Introduced Species

For other Echinoderms:

The animals in this class are either globular or flattened with an outer shell (test). In sea urchins and sand dollars, the test is divided into five equal parts, each with a pair of vertical rows of holes for tube feet and spines. Sea urchins have their mouth at the bottom of the test. This mouth extends into a very sophisticated feeding apparatus called an Aristotle's lantern which has five teeth that all work together to grind algae off rocks. They will also consume animal material when it is available. There are several species of urchin commonly kept at the Marine Discovery  Centre:

Goniocidaris tubaria - Pencil Urchin Picture: MDC

Habitat: Sheltered and moderately exposed reef; 0 - 630 m depth Distribution: WA to NSW and around Tasmania Maximum Size: Test diameter to 60 mm Diet: Algae Comments:  The spines of this urchin are often covered with encrusting invertebrates.

Centrostephanus rodgersii - Black Spiny Sea Urchin Barren (Andrew, 1999)

Habitat: Exposed reef; 0 - 35 m depth Distribution: Victoria to NSW and around Tasman Peninsula, Tasmania Maximum Size: Test diameter to 100 mm Diet: Kelp, other macroalgae Comments:  This has found it's way down the east coast from NSW and Tasmania and is seen as a pest in Tasmania. When found in large numbers, these urchins can eliminate kelp and other macroalgae and form urchin barrens of 'white rock'. They differ from Heliocidaris by having hollow spines rather than solid spines.

Amblypneustes ovum - Egg Sea Urchin Picture: MDC

Habitat: Sheltered and moderately exposed reef; 0 - 70 m depth Distribution: SA to Victoria and around Tasmania Maximum Size: Test diameter to 60 mm Diet: Algae Comments:  This is a short-spined urchin, often found amongst the fronds of seaweeds.

Heliocidaris erythrogramma - Purple Sea Urchin Picture: MDC

Habitat: Sheltered and moderately exposed reef; 0 - 35 m depth Distribution: WA to Qld and around Tasmania Maximum Size: Test diameter to 90 mm Diet: Large macroalgae Comments: Like Centrostephanus, this species has the ability to create urchin barrens by eating all the macroalgae when in large aggregations. This species also supports a commercially important fishery in Southern Australia.