Diadema palmeri
Palmer’s urchin
Distribution
Temperate Australasia
Description
When observed underwater it has a dark appearance, but torchlight or sunlight reveals intense orange-red hues and, in the centre of the upper surface, a light-brown structure (the anal cone) with a black central spot. This species is found only on the deeper temperate reefs off New South Wales and New Zealand.
Information
Max Size: 7 cm
Sea Temperature Range: 15.4-24.5°C
Depth: 10-60m
Habitat Generalization Index: N/A
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: Infrequent (3.4% 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: Solitary (1 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