Orangespotted filefish (Oxymonacanthus longirostris) care guide

Group
Marine fish
Family
Monacanthidae (filefishes)
Origin
Indo-Pacific coral reefs
Water
saltwater
Maximum size
13 cm
Temperature
24–27°C
pH
8.1–8.4
Hardness
Salinity SG 1.023–1.026
Minimum tank
250 litres
Care level
expert
Temperament
peaceful
Reef safe
no

Care

A small, green filefish covered in orange spots, with a long pointed snout. It is one of the hardest marine fish to keep, because it needs a steady supply of live Acropora polyps. Only experienced aquarists who can provide this should consider it. Wikipedia article not checked for this entry; details are from the list and general marine husbandry. Water figures here are general marine aquarium guidance, not species-specific: 24–27 °C, pH 8.1–8.4, salinity SG 1.023–1.026. Minimum tank size of about 250 litres is our estimate from the adult size and habits, not a published figure. Sources: Wikipedia, List of marine aquarium fish species (en.wikipedia.org/wiki/Listofmarineaquariumfishspecies). Checked October 2026.

Diet

An obligate coral eater: in the wild it feeds on the polyps of Acropora corals. Very few individuals accept substitute foods, which is why it often starves in captivity.

Breeding

Breeding in home aquaria has not been reported in the sources used here.

Compatibility and tank mates

Not reef safe: it eats Acropora and other small-polyp stony corals. Peaceful with other fish; pairs may be kept together.

Last updated 8 October 2026. Community-edited care guide on Aquatic-Auctions.

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