Feature Creature

Pinnotheres hickmani Guiler, 1950

Common Name: Pea Crab

Family: Pinnotheridae

Class: Malacostraca

Distribution: Shark Bay, WA to Morten Bay, Qld and around Tasmania

Have you ever experienced an unexpected ‘crunch’ whilst eating mussels?

If so you may have accidently eaten a pea crab or Pinnotheres hickmani. These little crustaceans named pea crabs for their general size and appearance of a pea are commonly found living inside live mussel shells. They may also be found inside the shells of other bivalves, while other species of the family may be found living with such animals as tube dwelling polychaetes, holothurians, and echinoids, with a few species being free living.

These crabs likely gain protection and a food source from their host mussel, it is however not entirely clear what advantages the host gains from the relationship.

Figure 1