Carnivorous sea sponge gives prey the kiss of death

A newly-discovered carnivorous sponge with a taste for shrimp gives its prey the kiss of death before sucking the life out of it.

"It's just like a fly getting caught in a spider's web," Niwa marine scientist Michelle Kelly said.

She helped classify the sponge, after it was dragged up from 1000 metres under the sea on the Macquarie Ridge, which runs south from New Zealand.

The sponge has not been given a formal name.

However, Dr Kelly has taken to calling it "the paperclip sponge" because of lip-shaped skeleton-like structures on its outside.

"It's like it's covered in Velcro. It has these little hooks on it," she said.

"If a silly little crustacean comes along it gets tangled up in the hooks. The more it struggles the more it gets tangled. Then cells digest the animal. It gets sucked dry basically."

The sponge doesn't have a mouth or stomach. Its dining method was "a very passive process", Dr Kelly said.

"Basically the nutrients from the sponge are transported into the sponge."

The sponge is new to science and was found in 2008, but was only recently classified.

It probably became carnivorous because it lived at great depths, Dr Kelly said.

"There is not a lot of filterable food below 1000 metres. These sponges seem to have evolved a prey-capture mechanism to take advantage of these opportunities in the deep sea."

The Macquarie Ridge was the first place the species has been found.

The specimen that Dr Kelly helped classify is now in France being scanned by colleagues to find out more of its secrets.

The first carnivorous sponge was found in 1995 by professors Jean Vacelet and Nicole Boury-Esnault in the Mediterranean Sea.

"It changed the way we think about the sponges," Dr Kelly said.

"Until then, they were known only as filter feeders. Marine scientists are discovering species that are new to science all the time.

"The ocean is full of mysteries, unknown species, and never-before seen phenomena."

- © Fairfax NZ News