Throughout his studies to become a marine biologist, Dr. Christian Heesch became fascinated with the organisms known as cnidarians. This phylum is home to the true jellyfish. A true jellyfish is one that has offensive and defensive capabilities, such as the ability to sting its prey or a threatening predator. Stinging smaller forms of copepod zooplankton is what helps to keep the copepod population at a reasonable level in all of the oceans around the world.