People | Jonathan H Cohen

• B.S., magna cum laude, Biology & Environmental Science, Dickinson College, 1999.
• Ph.D., Biology, Duke University, 2004.

Comparative physiology and behavior of marine animals; Neurobiology; Visual ecology; Zooplankton ecology

Visual ecology of marine invertebrates

We are broadly interested in the structure and function of visual systems in marine animals, particularly invertebrates, and the behaviors that emerge from their ability to sense and respond to light.  We are using microscopy, electrophysiology, and behavioral approaches at multiple levels of organization (cells, tissues, whole animals) to explore the ways in which visual systems are used in predator/prey interactions, mating, orientation, and habitat selection.  Also of interest are interactions among multiple sensory modalities, such as chemical and visual cues. Current projects include:

• Mediation of larval crab photosensitivity by predator kairomones
• Orientation of talitrid amphipods
• Vision in the deep-sea metridinid copepod Gaussia princeps
• Sexually dimorphic eye designs in pontellid copepods involved in mate finding

Other recent visual ecology work has involved:

• Pupillary responses and lateral assymetry in the squid Lolliguncula brevis

• Visual capability in coral planula larvae and its role in habitat selection

• Vision in crustaceans from cryptic habitats: seagrass beds and sargassum rafts
• Visual physiology of Antarctic krill species

Lethal and sublethal effects of MC-252 crude oil & chemical dispersant on zooplankton

This project is examining the lethal and sublethal responses of ecologically important zooplankton taxa to oil, chemical dispersants, and oil/dispersant mixtures.  Experiments include mortality, reproduction, swimming and photobehavior assays, which are done at shore-based labs and at sea.  This ecotoxicological work is being conducted in conjunction with field sampling of zooplankton by colleagues at the Univ. of South Florida to better understand impacts of MC-252 oil releases in the Gulf of Mexico on the zooplankton community.

Behavior of invasive crab species in Delaware Bay

We are conducting laboratory experiments on vertical swimming behaviors of larval invasive mitten crabs (Eriocheir sinensis) in response to exogenous environmental factors (light and pressure) and endogenous activity rhythms.  Data from these experiments are being used in a circulation model of Delaware Bay to better understand the threat of invasion from this species now, and under future conditions of environmental change.

Corie Charpentier, M.S. student (B.S. with high honors, Eckerd College, 2012)

Ryan Peiffer, M.S. student (B.S. with honors, Gettysburg College, 2010)

Lilly McCormick, research technician (B.S. with high honors, Eckerd College, 2011)

MAST 451: Marine Invertebrate Biodiversity (Fall)

MAST 623: Physiology of Marine Organisms (Spring)

Charpentier, C.L. and J.H. Cohen (2013) Fish kairomone-induced defenses during larval development of an estuarine crab.  Integrative and Comparative Biology 53:E262.

Lessios, N., R.L. Rutowski, and J.H. Cohen (2013) Visual ecology of two ephemeral pool crustaceans: phototaxis and light-orientation behavior of Triops (Branchiopoda: Notostraca) and Streptocephalus (Branchiopoda: Anostraca). Integrative and Comparative Biology 53:E125.

McCormick, L.R. and J.H. Cohen (2012) Pupil light reflex in the Atlantic brief squid, Lolliguncula brevis. Journal of Experimental Biology 215:2677-2683.

Mason, B.M. and J.H. Cohen (2012) Long wavelength photosensitivity in coral planula larvae. Biological Bulletin 222:88-92.

Smith, N.F. and J.H. Cohen (2012) Comparative photobehavior of marine cercariae with differing secondary host preferences. Biological Bulletin 222:74-83.

Cournoyer, B.L. and J.H. Cohen (2011) Cryptic coloration as a predator avoidance strategy in seagrass arrow shrimp colormorphs. Journal of Experimental Marine Biology and Ecology 402:27-34.

Ziegler, T.A., J.H. Cohen and R.B. Forward, Jr. (2010) Proximate control of diel vertical migration in phyllosoma larvae of the Caribbean spiny lobster Panulirus argus. Biological Bulletin 219:207-219.

Cohen, J.H., T.W. Cronin, N.N. Lessios and R.B. Forward, Jr. (2010) Visual physiology underlying orientation and diel behavior in the sand beach amphipod Talorchesita longicornis. Journal of Experimental Biology 213:3843-3851.

Forward, R.B., Jr. and J.H. Cohen (2010) Vertical Migration of Aquatic Animals in Encyclopedia of Animal Behavior, M.D. Breed, J. Moore (eds.), vol. 3, pp. 485-490. Oxford: Academic Press.

Forward, R.B., Jr., M.H. Bourla, M.Z. Darnell, and J.H. Cohen (2009) Entrainment of the circadian rhythm of the supratidal amphipod Talorchestia longicornis by light and temperature: mechanisms of detection and hierarchical organization. Marine & Freshwater Behaviour & Physiology 42:233-247.

Forward, R.B., Jr., M.H. Bourla, N.N. Lessios, and J.H. Cohen (2009) Orientation to shorelines by the supratidal amphipod Talorchestia longicornis: Wavelength specific behavior during sun compass orientation.  Journal of Experimental Marine Biology & Ecology 376:102-109.

Cohen, J.H. and R.B. Forward, Jr. (2009) Zooplankton diel vertical migration: a review of proximate control.  Oceanography and Marine Biology: An Annual Review 47:77-110. 

Cohen, J.H. and T.M. Frank (2007) Vision in the hyperiid amphipod Scina crassicornis.  Journal of the Marine Biological Association of the U.K. 87:1201-1206.

Cohen, J.H., P.A. Tester, and R.B. Forward, Jr. (2007) Sublethal effects of the toxic dinoflagellate Karenia brevis on marine copepod behavior.  Journal of Plankton Research 29:301 – 315.

Cohen, J.H. and T.M. Frank (2006) Visual physiology of the Antarctic amphipod Abyssorchomene plebs.  Biological Bulletin 211:140-148.

Forward, R.B., Jr., J.H. Cohen, M.Z. Darnell, and A. Saal (2005) The circatidal rhythm in vertical swimming of female blue crabs, Callinectes sapidus, during their spawning migration: a reconsideration.  Journal of Shellfish Research 24:587-590.

Forward, R.B., Jr., H. Diaz, and J.H. Cohen (2005) The tidal rhythm in activity of the mole crab Emerita talpoida.  Journal of the Marine Biological Association of the U.K. 85:895-901.

Cohen, J.H. and R.B. Forward, Jr. (2005) Photobehavior as an inducible defense in the marine copepod Calanopia americana. Limnology and Oceanography 50:1269-1277.

Cohen, J.H. and R.B. Forward, Jr. (2005) Diel vertical migration in the marine copepod Calanopia americana. I. Twilight DVM and its relationship to the diel light cycle. Marine Biology 147:387-398.

Cohen, J.H. and R.B. Forward, Jr. (2005) Diel vertical migration in the marine copepod Calanopia americana. II. Proximate role of exogenous light cues and endogenous rhythms. Marine Biology 147:399-410.

Forward, R.B., Jr., N.B. Reyns, H. Diaz, J.H. Cohen, and D.B. Eggleston (2005) Endogenous swimming rhythms underlying secondary dispersal of early juvenile blue crabs, Callinectes sapidus.  Journal of Experimental Marine Biology and Ecology 316:91-100.