Ann Bucklin

My research focus is the molecular ecology and evolution of zooplankton. My laboratory group uses diverse molecular approaches to study population ecology, population genetics, phylogeography, species diversity, and evolution of marine holozooplankton, especially copepods and euphausiids.

Environmental Transcriptomics: We use genomic and transcriptomic approaches to examine gene expression profiles in zooplankton using RNA sequencing, quantitative real-time PCR (QPCR) of target genes, and DNA microarrays. Current focus includes the copepod Calanus finmarchicus in the North Atlantic and the salp Salpa thompsoni in the Southern Ocean.  For more about our studies on the Southern Ocean salp and Antarctic krill studies, see

Population Genetics / Phylogeography: We are using various genetic markers – including multigene sequences, Single Nucleotide Polymorphisms (SNPs), and Restriction-site Associated DNA (RAD) markers – to examine spatial patterns of genetic variation of zooplankton from small-scale patches to ocean-basin scale gyres, and to measure population connectivity and infer pathways of transport in ocean currents.

Species biodiversity: We have worked to develop a new global view of zooplankton species diversity through the Census of Marine Zooplankton (CMarZ, see, an ocean realm field project of the Census of Marine Life (CoML).  We use DNA sequences for mitochondrial cytochrome oxidase I as barcodes (i.e., short DNA sequences for species recognition and discrimination) to characterize global-scale patterns of zooplankton species distribution and diversity. We are analyzing zooplankton samples by metabarcoding, which entails NGS (Illumina Mi-Seq) amplicon sequencing of selected marker genes (COI and 18S rRNA hypervariable regions) from unsorted zooplankton samples to allow rapid analysis of species diversity.

Phylogeny: We are using multigene datasets to analyze the evolutionary history and molecular phylogeny of copepods and euphausiids. A particular goal is to integrate molecular and morphological phylogenies for improved understanding of the timing and mode of speciation of these ecologically important and taxonomically complex zooplankton groups.

Research Projects

Environmental Genomics of Salpa thompsoni in the Southern Ocean – National Science Foundation / Office of Polar Programs

Strategic Initiative − The Arctic Ocean Ecosystem (SI_ARCTIC) – Norwegian Institute of Marine Research (Bergen and Tromsoe, Norway)

The Chukchi Borderlands: Exploration of Pelagic Life in a Complex Polar Environment – NOAA Office of Ocean Exploration and Research

Expedition ANTARCTIC BLANC, in collaboration with Ocean Genome Legacy ( More information about the Expedition at

Current Research Group Members

Jennifer Questel (Postdoctoral Fellow)

Heidi D. Yeh (PhD Student)

Birgitte Nilsson (Visiting PhD Student, Roskilde University, Denmark)

Hayley Mills DeHart (Research Intern)

Oceanography Alumni

– Kayla Erikson – M.Sc. 2015

– Paola Batta Lona – Ph.D. 2014

– Ebru Unal – Ph.D. 2011

– Brian Ortman – Ph.D. 2008

Honors Received

Fulbright Senior Fellowship, Institute of Marine Research, Bergen, Norway (1993-1994)

Fellow of the American Association for the Advancement of Science (Elected 1995)

Member, Connecticut Academy of Science and Engineering (Elected 2006)

Publications (2010-2018)

For full reference list, see my ORCID page and Google Scholar Profile at


Bucklin, A. K. DiVito, I. Smolina, M. Choquet, J.M. Questel, G. Hoarau and R.J. O’Neill (In Press) Population Genomics of Marine Zooplankton. In: Population Genomics: Marine Organisms, O.P. Rajora and M. Oleksiak (Eds.), Springer Publ.


Batta-Lona, P.G., A. Maas, R. O’Neill, P.H. Wiebe, and A. Bucklin. 2017. Transcriptomic profiles of spring and summer populations of the Southern Ocean salp, Salpa thompsoni, in the Western Antarctic Peninsula region. Polar Biol. 40: 1261–1276. doi:10.1007/s00300-016-2051-6

Choquet, M., M. Hatlebakk, A.K.S. Dhanasiri, K. Kosobokova, I. Smolina, J.E. Søreide, C. Svensen, W. Melle, S. Kwasniewski, K. Eiane, M. Daase,V. Tverberg, S. Skreslet, A. Bucklin and G. Hoarau. 2017. Genetics redraws pelagic biogeography of Calanus. Biol.  Lett. 13: 20170588.

Wiebe, P.H., M.C. Benfield, and A. Bucklin. 2017. Sampling, preservation, and counting of samples: ii) Zooplankton, Chapter 10: In: Marine Plankton: A Practical Guide to Ecology, Methodology, and Taxonomy. Claudia Castellani and Martin Edwards [Eds.] Oxford University Press.


Bucklin, A., P.K. Lindeque, N. Rodriguez-Ezpeleta, A. Albaina, and M. Lehtiniemi. 2016. Metabarcoding of marine zooplankton: Progress, prospects and pitfalls.  J. Plankton Res. Horizons 38: 393-400.  doi:10.1093/plankt/fbw023

Blanco-Bercial, L. and A. Bucklin. 2016. New view of population genetics of zooplankton: RAD-seq analysis reveals population structure of the North Atlantic planktonic copepod Centropages typicus. Molec. Ecol. 25: 1566-1580  doi: 10.1111/mec.13581

Jue, N., P.G. Batta-Lona, S. Trusiak, C. Obergfell, A. Bucklin, M. O’Neill, and R.J. O’Neill. 2016. Rapid evolutionary rates and unique genomic signatures discovered in the first reference genome for the Southern Ocean salp, Salpa thompsoni (Urochordata, Thaliacea). Genome Biol. Evol. 8: 3171-3186 doi: 10.1093/gbe/evw215

Nigro, L.M., M.V. Angel, K. Blachowiak-Samolyk, R.R. Hopcroft, and A. Bucklin. 2016. Identification, discrimination, and discovery of species of marine planktonic ostracods using DNA barcodes. PLoS-One 11(1): e0146327.  doi:10.1371/journal.pone.0146327

Questel, J.M., L. Blanco-Bercial, R.R. Hopcroft, and A. Bucklin. 2016. Phylogeography and connectivity of four sibling species of Pseudocalanus (Copepoda: Calanoida) in the North Pacific and Arctic Ocean. J. Plankton Res. doi:10.1093/plankt/fbw025

Snelgrove, P., E. Vanden Berghe, P. Miloslavich, N. Bailly, A. Brandt, A. Bucklin, and 23 others. 2016. Chapter 34. Global patterns in marine biodiversity. In: United Nations World Ocean Assessment I. See

Wiebe, P.H., A. Bucklin, S. Kaartvedt, A. Røstad, and L. Blanco-Bercial. 2016. Vertical distribution and migration of euphausiid species in the Red Sea. J. Plankton Res.  doi:10.1093/plankt/fbw038


Bucklin, A., D.J. McGillicuddy, P.H. Wiebe and C.S. Davis. 2015. Habitat usage by the cryptic copepods Pseudocalanus moultoni and P. newmani on Georges Bank (Northwest Atlantic). Cont. Shelf Res. 111: 83-94. doi:10.1016/j.csr.2015.11.001

Nair, V.R., F.X. Kidangan, R.G. Prabhu, A. Bucklin and S. Nair. 2015. DNA barcode of Chaetognatha from Indian Waters. Indian J. Geo-Marine Sci. 44: 1366-1376.

Viñas, M.D., L. Blanco-Bercial, A. Bucklin, H. Verheye, J. Guilherme, F. Bersano, and S. Ceballos. 2015. Phylogeography of the copepod Calanoides carinatus s.l. (Krøyer) reveals cryptic species and delimits C. carinatus s.s. distribution in SW Atlantic Ocean. J. Exp. Mar. Biol. Ecol. 468: 97-104. doi:10.1016/j.jembe.2015.03.012


Aarbakke, O.N., A. Bucklin, C. Halsband, and F. Norrbin. 2014. Comparative phylogeography and demographic history of five sibling species of Pseudocalanus (Copepoda: Calanoida) in the North Atlantic Ocean. J. Exp. Mar. Biol. Ecol. 461: 479-488. doi:10.1016/j.jembe.2014.10.006

Blanco-Bercial, L., A. Cornils, N.J. Copley, and A. Bucklin. 2014. DNA barcoding of marine copepods: assessment of analytical approaches to species identification. PLOS-Currents Tree of Life [2014 June 23]. doi: 10.1371/currents.tol.cdf8b74881f87e3b01d56b43791626d2


Christie, A.E., V. Roncalli, P. Batta-Lona, M.D. McCoole, B.L. King, A. Bucklin, D.K. Hartline, and P.H. Lenz. 2013. In silico characterization of the insect diapause-associated protein couch potato (CPO) in Calanus finmarchicus (Crustacea: Copepoda). Comp. Biochem. Physiol. Part D 8: 45–57. doi:10.1016/j.cbd.2012.11.002

Unal, E., A. Bucklin, P.H. Lenz, and D.W. Towle. 2013. Gene expression of the marine copepod Calanus finmarchicus: Responses to small-scale environmental variation in the Gulf of Maine (NW Atlantic Ocean). J. exp. Mar. Biol. Ecol. 446:76-85. doi:10.1016/j.jembe.2013.04.020


Cepeda, G.D., L. Blanco-Bercial, A. Bucklin, C.M. Berón, M.D. Viñas. 2012. Molecular taxonomic analysis of three species of Oithona (Copepoda, Cyclopoida) from the Argentine sector of the South Atlantic Ocean: comparative analysis using 28S rDNA. PLoS-One 7 (4): e35861. doi:10.1371/journal.pone.0035861

Kozol, R., L. Blanco-Bercial, and A. Bucklin. 2012. Lack of genetic divergence between Calanus agulhensis and C. sinicus (Copepoda; Calanoida). PLoS-One 7(10): e45710. doi:10.1371/journal.pone.0045710

Lenz, P.H., E. Unal, R.P. Hassett, C.M. Smith, A. Bucklin, A.E. Christie, and D.W. Towle. 2012. Functional genomics resources for the North Atlantic copepod, Calanus finmarchicus: EST database and physiological microarray. Comp. Biochem. Physiol. Part D, 7: 110–123. doi:10.1016/j.cbd.2011.12.001


Aarbakke, O.N.S., A. Bucklin, C. Halsband-Lenk, and M.F. Norrbin. 2011. Discovery of Pseudocalanus moultoni Frost 1989 in Northeast Atlantic waters based on mitochondrial COI sequence variation. J. Plankton Res.   33:1487-1495. doi: 10.1093/plankt/fbr057

Batta-Lona, P.G., A. Bucklin, T. Patarnello, N.J. Copley, and P.H. Wiebe, 2011. Population genetic variation of the southern ocean krill, Euphausia superba, in the western Antarctic Peninsula region using Single Nucleotide Polymorphisms (SNPs).   Deep-Sea Res. II 58:1652-1661 doi:10.1016/j.dsr2.2010.11.017

Blanco-Bercial, L. F. álvarez-Marqués, and A. Bucklin. 2011. Comparative phylogeography and connectivity of sibling species of the marine copepod Clausocalanus (Calanoida). J. Exp. Mar. Biol. Ecol. 404: 108-115  doi:10.1016/j.jembe.2011.05.011

Blanco-Bercial, L., J. Bradford-Grieve, and A.Bucklin. 2011. Molecular phylogeny of Calanoida (Copepoda). Mol. Phylogen. Evol. 59:103–113 [ ]

Bortolotto, E., A. Bucklin, M. Mazzavilaa, L. Zane, and T. Patarnello. 2011. Gone with the currents: lack of genetic differentiation at the circum-continental scale in the Antarctic krill Euphausia superba. BMC – Genetics 12: 32  doi:10.1186/1471-2156-12-32

Bucklin, A., D. Steinke, and L. Blanco-Bercial, 2011. DNA barcoding of marine metazoa. Annual Review of Marine Science 2011, Vol. 3: 471–508 doi:10.1146/annurev-marine-120308-080950

Govindarajan, A.F., A. Bucklin, and L.P. Madin. 2011. A molecular phylogeny of the Thaliacea. J. Plankton Res. 33:843-853 doi:10.1093/plankt/fbq157


Bucklin, A., R.R. Hopcroft, K.N. Kosobokova, L.M. Nigro, B.D. Ortman, R.M. Jennings, and C.J. Sweetman. 2010. DNA barcoding of Arctic Ocean holozooplankton for species identification and recognition.  Deep-Sea Res. II 57:40-48. doi:10.1016/j.dsr2.2009.08.005

Bucklin, A., S. Nishida, S. Schnack-Schiel, P.H. Wiebe, D. Lindsay, R.J. Machida, and N.J. Copley. 2010. Chapter 13. A Census of Zooplankton of the Global Ocean, In: Marine Life: Diversity, Distribution, and Abundance. A. McIntyre [Ed.], Wiley-Blackwell, Oxford.  Pp. 247-265

Bucklin, A., B.D. Ortman, R.M. Jennings, L. Nigro, C.J. Sweetman, N.J. Copley, and P.H. Wiebe. 2010. A “Rosetta Stone” for zooplankton: DNA barcode analysis of holozooplankton diversity of the Sargasso Sea (NW Atlantic Ocean). Deep-Sea Res. II 57:2234-2247. doi:10.1016/j.dsr2.2010.09.025

Grabbert, S., J. Renz, H.-J. Hirche, and A. Bucklin. 2010. Species-specific PCR (SS-PCR) discrimination of species of the calanoid copepod Pseudocalanus, P. acuspes and P. elongatus, in the Baltic and North Seas. Hydrobiologia 652:289-297. doi:10.1007/s10750-010-0360-2

Jennings, R.M., A. Bucklin, H. Ossenbrügger, and R.R. Hopcroft. 2010. Analysis of genetic diversity of planktonic gastropods from several ocean regions using DNA barcodes. Deep-Sea Research II 57:2199-2210. doi:10.1016/j.dsr2.2010.09.022

Jennings, R.M., A. Bucklin, and A.C. Pierrot-Bults. 2010. Barcoding of arrow worms (Phylum Chaetognatha) from three oceans: genetic diversity and evolution within an enigmatic phylum. PLoS-ONE. doi:10.1371/journal.pone.0009949

Ortman, B. D., A. Bucklin, F. Pages, and M. Youngbluth. 2010. DNA barcoding of the Medusozoa. Deep-Sea Res. II 57:2148-2156. doi:10.1016/j.dsr2.2010.09.017

Sutton, T.T., P.H. Wiebe, L.P. Madin and A. Bucklin. 2010. Diversity and community structure of pelagic fishes to 5000 m depth in the Sargasso Sea. Deep-Sea Res. II 57:2220-2233. doi:10.1016/j.dsr2.2010.09.024

Unal, E. and A. Bucklin. 2010. Basin-scale population genetic structure of the planktonic copepod Calanus finmarchicus in the North Atlantic Ocean. Prog. Oceanogr. 87:175-186. doi:10.1016/j.pocean.2010.09.017

Wiebe, P.H., A. Bucklin, L.P. Madin, M.V. Angel, T. Sutton, F. Pagés, R.R. Hopcroft, and D. Lindsay. 2010. Deep-sea holozooplankton species diversity in the Sargasso Sea, Northwestern Atlantic Ocean. Deep-Sea Res. II 57:2157-2166. doi:10.1016/j.dsr2.2010.09.018