Calling all beachcombers – have you seen this sponge?

Not an Agelasaxifera, but this specimen from the Houtman Abrolhos Islands looks similar to the rare sponge the Museum is looking for.

Not an Agelasaxifera, but this specimen from the Houtman Abrolhos Islands looks similar to the rare sponge the Museum is looking for.

Beachcombers, divers, swimmers and anglers are being asked to help the Western Australian Museum find examples of a very rare marine sponge, Agelasaxifera, known only to the Champion Bay area in Geraldton.  

The Museum is hoping recent storms in the area might have washed the sponges onto the beach. 

WA Museum Head of Aquatic Zoology Dr Jane Fromont said the species was first described in 1911 from the holotype collected at Champion Bay in 1905 – the only known location of Agelasaxifera worldwide. 

A holotype is the first example of a named species ever identified, described and published. The Agelasaxifera holotype was taken to Germany early last century for scientific study and lodged with a museum in Hamburg, but was destroyed during World War II. 

“The WA Museum is looking for a new specimen of this sponge to replace the holotype, which would be known as a neotype,” Dr Fromont said.  

“I would encourage everyone in the Geraldton area who explores the beach to look out for a cup-like sponge with a bumpy surface, and possibly a light brown colour. 

“The best time to make such a discovery is after a storm or whenever Geraldton has big seas. This is when kelp and sponges are torn off the bottom of the ocean and are washed onto the shore.” 

People are asked to first photograph a sponge in situ using their camera or smart-phone so the image records the GPS location of the find. They can then take their discovery to the WA Museum – Geraldton to be tested.  

“Museum staff will perform a bleach test on a small piece of the sponge to determine if it has the characteristic spicules of the Agelas species and, if this is the case, they will preserve the collected specimen in ethanol and arrange for its transport to Perth,” Dr Fromont said. 

“Sponges up to 12 months old may still have molecular value so if you think you found something like the Agelasaxifera in recent times, and you still have it, you can also bring this to the Museum to be assessed.” 

The discovery of a neotype would help the WA Museum identify other sponge specimens in the State Collection, by providing a known example of Agelasaxifera for comparison.