Berthellina citrina

Orange side-gilled slug
Berthellina citrina
Berthellina citrina, NSW, Australia, Photo: Tom Davis
Berthellina citrina
Berthellina citrina, Narooma, NSW, Photo: Andrew Green
Berthellina citrina
Berthellina citrina, Port Davey, TAS, Australia, Photo: Ian Shaw
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Berthellina citrina
Berthellina citrina
Berthellina citrina

Similar Species


Temperate Australasia, Tropical Indo-Pacific


Colour varies from pale to dark orange. Glands across mantle appear as white spots. Cylindrical shape and uniform colour, which can be either yellow or orange. Two prominent rhinophores, which are fused at their base, project out from under the front of the mantle. The species feeds on sponges.


Max Size: 5 cm

Sea Temperature Range: 12.3-23.9°C

Depth: 0-60m

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: Rare (0.5% 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