They look like fuzzy fingers, waving gently from the depths of the ocean floor but make no mistake — they're stone cold killers.
Scientists have discovered four new species of carnivorous sponge off the Pacific Coast, including one deadly variety found hanging from the deep-sea ridges off southern Vancouver Island.
Fortunately, these killers are about the size of a piece of spaghetti and they feed only on the tiny, shrimp-like amphipods and copepods that drift through the sea.
"Sponges characteristically feed on small particles, like bacteria, little tiny guys," said Henry Reiswig, a retired professor of biology at McGill University, volunteer taxonomist at the University of Victoria and the Royal British Columbia Museum, and self-described "sponge guy."
But these meat eaters feed on tiny crustaceans.
"It's a snaring process involving spicules, pieces of glass on their surfaces that they use to snare," said Reiswig, who is "77 or something like that."
Two of the newly discovered species were collected by the Monterey Bay Aquarium Research Institute off the California coast and another from a hydrothermal vent field in the Gulf of California off Mexico. The fourth hails from a formation called the Endeavour Segment on the Juan de Fuca Ridge, off south Vancouver Island.
The Canadian beast, Cladorhiza caillieti, looks like a skinny bottle brush. The samples were five to seven centimetres long and only millimetres wide, found attached to the underside of overhanging ledges of basalt more than two thousand metres below sea level.
Reiswig and William Austin, of the Khoyatan Marine Laboratory on Vancouver Island, were enlisted by marine biologist Lonny Lundsten from Monterey Bay Aquarium Research Institute to help identify the sponges.
Carnivorous sponges were only discovered in 1995. Since then, only 137 species have been described, including these four. Just 11 of them were found in the North Pacific.
They've been described as the Venus fly traps of the deep sea, a "truly extraordinary species," wrote Lonny Lundsten, the lead author of an article published in the most recent edition of the scientific journal Zootaxa.
Lundsten said the samples were collected by remotely operated vehicles during other research, most of it geological surveys of the sea floor.
Their meat-eating ways are believed to be an adaptation to the nutrient-poor environs of the deep sea, where most are found.