WhatTheyThink    WhatTheyThink.com    Blogs    PrintPlanet


Spongebarb

By on November 16th, 2012

Sometimes people know exactly what kind of headline will grab my attention, and the phrase “meat-eating sponge” will certainly do the trick.

A specimen for Liberace’s aquarium, perhaps: the harp sponge. (Photo: Monterey Bay Aquarium Research Institute)

In the ocean depths off the coast of Monterey, Calif., researchers have identified—by means of a remote-controlled deep-sea exploration vehicle—a new carnivorous sponge that resembles a candelabra or, in fact, a harp, which they have called the “harp sponge.” Living at a depth of about 11,000 feet, the harp sponge (Chondrocladia lyra) is carnivorous, having barbs on its branching limbs that snag passing crustaceans.

The sponge was first identified in 2000, several were captured, others were videotaped, and researchers have been poring (as it were) over the sponges ever since, finally publishing new insights into its behavior in the Oct. 18 issue of the journal Invertebrate Biology.

Although most sponges feed by filtering bacteria and micro-organisms out of the water, a few carnivorous species are known. Sponges are classified as animals in the phylum Porifera, meaning “pore bearer” as, indeed, they—like their household namesakes—comprise pores and channels through which water circulates. Sponges lack traditional organs and often filter what they require for feeding and respiration out of the water.

The harp sponge captures its prey using the Velcro-like barbs, envelops it in a thin membrane, and digests it. The largest harp sponges observed had limbs that stretched as high as 14 inches.