Animals Behaving Like Plants

Meet a curious single-celled organism called Mesodinium rubrum. They are shaped like “8”s with hairlike cilia around them that they use to swim in the ocean. They usually graze on algae, but M. rubrum also have the capability to make their own food. They can steal organelles from the algae they eat, incorporating algal nuclei and chloroplasts inside their own cells. The pilfered organelles perform photosynthesis to make food for M. rubrum, allowing the animal to temporarily behave like a plant. WHOI biologist Matt Johnson and former WHOI postdoctoral fellow Holly Moeller study this metabolic strategy, which is called acquired phototrophy. (Matt Johnson Woods Hole Oceanographic Institution)