[Ebook] Encyclopedia of Aquarium & Pond Fish – Directory of Marine Fish – Damselfish

Directory of Marine Fish

Damselfish

These hardy fish are often recommended as the initial occupants of a newly established marine aquarium. Many species of damselfish adapt well to the fluctuations in water chemistry that will inevitably occur until the filtration system is fully established. In addition, damselfish are easy to feed, and they can also be kept in small groups when young. However, once settled in their quarters, they are likely to become more territorial by nature, which can lead to the bullying of weaker individuals. There is a large number of species, some of which are very similar, and distinguishing between them is not always straightforward.

Domino Damselfish (Dascyllus trimaculatus)

• ORIGINS: The Pacific, from southeast Asia to southern Japan and eastern Australia, extending to Oceania.
• SIZE: 2 1⁄2 in (6.25 cm).
• DIET: Eats most marine foods, including flake.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.
• TEMPERAMENT: Territorial by nature.

The white markings on a black background are reminiscent of the spots on a domino, but this characteristic is seen only in juveniles. As the fish mature, they become grayer and the spots fade. Young Dominos often seek the protection of sea anemones, forming a relationship similar to but less permanent than that seen in their relatives, the clownfish.

Cloudy Damsel (Dascyllus carneus)

• ORIGINS: The Pacific region adjacent to southeast Asia, north to southern Japan and south to eastern Australia.
• SIZE: 3 1⁄4 in (8 cm).
• DIET: Takes fresh and dried marine foods.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.
• TEMPERAMENT: May quarrel with its own kind.

The body patterning of this fish, which is predominantly grayish with blue spots, is less distinct than in most other damselfish, giving rise to its common name. This species can sometimes be confused with the Reticulated Damselfish (D. reticulatus), although the latter can be identified by a dark band that extends vertically down the rear edge of the body.

Three-Stripe Damsel (Dascyllus aruanus)

• ORIGINS: Extends from the Red Sea eastward through the Indo-Pacific region to the east coast of Australia.
• SIZE: 3 1⁄4 in (8 cm).
• DIET: Marine foods, including flake.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.
• TEMPERAMENT: Intolerant of other damselfish.

This damselfish resembles the Blacktail Damsel (see opposite, top left), but it can be distinguished by the black edging on the dorsal fin and its white caudal fin. Three-Striped Damselfish can be quarrelsome among themselves, especially as they grow older. If an individual is harassed, it should be removed from the aquarium.

Blacktail Damsel (Dascyllus melanurus)

• ORIGINS: The Pacific region, extending from eastern Asia and Australia eastward to the reefs of Oceania.
• SIZE: 4 in (10 cm).
• DIET: All types of marine food.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.
• TEMPERAMENT: Bullying can be a problem.

The Blacktail is one of several damselfish with a predominantly black-and-white striped pattern. It will sample virtually all types of food, but take extra care not to overfeed this and other damselfish in a newly established tank, since rotting food scraps are likely to seriously decrease the water quality. Regular monitoring of the water is essential to safeguard the health of the fish.

Black Neon Damsel (Neoglyphidodon oxyodon)

• ORIGINS: The Pacific region off the shores of eastern Asia down to Australia, and north to southern Japan.
• SIZE: 3 in (7.5 cm).
• DIET: A varied range of marine foods.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.
• TEMPERAMENT: Territorial by nature.

The Black Neon has horizontal wavy blue lines on its head and also farther down the body on its flanks. A contrasting yellow vertical stipe extends over the back. Although the blue stripes may become less vivid with age, overall loss of color in Abudefduf damsels is not necessarily a sign of poor health, since it can also be associated with male fish coming into spawning condition.

SAFETY IN SHOALING

Shoaling in a particular area of the reef, typically close to a “head” of coral, is an important survival technique used by damselfish. Rather than relying on just its own senses for survival, each individual benefits from the combined alertness of the group. When danger is detected, the shoal darts back into the shelter of the coral, almost as if it were a synchronized movement. The sudden flash of stripes or contrasting colors gives added protection, making it difficult for predators to select a victim from the mass of fleeing bodies.

Scissor-Tail (Abudefduf sexfasciatus)

• ORIGINS: Northeast coast of Africa, in the northern and western parts of the Indian Ocean and in the Red Sea.
• SIZE: 6 in (15 cm).
• DIET: Flake and other prepared foods.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.
• TEMPERAMENT: Not to be trusted with its own kind.

These damsels display a series of bold, vertical black stripes down the body. There is also a small, broad stripe at the base of the caudal peduncle, with black stripes running from here in a more horizontal fashion along the tail forks. These features help to distinguish the Scissor-Tail from similarly patterned species. In addition, the dark head stripe tends to extend only to the eye, rather than down to the throat.

Sergeant Major (Abudefduf saxatilis)

• ORIGINS: Circumtropical range through the Indian and Pacific Oceans, as well as the Atlantic.
• SIZE: 6 in (15 cm).
• DIET: Thawed, fresh, and dried foods.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.
• TEMPERAMENT: Forms a dominance hierarchy.

The huge range of these striped damselfish means that they have been split into three distinct species, based essentially on their distribution, although the appearance of the adults is virtually identical around the globe. Differences are most marked in juveniles, with those from the Atlantic being silvery and having yellow upperparts to their body. As the name suggests, Sergeant Majors may bully other fish, so keeping two together in a relatively small aquarium is likely to result in persistent territorial disputes. Sergeant Majors are highly valued by marine aquarists, because their readiness to feed on a wide variety of foods can stimulate other fish in the aquarium to sample unfamiliar foods. Including fresh food in the diet of Sergeant Majors may help to encourage breeding behavior.

Blue Chromis (Chromis cyanea)

• ORIGINS: Caribbean region, ranging from Florida down to the coast of northern South America.
• SIZE: 2 in (5 cm).
• DIET: Eats all types of marine fish food.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.
• TEMPERAMENT: Has a territorial disposition.

A long, highly forked caudal fin gives the Blue Chromis a very elegant appearance and also sets it apart from other damselfish. The body, too, is narrower, emphasizing the streamlined shape. The top of the body is blackish, with dark coloration also evident on some of the fins, while on the flanks there are black markings on the individual blue scales, creating a speckled appearance. Blue Chromis can be sexed visually, although this is not easy. Just prior to spawning, females have an orange egg-laying tube, or ovipositor, that protrudes out of the vent. When a pair of these damselfish are ready to spawn, they prepare a site, usually on rocks, where the female lays up to 50 eggs, which the male then fertilizes. The eggs are guarded by the male until the fry hatch about two days later. The young, freeswimming Blue Chromis should be fed on rotifers as a first food.

Green Chromis (Chromis viridis)

• ORIGINS: Occurs in the Pacific Ocean, east of the Philippines, New Guinea, and eastern Australia.
• SIZE: 2 1⁄2 in (6.5 cm).
• DIET: Will take a varied diet, including flake.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.
• TEMPERAMENT: Relatively social.

Chromis species, such as the Green Chromis, generally rank among the most placid of all damselfish and are unlikely to be disruptive in a reef aquarium. Even so, they should not be mixed with other similar species, since they may be harried by more belligerent companions. At night, they retreat out of sight into a favorite nook or cranny, emerging again the following morning.

Allen’s Damselfish (Pomacentrus alleni)

• ORIGINS: Ranges from the Red Sea through the Pacific; common around the Similian Islands adjoining Thailand.
• SIZE: 4 in (10 cm).
• DIET: Eats both fresh and dried marine fish foods.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.
• TEMPERAMENT: Cannot be kept in groups.

Named after a famous ichthyologist, Dr. Gerald Allen, this damselfish can be identified by its fin markings. The lower part of the caudal fin bears a distinctive black area, with yellow extending from the anal fin along the ventral side of the body. The dorsal fin is dark, becoming whitish at the rear. Allen’s Damselfish has care needs similar to other damsel species, and, like many damselfish, it will be aggressive toward its own kind in the aquarium.

Neon Damselfish (Pomacentrus coelestis)

• ORIGINS: Widely distributed off the eastern coast of Asia and Australia, including the Great Barrier Reef.
• SIZE: 5 in (12.5 cm).
• DIET: Fresh, thawed, and freeze-dried foods; also flake.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.
• TEMPERAMENT: Individuals are territorial.

The behavior of these damselfish changes as they mature. The young associate in groups but become more aggressive and territorial with maturity. Weaker individuals may have to be removed. To reduce the risk of disputes, design the aquarium with plenty of retreats, and use rocks to help divide the tank into different territories. Neon Damselfish are not likely to be aggressive toward unrelated fish sharing their tank.

Yellow-Bellied Blue Damsel (Pomacentrus caeruleus)

• ORIGINS: From the east coast of Africa through the IndoPacific region to eastern Asia and south to Australia.
• SIZE: 4 in (10 cm).
• DIET: A varied range of marine fish foods.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.
• TEMPERAMENT: Intolerant toward its own kind.

Identifying these fish can be difficult, because their wide distribution means that there are regional differences between individual populations. In addition, their coloration can change with age; young fish are essentially blue but develop more pronounced yellow markings as they mature. Although territorial, these fish are not aggressive toward invertebrates, so they are suitable for inclusion in a reef aquarium.

Lemon Damsel (Pomacentrus moluccensis)

• ORIGINS: From Indonesia, including the Moluccas, east into the Oceania region of the Pacific.
• SIZE: 4 1⁄2 in (11 cm).
• DIET: Eats all types of marine fish foods.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.
• TEMPERAMENT: Adults are territorial.

This attractive yellow Asiatic species has fine blue markings on its body and fins. Lemon Damsels can be quarrelsome with each other. To reduce the likelihood of aggression when introducing them to the tank, obtain an odd number of fish and choose specimens of a similar size. Also, choose juveniles rather than adults, because they are likely to settle better in aquarium surroundings.

Yellowtail Damselfish (Microspathodon chrysurus)

• ORIGINS: Found in the Caribbean region, from Florida down to the northern coast of South America.
• SIZE: 8 in (20 cm).
• DIET: Will take prepared and fresh marine foods.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.
• TEMPERAMENT: Tends to quarrel with its own kind.

This large damselfish changes color with age, its blue spots fading as it matures. The caudal fin, which is transparent in juveniles, turns bright yellow at this stage. Yellowtail Damselfish often associate with Fire Corals (Millepora spp.) in the wild, being immune to the invertebrate’s stinging cells. When threatened, the fish dart back among the coral, where predators are unlikely to follow.

Three-Spot Damsel (Stegastes planifrons)

• ORIGINS: In the Caribbean region, where it is commonly encountered from Florida to northern South America.
• SIZE: 6 in (15 cm).
• DIET: Eats almost any marine fish food.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.
• TEMPERAMENT: Watch for territorial disputes.

Three-Spots are among the largest of damselfish. The juvenile, pictured below, is easily identified by the orange-yellow coloration, offset with black spots—one on the caudal peduncle and one on each side of the dorsal fin. Unfortunately, this attractive coloration does not last, and adults become dark gray. Mature Three-Spot Damsels are relatively aggressive and less compatible together than smaller species. They are easy to feed, however, taking flake and freeze-dried foods readily. Although damselfish have a reputation for being hardy and adaptable, there is no excuse for letting conditions in the tank deteriorate, even if they are the only fish in residence. Keep the nitrate reading low, carrying out regular water tests and making partial water changes as necessary.

DISPUTES AND DOMINANCE

In aquariums, most damsels prove to be aggressive as they mature, but on the reef they live in larger groups, which lessens the level of aggression between individuals. An order of dominance is established within each group, resulting in fewer challenges. The fish are also less confined in the wild, and there are many more retreats, which further reduces the likelihood of conflict. Some damsels lay claim to specific feeding grounds, where algae are plentiful. They will defend these sites to ensure that they have access to an ongoing food supply

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