Abundant Tiny Hosts

Under a microscope, a copepod looks fearsome, but at only one-sixteenth of an inch, it won’t bother you on a swim. People seldom see these tiny marine crustaceans, but they may be the most abundant animals in the sea. Copepods live in all oceans and are a vital link in ocean food chains. They also serve as homes for a wide variety of bacteria. MIT-WHOI Joint Program student Amalia Aruda recently examined copepods and their bacterial assortments, or “microbiomes.”(Photo by Ann Tarrant, Woods Hole Oceanographic Institution)