Killer sponges sound like creatures from a B-grade horror movie. In fact, they thrive in the lightless depths of the deep sea. Scientists first discovered that some sponges are carnivorous about 20 years ago. Since then only seven carnivorous species have been found in all of the northeastern Pacific. A new article describes four new species of carnivorous sponges living on the deep seafloor, from the Pacific Northwest to Baja California....