Diodon nicthemerus

Globe fish
Diodon nicthemerus
Diodon nicthemerus, Hobart, TAS, Photo: Graham Edgar
Diodon nicthemerus
Diodon nicthemerus, Busselton, WA, Photo: Graham Edgar
Diodon nicthemerus
Diodon nicthemerus, Bermagui, NSW, Photo: Andrew Green
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Diodon nicthemerus
Diodon nicthemerus
Diodon nicthemerus


Temperate Australasia


Dark-grey back, black blotches on the sides, a white belly, and yellow spines. When threatened, the fish inflates its body rapidly into a sphere with outwardly radiating spines. The species occurs in a range of habitats along the southern coast and is most abundant on sheltered coastal reefs.


Max Size: 40 cm

Sea Temperature Range: 10.2-22.6°C

Depth: 0-50m

Habitat Generalization Index: 8.38

Also referred to as the SGI (Species Generalisation Index), this describes the habitat niche breadth of the species. Species with values less than 15 are found in a relatively narrow range of reef habitat types (specialists), while those over 25 may be found on most hard substrates within their range (generalists). Learn more here.

Conservation and Rarity

IUCN Status: Not Evaluated

Occurrence: Common (33.1% of sites)

Occurrence describes how often the species is found on surveys within its distribution. It is calculated as the % of reef sites surveyed by RLS divers across all the ecoregions in which the species has been observed

Abundance: Few (2 per transect)

Abundance is calculated as the average number of individuals recorded per RLS transect, where present.

Edit by: GJ Edgar. 2008. Australian Marine Life. New Holland, Sydney