Todd LaJeunesse


Todd LaJeunesse is a tenured professor in the Biology Department at Penn State. While as a boy and living on the coast of Maine, he cultivated a fascination and personal connection with nature, especially marine invertebrates. He received his undergraduate degree from Cornell University and his PhD from the University of California, Santa Barbara in 2000.

LaJeunesse’s laboratory relies on molecular-genetic analyses to characterize the diversity, ecological niche and geographic range of the corals’ symbionts. These observations yield considerable knowledge about corals and how environmental factors govern these partnerships.

He has published approximately 60 research articles in peer-reviewed international journals and his research is funded by the National Science Foundation and by The Pennsylvania State University. For more information, please visit his laboratory’s website More information on coral symbionts is available on the Wikipedia page.

Zooxanthellae, corals and symbiosis

The evolution of complex life forms on our planet ultimately resulted from the fusion of simple, yet different, single-celled organisms during the early part of Earth’s natural history. Today all of life on our planet depends on the mutualism exhibited by many different kinds of both complex and simple organisms: plants, animals, fungi, bacteria etc..

Even as humans, we are highly dependent on the bacteria that live in our guts. Coral Reef ecosystems are a prime and vivid example of the importance of symbiotic interactions. Simple animals in the phylum Cnidaria have developed close relationships with single-celled, yet complex, species of dinoflagellate, an algal group important to the ocean’s plankton and marine food webs.

These seemingly humble combinations are why coral reef ecosystems exist today; and why they are potentially endangered in the coming decades. As enthusiasts that grow, propagate, and trade in live coral come, learn more about these amazing mutualisms and how they function. Perhaps in doing so, raise your appreciation for them in ways previously unfathomable.