Pagurus sinuatus Click to enlarge image
Hermit crab without shell, Pagurus sinuatus Image: Dr Isobel Bennett
© Australian Museum

Fast Facts

  • Classification
    Species
    sinuatus
    Genus
    Pagurus
    Family
    Paguridae
    Suborder
    Pleocyemata
    Infraorder
    Anomura
    Order
    Decapoda
    Superorder
    Eucarida
    Class
    Malacostraca
    Subphylum
    Crustacea
    Phylum
    Arthopoda
    Kingdom
    Animalia
  • Size Range
    10 cm

Introduction

Sydney has several species of hermit crabs, which are mostly found in intertidal areas of rocky shores, beaches and mangroves. Pagurus sinuatus is a common species found on Sydney's rocky shore.

Identification

The Hermit Crab is easily identified by its red colour and hairy claws.

Habitat

The Hermit Crab lives on intertidal rocky shores and in mangroves and estuaries.

Distribution

The Hermit Crab is found from Sydney in New South Wales; Victoria; South Australia to Shark Bay in Western Australia. Also New Zealand.

Feeding and diet

Like most hermit crabs, Pagurus sinuatus is a scavenger but may also feed on crabs and other live prey.

Other behaviours and adaptations

Hermit crabs are unlike other crabs because their abdomen is not covered by an exoskeleton, but is soft and delicate. To overcome this problem, they use discarded snail shells for protection. Like other crustaceans, hermit crabs moult in order to grow, but when their shell becomes too small they must go in search of another one. They inspect the shells by holding them up and turning them over before leaving the safety of their current home. Sometimes the chosen shell just isn't right so they move back to their original shell and start the search again. Competition can be tough for the best shells and occasionally fights break out between hermit crabs.