Species focus: Clown Toado

The clown toado or sharp-nosed pufferfish is a species of sub-tropical origin distributed throughout eastern Australia and the southwest Pacific up to New Caledonia.

In New Zealand, whilst abundant at the Kermadecs, it is also found in the north, especially in places where the tropical currents reach (that is, islands and headlands). Recent evidence suggests the species is becoming more common at these places, likely as a result of the warming seas around New Zealand.

The clown toado is a member of a very diverse genus of pufferfishes, being one of 36 Canthigaster species. It’s brightly coloured, green above and white below, with two dark parallel stripes running along the body and covered in iridescent blue wavy lines and dots throughout. In courting males, the dark stripes fade completely and the blues and greens become more vivid (as depicted in the photograph).

Males are territorial and likely to breed with females exclusively within their territory, defending their boundaries against other males.

Like other pufferfishes, the clown toado possesses one of the most potent naturally occurring toxins. This neurotoxin called tetradotoxin (named after the pufferfish family) is present in the skin and other tissues of the fish, thus making it unpalatable to predators. Their ability to ‘puff’ or inflate themselves with water, together with their poisonous skin and tissues, explains why these small, slow-moving, colourful fish are often found out in the open sand and rubble environs and not predated upon by large piscivorous predators such as snapper.

8 facts about the clown toado - Canthigaster callisterna

1. Also known as a sharp-nosed pufferfish or clown toby.
   
2. Found in northern New Zealand but also Australia and the SW Pacific.
   
3. 15-20 cm in length.
   
4. One of 36 species in the genus Canthigaster.
   
5. Males defend territories, primarily for breeding.
   
6. Males display extravagant colouration during courting.
   
7. Containing the pufferfish-specific neurotoxin, tetrodotoxin which is highly poisonous if ingested.
   
8. Like all pufferfishes, will inflate itself with water to become 3-4 times its size when alarmed