Reproduced from Marine Aquarium Advice:
Yellow Tangs - Zebrasoma Flavescens
Mellow Yellow.. Maybe Not
By: Terry D. Bartelme
When marine aquarists talk about some of their favorite species of fish the Zebrasoma flavescens, commonly known as Yellow tangs, is bound to come up sooner or later. Although the clownfish family is probably the most-sought after group of fish, Yellow tangs may just be the most widely kept single species of reef fish. They are frequently imported in sizes as small as 2 in. and can grow to about 8 in. in length.
What makes them so wildly popular? I think that their bright yellow coloration with a white stripe through their body is the first thing that catches people's attention. Once they have your attention they can keep it with their quirky and amusing behavior. This fish seems to be excited most of the time. They are interested in whatever is going on inside and often outside of the aquarium. They are usually the first to inspect a new rock, invertebrate or fish in their tank.
This species likes to take ownership of their tank and they will let you know if they don't approve of whatever is going on. They are likely to nip it, flip it, chase it, bully it, or generally try to intimidate newcomers when they are introduced into the aquarium. The last thing I would expect them to do is ignore a new neighbor. Once they have established some ground rules (like don't go near my favorite sleeping place) they will occasionally check to see if the other fish are behaving themselves.
I bought my first and only Zebrasoma flavescens in 1975. This was before many people (including myself) understood their needs and how to keep them happy and healthy. It didn't take me long to know I was doing something wrong. My Yellow tang seemed to be getting thinner, even though I fed all the fish generously twice a day. I started offering smaller feedings several times a day. I also soon figured out that my tang was not as tolerant of less-than-ideal water conditions as my other fish.
My tank was overcrowded because all the fish I kept were ravenous eaters that produced a lot of waste. It was a 75-gallon tank that contained a Panther grouper, Blueface angel, and a batfish along with the tang. Don't try this at home friends, I was guilty out of ignorance. Back then there wasn't as much information available about the space requirements of these fish. Overstocking caused me to struggle to keep the pH above 8.0. If the pH was too low my Yellow tang would let me know right away because its color would fade. Sometimes it would begin to get a pinkish hue or red around the fins. Just like magic, the coloration would return to normal shortly after a water change.
Habitat
Yellow tangs will spend most of the time out in the open. Size does matter when it comes to choosing an aquarium to house them. A 4-ft.-long tank is a minimum for a small specimen. Consider the fact that they will grow and a larger one should be kept in an aquarium that is 100 gal. or more. They will suffer from confinement stress in smaller tanks. Provide them with lots of swimming room and several nooks and caves so they can chose a favorite place to sleep or hide. They are strong swimmers and in the wild they can be found in areas with brisk water movement. Their natural habitat is in areas of intense light where the algae they feed upon can be found.
Feeding
This species is usually always ready to eat. If you can't feed them small amounts several times a day then keep some type of algae available in the aquarium throughout the day. They will eat a wide variety of fresh, frozen, freeze dried, live, flake and prepared foods. The mainstay of their natural diet is algae, but they will often eat the meaty foods first if given the choice. Feed them foods like Formula Two™, spirulina, or algae before offering the meaty foods. You can supplement the diet with foods like blanched or frozen broccoli, peas, shredded carrot and romaine lettuce, but foods that are found in the ocean are a better choice. Enrich the diet by adding vitamins, fatty acids, etc. I prefer to soak the food alternately with Zoe™ or Selcon™. Freeze-dried foods are especially absorbent. If you tang's color is fading then it probably needs more carotennoids and algae in its diet. These guys are fast eaters so they can hold their own at mealtime. Less aggressive eaters may not get enough to eat especially if they share the same kind of dietary needs.
Compatibility
Yellow tangs will usually try to bully anything that will let them. Avoid mixing them with tangs that have a similar color or shape, because they will squabble. They have a white scalpel on each side near the tail that can inflict deep wounds. Zebrasoma flavescens do best when kept singly. It is possible to keep a small school of this species in the large aquarium. Their aggression will be dissipated throughout the group. However, do not attempt to keep two Yellow tangs in the same aquarium. They may fight one another until one becomes sick and dies.
Selecting a healthy specimen
There are several things that you should observe when selecting a Zebrasoma flavescens. Watch for behaviors that would indicate the physical condition of the fish. Eating is a good sign! Does the fish swim normally? Can it hold its fins erect or are they held close to the body? Does it scratch itself on the rocks or sand? Is the respiration steady and at a normal pace? Choose a fish that spends most of the time swimming out in the open.
How is the body weight? The stomach area of Yellow tangs often appear to be pinched. This means they haven't gotten enough to eat lately. A lot of them look this way when they arrive at the retailer. Be more concerned with the area above and behind the eyes. Loss of weight in the upper body indicates long-term starvation. Their colors should be bright. Check for all the usual indicators of injury or disease such as torn fins, cloudy eyes, and missing scales. Fish that have white or black spots that looked like they have been sprinkled with salt or pepper are infected with parasites.
This species seems to adapt better to handling and captivity than other tangs when they are small. Just be sure to offer them food frequently if they are only about three inches long.
Special care
Tangs can easily become badly entangled in nets. This can result in injury. Try to herd them into a plastic bag or container whenever you move them.
Pay special attention to the oxygen level in your aquarium. A tang will be among the first to expire if there's not enough oxygen available. Keep the water circulation strong and maintain good water-surface agitation. This will help ensure an active gas exchange between the water and surrounding atmosphere. A powerful protein skimmer will help to keep the oxygen level high and the amount of dissolved organics in the water low.
Diseases
Yellow tangs have a reputation for being susceptible to parasites. Aquarists certainly seem to have their share of problems in this area. Does this mean that tangs in general are delicate fish? No, many species of tangs are quite hearty, including the Zebrasoma flavescens, provided their minimum requirements are met. The problem is that in all too many instances they do not receive an adequate diet, or their needs for a proper habitat, high water quality and compatible tankmates are not met. These unmet needs all contribute stress. This reduces their immune system function making the fish more susceptible to infections. This can be particularly true when high levels of dissolved organics (DOC) are allowed to accumulate in the water. Opportunistic bacteria will readily reproduced in this food rich environment. As the numbers of bacteria in the water multiply, so does the likelihood of microbial infection. Be on the alert for red or pinkish streaks and faded colors that can indicate a bacterial infection (most often vibriosis).
Summary
Are Yellow tangs for everyone? I don't think any one species of fish makes a good choice for every marine aquarist. People seem to either love them or hate them. Sometimes they can wear their welcome thin with their obnoxious, aggressive behavior. Beginners should avoid them for the first six months or more in favor of hardier species of fish. Can they be a great addition to your aquarium? Absolutely, they are popular for good reason. There are active, good eaters, can be kept in reefs or fish-only systems, are compatible with a large variety of fish and are rarely boring. Weigh the pros and cons carefully and consider the zebrasoma flavescens or yellow tangs compatibility with the other fish you intend to keep.
Copyrights: Terry D. Bartelme, 2000
Terry D. Bartelme
Manuscript length: Approximately 1,500 word
-- i just wanted to check
