Cyclicthys is a genus of fish in the porcupinefish family, Diodontidae. Species in the genus are often known as swelltoads.
Fish of the genus Cyclicthys have three-rooted, rigid spines (actually modified scales) distributed over their bodies, and beak-like jaws, used to crush their hard-shelled prey (crustaceans and molluscs). They differ from members of the genus Diodon, which have moveable spines.
Like Tetraodontidae (blowfish) they have the ability to inflate themselves. Their inflated size combined with their spines make them extremely difficult to swallow. They may be poisonous, through the accumulation of tetrodotoxin or ciguatera.[1]
There are currently 3 recognized species in this genus:[2]
| Image | Scientific name | Common Name | Distribution |
|---|---|---|---|
| Cyclichthys hardenbergi (de Beaufort, 1939) | Hardenburg's burrfish | Western Pacific: southern New Guinea and tropical Australia east of Cape York | |
| Cyclichthys orbicularis (Bloch, 1785) | Birdbeak burrfish | Indo-West Pacific region from Red Sea to the Philippines | |
| Cyclichthys spilostylus (Leis & J. E. Randall, 1982) | Spotbase burrfish | Red Sea to South Africa and east to southern Japan, the Philippines, Australia and New Caledonia. | |