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

Directory of Marine Fish

Filefish

Closely related to the triggerfish, filefish are not so boisterous in aquarium surroundings as their cousins, nor as destructive. Most species are smaller than triggers, but they share with them the split configuration of the dorsal fin (the first part forms a spine used to anchor the fish in a cave). The ventral fin on the underside of the body is similarly modified, providing additional support. Filefish have small mouths, with teeth designed for nibbling at foods such as algae. They must not be housed in a reef tank, because they naturally feed on coral polyps. Although usually tolerant of their own kind, some filefish may occasionally harry other fish.

Fan-Bellied Leatherjacket (Monacanthus chinensis)

• ORIGINS: The Pacific region, north to southern Japan, and south via Malaysia to Australia’s Great Barrier Reef.
• SIZE: 10 in (25 cm).
• DIET: Omnivorous, but prefers algae and meat-based foods.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.4) with SG 1.020–1.025.
• TEMPERAMENT: Not normally aggressive.

The blotched coloration of this species may vary between individuals. It is also affected by the fish’s surroundings—the Fan-Bellied Leatherjacket can alter its appearance to some extent to blend in with the background. Since it is not a strong swimmer, its survival relies more on avoiding detection rather than fleeing from predators.

Slender Filefish (Monacanthus tuckeri)

• ORIGINS: The Caribbean region, extending from Florida down to the coast of Venezuela.
• SIZE: 3 1⁄2 in (9 cm).
• DIET: Fresh and thawed meat-based foods, plus algae.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.4) with SG 1.020–1.025.
• TEMPERAMENT: Placid

A narrow, rather elongated body sets the Slender Filefish apart from related species. It displays variable coloration, depending partly on its environment, although the body patterning is often blotchy. These filefish will not only browse on marine algae in the aquarium but also feed quite readily on prepared diets featuring invertebrates, such as cockles and crustaceans, especially once they are established.

White-Spotted Filefish (Cantherhines macrocerus)

• ORIGINS: The Atlantic, from the eastern U.S. and down through the Caribbean to northern South America.
• SIZE: 18 in (46 cm).
• DIET: Algae and meat-based foods.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.4) with SG 1.020–1.025.
• TEMPERAMENT: Not normally aggressive.

It is the juveniles of this species that most strongly display the characteristic patterning of white spots on a dark background. Orange coloration is apparent, too, typically toward the rear of the body. Breeding has yet to be accomplished in aquariums. In the wild, filefish lay green eggs, which sink to the bottom. The fry develop in the upper layer of the water, feeding on plankton.

Orange-Head Filefish (Pervagor melanocephalus)

• ORIGINS: Throughout the Indo-Pacific region, including the coastal area of Australia and eastward to Hawaii.
• SIZE: 4 in (10 cm).
• DIET: Will take meat-based foods and algae.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.4) with SG 1.020–1.025.
• TEMPERAMENT: Placid.

This filefish tends to have a light-colored body and a bluish head, although its appearance can differ throughout its range. Hawaiian specimens are the most colorful, with red bodies. House this filefish in an aquarium with decor that is as bright as the fish itself, because in the wild it frequents colorful areas on the reef, where its slow movements help to disguise its presence.

Tasseled Filefish (Chaetodermis penicilligerus)

• ORIGINS: The Pacific region, from Malaysia to Japan in the north, and Australia’s Great Barrier Reef in the south.
• SIZE: 10 in (25 cm).
• DIET: Feeds on algae and meat-based foods.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.4) with SG 1.020–1.025.
• TEMPERAMENT: Not normally aggressive.

The horizontal body stripes and the unusual tassellike appendages of this slow-swimming filefish help to conceal it among the seaweed fronds on which it often feeds. The black blotches on each side of the body behind the eyes become less prominent as the Tasseled Filefish grows older.

ROUGH DEFENSE

The small scales on a filefish’s body are arranged randomly, producing raised areas that give a rough, ridged texture like the surface of a file. The scales form a tough, protective covering—hence the alternative common name of Leatherjacket, which is given to various filefish species. Because of their rough skin and their dorsal and ventral spines, it is better to use a container rather than a net when trying to catch them.

Fantail Filefish (Pervagor spilosoma)

• ORIGINS: The Pacific region, north and east of Indonesia, and north of New Zealand to Hawaii.
• SIZE: 5 in (13 cm).
• DIET: Eats meat-based foods and algae.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.4) with SG 1.020–1.025.
• TEMPERAMENT: Not normally aggressive.

This species should not be confused with the Hawaiian Redtail Filefish (P. aspricaudus), in which the blotches on the body are replaced by fine dots. In order to feel secure, the Fantail Filefish—like all filefish—needs plenty of small caves in the aquarium for use as retreats. When threatened, it anchors itself in place with its spines and inflates its body slightly, becoming difficult to dislodge.

Long-Nosed Filefish (Oxymonacanthus longirostris)

• ORIGINS: The Red Sea and eastward through the IndoPacific region to the vicinity of Hawaii.
• SIZE: 4 in (10 cm).
• DIET: Algae and meat-based foods.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.4) with SG 1.020–1.025.
• TEMPERAMENT: Shy and docile.

Long-Nosed Filefish can be identified by their striking patterning of orange spots set against a sky-blue background. They are regarded as the most colorful of all the filefish, with attractive alternating spokes of blue and yellow surrounding the pupil of each eye. These filefish often prove difficult to wean off of coral polyps—especially the Acropora species, which they consume in the wild—and onto substitute diets.

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