Cyclicthys is a genus of the family Diodontidae, are usually known as Swelltoads.

Cyclichthys spilostylus.jpg
Cyclichthys spilostylus
Scientific classification

Kaup, 1855

Distinguishing featuresEdit

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).[1] They differ from the porcupinefishes of the genus Diodon, which have moveable spines.

Defensive mechanismsEdit

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.


  1. ^ a b Lieske, E. & Myers, R.F. (2004): Coral reef guide; Red Sea London, HarperCollins ISBN 0-00-715986-2
  2. ^ Matsuura, K. (2014): Taxonomy and systematics of tetraodontiform fishes: a review focusing primarily on progress in the period from 1980 to 2014. Ichthyological Research, 62 (1): 72-113.