Todd Lajeunesse

Professor of Biology

Todd Lajeunesse

Research Summary

Microbial Ecology and Evolution

Huck Graduate Students

Huck Affiliations


Publication Tags

Coral Reefs Ecology Anthozoa Symbiodinium Miozoa Symbiosis Coral Dinoflagellate Corals Population Genetics Sampling Reefs Symbionts Endosymbionts Symbiont Phylogeny Coral Reef Iron Ribosomal Dna Symbiodiniaceae Dinoflagellida Species Diversity New Species Genetic Markers Scleractinia

Most Recent Papers

Iron Availability Modulates the Response of Endosymbiotic Dinoflagellates to Heat Stress

Hannah G. Reich, Wan Chen Tu, Irene B. Rodriguez, Yalan Chou, Elise F. Keister, Dustin W. Kemp, Todd C. LaJeunesse, Tung Yuan Ho, 2021, Journal of Phycology on p. 3-13


Todd C. LaJeunesse, 2020, Current Biology on p. R1110-R1113

Endosymbiotic dinoflagellates pump iron:differences in iron and other trace metal needs among the Symbiodiniaceae

Hannah G. Reich, Irene B. Rodriguez, Todd C. LaJeunesse, Tung Yuan Ho, 2020, Coral Reefs on p. 915-927

Iron availability modulates the response of endosymbiotic dinoflagellates to heat stress

Hannah Reich, Wan-Chen Tu, Irene Rodriguez, Yalan Chou, Elise Keister, Dustin Kemp, Todd Lajeunesse, Tung-Yuan Ho, 2020, Journal of phycology

Cladocopium infistulum sp. nov. (Dinophyceae), a thermally tolerant dinoflagellate symbiotic with giant clams from the western Pacific Ocean

Sung Yeon Lee, Hae Jin Jeong, Todd C. Lajeunesse, 2020, Phycologia on p. 515-526

Considerations for maximizing the adaptive potential of restored coral populations in the western Atlantic

Iliana B. Baums, Andrew C. Baker, Sarah W. Davies, Andréa G. Grottoli, Carly D. Kenkel, Sheila A. Kitchen, Ilsa B. Kuffner, Todd C. LaJeunesse, Mikhail V. Matz, Margaret W. Miller, John E. Parkinson, Andrew A. Shantz, 2019, Ecological Applications

Host–symbiont combinations dictate the photo-physiological response of reef-building corals to thermal stress

Kenneth D. Hoadley, Allison M. Lewis, Drew C. Wham, D. Tye Pettay, Chris Grasso, Robin Smith, Dustin W. Kemp, Todd C. LaJeunesse, Mark E. Warner, 2019, Scientific Reports

Correction to

Samantha Goyen, Emma F. Camp, Lisa Fujise, Alicia Lloyd, Matthew R. Nitschke, Todd C. LaJeunesse, Tim Kahlke, Peter J. Ralph, David Suggett, 2019, Coral Reefs on p. 877

Photosynthesis by symbiotic sponges enhances their ability to erode calcium carbonate

Michelle Achlatis, Christine H.L. Schönberg, Rene M. van der Zande, Todd C. LaJeunesse, Ove Hoegh-Guldberg, Sophie Dove, 2019, Journal of Experimental Marine Biology and Ecology on p. 140-149


Benjamin C.C. Hume, Edward G. Smith, Maren Ziegler, Hugh J.M. Warrington, John A. Burt, Todd C. LaJeunesse, Joerg Wiedenmann, Christian R. Voolstra, 2019, Molecular Ecology Notes on p. 1063-1080

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

Improved resolution of reef-coral endosymbiont (Symbiodinium) species diversity, ecology, and evolution through psbA non-coding region genotyping

Todd C. LaJeunesse, Daniel J. Thornhill, 2011, PLoS One

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

Species delimitation of common reef corals in the genus Pocillopora using nucleotide sequence phylogenies, population genetics and symbiosis ecology

Jorge H. Pinzón, Todd C. Lajeunesse, 2011, Molecular Ecology on p. 311-325

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

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.