Patiriella calcar Click to enlarge image
Carpet Sea Star, Patiriella calcar Image: Dr Isobel Bennett
© Australian Museum

Fast Facts

  • Classification
    Species
    calcar
    Genus
    Patiriella
    Family
    Asterinidae
    Order
    Valvatida
    Class
    Asteroidea
    Phylum
    Echinodermata
    Kingdom
    Animalia
  • Size Range
    5 cm

Introduction

The three most common sea stars in Sydney belong to the genus Patiriella. They may be difficult to see at first because of their small size and excellent camouflage in rock pools, crevices or under boulders.

Identification

The colour and pattern of individual Carpet Sea Stars vary greatly. They usually have a grey-green background with splotches of orange, yellow or red. You may also notice several tiny sea stars surrounding a larger one.

Habitat

Carpet Sea Stars live on intertidal rocky shores to a depth of 3 m.

Distribution

Carpet Sea Stars are found in Queensland, New South Wales, Victoria, South Australia, Western Australia and Tasmania.

Other behaviours and adaptations

The Carpet Sea Star has well-defined arms, whereas the arms of the other two common species in the area (Patiriella exigua and P. gunnni) are not well developed, giving these sea stars a pentagonal or hexagonal shape.

Life history cycle

Sea stars from the genus Patiriella differ from most other echinoderms by being 'viviparous', meaning that they give birth to live young. The juveniles develop within the parent.