The orange-spot filefish, Oxymonacanthus longirostris, is a very enigmatic reef fish which has been the envy of fishkeepers for decades. Once thought to be ‘impossible’ to keep, the orange-spot filefish now joins the growing list of marine species which were once thought too delicate for captivity including stony corals, many anthias, purple tilefish, Moorish Idols and more. The orange-spot filefish is still a great challenge to house in captivity, and most successes with Oxymonacanthus have taken place in reef aquariums where the filefish had the option to munch on a little bit of SPS corals to supplement its diet.

Please don’t get the impression that we are encouraging all to consider this fish for your next reef aquarium purchase. Just consider this video an example of what this colorful and uniquely colored reef fish can look like when well adjusted in captivity. Reef Builders writer Matt Pedersen has bred the orange spot filefish, or as he likes to call it the ‘harlequin filefish’, and he still considers this fish extremely hard to keep alive in an aquarium:

In the 2 years since I published my CORAL article [on breeding the harlequin filefish], there’s been a more responsible attitude towards this fish at the retail level and in the supply chain.  I think this resulted in more hobbyists working with them successfully.  Still, I want to see someone else BREED them.  I should again state they’re still freakin’ terribly difficult – expert only isn’t a joke or something to be brushed aside.