New NSF grant funded


Collaborative Research: The ecological impact of mixotrophic algae in a changing Arctic marine climate. National Science Foundation, Arctic Natural Sciences. Co-PIs: R.J. Gast (Woods Hole Oceanographic Institution) and R.W. Sanders. 2016-2019.

DeVaul presents at NEAS Annual Meeting


Sarah gave a talk at the annual meeting of the Northeast Algal Society in April 2016 (Vertical distribution of mixotrophic nanoflagellates in a mesotrophic lake; S. DeVaul & R. Sanders). Bob presented a poster of Zaid’s last dissertation chapter (Competitive interactions of two Antarctic mixotrophs with either phototrophic or phagotrophic specialists; Z. McKie-Krisberg & R. Sanders).

Sarah DeVaul & Bob Sanders present at Ocean Sciences Meeting in New Orleans


Sarah presented some of her Ph.D. work on mixotrophy at the winter meeting (February 21-26) of the Association for the Sciences of Limnology and Oceanography (ASLO) . Bob presented work from his last ocean voyage in the Antarctic with Rebecca Gast of Woods Hole Oceanographic Institution. There are also a number of graduate students from the Cordes lab that presented at the meeting.

New pubs: DeVaul et al. in J. Phycol.; Mitra et al. in Protist


Temperature-dependent phagotrophy and phototrophy in a mixotrophic chrysophyte by Sarah DeVaul Princiotta, Brian T. Smith and Robert W. Sanders has been published in the Journal of Phycology (52:432-440) and can be found here.

Defining planktonic protist functional groups on mechanisms for energy and nutrient acquisition: incorporation of diverse mixotrophic strategies by Aditee Mitra and 22 co-authors (including R.W. Sanders) was published in Protist (167:106-120) and is available online at

Sarah DeVaul Awarded Best Grad Student Talk at PSA


At the 2015 Annual Meeting of the Phycological Society of America, which happened to be in Philadelphia this year, Sarah was awarded the Bold Award for the best graduate student talk during the conference. Her talk was entitled “Striking a Balance between Phototrophy and Heterotrophy in the Mixotrophic Chrysophyte Dinobryon sp.” Congrats to Sarah!

Three presentations from the lab at PSA Annual Meeting


The lab will have three presentations at the Phycological Society of America annual meeting that is taking place in Philadelphia this month.

Sarah DeVaul has an oral presentation entitled: Striking a balance between phototrophy and heterotrophy in the mixotrophic chrysophyte Dinobryon sp.;

Grier Sellers talk with Rebecca Gast (Woods Hole Oceanographic Institution is entitled: Dark survival and recovery of a foreign organelle-retaining dinoflagellate and its haptophyte prey and plastid source following a simulated austral winter

and Bob Sanders will present a poster by Zaid McKie-Krisberg, Rebecca Gast and Bob Sanders entitled:  Gene expression and gene ontology in two species of mixotrophic Antarctic phytoplankton.

Papers published in ‘Limnology & Oceanography’ and ‘Freshwater Biology’


Sanders, R.W., S.L. Cooke, J.M. Fischer, S.B. Fey, A.W. Heinze*, W.H. Jeffrey, A.L. Macaluso*, R.E. Moeller, D.P. Morris, P.J. Neale, M. Olson, J.D. Pakulski, J.A. Porter, D.M. Schoener*, C.E. Williamson. 2015. Shifts in microbial food web structure and productivity after additions of naturally occurring dissolved organic matter: results from large-scale lacustrine mesocosms. Limnology & Oceanography. 60: 2130-2144. DOI: 10.1002/lno.10159

Cooke, S.L., J.M. Fischer, K. Kessler, Craig E. Williamson, R.W. Sanders, D.P. Morris, J.A. Porter, W.H. Jeffrey, S.B. DeVaul*, J.D. Pakulski. 2015. Direct and indirect effects of additions of chromophoric dissolved organic matter on zooplankton during large-scale mesocosm experiments in an oligotrophic lake. Freshwater Biology. 60:2362-2378.  DOI:10.1111/fwb.12663

*Current or former graduate students in the lab.

Graham paper published in JEMBE


Erin’s final paper from her Ph.D. work was published: Graham, E.R., A. Parekh, R.K. Devassy and R.W. Sanders. 2015. Carbonic anhydrase activity changes in response to increased temperature and pCO2 in Symbiodinium-zoanthid associations.Journal of Experimental Marine Biology and Ecology 473:218-226.  Here’s a link.

Amy Parekh and Roni Devassy were undergraduate researchers in the lab.

Congrats to them all!


McKie-Krisberg paper published in Microbial Ecology


McKie-Krisberg, Z.M., R.J. Gast and R.W. Sanders. 2015. Physiological responses of three species of Antarctic mixotrophic phytoflagellates to changes in light and dissolved nutrients. Microbial Ecology 70:21-29.

Abstract: Antarctic phototrophs are challenged by extreme temperatures, ice cover, nutrient limitation and prolonged periods of darkness. Yet this environment may also provide niche opportunities for phytoplankton utilizing alternative nutritional modes. Mixotrophy, the combination of photosynthesis and particle ingestion, has been proposed as a mechanism for some phytoplankton to contend with the adverse conditions of the Antarctic. We conducted feeding experiments using fluorescent bacteria-sized tracers to compare the effects of light and nutrients on bacterivory rates in three Antarctic marine photosynthetic nanoflagellates representing two evolutionary lineages: Cryptophyceae (Geminigera cryophila), and Prasinophyceae (Pyramimonas tychotreta and Mantoniella antarctica). Only G. cryophila had previously been identified as mixotrophic. We also measured photoautotrophic abilities over a range of light intensities (P vs. I) and used dark survival experiments to assess cell population dynamics in the absence of light. Feeding behavior in these three nanoflagellates was affected by either light, nutrient levels, or a combination of both factors in a species-specific manner that was not conserved by evolutionary lineage. The different responses to environmental factors by these mixotrophs supported the idea of tradeoffs in the use of phagotrophy and phototrophy for growth.

Sarah DeVaul receives PSA Fellowship


Sarah had a busy week. While she was at the Northeast Algal Society Symposium giving a talk and winning awards, she learned that she had received the Hannah T. Coasdale Fellowship from the Phycological Society of America to cover some of her costs toward attending a workshop on Molecular Methods for Algae Research offered by The Scottish Association for Marine Science in Oban, Scotland.

Sarah DeVaul receives NEAS awards


Sarah attended the Northeast Algal Society Symposium in Syracuse, NY and received an NEAS Travel Award plus the Robert T. Wilce Award for Best Graduate Student Presentation. Her talk was: “Temperature-Dependent Phagotrophy and Phototrophy in a Mixotrophic Chrysophyte.”