Tripneustes gratilla Click to enlarge image
Hairy Sea Urchin, Tripneustes gratilla Image: Dr Isobel Bennett
© Australian Museum

Fast Facts

  • Classification
    Species
    gratilla
    Genus
    Tripneustes
    Family
    Toxopneustidae
    Order
    Echinoida
    Class
    Echinoidea
    Phylum
    Echinodermata
    Kingdom
    Animalia
  • Size Range
    15 cm

Introduction

The Pin-cushion Urchin is a tropical species and its population in Sydney fluctuates. In some years it can be abundant while in other years quite rare.

Identification

The Pin-cushion Urchin has a brown or purple test (body), short white spines sometimes tipped with orange, and brownish-red tube feet.

Habitat

Pin-cushion Urchins live in intertidal areas and coastal waters to a depth of 75 m.

Distribution

The Pin-cushion Urchin is found in Queensland, New South Wales and Western Australia. Also found in the Indo-Pacific region.

Other behaviours and adaptations

This species has a habit of grabbing pieces of seaweed, shell or pebbles with its tube feet and covering itself. This may act as camouflage and protect it from predators and the sun.