hardiest of all surgeonfish.  A healthy juvenile will be curious about you and its environment, and will be active all day.  Bold in nature, Yellow Tangs quickly adapt to aquarium food and is easy to care for once it is settled. They are highly disease resistant in a quality environment and they respond well to treatment.  Adding to a mature tank and stable tank is key.  Avoid tiny babies under 2″ long unless feeding 5 to 6 times a day is possible.  Like all tangs, they are susceptible to Crypt or “saltwater ich,” bacterial disease from a poorly kept tank, and Lateral Line and Hole in the Head Disease.  All three of these issues can be allayed by quarantining all new comers, keeping the water clean and oxygenated and feeding them appropriate marine based algae.  By having a separate tank to grow macro algae like Chaetomorphia, you can have a “free” supply of food for your tang! 

   The Yellow Tang makes a wonderful addition to the marine aquarium, especially a peaceful community aquarium. It is relatively peaceful and will get along with a wide variety of tank mates, however the tang should be added last in a peaceful reef or peaceful fish only tang.  It is usually best kept singly as it does not generally mix with others of its genus. Unlike any of the other Zebrasoma species though, if it is added with others of its same species when very young they may be successfully kept together and will school.  

  The minimum tank size should be 6 feet long and 125 gallons for adults, due to their very active nature.  A juvenile up to 4 to 5″ can be kept in a 75 gallon, but should be moved to a 125 gallon by the time they are 5″ long or they can start to develop a bad attiude.  Yellow Tangs, in fact all tangs for that matter, like plenty of strong water movement to provide an oxygen rich environment rather than a calm aquarium.  A good skimmer will help with the copious amounts of waste they produce and will help keep the water clean.  Provide some swimming space above rock work and lots of crevices among corals/ rocks to retreat into (especially juveniles) and for sleeping at night. 

For more Information on keeping marine fish see:
Guide to a Happy, Healthy Marine Aquarium

Habitat: Distribution / Background

   The Yellow Tang, Zebrasoma flavescens, was described by Bennett, in 1828.  They only have a few common names, which are all descriptive of their coloring and shape.  These are:  Yellow Tang, Yellow Sailfin Tang, and Lemon Tang.   The genus Zebrasoma means “horse body,” which comes from the word “Zebra” for horse in African and “soma” for body in Greek. 

   They are found in the Pacific Ocean from Japan to Hawaii; Ryukyu, Mariana, Marshall, Marcus, Wake and Hawaiian islands. It has also been reported off the coast of Florida in the Western Central Atlantic.  They inhabit areas of dense coral in lagoons and seaward reefs below the surge zone (10 feet or 3 meters) to 150 feet (46 meters).  They are herbivores that feed on various types of filamentous algae.  Adults occur singly, in pairs, or in loose groups both small and large depending on the area.  Juveniles are solitary and very secretive, hiding among the corals.  They will interbreed with the Scopas Tang where their ranges cross.

   The Yellow Tang is on the IUCN Red List for least concerned with a stable population trend.

• Scopas or Twotone Tang, Zebrasoma Scopas:  This brown tang has a shorter mouth, however they have been known to interbreed with each other.
• Purple Tang, Z. xanthurum:  This all purple tang has a yellow tail fin and pectoral fins and also has the same shape as the Scopas Tang.
• Black Longnose Sailfin Tang, Zebrasoma rostratum:  This black tang has a slightly longer mouth, however they have been known to interbreed with each other, and it is black, not dark brown.

• Scientific Name: Zebrasoma flavescens
• Social Grouping: Varies – Adults: Solitary, pairs, groups and schools Juveniles: Solitary
• IUCN Red List: LC – Least Concern – 35% increase in population in 2011

Description

   The Yellow Tang has a disk like shaped body similar to all surgeonfish, but with large dorsal and anal fins. When the fins are fully extended, the total height of these fish is about the same as the length. Like all the Zebrasoma tangs, they have a slightly extended snout to reach algae in crevices that other tangs are not equipped reach into.  True to their name, the body is a beautiful rich yellow.

   On each side of their caudal peduncle is a single white spine or “scalpel” used for defense or dominance.  While the venom gland is present in juveniles, adults loose the venom according to new research.  Their spine is folded down into a groove when not in use, but with juveniles, care needs to be exercised when handling them since a cut from its scalpel can cause discoloration and swelling of the skin with a high risk of infection. The pain lasts for hours then still ends up having a dull ache.  

   Yellow Tang males are larger than females and grow to about 8,” however they will reach about 6.5” by 4 or 5 years old.  This genus is known to live for 30 to 45 years (Choat and Axe, 1996).

• Size of fish – inches: 8.0 inches (20.32 cm)
• Lifespan: 45 years – up to 45 years (Choat & Axe, 1996)

Fish Keeping Difficulty

   The Yellow Tang is a hardy fish, and like all tangs, they need at least 6 feet of tank length for their at times, insane bouts of energy!  Without it, they will start to become aggressive, especially if housed with other tangs or filamentous algae eaters.  It is a great addition to the marine aquarium and fairly easy to keep if its diet and environment are well maintained and matured.  They do well in an environment that has consistent water, quality, temperature, decor and tank mates.  It can be housed in a fish only tank or in a reef environment, but on occasion they have been known to nip various corals/inverts.  (See Social Behaviors)  Provide plenty of space, especially for adult specimens, along with lots of rocks/ corals with crevices for retreating, feeding from and for sleeping.  All surgeonfish need an aquarium with plenty of aeration, a strong current will help to provide good oxygenation.  

   Surgeonfish and tangs are continuous feeders and they need to be provided a proper diet. They are susceptible to nutritional disorders which may cause color loss and LLD (lateral line disease) and bacterial infections resulting from poor water quality.  Consequently they will need vigorous filtration, protein skimming, and regular small water changes.  Tangs do not produce as much skin mucus on their bodies as other fish and can be susceptible to diseases such as Marine Ich and Marine Velvet. Surgeonfish are definitely a candidate for quarantine when you first receive them. (See Diseases)

• Aquarium Hardiness: Moderately hardy – Very hardy once settled and fed an herbivorous diet.
• Aquarist Experience Level: Beginner

Foods and Feeding

   Yellow Tangs are herbivores. In the wild, they feed on filamentous algae which they scrape from hard surfaces.  Stomach contents on fishbase.org only reveal algae and nothing else.  This genus can store fat in their body cavities so may go through periods of non-feeding.
   In the aquarium, the majority of their intake will be vegetable matter, and they will eat some copepods living within the algae they eat, but they do not need meaty foods as a main meal.  Provide lots of marine algae, prepared frozen formulas containing algae or spirulina, frozen brine and mysid shrimp, and flake foods. Japanese Nori or other seaweed can be adhered to the aquarium glass with a vegetable clip.  Culturing macro algae like chaetomorphia in the tank is also a great idea. Feed 3 times a day, (more for juveniles) in smaller amounts instead of a large quantity once a day. As continuous grazers, they will benefit from this and it will also keep the water quality higher over a longer period of time.

   Providing a vitamin supplement (including vitamin C) can help provide for their nutritional needs, and vitamin C can help prevent or reduce Lateral Line Erosion (LLE). This can be done by soaking dried pellets with liquid vitamins, adding vitamins to the food, or adding a liquid vitamin into the water. It is also said that pellets soaked in garlic may help fend off Marine Ich. Some hobbyists also report success with supplemental foods such as previously boiled or frozen zucchini, broccoli, spinach, and leaf lettuce.  Feeding marine based algaes are best because they are much more dense in calories and nutrition.

• Diet Type: Herbivore
• Flake Food: Yes
• Tablet / Pellet: Yes
• Vegetable Food: All of Diet
• Meaty Food: Some of Diet – VERY little, and only if there are no live organisms living in the algae they feed from.
• Feeding Frequency: Several feedings per day – 3 times a day, juveniles more.

Aquarium Care

   A large and quick agile swimmer it will spend a good deal of its time in the open water and moving in and out of crevices. 

Reef tanks:
-Medium sized up to 90 gallons, perform 15% bi-weekly. 
-Large Tanks 100 gallons and over, once water is aged and stable can be changed 10% bi-weekly to 20% monthly, depending on bioload.

Fish only tanks:*
-Medium sized up to 90 gallons, perform 20% to 30% monthly depending on bioload. 
-Large Tanks 100 gallons and over, once water is aged and stable can be changed 20% to 30% every 6 weeks depending on bioload.

For more information on maintaining a saltwater aquarium see: Saltwater Aquarium Basics: Maintenance. A reef tank will require specialized filtration and lighting equipment. Regular water changes done  bi-weekly will help replace the trace elements that the fish and corals use up.  

*Note:  If this is the ONLY fish in the tank, with no corals or other fish you can get away 20% monthly.

• Water Changes: Bi-weekly

Aquarium Setup

    Your happy Yellow Tang needs a minimum tank size of 125 gallons by the time they are 5″ long, and the tank should be at least 6 feet long due to their active swimming habits.  Juveniles that are very small (up to 5″) can be started out in a 75 gallon tank that is 4 feet long.  To feel secure they also need rocks and corals with many nooks and crannies to hide in and to wedge themselves into at night for sleeping.  Provide areas that are large enough for them to sleep in as they grow.  Provide an open area towards the top for them to swim in as well.  It will mainly graze on algae if it is available.  Keep corals glued down, as their quick speeds may topple a coral or two.  Because they thrive well in tanks with algae growth, the tank should be mature and if it is a fish only tank, provide lighting to help algae growth.  The temperature they prefer is 74 to 82˚F (24 to 28˚C), which is higher than many tangs, making them easier to care for.  Provide normal ocean salinity of at least 1.023, and a pH that is 8.1 to 8.4.   Provide an area of strong linear water flow for them to swim against and be sure the water quality stays high.  They are found on all levels of the tank.  Tangs produce a lot of waste, so the larger the tank, the easier it is to keep clean.  A strong skimmer and good filtration is recommended for long term health.

• Minimum Tank Size: 125 gal (473 L) – 75 gallons only for juveniles up to 5″
• Suitable for Nano Tank: No
• Live Rock Requirement: Typical Plus Hiding Places
• Substrate Type: Any
• Lighting Needs: Moderate – normal lighting – Enough to encourage algae growth.
• Temperature: 75.0 to 82.0° F (23.9 to 27.8&deg C) – They can tolerate higher temps than many tangs.
• Breeding Temperature: – Unknown
• Specific gravity: 1.023-1.025 SG
• Range ph: 8.1-8.4
• Brackish: No
• Water Movement: Strong
• Water Region: All

Social Behaviors

   Yellow Tangs are probably the mellowest, being about a 2-3 on the scale of 1 to 10, with 10 being the most aggressive Zebrasoma genus.  While they are listed as more semi-aggressive, they do not bother other fish, unless the tank is too small.  There should only be one Yellow Tang per tank, unless the tank is hundreds of gallons and several juveniles are added at once.  Do not keep with others from this genus unless the tank is over 400 gallons, in which case they could be housed with the Purple Tang and Black Longnose Sailfin Tang.

   If you wish to house them with other tangs, choose those who eat different foods, look different and are from different genus.  One example of mixing tangs, would be Yellow Tang, Naso Tang (more of a planktivore/herbivore), Yelloweyed Kole Tang (detritus eater), and a Hippo Tang (planktivore/herbivore).  These tangs are from different genus’ and this can be done in a tank that is 400 gallons or more (due to the size of those other tangs listed).  Adding them together as juveniles is best (again adding the bristletooth first), rather than adding a new one later when territories have been established.  Though a large aquarium can help alleviate many problems, be aware of the social behaviors of any species you are considering to prevent compatibility problems with other tangs.  Adding a tang to a tank that already has tangs that have staked out there territory can cause problems, however, rearranging rock work can help alleviate the stress.  There will be aggression towards the new tang, so keep an eye on their behavior and remove them if they are constantly hiding or up in the corner of the tank.  Avoid triggers, puffers, and other aggressive fish which can stress your tangs out.  If your tang is “posturing” and using his scalpel to whack a tank mate, then remove that tank mate or the tang.

   The Yellow Tang will graze on various algae, but prefer filamentous algae, so can be an asset to a reef environment keeping corals free of algae encroachments!  The downside is that have been occassionally known to nip on large polyp stony corals.  They have been known to occasionally go after star polyps, gorgonians, and zooanthid if not well fed.

  Some inverts are also at risk.  Zebrasoma have been known to pick on the mantels of clams.  They have been known to eat very small fan worms and have accidentally chewed through the tubes of Feather Dusters that had algae on them.  Hiding the tube worm’s base can help alleviate this problem. 

• Venomous: No – Juveniles have the venom, however adults lose it.
• Temperament: Semi-aggressive – Peaceful toward non-tangs in appropriately sized tangs.
• Compatible with:
  • Same species – conspecifics: Yes – Added as juveniles in tank that is hundreds of gallons.
  • Peaceful fish (gobies, dartfish, assessors, fairy wrasses): Safe
  • Semi-Aggressive (anthias, clownfish, dwarf angels): Safe
  • Monitor – Large damselfish may be too aggressive to a juvenile and subadult, especially if they eat the same foods.
  • Large Semi-Aggressive (tangs, large angels, large wrasses): Monitor – Avoid other Zebrasoma, aggressive tangs or large angels that eat the same foods.
  • Large Aggressive, Predatory (lionfish, groupers, soapfish): Monitor – These fish, including frogfish and toadfish should be smaller than the tang or it will be eaten.
  • Monitor – They will not bother mandarins and seahorses and pipefish should have their own tank.
  • Anemones: Safe
  • Mushroom Anemones – Corallimorphs: Safe
  • LPS corals: Monitor – They have been known to nip at LPS.
  • SPS corals: Safe
  • Gorgonians, Sea Fans: Monitor – They may occasionally nip if not well fed.
  • Leather Corals: Safe
  • Soft Corals (xenias, tree corals): Safe
  • Star Polyps, Organ Pipe Coral: Monitor – They may occasionally nip if not well fed.
  • Zoanthids – Button Polyps, Sea Mats: Monitor – They may occasionally nip if not well fed.
  • Sponges, Tunicates: Safe
  • Shrimps, Crabs, Snails: Safe
  • Starfish: Safe
  • Feather Dusters, Bristle Worms, Flatworms: Monitor – Some species have been known to chew through the Feather Dusters tube as they eat algae stuck to it.
  • Clams, Scallops, Oysters: Monitor – May nip mantles if not well fed.
  • Copepods, Amphipods, Mini Brittle Stars: Safe

Sex: Sexual differences

   The male Zebrasoma is larger than the female and the males have white setae (hair-like bristles) in front of their peduncular spines.  Females also have larger cloacas (reproductive/intestinal opening) than males. 

Breeding / Reproduction

   Male and female Zebrasoma tangs have been known to spawn in groups, having multiple partners; however, they have also been seen spawning only in pairs.  Large groups will start to form right before they spawn, as males start changing color.  This all coordinates with the lunar cycle in winter or early spring, however in warmer waters it can occur all year long.  Once they have shot up to towards the surface and released their gametes, the eggs form and are very small, less than 1 mm; with a single oil droplett that helps them stay afloat.  They hatch in only 24 hours and the larvae are poorly developed.  The order in which they form into a recognizeable Yellow Tang is a step by step process.  First they develop serrate ridges on the head, then the pelvic fin and second dorsal spines form followed by a second anal spine.  Next, the head and body deepen becoming kite-shaped, with a long pelvic spine, dorsal spine and anal spine.  After that, triangular scales appear in vertical rows on the body and last, the juvenile coloring starts to show along with the base of their tail fin forming their little spine or scalpel.  At this point, they are ready to settle into the reef and have to wait 1 to 2 years before they can have their own offsrping.

   Some species of surgeonfish have spawned in public aquariums and there have been a few scattered reports of spawning in home aquariums, but regular spawning and the rearing of the young has not yet been reported.

​   For information on breeding and the development of the fry, see: Marine Fish Breeding: Tangs.

• Ease of Breeding: Unknown

Fish Diseases

   Tangs produce less body slime than other saltwater fish and have been termed “dry skinned” fish by some.  This makes them very susceptible to Cryptocaryon (saltwater ich) and other diseases.  The most common ailments are bacterial diseases, Lateral Line Disease, and parasitic infections such as protozoas (including Cryptocaryon), worms, etc.  

   For Crypt, in the wild a cleaner wrasse (Labroides sp.) will help them by taking parasites from their bodies, however these wrasses are extremely difficult to sustain in captivity. Alternative fish such as Neon Gobies (Gobiosoma spp.) or cleaner shrimp can help them by providing this cleaning service in the home aquarium.  As for treatment, some tangs are sensitive to copper because they have an important microfauna in their digestive system, soprolonged or continuous use of a copper treatment is not advisable.  It is also said that pellets soaked in garlic may help fend off Marine Ich

   Providing a vitamin supplement (including vitamin C) can help provide for their nutritional needs, and vitamin C can help reduce Lateral Line Erosion (LLE) which may be caused by activated carbon. Enriching foods can be done by soaking dried pellets with liquid vitamins, adding vitamins to the food, or adding a liquid vitamin into the water.  Some hobbyists also report success with supplemental foods such as previously boiled or frozen zucchini, broccoli, spinach, and leaf lettuce.

  The best routine is a quarantine tank and a stress free environment with good quality veggie foods, places to hide and a quiet area for the aquarium.  

   Diseases that Surgeonfish and Tangs are susceptible to:
Marine Ich (white spot disease), Marine Velvet and Lateral Line Erosion (LLE)

   For more information see Fish diseases.

Availability

http://www.int-res.com/articles/meps/134/m134p015.pdf  The Yellow Tang or Yellow Sailfin Tang is readily available at retailers and is inexpensive. They are priced starting at about $35.00 USD (Jan 2015).

References

MARINE FISH AND REEF 
2006 ANNUAL Beautiful and Hardy Surgeonfish
By Nick Ireland
Copyright © 2005 by BowTie, Inc. All rights reserved

WEBSITES:
ADVANCED AQUARIST’S ONLINE MAGAZINE
The feel-good story of Yellow Tangs in the wild
by Leonard Ho
Copyright © 2002-2015 by Pomacanthus Publications, LLC, all rights reserved.
AQUARIUM FISH:   Activated carbon affirmed as causative agent for HLLI disease
By Leonard Ho 
Copyright © 2002-2013 by Pomacanthus Publications, LLC, all rights reserved.

AQUARIUM FISH:  Surgeonfishes, A.K.A. the Tangs
By James W. Fatherree, M.Sc.
Copyright © 2002-2013 by Pomacanthus Publications, LLC, all rights reserved.

FISHCHANNEL
Hexamita:  Fish Hole in the Head Disease
By Neale Monks, Ph.D.
Copyright ©2013 I-5 Publishing, LLC. All rights reserved

IUCN REDLIST

INT-RES.COM
Growth and longevity in acanthurid fishes; an analysis of otolith increments 
J. H. Choat*, L. M. Axe 
Department of Marine Biology, Jarnes Cook University, Townsville, Queensland 481 1, Australia