Location: Bowdoin / Amy Johnson

Biology

Amy Johnson

James R. and Helen Lee Billingsley Professor of Marine Biology

Contact Information

ajohnson@bowdoin.edu
207-725-3026
Biology
130C Druckenmiller Hall



Fall 2014

  • Biology of Marine Organisms (BIOL 2319)
  • Biology of Marine Organisms (ENVS 2229)


Amy Johnson: Bowdoin College: Biology

Education

  • B.A. Biology, University of California, Los Angeles, 1978
  • Ph.D. Zoology, University of California, Berkeley, 1986

Teaching Area

  • Introductory Biology, Biology of Marine Organisms, Biomechanics, Evolution of Marine Invertebrates

Field of Active Research Interest and Activity

  • Biomechanics, functional morphology and ecophysiology of marine invertebrates and algae; mechanisms and modeling of growth of sea urchins, scaling of metabolic rate.

(*indicates undergraduate student co-author)

Ellers, O., Johnson A.S., Yoshimura, K., Motokawa, T.  (in review) Why not walk faster underwater?  Biology Letters.

Johnson, A.S., *Salyers J.M., *Alcorn N.J., Ellers, O, Allen, J. (in revision).  Externally visible fluorochrome marks on growing sea urchins.  Invert. Biol.

*Pfister, A. Johnson, A., Ellers, O., Horch, H.W. (in press). Quantification of dendritic and axonal growth after injury to the auditory system of the adult cricket Gryllus bimaculatus. Front. Physio. 3:367. doi: 10.3389/fphys.2012.00367

Ellers, O., Johnson, A.S. (2009) Polyfluorochrome marking slows growth only during the marking month in the green sea urchin Strongylocentrotus droebachiensis. Invert. Biol. DOI:10.1111/j.1744-7410.2008.00159.x.

*Selden, R., Johnson, A.S., Ellers, O. (2009) Crab scent induces thicker skeletons, smaller gonads and size-specific growth responses in sea urchins. Mar. Biol. 156:1057–1071  DOI : 10.1007/s00227-009-1150-0 pdf

*Butler, M., Johnson, A.S. (2004). Are melanized feather barbs stronger? J. Exp. Biol. 207: 285-293

*Lohrmann NL, Logan BA, Johnson AS (2004) Seasonal acclimatization of antioxidants in Chondrus crispus and Mastocarpus stellatus, two co-occurring red algae with differing winter tolerances. Biol Bull 2004 207: 225-232.

Johnson, A.S., Ellers, O., *Lemire, J., *Minor, M., *Leddy, H. (2002). Sutural loosening and skeletal flexibility during growth: determination of drop-like shapes in sea urchins. Proc. R. Soc. Lond. B, 269: 215-220.

*Pratt, M.P., Johnson, A.S. (2002). Strength, Drag, and Dislodgement of Two Competing Intertidal Algae from Two Wave Exposures and Four Seasons. J. Exp. Mar. Biol. Ecol. 272: 71-101

Johnson, A.S. (2001). Drag, drafting, and mechanical interactions in canopies of the red alga Chondrus crispus. Biological Bulletin 201: 126-135.

*Leddy, H.A., Johnson, A.S. (2000). Walking vs. breathing: mechanical differentiation of sea urchin podia corresponds to functional specialization. Biological Bulletin 198: 88-93.

Ellers, O, Johnson, A.S., Moberg, P. (1998). Sutural strengthening of urchin skeletons by collagenous sutural ligaments. Biological Bulletin 195: 136-144.

Johnson, A. (1997). Flow is genet and ramet blind: Consequences of individual, group and colony morphology on filter feeding and flow. Proceedings of the 8th International Coral Reef Symposium 2: 1093-1096.

Johnson, A.S. and Koehl, M.A.R. (1994). Maintenance of environmental stress factor in different flow habitats: Thallus allometry and material properties of a giant kelp. Journal of Experimental Biology 195: 381-410. Abstract; Full article

Johnson, A.S. (1993). Sag-mediated modulated tension in terebellid tentacles exposed to flow. Biological Bulletin 185: 10-19.

Johnson, A.S. and K.P. Sebens (1993). Consequences of a flattened morphology: Effects of flow on feeding rates of the scleractinian coral Meandrina meandrites (Linnaeus 1758). Marine Ecology Progress Series 99: 99-114.

*Trussell, G.C., A.S. Johnson, S.G. Rudolph, and E.S. Gilfillan (1993). Resistance to dislodgment: Habitat and size-specific differences in morphology and tenacity in an intertidal snail. Mar. Ecol. Prog. Ser. 100: 135-144.

Dudgeon, S.R. and A.S. Johnson (1992). Thick versus thin: Thallus morphology and tissue mechanics influence differential drag and dislodgement of two co-dominant seaweeds. J. Exp. Mar. Biol. Ecol. 165: 23-43.

Sebens, K.P. and A.S. Johnson. (1991). The effect of water movement on prey capture by reef corals. Hydrobiologia 216/217: 247-248.

Sebens, K.P. and A.S. Johnson. (1991). Effects of water movement on prey capture and distribution of reef corals. Hydrobiologia 226: 91-101

Johnson, A.S. (1990). Flow around phoronids: Consequences of a neighbor to suspension feeders. Limnol. and Oceanogr. 35(6): 1395-1401.

Johnson, A.S. (1988). Hydrodynamic study of the functional morphology of the benthic suspension feeder, Phoronopsis viridis (Phoronida). Mar. Biol. 100: 117-126.

Published or Printed Abstracts
(since 2005; *indicates Bowdoin student co-author)

Askins, M*, Lonati, G,* Guttenplan, K,* Fahey, A,* Johnson, A, Ellers, O. (2012) Externally visible polyfluorochrome marking of urchins: growth comparisons between lab-reared and tidepool urchins.  Integrative and Comparative Biology, Poster Presentation, Annual Meeting Abstract, Jan. 3-7, 2012 Charleston, NC

Johnson, A.S., Ellers, O., (2010) Precise measurement of growth using multiple fluorochrome markers, the cubed root of weight and a new growth function. Integrative and Comparative Biology, Annual Meeting, Jan. 3-7, 2010, Seattle, WA

Ellers, O., Yoshimura, K., Motokawa, T., Johnson, A.S. (2010). Why not walk faster, underwater?  Integrative and Comparative Biology, Annual Meeting Abstract, Jan. 3-7, 2010, Seattle, WA

Norton, E.*, Ellers, O., Johnson, A.S. (2010).  Testing an inverted pendulum model for underwater walking in the crab Carcinus maenus. Integrative and Comparative Biology, Annual Meeting Abstract, Jan. 3-7, 2010, Seattle, WA

Brasili, A.*, Johnson, A.S. (2010).  Temperature and size-dependent growth in a marine ectotherm: the green sea urchin Strongylocentrotus droebachiensis.  Integrative and Comparative Biology, Annual Meeting Abstract, Jan. 3-7, 2010, Seattle, WA

Ellers, O., Yoshimura, K., Motokawa, T., Johnson, A.S. (2009) An inverted pendulum model for underwater walking. Integrative and Comparative Biology, Annual Meeting Abstract 74.1, Jan. 3-7, 2009, Boston, MA

Johnson, A., Selden, R.*, Ellers, O. (2009) Crab scent induces thicker skeletons, smaller gonads and size-specific adjustments in growth rate in sea urchins. Integrative and Comparative Biology, Annual Meeting Abstract 74.1, Jan. 3-7, 2009, Boston, MA

Johnson, A.S., Ellers, O., Butler, M.* (2006). Barbs of a feather bend (and twist) together. Integr. Comp. Biol. 46(1): e70; doi:10.1093/icb/icl056

Lake, B.* Johnson, A.S. Mauck, R.A. (2006) Influence of orientation and flow speed on feeding behavior and metabolism of the barnacle Semibalanus balanoides. Integr. Comp. Biol. 46(1): e219; doi:10.1093/icb/icl056

Johnson, A.S., Ellers, O. (2006) A new fluorochrome-based identification tag for sea urchins for use in a hatchery and lease-site aquaculture. Northeast Aquaculture Conference and Exposition. Mystic, Connecticut. December, 2006.

Ellers, O., Johnson, A.S. (2006). Temperature determines size and time-to-size in urchins: calibration of size-temperature effects in marine ectotherms. International Echinoderm Conference, University of New Hampshire, August 2006.

Johnson, A.S., Ellers, O., *Wright, M., *Selden, R, *Stranges, B. (2006). Is there an oxygen-limited lag phase in early growth in sea urchins, Strongylocentrotus droebachiensis? International Echinoderm Conference, University of New Hampshire, August 2006.

Johnson, A.S., Ellers, O., *Wright, M., *Stranges, B. (2005). Implications of transport processes and 2/3 power metabolic scaling to Bertalanffy and bimodal growth in sea urchins. Integr. Comp. Biol. 44(6):709.

Note that as of October 2012 this is only working in Internet Explorer; we are working on a fix for other browsers.

Damped Pendulum Demonstration

This demonstration allows the user to manipulate the value of physically important variables in the system and the output is the motion of a pendulum as defined by the angular position of the pendulum bob relative to vertical.

The damped pendulum model is programmed in Mathematica by Olaf Ellers and is based on the math published by others in the following paper:

Neill D, Livelybrooks D & Donnelly R (2007).  A pendulum experiment on added mass and the principle of equivalence.  Am. J. Phys. 75(3): 226-229.

Neill et al. also provides an experimental test of the calculations.

Academic Spotlight: 

Bowdoin Researchers Seek Methods to Spur Sea Urchin Growth

Researchers Develop 'Bar Code' for Sea Urchins
 
Walking Crab

Campus News: Professors Raise Awareness, Aspirations of Women in Science

Summer Field Research




Kids, dogs, cats, music, reading, walking, gymnastics, light flecks on new spring leaves, thimble moon on night of first frost, full moon setting at the edge of an autumn morning mist

Urchin Jaw Marked with Fluorochromes

A demipyramid ossicle (jaw bone) from the sea urchin Strongylocentrotus droebachiensis.  The calcite ossicle was marked first with tetracycline and then with alizarin complexone.  These fluorescent markers become incorporated into the growing edge of the ossicle.  The marks are four days apart.  Image by A. Johnson and O. Ellers.  See:  Ellers, O., Johnson, A.S. (2009) Polyfluorochrome marking slows growth only during the marking month in the green sea urchin Strongylocentrotus droebachiensis. Invert. Biol. DOI:10.1111/j.1744-7410.2008.00159.x.