Restricted gilgie - Cherax crassimanus

This page was created in partnership with the Freshwater Fish Group and Fish Health Unit at Murdoch University

Identification

Restricted gilgie - Cherax crassimanus

Colour varies from light to dark greenish brown, generally with distinctive mottling and often with a central light brown/orange central stripe and basal portion of legs being reddish-orange.

Distinguished from other crayfish based on weight-of-evidence considering the following:

  • Four keels on the head although a very reduced central keel can sometimes be present (gilgie and marron have 5 keels, and typically more pronounced, and the koonac and glossy koonac have 4 keels);
  • A telson without spines (marron have 2 obvious telson spines);
  • A more acutely, anteriorly-curved and sharper spine on the inner edge of the wrist compared to the gilgie and koonac species.

Maximum total length (rostrum to tail) is 70 mm.

Distribution

A rare species (low numbers at sites where it is known to occur) with a restricted range on the south coast, from Margaret River to Denmark.

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Habitat

Occupies both permanent and ephemeral streams, however generally appears to prefer smaller, shallow systems

Biology

The biology of this species has not been studied.

Conservation status

Not listed as threatened, but work is required to better understand status.

Further information

Contact the Departments River Science team, or the Murdoch Freshwater Fish Group via email: fish@murdoch.edu.au, or go to their website: www.freshwaterfishgroup.com

Freshwater Fish Group Murdoch University    Harry Butler Institute