The researchers announced the discovery of three new species of carnivorous and carnivorous sponges – Nullarbora heptaxia, Abyssocladia oxyasters and Lycopodina hystrix. These species, recently described by scientists at the Queensland Museum, are the first recorded carnivorous species from South Australia.
“This find clearly demonstrates how many living things in the deep-sea oceans have yet to be studied,” said Merrick Ekins, one of the study’s authors and an employee of the Queensland Museum. The sponges found are unique in that they are only found in this particular area of the Great Australian Bight. Note that this region was planned to be used for deep-water oil development.
Usually sea sponges (Phylum Porifera) are multicellular filter feeders. These are aquatic animals that feed on small organisms of plankton or suspended organic particles – detritus, which are filtered out of the water. Sea sponges usually have leaky tissues for flowing water from which their cells extract oxygen and food. They are fairly simple creatures that do not have a nervous, digestive or circulatory system, but they have existed in one form or another for over 500 million years.
But with carnivorous sponges, the situation is different. Some predatory sponges still use a water flow system, while others (for example, three recently discovered species) have completely lost this ability and catch small crustaceans and other prey with special threads or hooks.
Biologists have discovered three new species of predatory sponges – Nullarbora heptaxia, Abyssocladia oxyasters, and Lycopodina hystrix. All of these species are found at depths ranging from 163 to over 3000 meters.
The new species are the first recorded carnivorous species from South Australia and increase the number of recorded species from across Australia to 25.
The discovered predators look more like flowers with spiky protrusions, but not like sea sponges.