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Harlequin Filefish (Oxymonacanthus longirostris)

Find Harlequin Filefish across reef-livestock retailers and from fellow hobbyists on ReefDock. Compare sources, check live pricing where available, and review source-tank parameters on Reef-Trak-verified fish listings before you buy.

Harlequin Filefish
Photo: Diego Delso · CC BY-SA 4.0
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Where to buy Harlequin Filefish

ReefDock searches the following reef retailers for this fish. Click through to see the live price.

  • Saltwaterfish

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    Search Saltwaterfish
  • Amazon

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  • Petco

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About Harlequin Filefish

A small, laterally compressed filefish with a distinctive long snout and bright coloration featuring orange-yellow body with blue and orange reticulated markings and spots. Males display more vibrant coloration than females.

Key facts

Diet
omnivore
Max Size
5
Diet Details
In the wild, feeds primarily on coral polyps and small benthic invertebrates. In captivity, requires a varied diet of small foods including frozen mysis shrimp, copepods, amphipods, and specialized prepared foods. Feeding small frequent meals is essential due to their small mouth and high metabolism.
Common Health Issues
Marine ich, Fin rot, Swim bladder disorder, Bacterial infections, Parasitic infestations, Starvation
Origin
Indo-Pacific coral reef regions, including the Great Barrier Reef and surrounding areas from Indonesia to the western Pacific.
Notes
Famous for eating Acropora coral polyps. Very difficult to feed in captivity. Often starves if not provided with live Acropora. Not recommended for most aquarists.
Care Level
Expert
Feeding Schedule
3-4 times daily
Water Parameters
Temperature: 72-78°F pH: 8.1-8.3 Salinity: 1.02-1.025
Family
Monacanthidae
Difficulty Level
Expert - Very difficult to feed in captivity. Often requires live Acropora corals. Best suited for expert aquarists only.
Care Requirements
• 75+ gallon aquarium with stable conditions • Water: 72–78°F, pH 8.1–8.3, sg 1.023–1.025 • Requires live coral polyps (acropora) as primary food source • Excellent water quality and minimal disturbance essential • Peaceful but highly specialized; not for beginner reefers

Looking for a hobbyist seller?

ReefDock's marketplace lets reef-keepers sell fish directly to other reef-keepers with Stripe-secured checkout and live-arrival photo confirmation. Browse current fish listings on ReefDock, or list your own.

Verify the source tank before you buy

ReefDock is the sister app to Reef Trak. Sellers who maintain a Reef Trak tank log can publish source-tank parameters on eligible fish listings — so you can see the conditions a fish was raised in before you buy. Log this fish on Reef Trak.

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