[Ebook] Encyclopedia of Aquarium & Pond Fish – Directory of Marine Fish – Surgeonfish and tangs

Directory of Marine Fish

Surgeonfish and tangs

These fish commonly include significant amounts of algae in their diet—in fact, the word “tang,” which is applied to smaller members of the group, is an abbreviation of the German Seetang, meaning “seaweed.” Just like land herbivores, these fish have beneficial populations of bacteria in their alimentary tracts to assist the breakdown of plant matter. Medications, especially those containing copper, need to be used very carefully so as not to wipe out these organisms and compromise the fish’s ability to digest its food.

White-Faced Surgeonfish (Acanthurus japonicus)

• ORIGINS: The tropical western Pacific, ranging from northern Australia, via Indonesia, and up to Japan.
• SIZE: 8 in (20 cm).
• DIET: Predominantly vegetarian.
• WATER: Temperature 79–82°F (26–28°C); alkaline (pH 8.1–8.3) with SG 1.021–1.024.
• TEMPERAMENT: Intolerant of its own kind.

This brightly colored surgeonfish has yellow, blue, and green areas on its tail, as well as a prominent reddish-orange stripe that arcs around the rear of the dorsal fin. The white on the face allows this tang to be distinguished from the related Powder Brown (A. nigricans). The WhiteFaced is easier to keep than the Powder Brown because it adapts more readily to an artificial diet.

Achilles Tang (Acanthurus achilles)

• ORIGINS: Occurs in more temperate, as well as tropical, parts of the western Pacific.
• SIZE: 11 in (28 cm).
• DIET: Predominantly vegetarian.
• WATER: Temperature 79–82°F (26–28°C); alkaline (pH 8.1–8.3) with SG 1.021–1.024.
• TEMPERAMENT: Intolerant of its own kind.

The vibrant red markings of the Achilles Tang make an attractive contrast with its overall mattblack coloration. The red blotch at the rear of the body extends to the caudal peduncle, while a red bar runs across the tail, and red stripes bordered by white extend along the bases of the dorsal and anal fins. White is also evident on the gill covers. The head has a very rounded profile, with the lips being prominent to help rasp algae from rocks.

Chocolate Surgeonfish (Acanthurus pyroferus)

• ORIGINS: From northern Australia to the southern and eastern Asiatic coasts, and out into the Pacific.
• SIZE: 8 in (20 cm).
• DIET: Predominantly vegetarian.
• WATER: Temperature 79–82°F (26–28°C); alkaline (pH 8.1–8.3) with SG 1.021-1.024.
• TEMPERAMENT: Intolerant of its own kind.

In spite of its name, the Chocolate Surgeonfish can be decidedly yellow, bearing some resemblance to the Yellow Sailfin Tang (see p.238). These species can be distinguished quite easily, however, since the mouthparts of the Chocolate Surgeonfish are shorter and more compact, while the dorsal fin has a more rounded and less angular shape.

Powder Blue Tang (Acanthurus leucosternon)

• ORIGINS: East Africa, via the Indo-Pacific, to Southeast Asia, including Indonesia and the Philippines.
• SIZE: 9 in (23 cm).
• DIET: Predominantly vegetarian.
• WATER: Temperature 79–82°F (26–28°C); alkaline (pH 8.1–8.3) with SG 1.021–1.024.
• TEMPERAMENT: Intolerant of its own kind.

This is one of the most stunningly colored tangs, but it does not always acclimatize to aquarium conditions, being prone to parasitic infections. The body is primarily blue, but the face is darker, and there is a white area under its mouth that extends to the base of the jaws. Try culturing marine algae, especially at the outset, to guarantee a constant supply for this fish.

Orange-Shoulder Surgeonfish (Acanthurus olivaceus)

• ORIGINS: Ranges from the coast of Southeast Asia eastward out into the Pacific.
• SIZE: 10 in (25 cm).
• DIET: Predominantly vegetarian.
• WATER: Temperature 79–82°F (26–28°C ); alkaline (pH 8.1–8.3) with SG 1.021–1.024.
• TEMPERAMENT: Intolerant of its own kind.

The juvenile of this species (see below) is yellow, but its body develops a greener hue with age. All individuals display the characteristic orange marking that extends back from the top of the gills and are blue near the jaws. The “shoulder patch” becomes more prominent in older fish. Good water quality and effective filtration, supported by regular partial water changes, are essential to ensure good health in this species.

Convict Surgeonfish (Acanthurus triostegus)

• ORIGINS: Extends from East Africa through the IndoPacific and eastward out into the Pacific.
• SIZE: 11 in (27 cm).
• DIET: Predominantly vegetarian.
• WATER: Temperature 79-82°F (26–28°C); alkaline (pH 8.1-8.3) with SG 1.021–1.024.
• TEMPERAMENT: Intolerant of its own kind.

The Convict Surgeonfish gets its name from the pattern of bold, black stripes on a bluish background, which is reminiscent of an old-fashioned jail uniform. There are six black stripes in total, not including the black marking on the caudal peduncle. Although Convict Surgeonfish are seen in shoals on the reef, they will not thrive if housed as a group in the aquarium, often disagreeing violently.

Clown Surgeonfish (Acanthurus lineatus)

• ORIGINS: Extends from East Africa, via the Indo-Pacific and Indonesia, into the Pacific.
• SIZE: 15 in (38 cm).
• DIET: Predominantly vegetarian.
• WATER: Temperature 79–82°F (26–28°C); alkaline (pH 8.1–8.3) with SG 1.021–1.024.
• TEMPERAMENT: Intolerant of its own kind.

The colorful, striped pattern of the Clown Surgeonfish allows this species to be identified easily. The stripes run in roughly horizontal lines along the sides of the body. Individual variations in the patterning occur, especially near the caudal fin, where vertical markings are likely to be evident. The stripes themselves are blue and yellow, separated by black lines. They do not extend over the entire body, however, with the keel of the body being a contrasting shade of light blue. Bright, vibrant coloration suggests a healthy individual. The Clown Surgeonfish requires a large aquarium, in view of its potential size when full grown. This fish should be offered a range of supplementary plant matter on a regular basis, since it cannot sustain itself on just the algae in the aquarium.

SURGEON’S SCALPEL

The name of this family—Acanthuridae—is derived from the Greek words for “spine” and “tail,” referring to the distinctive spines on these fish. The spines are located on each side of the body near the caudal peduncle, although not all are as colorful as the example shown here on a Sohal Surgeonfish (see p.238). It is because of the sharpness of these spines, which resemble the blade of a scalpel, that the popular name of surgeonfish was coined for this group. In the wild, the spines have a defensive role, protecting the fish from attack, and their bright, contrasting colors serve as a warning to would-be predators.

Sohal Surgeonfish (Acanthurus sohal)

• ORIGINS: Also known as the Red Sea Clown Surgeon because it is confined to the waters of the Red Sea.
• SIZE: 15 3⁄4 in (40 cm).
• DIET: Primarily plant-based foods.
• WATER: Temperature 79–82°F (26–28°C); alkaline (pH 8.1–8.3) with SG 1.021–1.024.
• TEMPERAMENT: Intolerant of its own kind

Closely set, horizontal, yet slightly wavy lines along the body help to identify this fish, along with a vibrant orange spine that stands out clearly near the base of the caudal peduncle. In spite of its large size, the Sohal Surgeon is essentially vegetarian. It feeds on algae in the wild, and persuading it to take artificial substitutes may be problematic. Do not mix this fish with other related species, since it is potentially aggressive.

Blue Tang (Paracanthurus hepatus)

• ORIGINS: Ranges widely from East Africa through the Indian Ocean and across much of the Pacific.
• SIZE: 10 in (25 cm).
• DIET: Mainly vegetarian.
• WATER: Temperature 79–82°F (26–28°C); alkaline (pH 8.1–8.3) with SG 1.021–1.024.
• TEMPERAMENT: Do not mix with any related fish.

The striking coloration and patterning of the Blue Tang, as well as the relative ease with which it can be kept, have made it a firm favorite with aquarists. The markings are distinctive, with a black stripe running through the eye to the tail on each side of the body, and looping around beneath to create a blue oval bordered by black. The tail is yellow, with black edging at top and bottom. On the reef, small shoals of Blue Tangs can be seen feeding in areas of profuse algal growth. However, they will be less social in the confines of an aquarium, unless the tank is very large. It is usually possible to wean these tangs onto a variety of foods, but initially they will instinctively seek out vegetable matter. Their aquarium should therefore be established well in advance of their introduction. It also needs to be very well lit, in order to ensure continued growth of marine algae on the rockwork and elsewhere.

Sailfin Tang (Zebrasoma xanthurum)

• ORIGINS: Another member of this group with distribution restricted to the Red Sea.
• SIZE: 8 1⁄2 in (22 cm).
• DIET: Mainly vegetarian.
• WATER: Temperature 79–82°F (26–28°C); alkaline (pH 8.1–8.3) with SG 1.021–1.024.
• TEMPERAMENT: Intolerant of its own kind.

The Sailfin Tang has a relatively oval, disklike shape. The upper part of the body and the anal fin have a distinctive blue coloration, while the caudal fin is bright yellow. The remainder of the body is darker, with speckling on the face, and the pectoral fin behind the gills is edged with yellow. Like other tangs, the Sailfin Tang will spend the day busily seeking food, before finding a suitable cave where it can shelter during the night.

Yellow Sailfin Tang (Zebrasoma flavescens)

• ORIGINS: From the Great Barrier Reef, off Australia’s eastern coast, across much of the Pacific.
• SIZE: 6 in (15 cm).
• DIET: Mainly vegetable matter.
• WATER: Temperature 79–82°F (26–28°C); alkaline (pH 8.1–8.3) with SG 1.021–1.024.
• TEMPERAMENT: Usually compatible with invertebrates

The brilliantly colored Yellow Sailfin Tang has a narrow, flattened body shape. It naturally feeds on algae and will require vegetable substitutes to supplement its diet in aquarium surroundings. When servicing the aquarium, be careful not to get caught by the white spine, which is located near the base of the caudal peduncle.

Pacific Sailfin Tang (Zebrasoma veliferum)

• ORIGINS: Much of the tropical Pacific region, eastward from southeast Asia and Australia’s Great Barrier Reef.
• SIZE: 16 in (40 cm).
• DIET: Vegetable matter, plus some meat-based foods.
• WATER: Temperature 79–82°F (26–28°C); alkaline (pH 8.1–8.3) with SG 1.021–1.024.
• TEMPERAMENT: Not well disposed toward its own kind.

The striped patterning of the Pacific Sailfin Tang varies markedly through its range, with some individuals being more brightly colored than others. Age is also significant: young fish are predominantly yellow with dark banding, while in adults, the color scheme is reversed. The tall, backward-sloping dorsal fin above and the curved anal fin below give the Pacific Sailfin a disklike appearance.

LOST IN THE CROWD

Aquarists may be puzzled that tangs such as these Yellow Sailfins (see opposite) can live in groups on the reef, even spawning communally in some cases, without serious quarrels developing, yet they cannot be housed together safely in the aquarium. Associating in groups helps to decrease the tangs’ natural levels of aggression. The large number of fish means that particular individuals come into contact with each other less frequently, so the risk of conflict is reduced. In the tank, where usually only two or three tangs are housed together, the scope for bullying is greater.

Brown Tang (Zebrasoma scopas)

• ORIGINS: From the Red Sea eastward through the IndoPacific through to the east Pacific.
• SIZE: 8 in (20 cm).
• DIET: Predominantly vegetarian.
• WATER: Temperature 79–82°F (26–28°C); alkaline (pH 8.1–8.3) with SG 1.021–1.024.
• TEMPERAMENT: Young fish rarely get along well together.

When Brown Tangs are young, they are yellow and may be confused with the Yellow Sailfin (see opposite). The coloration of these fish darkens as they mature, except for the white spine on each side of the caudal peduncle. The teeth in the small mouth are for grazing on algae and plankton, which form the basis of their diet in the wild. Healthy specimens have hearty appetites.

Unicorn Tang (Naso unicornis)

• ORIGINS: Extends from the Red Sea through the IndoPacific region and into the eastern Pacific.
• SIZE: 28 in (70 cm).
• DIET: Primarily requires vegetable matter.
• WATER: Temperature 79–82°F (26–28°C); alkaline (pH 8.1–8.3) with SG 1.021–1.024.
• TEMPERAMENT: Intolerant of its own kind.

The distinctive horn extending from between the eyes explains the common name of this fish. The horn is not evident in young individuals, which are also not so brightly colored. Well-oxygenated water is essential for unicorn fish, just as it is for other tangs. A lack of oxygen will cause them to sink to the bottom, where they will lie on their side and breathe heavily. Unicorn Tangs are very active and need plenty of space in order to thrive.

Naso Tang (Naso lituratus)

• ORIGINS: Extends from the Red Sea through the Indian Ocean to the eastern Pacific.
• SIZE: 18 in (45 cm).
• DIET: Primarily vegetable matter.
• WATER: Temperature 79–82°F (26–28°C); alkaline (pH 8.1–8.3) with SG 1.021–1.024.
• TEMPERAMENT: Do not mix with similar fish.

This large tang has striking yellow patterning on the forehead, with stripes running down the sides of the face and on the outer trailing edge of the caudal fin. The spine and the adjacent area around the tail are orange. Juveniles are duller in color, being primarily grayish with a plain-colored caudal fin. Naso Tangs occur not only on the reef but also in the open ocean. They need a large tank with a good circulation of water. They can be accommodated in a reef aquarium, but bear in mind that despite what seems like almost constant foraging, there will not be enough plant matter growing there to sustain these fish. They must eat large quantities of food in order to maintain good bodily condition, since their natural food has a relatively low nutritional value. Dietary supplements can include some meat-based foods as well as vegetable matter.

[Ebook] Encyclopedia of Aquarium & Pond Fish – David Alderton (Photo by Max Gibbs)