Deep waters near New Zealand have produced 6 bizarre new species of sponges
The biodiversity of the deep ocean is difficult to follow, given its inhospitality to us – the inhabitants of the soft, air-breathing land. In the darkness there is much more life than we have counted.
Nonetheless, a new discovery is exciting: six new species and a hitherto unknown genus of glass sponge, at depths of up to 4,820 meters (15,814 feet), hidden in aphotic (barely sunny) waters. off the coast of New Zealand. Scientists have also discovered two already known species that had never been seen before in New Zealand’s oceans.
These findings mean that the region is much more diverse than we thought, which can help inform and plan human activities and conservation efforts.
“The expedition was a great success,” said marine biologist Gert Wörheide from Ludwig Maximilian University in Munich, Germany.
“The findings nearly double the number of species in the Rossellidae sponge family found off New Zealand, from nine species in five genera to 17 species representing eight genera.”
Glass sponges (or hexatinellids) are known around the world, but are relatively rare. They are delicate sponges made up of spicules of silica – the natural substance so commonly found in sand, from which we make glass.
The waters around New Zealand beyond where light enters are increasingly known as a hotspot for glass sponges, but due to the challenges of mapping deep-sea biodiversity , we don’t know exactly how prolific life is there. A team of scientists therefore left on an expedition to explore using a remotely controlled underwater vehicle (ROV).
In 2017, the German research vessel Ring left Auckland, with the KIEL6000 ROV on board – a machine designed to probe the depths of the ocean, down to 6000 meters. For 31 days, researchers explored the distant southern oceans, recovering more than 200 sponge specimens from the seabed.
Among these specimens, the researchers used DNA and morphological analyzes to identify the six species hitherto unknown to science. Two of them were so new that they required a whole new genre that the researchers named Nubes.
The new species are Bathydorus poculum (1150 meters deep), Scyphidium variospinosum (1,630.5 meters), Caulophagus Serpens (4,816 meters), C. ramosus (4,819 meters), Tubular nubes (767 to 782 meters), and N. poculiformis (1,285 meters).
“Our expedition discovered that the deep waters off the coast of New Zealand are considerably richer in species than previously thought,” Wörheide said.
“In the context of plans to expand deep-sea mining and deep-sea fishing, these findings provide an important set of data that can aid efforts to protect these very special habitats.”
The description of the new sponges was led by the world’s foremost expert on glass sponges, marine biologist Henry Reiswig of the University of Victoria in Canada, cited as the first author of the article. Sadly, Reiswig passed away before the diary could be published; his colleagues dedicated the document to his memory.
“How are we going to continue? Well, continue on his behalf,” the team wrote. There were two other news sponges whose descriptions were not complete; these will soon be reported in a separate document.
The research was published in ZooKeys.