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Education: B.A. in Biology, Bowdoin College, 1960 Ph.D. in Zoology, University of North Carolina at Chapel Hill, 1970 Research Interests: Experimental studies assessing the endocrinological mechanism
of control of developmental processes such as morphogenesis (changes
in morphology), including metamorphosis (the drastic transition from
larva to juvenile), molting (the periodic sloughing of the external
skeleton), and growth, using larvae of the “snapping shrimp”
Alpheus heterochaelis as a model system. Neurosecretory
tissue in the paired eyestalks is thought to be the main source
of a “molt-inhibiting hormone” that acts on another
organ which produces the hormone (20-hydroxyecdysone) that actually
brings about the molt, and a factor that regulates morphogenesis,
either directly or by acting on another organ that produces a “juvenile
hormone.” Accordingly, effects of eyestalk removal are being
studied. Laboratory and field studies analyzing life histories and behavioral
responses of various species of the “grass shrimp” Palaemonetes
to differences in salinity, substrate, and cover (submergent vegetation).
These differences could contribute to habitat partitioning, allowing
the sympatric estuarine species P. pugio and P. vulgaris
to coexist. Osmotic relations, substrate preferences, and competitive
displacement have been suggested as factors determining the distribution
of these two species. Laboratory work includes salinity tolerance
experiments (adults and larvae), selection of substrate types and
vegetative covers with and without predators present, and one-on-one
interaction trials (to determine aggression). Field work consists
of periodic sampling of grass shrimp populations from various localities
in the mid-Atlantic and assessment of structural, reproductive,
and developmental characteristics. Descriptions of larval instars (stages) of various species of
shrimps in families Alpheidae, Palaemonidae, Hippolytidae. Survey of invertebrate and plant communities in saline conduit
lakes of San Salvador, Bahamas.
RECENT PUBLICATIONS 2006. [with D. Marshalonis and H. Merchant] Acute toxicity of Permethrin to four populations of ovigerous grass shrimp, Palaemoneter pugio Holthuis. Bulletin of Environmental Contamination and Toxicology, 77:543-550.
Bisc 130 - Invertebrate Zoology, Fall BiSc 167 - Marine Biology, Spring BiSc 168 - Tropical Marine Biology, Spring, even years BiSc 169 - Applied Marine Ecology, Spring, odd years Graduate: BiSc 204 -Seminar: Invertebrate Zoology, Fall, even years Daniel Marshalonis, M.S., 2003: “ Acute effects of Permethrin on four populations of grass shrimp, Palaemonetes pugio.” Ronald B. Gallin, Ph.D., 2002: “Effects of salinity and temperature on survival and behavior of two sympatric species of grass shrimp, Palaemonetes pugio and Palaemonetes vulgaris, and implications of these effects on their distribution at Point Lookout State Park, Maryland.”
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