Contact Information

Email: dbechler@valdosta.edu

Interests

Biology of Krytolebias marmoratus, the Mangrove killifish—What makes this fish unique is that it is a hermaphrodite and possesses an ovitestis (ovary and testis in one organ) that allows it to fertilize its own eggs and thus clone itself.  In the wild, populations of this unusual fish are composed mostly of hermaphrodites; however, in the wild and in the lab some individuals develop as primary (from hatching) or secondary (loose ovarian function) males with the capability of hybridizing with other clones.  This species is an excellent model for the study of innate and learned behaviors due to the fact that the clonal aspect of their biology permits the researcher to work with multiple individuals of a single clone that are all genetically identical to each other (See and at VSU for a more extensive discussion).  It is also possible to produce hybrids in the laboratory.  The first such hybrids ever conclusively produced via DNA analysis in the lab where produced at VSU in the fall, 2003 (See Publications in .)  Other interesting aspects of this fish's behavior is that is occupies crab burrows, is very tolerant of very poor water conditions and is semi-terrestrial often moving onto land.

Kelly Luke, master's graduate student, is currently working on mixed mating strategies in Krytolebias marmoratus.

Biology of Gopherus polyphemus, the Gopher Tortoise— Gopher tortoises are a threatened species in Georgia facing considerable habitat degradation from urban, agriculture, and highway development.  The Lake Louise Field Station in south Lowndes County has a small, but active population of tortoises on it and is protected by VSU.  My interests with the gopher tortoises are their use of atypical habitats such as the right-of-ways of road and railroad beds where they frequently build their burrows. 

Biogeography/Distribution, Ecology and Behavior of South Georgia Fishes—Georgia is the third most specious state with respect to the number of species of freshwater fish as a result of its multiple drainage basins involving the Tennessee River, the Gulf Coasts drainages, and the Atlantic Drainages.  South Georgia while somewhat depauperate in fish fauna, is unique because of the influence of fish species in Florida that make their way into South Georgia.  In my lab we are studying the occurrence and distribution of fish in barrow pits as well as the fish fauna of the Alapahoochee watershed of Lowndes and Echols counties, GA. Other interests include various aspects of species' ecology and behavior and the use of artificial systems such as flow-through streams to understand fish behavior.

Travis Key, master’s graduate student will work on microhabitats in coastal wetlands as refuges for juvenile fishes

 Biology of South Georgia Crayfish—For much of the same reasons as discussed above on South Georgia Fishes, Georgia is also one of the most specious with respect to the number of species and subspecies of crayfish.  My research interests in crayfish involves their life histories, ecology and behaviors, primarily mating and pheromone communication.

Philip Hightower, master’s graduate student, is currently working on a detailed life history and ecology of Procambarus spiculifer.

Josh Rousey, Philip Hightower and David Bechler--association behavior in crayfish using nest-traps.

The use of Captive Populations for Teaching Middle Grades and High School Biology—Dr. Leslie Jones and I are using a captive population of Terrapene carolina as a teaching tool to help middle grades science education students better understand the basics of population biology.  This population is also used in the teaching of Herpetology for biology majors.

Distribution of Alien Animal Species in South Georgia—Numerous species of alien plants and animals enter the country each year.  In South Georgia it is possible to find terrestrial flatworms from Southeast Asia and Central and South America, frogs and lizards from Caribbean islands, and fish from Europe and other states in the U.S.  Understanding the impact these animals have on the environment of South Georgia may permit us to preserve our native flora and fauna.

Population Structure and Movement Patterns the Water Moccasin, Agkistrodon piscivorous conanti—Much of South Georgia contains extensive wetlands.  Draining the eastern and central portion of Lowndes County and western Echols is the Alapahoochee Watershed..  The watershed runs form flatwoods in the northeast and central parts of  the county to up lifted hills overlying limestone and gravel beds.  Several species of snakes in the genus Nerodia and  Agkistrodon piscivorous conanti are found in the watershed, but show a patchy distribution from the headwaters to the confluence of the watershed with he Alapaha River in Hamilton County, FL.  This patchy distribution raises interesting questions regarding the small scale biogeography of the these species with respect to their population structure and genetics, foraging opportunities/diet and environmental factors controlling the spotty distributions.

Ashley Kirkley, master's graduate student, will start work on the above biogeography problem starting spring 2008.

Speleobiology—little is known about the ecology of the caves and cave fauna of South Georgia.  However, caves in the southwestern region of the state offer some excellent opportunities to study both terrestrial and aquatic species.  In areas where caves are not easily accessible, access to the fauna can be gotten by trapping in inactive wells.  For more on this see selected publications by Stephen Opsahl, Ph.D., Joseph W. Jones Ecological Research Center, Route 2, Box 2324, Newton, GA  39870-9651  USA ().

Course Information

Biological Diversity Laboratory (Non-majors)

Organismal Biology Laboratory (Non-majors)

Human Biology (Non-majors)

Principles of Biology (BIOL 2010)

Anatomy and Physiology I

Anatomy and Physiology II

Zoology

Ichthyology

Conservation and Field Biology of Fishes

Herpetology

Biogeography

Species and Speciation (Graduate only course, Fall 2007)

Senior Seminar and Topics Listing