Todd Lajeunesse

Professor of Biology

Todd Lajeunesse

Research Summary

Microbial Ecology and Evolution

Huck Graduate Students

Huck Affiliations


Publication Tags

Coral Reefs Ecology Symbiodinium Coral Anthozoa Corals Symbiont Symbionts Miozoa Dinoflagellate Symbiosis Population Genetics Dinoflagellida Coral Reef Reefs Endosymbionts Scleractinia Ecosystem Genotype Endosymbiont Reef New Species History Adaptive Radiation Genome

Most Recent Papers

Robert Kent Trench (1940–2021): a life devoted to symbiotic mutualisms and seeking nature’s truth.

Todd Lajeunesse, 2022, Symbiosis on p. 393–400

Revival of Philozoon Geddes for host-specialized dinoflagellates, ‘zooxanthellae’, in animals from coastal temperate zones of northern and southern hemispheres

Todd C. LaJeunesse, Joerg Wiedenmann, Pilar Casado-Amezúa, Isabella D’Ambra, Kira E. Turnham, Matthew R. Nitschke, Clinton A. Oakley, Stefano Goffredo, Carlos A. Spano, Victor M. Cubillos, Simon K. Davy, David J. Suggett, 2022, British Phycological Journal on p. 166-180

Robert Kent Trench (1940–2021)

Todd C. LaJeunesse, Anastazia T. Banaszak, Charles R. Fisher, J. Malcolm Shick, Mark E. Warner, James W. Porter, Armand M. Kuris, Roberto Iglesias-Prieto, William K. Fitt, 2021, Symbiosis on p. 393-400

Mutualistic microalgae co-diversify with reef corals that acquire symbionts during egg development

Kira E. Turnham, Drew C. Wham, Eugenia Sampayo, Todd C. LaJeunesse, 2021, ISME Journal on p. 3271-3285

Different functional traits among closely related algal symbionts dictate stress endurance for vital Indo-Pacific reef-building corals

Kenneth D. Hoadley, Daniel T. Pettay, Allison Lewis, Drew Wham, Chris Grasso, Robin Smith, Dustin W. Kemp, Todd LaJeunesse, Mark E. Warner, 2021, Global Change Biology on p. 5295-5309

Solar Symbionts: Casting new light on the ancient partnership of reef-building corals and the micro-algae known as zooxanthellae, family Symbiodiniaceae

John Parkinson, Todd Lajeunesse, 2021,

Stress endurance among critical Indo-Pacific reef building corals is influenced by the unique physiology of their recently evolved photobionts.

Kenneth Hoadley, Todd Lajeunesse, 2021, Global Change Biology on p. 5295–5309

Miliolidium n. gen, a New Symbiodiniacean Genus Whose Members Associate with Soritid Foraminifera or Are Free-Living

Xavier Pochon, Todd C. LaJeunesse, 2021, Journal of Protozoology

Philozoon: a new dinoflagellate genus of host–specialized endosymbionts found in Cnidaria from coastal temperate zones in northern and southern hemispheres.

Todd LaJeunesse, 2021, European Journal of Phycology

Bringing the ecology and evolution of coral-dinoflagellate symbioses into high resolution

Todd Lajeunesse, 2021,

Most-Cited Papers

Systematic Revision of Symbiodiniaceae Highlights the Antiquity and Diversity of Coral Endosymbionts

Todd C. LaJeunesse, John Everett Parkinson, Paul W. Gabrielson, Hae Jin Jeong, James Davis Reimer, Christian R. Voolstra, Scott R. Santos, 2018, Current Biology on p. 2570-2580.e6

Genomes of coral dinoflagellate symbionts highlight evolutionary adaptations conducive to a symbiotic lifestyle

M. Aranda, Y. Li, Y. J. Liew, S. Baumgarten, O. Simakov, M. C. Wilson, J. Piel, H. Ashoor, S. Bougouffa, V. B. Bajic, T. Ryu, T. Ravasi, T. Bayer, G. Micklem, H. Kim, J. Bhak, T. C. LaJeunesse, C. R. Voolstra, 2016, Scientific Reports

Assessing Symbiodinium diversity in scleractinian corals via next-generation sequencing-based genotyping of the ITS2 rDNA region

Chatchanit Arif, Camille Daniels, Till Bayer, Eulalia Banguera-Hinestroza, Adrian Barbrook, Christopher J. Howe, Todd C. Lajeunesse, Christian R. Voolstra, 2014, Molecular Ecology on p. 4418-4433

A genetics-based description of Symbiodinium minutum sp. nov. and S. psygmophilum sp. nov. (dinophyceae), two dinoflagellates symbiotic with cnidaria

Todd C. Lajeunesse, John E. Parkinson, James D. Reimer, 2012, Journal of Phycology on p. 1380-1391

Host-specialist lineages dominate the adaptive radiation of reef coral endosymbionts

Daniel J. Thornhill, Allison M. Lewis, Drew C. Wham, Todd C. Lajeunesse, 2014, Evolution; international journal of organic evolution on p. 352-367

Ecologically differentiated stress-tolerant endosymbionts in the dinoflagellate genus Symbiodinium (Dinophyceae) Clade D are different species

Todd C. Lajeunesse, Drew C. Wham, D. Tye Pettay, John Everett Parkinson, Shashank Keshavmurthy, Chaolun Allen Chen, 2014, Phycologia on p. 305-319

Microbial invasion of the Caribbean by an Indo-Pacific coral zooxanthella

D. Tye Pettaya, Drew C. Whama, Robin T. Smith, Roberto Iglesias-Prietoc, Todd C. LaJeunessea, 2015, Proceedings of the National Academy of Sciences of the United States of America on p. 7513-7518

Blind to morphology

Jorge H. Pinzón, Eugenia Sampayo, Evelyn Cox, Leonard J. Chauka, Chaolun Allen Chen, Christian R. Voolstra, Todd C. Lajeunesse, 2013, Journal of Biogeography on p. 1595-1608

Biogeography and molecular diversity of coral symbionts in the genus Symbiodinium around the Arabian Peninsula

Maren Ziegler, Chatchanit Arif, John A. Burt, Sergey Dobretsov, Cornelia Roder, Todd C. LaJeunesse, Christian R. Voolstra, 2017, Journal of Biogeography on p. 674-686

New insights into the dynamics between reef corals and their associated dinoflagellate endosymbionts from population genetic studies

Iliana B. Baums, Meghann K. Devlin-Durante, Todd C. Lajeunesse, 2014, Molecular Ecology on p. 4203-4215

News Articles Featuring Todd Lajeunesse

Scientists resurrect 'forgotten' genus of algae living in marine animals

In the late 1800s, scientists were stumped by the “yellow cells” they were observing within the tissues of certain temperate marine animals, including sea anemones, corals, and jellyfish. Were these cells part of the animal or separate organisms? If separate, were they parasites, or did they confer a benefit to the host?

Widespread coral-algae symbioses endured historical climate changes

One of the most important and widespread reef-building corals, known as cauliflower coral, exhibits strong partnerships with certain species of symbiotic algae, and these relationships have persisted through periods of intense climate fluctuations over the last 1.5 million years, according to a new study led by researchers at Penn State.

Coral’s resilience to warming may depend on iron

How well corals respond to climate change could depend in part on the already scarce amount of iron available in their environment, according to a new study led by Penn State researchers.

Iron deficiency in corals?

When iron is limited, the tiny algae that live within coral cells — which can provide the majority of a coral’s nutritional needs — change how they take in other trace metals, which could have cascading effects on vital biological functions.

Biology graduate student receives three awards for outstanding presentation

Penn State biology graduate student Hannah Reich has been honored with three awards for a presentation she gave at three scientific conferences during summer 2019.

How to restore a coral reef

New guidelines drafted by a consortium of concerned experts could enable corals to adapt to changing environments and help restore declining coral populations in the Caribbean.

Bleached Corals Compensate For Stress By Eating More Plankton

In healthy corals, symbiotic algae housed within the coral photosynthesize during the day while the coral itself feeds on zooplankton, tiny shrimp and bug-like organisms, during the night.

Algae and Coral Have Been BFFs Since the Dinosaur Age

A new study shows that the relationship between coral polyps and zooxanthellae that produces colorful coral reefs began 160 million years ago.

Coral reefs 'weathered dinosaur extinction'

Corals may have teamed up with the microscopic algae which live inside them as much as 160 million years ago, according to new research.