Researchers at James Cook University are beginning to unravel the larval life of a common Great Barrier Reef sponge, paving the way for sustainable ways to stock public aquariums.
The work has established how larvae of the sponge Coscinoderma mathewsi find their way to coral reefs where they then spend their adult lives.
Published online in the journal Coral Reefs, the work is part of a project funded by the Australian Research Council and the Great Barrier Reef Marine Park Authority's Reef HQ Aquarium, the world's largest living coral reef aquarium.
Dr Steve Whalan, a Research Fellow in the School of Marine and Tropical Biology at JCU, was one of the supervisors of the project, which was carried out by PhD student Muhammad Azmi Abdul Wahab.
The project will establish sustainable culture techniques for sponges, which are highly valuable to reef ecosystems.
"Their presence in coral reef ecosystems, coupled with their remarkable functional role in filtering large volumes of water, with high retention of suspended particles, make them ideal organisms to incorporate within a captive coral reef environment," Dr Whalan said.
"Reef HQ Aquarium was the perfect project partner for this research.
"Culturing and displaying sponges in a sustainable way has become a recent focus of Reef HQ Aquarium."
Reef HQ Aquarium Director Fred Nucifora said Reef HQ was the National Education Centre for the Great Barrier Reef and prides itself on showcasing and supporting reef research that contributes to better understanding and management of the Great Barrier Reef Marine Park.
"What this research does is help remove the reliance on collection of specimens from the wild," he said.
Dr Whalan said a move to sustainable culture of coral reef invertebrates for aquariums helps remove the impact directly and overall contributes to maintaining and conserving the reef biodiversity.
"Patterns of larval release, dispersal and settlement in sponges are poorly understood, despite their significance in explaining adult ecology.
"Sponges spend their adult lives in one place and are unable to move, but produce swimming larvae that spend two to three days looking for a suitable home.
"Our research has established when larvae are released and has identified a series of behaviours that help it make its decision of where it will spend its adult life.
"Once it changes from a larva into a sponge it is unable to move away from any nasty environmental conditions.
"As a larva it uses a complex range of processes that help it identify a suitable home including swimming at the surface for 24 hours before it moves to the bottom, relying on chemical cues associated with coral reef habitats, such as bacterial biofilms and coral rubble.
"Using this information will allow Reef HQ Aquarium to collect larvae and manipulate settlement surfaces to optimise larval recruitment which can then be grown as aquarium exhibits."
