Mixotrophs

Tiny Creatures, Part Plant and Part Animal, May Control the Fate of the Planet

Mixotrophs, tiny sea creatures that hunt like animals but grow like plants, can change everything from fish populations to rates of global warming

• By Aditee Mitra | Scientific American April 2018 Issue

SUCKER PUNCH: One mixotroph, Dinophysis (right), sucks photosynthesizing organs from another, Mesodinium. Credit: Mark Ross Studios

Summer sunlight flickers through warm waters off the coast of Spain. The sea looks calm and peaceful. Near the surface, invisible to the naked eye, a swarm of microscopic plankton, some orange-pink and others dark green, swim in lazy circles, capturing the sun's rays and using the solar energy to make nutrients through photosynthesis.

Suddenly, a tentacled creature called Mesodinium—at 22 microns, a giant next to some of the three-micron sun-gathering plankton—comes zigzagging through the waters, drawn by sugars and amino acids leaking from the smaller organisms. Its tentacles shoot out and engulf the hapless green prey, or nanoflagellates, which are completely consumed and digested./.../