''Tetractenos'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

Tetraodontidae Tetraodontidae is a family of primarily marine and estuarine fish of the order Tetraodontiformes. The family includes many familiar species variously called pufferfish, puffers, balloonfish, blowfish, blowies, bubblefish, globefish, swellfi ...

. The genus can be found throughout the Indo-West Pacific and Australia's southern and eastern coastlines.

Species

There are currently two recognized species in this genus: * '' Tetractenos glaber'' ( Fréminville, 1813) (Smooth toadfish) * '' Tetractenos hamiltoni'' ( J. Richardson, 1846) (Common toadfish)

Description

The general colour of the species in this genus varies, as at night they take on a deeper colour than during daytime, and, as with all toadfishes and puffers, the colour of skin changes slightly depending on the mood or stress level of the animal. For example, when a ''Tetractenos'' is in

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as we ...

-depleted water, its underbelly will be a darker colour than the usual whitish-cream. The body of both species is covered in small, gravel-like pustules (spots). Small,

sandpaper upright=1.35, Sheets of sandpaper with different grit sizes (40 (coarse), 80, 150, 240, 600 (fine)). Sandpaper and glasspaper are names used for a type of coated abrasive that consists of sheets of paper or cloth with abrasive material glued t ...

-like spines can be found on the body, and when the animal "puffs up" they stick out and make it feel even more rough. Although the colour varies, ''T. hamiltoni'' is sandy to whitish in colour, with small brown spots over most of the back and upper sides, and brown bars and blotches beneath.Australian Museum: Common Toadfish.
/ref> ''T. glaber'' has larger spots and blotches, and less prominent spines, hence its common name, smooth toadfish. The genus ''Tetractenos'' was once classed as '' Tetraodon'' or ''Tetrodon'',G.S. Hardy, "Revision of Australian species of ''Torquigener'' Whitley (Tetraodontiformes: Tetraodontidae), and two new generic names for Australian puffer fishes," ''Journal of the Royal Society of New Zealand'', Volume 13, No. 1/2, 1983, pp. 1–48

/ref> and is sometimes also confused with '' Torquigener''.

References

Marine fish genera {{tetraodontiformes-stub