The Orbiculate Burrfish (Cyclichthys orbicularis), also sold as the Birdbeak Burrfish, Fixed Spine Porcupinefish, or Rounded Porcupinefish, is a heavy-bodied Indo-Pacific pufferfish relative built along rounded, almost inflated lines. The body ranges from pale brown to near white and is marked with a dark honeycomb pattern or scattered round brown spots that become denser toward the tail, while the fins remain largely translucent. Unlike true porcupinefish, the spines are short, thick, and widely spaced, and they stay permanently fixed rather than folding flat against the body. Adults reach approximately 11.8 inches, with reported maximums spanning roughly 11 to 12 inches.

In nature this species occupies coastal shelves across the Indo-Pacific, ranging through the water column from the surface down to about 150 meters. It favors soft sediment habitats such as open sand flats and only occasionally appears over reef structure. That preference should guide the aquarium build: open swimming lanes, generous unobstructed sand, and rockwork placed to frame rather than fill the tank. Housing requirements are substantial, and published guidance varies widely, from a 50-gallon minimum at the low end to aquariums of roughly 264 gallons. Given the adult bulk and slow, deliberate swimming style of a fish this size, the larger figure is the realistic long-term target. This is an expert-level species, and its toxicity in aquarium conditions is not documented, so it belongs only with aquarists prepared for an unpredictable, specialized animal.

Wild Orbiculate Burrfish are believed to feed on hard-shelled invertebrates, crushing prey with the fused, beak-like jaws characteristic of the group. In captivity the species is maintained as a carnivore, and a varied menu of meaty marine items best reflects that natural feeding mode. Shell-on offerings are particularly valuable because they give the beak the resistance it needs; jaw hardware on these fish grows continuously, and a diet of soft foods alone provides nothing to wear it down.

Offer chopped shrimp, clam, mussel, squid, and krill, supplementing with prepared frozen carnivore mixes for marine predators. Feeding several times per week suits a fish of this mass, with portions sized so that food is consumed rather than left to foul the sand bed. Newly imported specimens may need patience before they accept prepared foods, so present items individually and allow the fish to approach on its own terms rather than forcing competition at feeding time.

Chopped Shrimp Clam Mussel Squid Krill Frozen Carnivore Mix
Temperament in this species is semi-aggressive, and the combination of size, slow confidence, and a powerful beak means it dictates terms in most community settings. Expect a deliberate cruiser that patrols open water and sandy expanses rather than wedging into caves. Keep one per aquarium unless the system is genuinely enormous, and select tankmates that are large enough to avoid being treated as food yet calm enough not to harass a fish whose fixed spines offer limited defense against persistent nipping. Small, delicate fishes and anything that fits the beak are poor choices.

Reef compatibility is the central concern. Because the natural diet centers on hard-shelled invertebrates, ornamental shrimp, crabs, snails, and clams are all at meaningful risk in the same system. Specific behavior toward corals is not documented for this species, and its toxicity in aquarium conditions is likewise unknown, which argues for keeping it in a fish-only or predator-oriented display rather than a stocked reef. A dedicated system with open sand, sturdy tankmates, and no prized invertebrates is where this burrfish performs best.

FAQ

Frequently Asked Questions

About the Orbiculate Burrfish

  • How big of a tank does an Orbiculate Burrfish need?
    Published guidance ranges from a 50-gallon minimum up to roughly 264 gallons, and the larger figure better suits an adult of this bulk. Prioritize open swimming space and a broad sand bed over heavy rockwork.
  • How large does the Orbiculate Burrfish get?
    Adults reach about 11.8 inches, with reported maximum sizes spanning roughly 11 to 12 inches depending on the source.
  • Is the Orbiculate Burrfish safe with invertebrates?
    No. Its natural diet of hard-shelled invertebrates means ornamental shrimp, crabs, snails, and clams are likely targets, so a fish-only or predator system is the safer choice.