Who we are:

Current lab members (2005) and their research

	Elena Bowser (independent research).  Triglyceride consumption during overwintering in plethodontid salamanders.
	Dr. Michael Finkler (Steel-driving man).   Biology of the Snapping Turtle, ed. by A.C. Steyermark, M. S. Finkler, and R. J. Brooks. Sex-related differences in the energetic cost of reproduction in spring-breeding amphibians. Effects of high nest water contents on embryonic respiration and survivorship in snapping turtles.
	Ashley Gillem (URSI research fellow) Bacterial content and diversity in snapping turtle eggs during early embryonic development. Sex-related differences in stored energy in spring-breeding amphibians
	Mark Westerfield (Independent study) Incidence of leech parasitism in breeding spotted salamanders.

Past lab members

Greta Bolin, University of North Texas

Dr. Warren Burggren, University of North Texas

Dr. Christian Chauret, Indiana University Kokomo

Dr. Dennis Claussen, Miami University

Dr. Edward Dzialowski, University of North Texas

Gary Gerald, Miami University

Lawrence Spezzano, Miami University

Dr. Anthony Steyermark, University of St. Thomas

Dr. Mark Sugalski, New England College

Dr. Jerry Sweeten, Manchester College

Dr. Albert Williams, Manchester College

What we do:

Ecological physiology (sometimes referred to as ecophysiology, physiological ecology, or environmental physiology) is a subdiscipline of comparative physiology that examines physiological diversity in relation to the environments in which organisms live or have lived.  Researchers in the field explore the ability of organisms to maintain constancy in the conditions inside the body in environments that tend to drive those conditions away from levels needed to maintain life.

Our laboratory examines this interaction between physiology and environment primarily in reptiles and amphibians collectively.  We focus on the ecological physiology of reproduction--particularly in species that must migrate from their normal home ranges as part of their reproductive ecology.  We investigate the impact of variation in such environmental conditions as temperature and water availability on the ability of these organisms to successfully survive and reproduce.

Current Topics of Study:

Ecological physiology of snapping turtle hatchlings.

Abiotic factors in the nest environment, such as temperature, moisture, and gas composition, have considerable impact on embryonic development and subsequent hatchling phenotype in reptiles.  Our research examines the consequences of  environmentally induced differences in size and body composition on performance and behavior in hatchling snapping turtles (Chelydra serpentina) to determine whether these differences may ultimately influence neonatal survival under various environmental conditions.  Current projects include a study of evaporative water loss from juvenile turtles at variable relative humidity, an examination of geographic variation in egg composition (in collaboration with Dr. Tony Steyermark of the University of St. Thomas), and research on metabolism and energy stores in neonates during the first year of life.

Microbiology of snapping turtle eggs.

At oviposition, the eggs of turtles pass through the cloaca (a common opening for the urinary, digestive, and reproductive tracts) and are deposited in a subterranean nest.  The eggs may therefore be exposed to a large number or microorganisms (both maternal and environmental in origin) during embryonic development.  Whereas the effects of abiotic factors on embryonic growth and development have been examined extensively in turtles, little is known about what might be thought of as the community ecology of the embryonic environment: the interactions between the developing embryo and other organisms that inhabit the interior of the egg and the surrounding soil.  Some of these organisms may be pathogenic in nature, or may simply compete with the embryo for resources such as nutrients in the egg and oxygen in the nest soil.  In collaboration with Dr. Christian Chauret of Indiana University Kokomo, we are currently conducting research on bacterial diversity and abundance within snapping turtle eggs, as well as how abiotic factors such as temperature and moisture conditions influence interactions between the embryo and the bacteria found within the egg. 

Water balance and desiccation tolerance of semi-terrestrial 
and terrestrial crustaceans.

As a group, crustaceans are aquatic organisms; they are morphologically and physiologically adapted to life in aquatic environments.  They use gills as respiratory structures, and have a cuticle that is relatively permeable to water.  However, members of some crustacean orders (e.g., Decapoda and Isopoda) are either semi-terrestrial or terrestrial even though they retain characters adapted to aquatic habitats.  Study of such organisms can give us insight into some of the problems facing animals as they began making the transition from aquatic to terrestrial habitats, as well as the physiological adaptations evolved to deal with these problems.  We are currently examining the effects of dehydration on metabolism and circulatory physiology in the rusty crayfish, Orconectes rusticus, a species that frequently inhabits intermittent streams and may occasionally be exposed to extended periods out of water.

Locomotion and energetics of spring-breeding amphibians.

For animals which migrate to breeding areas, the energy expended on locomotion to the breeding area is, in effect, part of the cost of reproduction.  Because in many organisms the mass of mature gametes carried by a gravid female may lead to considerable weight loading, the cost of transport to the breeding areas may be substantially higher for females than for males.  Thus, the locomotor patterns in females migrating to the breeding ponds may be different than those employed by males in order to minimize the energetic cost incurred.  This may lead to differences between the sexes in the time of arrival at the breeding pond and possibly the susceptibility to predation by terrestrial predators during overland migration.  In collaboration with Drs. Al Williams and Jerry Sweeten of Manchester College, Lawrence Spezzano of Miami University, and Asherwood Environmental Science Center,  we are currently examining metabolism during locomotion, thermal effects on metabolism and locomotion, and energy reserves of males and females of several species of Ambystoma (mole salamanders) and Pseudacris (chorus frogs) to evaluate differences in the overall cost of reproduction between the sexes. 

Energetics of overwintering salamanders

Northern species of salamanders overwinter either under water or in underground passages below the frost line.  Many species appear to be active and forage during the winter.  While foraging may help supplement fat reserves and enhance the chances that the animal will survive the winter and potentially increase gamete production in , being active during the winter requires increased energetic expenditure.  Thus, active foraging may enhance energy stores only if prey availability is also relatively high.  If prey availability is low, foraging may be restricted in order to conserve energy.  We are currently conducting a study that investigates the availability of prey on metabolism and energy reserves in the red-backed salamander, Plethodon cinereus, and the southern two-lined salamander, Eurycea cirrigera.  We are also examining the effects of temperature variation on the annual energy budgets of red spotted newts (Notophthalmus viridescens) and have planned a similar study on mudpuppies (Necturus maculosus).

Thermal effects on active ventilation in large insects

Large insects actively ventilate their tracheal system with compressions of abdominal muscles on bladder-like air sacs positioned intermittently within the tracheal system.  Variation in temperature affects metabolic rate in these insects, and subsequently the need to ventilate the tracheal system for effective gas exchange.  We are currently conducting an experiment on correlates between abdominal muscle activity and respiration rates in the Madagascan hissing roach, Gromphadorhina portentosa.
 

Egg Composition Influences on Embryonic Metabolism, Growth, and Hatchling Phenotype in Birds

The avian egg serves as a microhabitat in which the embryo develops in preparation for the next phase of its life in the external environment. The resources contained within an egg (water and nutrients) can thus greatly influence the development of the embryo contained within, as well as its success as a hatchling.  Work I conducted in the laboratories of Drs. Paul Sotherland, Warren Burggren, and Ed Dzialowski examined how experimental manipulation of the contents and composition of chicken eggs influenced the size, body composition and metabolic rate of embryos and hatchlings.  Future research will focus on how manipulating the protein content of egg albumen affects the development of the intestinal tract near the end of embryonic development.
 

 

Sounds pretty cool!  How can I get a piece of the action?

Contact:

Michael S. Finkler, Ph.D.
Department of Natural, Information and Mathematical Sciences
Indiana University Kokomo
P.O. Box 9003
Kokomo, IN 46904-9003
Phone: (765) 455-9244
Fax: (765) 455-9310
Email: mfinkler@iuk.edu