Nemadactylus douglasii

Grey morwong | Blue Morwong | Nemadactylus douglasi
Nemadactylus douglasii
Nemadactylus douglasii, Northland, New Zealand, Photo: Graham Edgar
Nemadactylus douglasii
Nemadactylus douglasii, adult, Jervis Bay, NSW, Australia, Photo: Rick Stuart-Smith
Nemadactylus douglasii
Nemadactylus douglasii, adult, Coffs Harbour, NSW, Photo: Ian Shaw
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Nemadactylus douglasii
Nemadactylus douglasii
Nemadactylus douglasii


Temperate Australasia


Similar shape to the jackass morwong, but is easily recognised by its distinctive blue colouration, particularly on the fins. The largest schools occur below diveable depths, where they are commercially trawled.


Max Size: 74 cm

Sea Temperature Range: 13-23.8°C

Depth: 10-100m

Habitat Generalization Index: 14.19

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: Frequent (16.0% 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