Academic Spotlight: Coastal Studies Span Walking Crabs and Artful Tourists
Summer Research at Bowdoin: Researchers Develop 'Bar Code' for Sea Urchins
Academic Spotlight: Bowdoin Researchers Seek Methods to Spur Sea Urchin Growth
Olaf Ellers
Affiliation: Biology, Mathematics
Research Associate in Biology and Mathematics
Research Areas
Biomechanics, functional morphology and ecophysiology of marine invertebrates and algae; mechanisms and modeling of growth and aquaculture in sea urchins, scaling of metabolic rate, effects of temperature on growth, underwater walking especially of sea stars, and catch connective tissue in echinoderms.
Other Interests
My kids, dogs, cats, music, reading, walking, piano, skiing, gymnastics
Education
- PhD, Duke University, 1988
- BS, University of Toronto, 1983
(* indicates Bowdoin student coauthor)
Johnson, A.S., Ellers, O., Motokawa, T. Sea stars have gaits. To be submitted to Proceedings of the Royal Society B.
Ellers, O., Heydari, S, Ellers, K.I., Po, T., Johnson, A.S., Kanso, E., McHenry, M.J. Soft skeletons transmit force with variable gearing. to be submitted to Journal of the Royal Society Interface.
Ellers, O.,Khoriaty, M*, Johnson, AS (2021). Kinematics of sea star legged locomotion. Journal of Experimental Biology, 224(22), jeb242813. doi.org/10.1242/jeb.242813
Heydari, S., Johnson, A., Ellers, O., McHenry, M. J., Kanso, E. (2020). Sea star inspired crawling and bouncing. Journal of the Royal Society Interface, 17(162), 20190700.
Horch, HW, Pfister, A*, Ellers, O, Johnson, A.S. (2017). Plasticity in the Cricket Central Nervous System. In The Cricket as a Model Organism (pp. 105-128). Springer Japan.
Dickinson, ES*, Johnson AS, Ellers, O, Dickinson, PS (2016). Forces generated during stretch in the heart of the lobster Homarus americanus are anisotropic and are altered by neuromodulators. Journal of Experimental Biology, 219:1187-1202.
Johnson, A.S., Salyers, J.M.*, Alcorn, N.J.*, Ellers, O., Allen, J.D. (2013). Externally visible fluorochrome marks and allometries of growing sea urchins. Invertebrate Biology, 132(3): 251-269.
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. Link to abstract
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.
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.
Ellers, O. 2001. Size matters. Book Review of Scaling in Biology, J.H. Brown and G.B. West eds. Oxford Univ. Press. Complexity 6(4): 23-26. Link to issue
Ellers, O. 2000. Orientation to, and acoustic detection of, beach waves during swash-riding and migration of donacid clams and other sandy beach invertebrates. Pp. 177-194, In Biomechanics and Behaviour, P. Domenici & B. Blake (eds.). publ. BIOS., Oxford. Link to book description
Hui, C.A. & O. Ellers. 1999. Effect of high aluminum consumption on mechanics and composition of furculae of free-ranging coots. Environmental Toxicology and Chemistry 18: 970-975. Link to abstract
Ellers, O, Johnson, A.S., Moberg, P. 1998. Sutural strengthening of urchin skeletons by collagenous sutural ligaments. Biological Bulletin 195: 136-144. Link to abstract
Ellers, O. 1998. Swash-riding in the clam, Donax variabilis. McGraw-Hill 1998 Yearbook of Science and Technology, 31- 32. Link to book
Telford, M. and O. Ellers. 1998. The moving teeth of echinoids. Pp. 843-848, In Echinoderms: San Francisco, R. Mooi and M. Telford (eds.). publ. Balkema, Rotterdam.
Telford, M. & Ellers, O. 1997. Tooth advancement muscles in the sand dollar, Echinarachnius parma. Invertebrate Biology 116: 255-261. Link to abstract
Ellers, O. & Telford, M. 1997. Muscles advance the teeth in sand dollars and other sea urchins. Proc. R. Soc. Lond. B 264: 1525-1530. Link to abstract
Ellers, O., 1997. Book Review of Echinoderm Studies 5,. M. Jangoux and J.M. Lawrence, eds., A.A. Balkema, publ. The Quarterly Review of Biology 72(3): 340.
Ellers, O. & M. Telford. 1996. Advancement mechanics of growing teeth in sand dollars (Echinodermata, Echinoidea): a role for mutable collagenous tissue. Proc. R. Soc. Lond. B 263: 39-44. Link to abstract
Irschick, D. J., C. C. Austin, K. Petren, R. N. Fisher, J. B. Losos and O. Ellers. 1996. A comparative analysis of clinging ability among pad-bearing lizards. Biological Journal of the Linnean Society 59: 21-35. Link to abstract
Ellers, O. 1995. Behavioral control of swash-riding in the clam Donax variabilis. Biol. Bull. 189: 120-127.
Ellers, O. 1995. Discrimination among wave-generated sounds by a swash-riding clam. Biol. Bull. 189: 128-137.
Ellers, O. 1995. Form and motion of Donax variabilis in flow. Biol. Bull. 189: 138-147.
Lelievre, B., Telford, M. , Ellers, O. 1995. The role of collagen in reacting axial forces in the teeth of sand dollars (Echinoidea: Clypeasteroida). Fourth European Echinoderms Conference, London
Ellers, O. 1993. A mechanical model of growth in regular sea urchins: predictions of shape and a developmental morphospace. Proc. R. Soc. Lond. B 254: 123-129. Link to abstract
Moore, A.M.F. , O. Ellers 1993. A functional morphospace, based on dimensionless numbers, for a circumferential calcite stabilizing structure in sand dollars. J. Theor. Biol. 162: 253-266.
Ellers, O., Telford, M. 1992. Causes and consequences of fluctuating coelomic pressure in sea urchins. Biol. Bull., 182: 424-434.
Ellers, O., Telford, M. 1991. Forces generated by the jaws of clypeasteroids (Echinodermata: Echinoidea). J. exp. Biol., 155: 585-603.
Ellers, O. 1987. Passive orientation of benthic animals in flow. In W. F. Herrnkind & A. B. Thistle (Eds.), Signposts in the Sea, Proceedings of a multidisciplinary workshop on marine animal orientation and migration, (pp. 45-68). Tallahassee: Dept. of Biological Science, Florida State University.
Telford, M., Mooi, R. , Ellers, O. 1985. A new model of podial deposit feeding in the sand dollar, Mellita quinquiesperforata (Leske): The sieve hypothesis challenged. Biol. Bull., 169: 431-448.
Ellers, O., Telford, M. 1984. Collection of food by oral surface podia in the sand dollar, Echinarachnius parma (Lamarck). Biol. Bull., 166: 574-582.
Starfish Gallop With Hundreds of Tubular Feet | Deep Look, PBS,KQED See https://www.kqed.org/science/1970271/starfish-gallop-with-hundreds-of-tubular-feet/ This program, and accompanying article, highlights the work of Johnson and Ellers and collaborators on the bouncing gait of sea stars and how tube feet coordinate to produce this gait.
(* indicate undergraduate authors)
Johnson AS, Ellers O, Etzel R*, Khoriaty J* (2019) The oscillatory gait of high-speed sea stars: Do sea stars of varying morphology vary stride length or step frequency to change speed? Society of Integrative and Comparative Biology: 59: E114 (abstract link).
* This talk and the following student poster were covered by Science News Highlights of
Meeting: https://www.sciencemag.org/news/2019/01/watch-sea-star-bounce-get-around*
Etzel R*, Khoriaty J*, Ellers O, Johnson, AS (2019) The contribution of morphological characteristics on the bouncing gait of sea stars: A cross-species comparison. Integr. Comp. Biol.(abstract link).
Kukaj A*, Escalante G*, Ellers O, Dickinson P, Johnson, AS (2019) Force-velocity relationships in cardiac muscles of the American lobster, Homarus americanus Society of Integrative and Comparative Biology (abstract link).
*The Crustacean Society Honorable Mention for Best Student Poster at the SICB meeting*
Maguire MC*, Hambelton G*, Ellers O, Dickinson P, Johnson, AS (2019) Contributions of artery and sarcomere length changes to the heart’s ability to generate tension in the American lobster, Homarus americanus Society of Integrative and Comparative Biology (abstract link).
Schleifer, HJ*, Ellers O, Johnson, AS (2019) Using circuit theory to model flow and pressure outputs of the circulatory system of the American lobster, Homarus americanus Society of Integrative and Comparative Biology. (abstract link).
Ellers O, Johnson AS, Motokawa T. (2018) Do general theories of locomotion apply to underwater walkers? Integr. Comp. Biol. (abstract link).
Johnson AS, Novak, K*, Kim D*, Ellers O, Motokawa T (2017) A high speed, oscillatory gait in sea stars. North American Echinoderm Conference, Worcester, Massachusetts July 9-13, 2017
Johnson AS, Ellers O, Qu X*, Dickinson ES*, Harmon K*, Armiyaw A*, Dickinson P (2017) The role of feedback from physiologically relevant stretches in controlling heart contraction in the American lobster, Homarus americanus. Integr. Comp. Biol. (abstract link).
Ellers O, Johnson AS (2016) Integrating size and temperature specific growth rates of green sea urchins. Abstract and oral presentation. Benthic Ecology Meetings, Portland Maine, March 16-19, 2016 (abstract link)
Suchyta KJ*, Goroff MS*, Qu X*, Dickinson ES*, Harmon K*, Johnson AS, Ellers O, Dickinson PS (2016). Mechanisms of stretch feedback and interactions with neuromodulators in the cardiac ganglion of the American lobster. Integr. Comp. Biol. (abstract link).
*Division of Comparative Neurobiology Award for Best Student Poster at the SICB meeting*
Dickinson PS, Qu X*, Dickinson ES*, Harmon KE*, Johnson AS, Ellers O (2016) Generation of flexible rhythmic behaviors resulting from interactions between intrinsic sensory feedback and extrinsic neuromodulators. March 2016, San Diego, CA, Experimental Biology.
Dickinson PS, Dickinson ES*, Harmon KE*, Qu X*, Johnson AS, Ellers O (2015) Mechanisms of sensory feedback and interactions with neuromodulators in a rhythmic pattern generator. March 2015, Boston, MA, Experimental Biology, Poster #841.4. http://www.fasebj.org/content/29/1_Supplement/841.4
Horch HW, Saidenbert L*, Chong M*, Fiorillo B*, Vergara-Benitex J*, Zhand A*, Pfister A*, Ellers O, Johnson A (2014) Exploration of two different compensatory strategies for recovery from injury in the adult cricket CNS. Neuroscience Annual Meeting, Nov 15-19, Wash DC.http://sfn14.hubbian.com/id_15151/
Harmon K*, Chin-Purcell M*, Dickinson ES*, Hartley TM*, Ellers O, Johnson AS, Dickinson, PS (2014) Mechanisms and effects of stretch feedback in the heart of the American lobster, Homarus americanus. Neuroscience Annual Meeting, Nov 15-19, Wash DC. http://sfn14.hubbian.com/id_4890/
Ellers O, Johnson AS, Guttenplan K*, Motokawa T (2014) The bounce in a seastar’s step: classifying gaits in underwater legged locomotion Integr. Comp. Biol. (2014) 54 (suppl 1): e59 doi:10.1093/icb/icu008
Dickinson E*, Johnson AS, Ellers O; Dickinson PS (2014) Cardiac muscle in Homarus americanusresponds differently to loading in transverse and longitudinal directions. Integr. Comp. Biol. (2014) 54 (suppl 1): e59 doi:10.1093/icb/icu008
*The Crustacean Society Award for Best Student Poster presented at the SICB meeting*
Ellers O, Johnson AS, Guttenplan K*, Motokawa T (2013) Does the starfish Protoreaster nodosus use a pendular gait while walking underwater? Japan Zool. Soc. Symp, Tokyo Inst. of Tech. Mar 16, 2013
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
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 Abstract, Jan. 3-7, 2010 Seattle, WA
Brasili, A.*; Johnson, A.S.; Ellers, O. (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
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
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
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.
