A team of scientists led by Dr Lonny Lundsten of the Monterey Bay Aquarium Research Institute (MBARI) in Moss Landing, California, has discovered an extraordinary new species of carnivorous sponge.
The new species is named the harp sponge, or Chondrocladia lyra, because its basic structure is shaped like a lyre or harp.
Typically, sponges feed by straining bacteria and bits of organic material from the seawater they filter through their bodies. However, C. lyra is a deep-sea predator.
Harp sponges snare their prey – tiny crustaceans – with barbed hooks that cover the sponge’s branching limbs. Once the harp sponge has its prey in its clutches, it envelops the animal in a thin membrane, and then slowly begins to digest it.
Using MBARI’s remotely operated vehicles, the team collected two sponges and made video observations of ten more. The first harp sponges that they found had only two vanes. However, additional dives revealed sponges with up to six vanes radiating out from the organism’s center. Scientists believe the harp sponge has evolved this elaborate candelabra-like structure in order to increase the surface area it exposes to currents, much like sea fan corals. The findings appear in a paper published in the journal Invertebrate Biology.
It has been less than twenty years since scientists first discovered that sponges could be carnivores. Since then, marine biologists have discovered dozens of new carnivorous species. In fact, all the members of the harp sponge’s family Cladorhizidae are carnivores.
“C. lyra is an extraordinary example of the kind of adaptations that animals must make in order to survive in such a hostile environment.”
Bibliographic information: Lee W.L. et al. An extraordinary new carnivorous sponge, Chondrocladia lyra, in the new subgenus Symmetrocladia (Demospongiae, Cladorhizidae), from off of northern California, USA. Invertebrate Biology, published online before print 18 October 2012; doi: 10.1111/ivb.12001