Its spines are already up. That is the difference between a burrfish and the porcupinefishes it shares the reef with: theirs fold flat until the animal inflates, and this one's are short, thick, three-sided at the base and permanently erect, so the fish is prickly whether or not it has bothered to swell.
The trade is mobility for readiness. Permanent spines cost drag every time it swims, and a burrfish is a slow, deliberate mover that sculls with its pectoral fins and does not go far. In exchange it is never caught unprepared.
By day it wedges itself into something - a large sponge, a crevice, the underside of a ledge - and waits. After dark it comes out over sand and rubble and eats things with shells, crushing them with teeth fused into a solid beak, which is where the family name comes from.
It goes deep for a reef fish, recorded down past a hundred and fifty meters, and juveniles look like a different animal: covered in black spots, drifting in open water long before they settle.
The genus. Cyclichthys Kaup 1855 - cyclos (round or circular) + ichthys (fish). ETYFish
The species. Cyclichthys orbicularis (Bloch 1785) - circular or disc-shaped. ETYFish
- short stout spines on triangular bases, standing up permanently
- brown to gray body with clusters of black spots on the back and sides
- beak-like fused teeth and large eyes
- often wedged inside a large sponge during the day
- up to 30 cm
