Franklin H. Barnwell
Professor, Dept. of Ecology, Evolution, and Behavior
Morse-Alumni Distinguished Teaching Professor
Ph.D., Northwestern University, 1965
Contact Information
Phone: 612-625-5296
Fax: 612-624-6777
E-mail: fhb@umn.edu
Graduate Faculty Memberships
Conservation Biology; Ecology, Evolution, and Behavior.
Research Interests
Invertebrate behavior; circadian rhythms; adaptations of intertidal shore crabs.
Statement
Our laboratory's current research focuses on understanding adaptive functions of circadian rhythms and their mechanistic basis. We have chosen to examine these functions in the intertidal fiddler crabs, which adapt their behavior and physiology to both the day-night cycle and the cycle of the ocean tides. How fiddler crabs solve this problem of adjusting simultaneously to two major environmental periodicities can provide insight into the interaction of periodic components in complex multioscillator timing systems. These systems seem increasingly to be the rule among higher animals, including human beings. Much of our work to date has been to characterize the rhythmic patterns of crabs from coastlines around the world with differing degrees of complexity in the form of the local tide. Experiments have included animals from regions of semidiurnal tides (Eastern U.S., Fiji), mixed tides (Gulf and Northern Pacific coasts of Mexico) and diurnal tides (Philippines). This work has positioned us to select the most favorable populations for experimental manipulation of daily and tidal components by appropriate zeitgebers in tidal aquariums and to begin the neurobiological study of their regulation. Work is also underway on the functional morphology of reproduction, communication and feeding in fiddler crabs; each of these processes is being studied from a comparative standpoint, using museum collections and techniques such as scanning electron microscopy and high speed cine and infrared video imaging. There is need for field and laboratory work in all of these areas.
Selected Publications
Barnwell, F.H., and C.L. Thurman. 1984. Taxonomy and biogeography of the fiddler crabs (Ocypodidae: Genus Uca) of the Atlantic and Gulf coasts of eastern North America. Zool. J. Linnean. Soc., London. 81:23-87.
Barnwell, F.H., and J.H. Stillman. 1990. Differences in daily and tidal rhythms in populations of the fiddler crabs Uca princeps and U. monilifera. Amer. Zool. 30(4):138A.
Barnwell, F.H., and C. Sullivan. 1991. Buccal chamber morphometry and feeding habits in ghost crabs (genus Ocypode). Amer. Zool. 31(5):90A.
Barnwell, F.H., and J. Martini. 1993. Daily and tidal rhythms of locomotor activity in the Andalusian fiddler crab Uca tangeri. Amer. Zool. 33(4).
Neiman, M., and F.H. Barnwell. 1997. Morphometric differences in small claws of the deposit-feeding fiddler crabs (Uca spp.) Amer. Zool. 37:47A.
Harris, S.E., D.M. Woodward, J.L. Fontaine, and F.H. Barnwell. 1998. Visual and acoustic signalling in the musical fiddler crab (Uca musica) from western Mexico. Amer. Zool. 38 (in press).
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