Moorish Idol (Zanclus cornutus)

Moorish Idol Zanclus cornutus
Name	Moorish Idol
Name Lat.	Zanclus cornutus
Family	Moorish Idol
Family lat.	Zanclidae
Order	Surgeonfishes
Order lat.	Acanthuriformes
Origin	Indo-Pacific
Habitat	Lagoons, seaward reefs
Diet	Omnivore
pH	8,1-8,4
Hardness	8-10 °KH
Behavior	Peaceful
Keeping	Pair, group
Reef Compatible	Yes
Care Level	Difficult
Life Span	2-4 years
Protection	No
Metric Units
Size	21 cm
Temperature	24-28 °C
Salinity	33-36 ‰
Aquarium	~ 800 l
US Units
Size	9"
Temperature	75-82 °F
Salinity	1.020-1.025 sg
Aquarium	~ 200 gal

Distribution and habitat

The distribution area of Zanclus cornutus is the entire tropical Indian and Pacific Oceans. They live mostly in small groups in coral-covered lagoons and on outer reefs up to 180 m depth.

Maintenance

They require a well-structured aquarium with plenty of swimming space and a reef structure (shelters) with live stones that they can graze on (sponges, algae, small crustaceans) and which act like a biological filter. Only lime-rich, heavy metal-free sands, gravels, stones or sea sand of various grain sizes may be used as substrate.

Filters, skimmers and heaters are necessary to ensure water quality, as well as pumps to simulate tides, swells and bottom currents. Lighting must correspond to the species-appropriate day-night rhythm of the animals

Salinity: 33-36 ‰	pH value: 8.1-8.4
Carbonate hardness: 8-10 °KH	Nitrate content: 2-8 mg/l
phosphate content: 0.01-0.1 mg/l	nitrite content: 0.0-0.05 mg/l

For salinity, an average value should be aimed for, which may only vary slightly by +/- 0.5 ‰. Ammonia and ammonium must not be measurable. Special attention must be paid to constantly good water quality.

Diet

In nature they feed mainly on algae and small crustaceans scraped from rocks. Sponges (Porifera) are also eaten with pleasure. The food change does not always succeed without problems. The food supply should consist mainly of commercially available algae (e.g. spirulina, nori), supplemented with a combination of live and frozen food, such as mysis, artemia and cyclops, as well as chopped mussel meat or a frozen food mixture enriched with vitamins and sponges. After acclimation, dry food (flakes, granules) with a high vegetable content is usually also accepted.

It is recommended to feed small portions several times a day (3-5 times). Regular and varied feeding promotes health and increases resistance.

Behaviour and compatibility

It is recommended to keep them in pairs or in a group. To avoid territorial fights, they should be placed in the aquarium at the same time. Each animal takes a shelter, which becomes its territorial center and in which it remains dominant. In rivalry fights, they try to push the competitor away forehead to forehead. They behave very peacefully towards other fish, but should not be socialized with large species.

Sex dimorphism

There are no known external sex differences.

Reproduction and breeding

There are no known reports of successful breeding in the aquarium.

Important

As reef dwellers they should not be kept in a fish-only aquarium. If kept in pairs, with sufficient activity (live stones, large reef surface) and frequent as well as varied feeding, they can be maintained even in demanding coral tanks without serious attacks on the corals. When socialized with too lively or aggressive fish, they sometimes stop feeding.

If different species are kept together, care should be taken to match the fish in terms of water quality and temperature requirements and social behavior, and to ensure that the setup meets the needs of all species kept together. New fish to be introduced must be acclimated slowly to the water in the aquarium

Further literature can be found in your pet store.

References

Text: Lucie Schiemer; Image: Franz Lowak

Source: BAENSCH & DEBELIUS (2006): Meerwasser Atlas Bd. 1, Mergus Verlag; ENGELMANN (2005): Zootierhaltung - Tiere in menschlicher Obhut: Fische, Verlag Harri Deutsch

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