Margined Coralfish (Chelmon marginalis)

Margined Coralfish Chelmon marginalis
Name	Margined Coralfish
Name Lat.	Chelmon marginalis
Family	Butterflyfishes
Family lat.	Chaetodontidae
Order	Surgeonfishes
Order lat.	Acanthuriformes
Origin	Indo-West Pacific
Habitat	Coastal reefs
Diet	Carnivore
pH	8.1-8.4
Hardness	8-10 °KH
Behavior	Peaceful
Keeping	Individual, pair
Reef Compatible	With caution
Care Level	Difficult
Life Span	4-7 years
Protection	No
Metric Units
Size	18 cm
Temperature	23-28 °C
Salinity	33-36 ‰
Aquarium	~ 650 l
US Units
Size	7"
Temperature	73-82 °F
Salinity	1.020-1.025 sg
Aquarium	~ 170 gal

Distribution and habitat

Chelmon marginalis is a reef dweller distributed along the entire coast of northern Australia, from west to the Great Barrier Reef in the east and as far east as New Guinea.

Maintenance

They require a well-structured aquarium with plenty of swimming space and a reef structure (hiding, resting and retreat possibilities) with living stones which they can graze on and which act like a biological filter. Only lime-rich, heavy metal-free substrates 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 match 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

They are permanent eaters, feeding mainly on small crustaceans as well as coral polyps. If they are stress-free, the change of food usually succeeds without problems. The food supply should consist of a commercially available, vitamin-enriched frozen special food mix or a combination of chopped shrimp, squid and mussel meat with live and frozen food such as mysis, krill, bosmids and artemia as well as live cyclops, which also serve to keep them busy. High quality flake food is also usually accepted after an acclimation period. 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. To avoid ranking fights, two different sized or two juvenile animals should be placed in the aquarium at the same time. The dominant, larger animal always develops into the male. They should only be socialized with very calm, peaceful fish, as they are very susceptible to stress.

Sex dimorphism

Presumably, all butterflyfishes are sequential hermaphrodites, meaning they possess both male and female sexual expressions. External sexual characteristics are not known.

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. However, caution is advised with tubeworms and clams. They are well suited to control unwanted glass lice (Aiptasia)

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

Further literature can be found in your pet store.

References

Text: Werner Knapp; Image: Franz Lowak

Source: KUITER, DEBELIUS (2007): Atlas der Meeresfische: Die Fische an den Küsten der Weltmeere, Kosmos Verlag; ENGELMANN (2005): Zootierhaltung - Tiere in menschlicher Obhut: Fische, Verlag Harri Deutsch

• Gemäß § 21 Abs. 5 Tierschutzgesetz idgF