The carnivorous candelabra sponge

Scientific papers are conservative and dry, and taxonomic papers are often even more notoriously dry and conservative than normal. So when a new species is described in the title as “extraordinary,” it’s worth popping open the PDF and having a peek at the figures.

Whoa.

This is a sponge.

Not exactly the loofa-shaped blob most people think of as sponges, is it?

This picture above is my favourite, but there is a lot of variation in the number and directions of the main branches, as shown in this set of images:

Not only does this deep sea sponge have the sort of otherworldy appearance that inspired James Cameron for Avatar, Lee and colleagues claim that it’s also a meat eater.

Carnivorous spongers were discovered back in the 1990s. They’re not active “chase and kill” predators, but “wait and digest” predators. Carnivorous sponges have places where invertebrates get snagged on spiny bits (spiracles), and the sponge then sort of dissolves the captured corpses that sits on their body.

Disappointingly, the paper does not have pictures of invertebrates speared on the sponge. In close up, it features some nasty looking hooks and spines:

The evidence that the authors use to claim that this sponge is carnivorous is the combination of the spikey spiracles plus the comb-like arrangement of the vanes, which would seem to provide maximum capturing opportunities for unwary crustaceans swept along in the current. Lee and colleagues note that you see the same sort of arrangement in other filter-feeding carnivores. Just how the sponge might digest its prey remains to be seen. Given how deep it lives – all the specimens found were at least 3,000 meters down – it’ll probably be a while before anyone is able to do some detailed research on this animal’s feeding.

Reference

Lee WL, Reiswig HM, Austin WC, Lundsten L. 2012. An extraordinary new carnivorous sponge, Chondrocladia lyra, in the new subgenus Symmetrocladia (Demospongiae, Cladorhizidae), from off of northern California, USA. Invertebrate Biology: in press. http://onlinelibrary.wiley.com/doi/10.1111/ivb.12001/abstract DOI: 10.1111/ivb.12001