Marine Life
Invertibrates
Sea stars, urchins, sponges, molluscs and other invertebrates are fundamental to reef health and biodiversity.
Ecology and Diversity
Invertebrates of Southern Australia
Animals without backbones make up much of the visible life on the Great Southern Reef, including molluscs, echinoderms, worms and sponges. They occur from shallow rocky shores to deeper reefs, filling surfaces, crevices and the seafloor.
Some graze algae, others filter food from the water, and many are predators or scavengers. Their varied forms and feeding strategies connect habitats and food webs throughout southern Australia’s temperate marine environment.
Invertibrates of the Great Southern Reef
-
![]()
long spined sea urchin (Centrostephanus Rodgersii)
A large echinoderm recognised by its exceptionally long dark spines and its powerful grazing activity on rocky reefs.
-
![]()
Nudibranch (Order Nudibranchia)
A diverse group of shell-less marine molluscs celebrated for their extraordinary colours, patterns and specialised body forms.
-
![]()
Abalone (Haliotis laevigata)
A reef-dwelling marine snail with a broad muscular foot that holds tightly to rock while the animal grazes on algae.
-
![]()
sea stars (Nectria ocellata)
A reef-dwelling echinoderm with radial symmetry, tube feet and a textured surface characteristic of the group’s “spiny skin.”
-
![]()
Southern Fan Worms (Sabellastarte australiensis)
A tube-dwelling worm that extends an intricate feather-like crown into the water to breathe and capture suspended food.
-
![]()
Sponges (Phylum Porifera)
Simple multicellular animals whose porous bodies circulate seawater, allowing them to filter food and oxygen from the water.
Explore more Marine Life
-
![]()
Cephalopods
Learn about southern Australia’s octopuses, squid and cuttlefish.
-
![]()
Seaweeds
More than 1,500 seaweed species occur across the Great Southern Reef, including the kelps that create its underwater forests.
-
![]()
Fish
From tiny reef fish to iconic seadragons and large pelagic species, the Great Southern Reef supports remarkable fish diversity.
-
![]()
Crustaceans
Crabs, lobsters, prawns and other crustaceans play important roles in reef food webs and nutrient cycling.
Join Our Community
Sign up to our monthly newsletter to receive the latest updates from around the GSR.
Monthly Great Southern Reef updates. Unsubscribe at any time.