MONTEREY, Calif., April 15 (UPI) -- Carnivorous sponges are the venus flytraps of the ocean floor; they're also exceedingly rare. Scientists have only discovered seven since the first was observed 20 years ago.
But now, marine biologists have found and studied in great depth four new species found off the California coast, from the Pacific Northwest to Baja California: Asbestopluma monticola, Asbestopluma rickettsi, Cladorhiza caillieti and Cladorhiza evae.
The new study was written by marine biologist Lonny Lundsten, of the Monterey Bay Aquarium Research Institute, with the help of two Canadian researchers. It was published this week in the journal Zootaxa.
Sea-floor sponges are typically filter feeders, meaning they subsist off of bacteria and tiny, single-celled organisms sucked up by their cells from the surrounding ocean water. Many sponges wave long tentacle-like branches back and forth, creating a current. The small current draws in nutrient-rich water and nourishes their specialized cells called choancytes.
But carnivorous sponges, like the ones detailed in this latest paper, don't employ choancytes. "To keep beating the whip-like tails of the choancytes takes a lot of energy," explained author Lonny Lundsten. "And food is hard to come by in the deep sea. So these sponges trap larger, more nutrient-dense organisms, like crustaceans, using beautiful and intricate microscopic hooks."
While these various sponges all continue to feed on small bacteria, their tiny hooks are also capable of trapping small sea animals such as shrimp-like amphipods. Once in the grasp of the killer sponge, these crustaceans only take a few hours to be digested. Soon, all that is left is the shell.
[Monterey Bay Aquarium Research Institute]