This is a small crab that is cryptic in nature often not noticed due to it's size and colourations blending it into the environments it lives in.

Around Tasmania this crab is common and found under rocks and amongst seaweeds the common name comes from the features of it's rostrum being 3 short blunt spikes

At a glance

Three-Pronged Flat Spider Crab at a glance

Habitat under rocks and amongst seaweed
Size Can grow to around 15mm
Origin Native
Distribution can be found around Southern Australia including Tasmania
Descriptions
Distribution
can be found around Southern Australia including Tasmania
Habitat
under rocks and amongst seaweed
Size
Can grow to around 15mm

Identification

A small crab that varies in colour greatly the carapace features a prominent spine on each side of the carapace whilst another less prominent can be seen on some individuals.

The rostrum the section between the eyes features three blunt spines, The legs are thin and rounded with a small spine on the distal end of the meri.

Common Name Three-Pronged Flat Spider Crab
Aliases No Known Aliases
Origin Native
Conservation No Conservation Status
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Distribution and map

Distribution provided by The Atlas of Living Australia

Classification

Classification

KingdomAnimalia
SubphylumCrustacea
SuperclassMulticrustacea
SuperorderEucarida
SuborderPleocyemata
InfraorderBrachyura
SuperfamilyHymenosomatoidea
Synonyms

Synonyms

Halicarcinus krefftii (Hess, 1865)
Hymenicus Haasti Filhol, 1885
References and dates
Original No original text available
Bibliography View page references
Added Thu 20 Aug 2026 @ 16:10 PM
Updated Thu 20 Aug 2026 @ 16:10 PM
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Disclaimer: A lot of work goes into trying to identify and ensure accurate identifications are made, and that the listed Descriptions, Sizes, Habitats and Distribution information is as accurate and valid as possible. Unfortunately, information in this arena is ever changing and as such no guarantee can be offered that it is correct or currently valid — the information is provided as a guide, and it is always suggested that you do a little research to ensure you have the latest and most accurate information. View the references or bibliography. Feedback and comments on the information provided are always welcome.