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Section I: Biological Sciences Bailey Science Center, room 3009 Paul Arnold, presiding.

1:00 THE FUNCTIONAL MORPHOLOGY OF TENSILE ELEMENTS IN SPANISH MOSS. TILLANDSIA USNEOIDES (L.) L. **, William H. Dawe * and T.A. Uyeno, Valdosta State University, Valdosta, GA 31602. Spanish moss is a rootless, epiphytic relative of the pineapple that hangs in clumps from tree branches and grows downward as chains of nodes and internodes. Propagation occurs via seed production and also through fragmentation in which young tip nodes may continue to grow if appropriately relocated. This preliminary study describes the tensile structure of the plant using histological techniques and investigates the mechanics of fragmentation using tensile tests. As histology indicates that older nodes develop a more lignified core, we hypothesized that tip nodes would be weakest and nodes above would be progressively stronger. A load cell and a micro-manipulator were used to measure the tensile force at failure for each node in the chain. We found two different strength profiles: one showed increasing breaking strength at each node from tip to branch. The other showed a strength increase from tip to middle, but then top nodes near the branch became weaker. We conclude that Spanish moss may be modulating node strength to strengthen clump branch attachment or to facilitate fragmentation. Further stress/strain tests are needed to describe the mechanics of Spanish moss chains (e.g., Young's modulus of elasticity & work to fracture), and we are modeling chain architecture to characterize its effect on the plant's overall ability to form hanging clumps. Project funding; VSU Faculty Research Seed Grant 2011-12 to T.A.U.

1:15 THE D1STRUBUTION OF TOPMINNOWS (FUNDULIDAE) IN SOUTH AND SOUTHEAST GEORGIA **, Ashley L. Barnes * (1). D.L. Bechler (1), J.S. Salter (1) and B. Albanese (2). (1) Valdosta State University. Valdosta, GA 31602 and (2) Department of Natural Resources, Social Circle, GA 30025. Two major species complexes in the family Fundulidae are found in South and Southeast Georgia. This study is examining the distribution of the members of each complex from the Aucilla River in the western portion of the study area to the east side of the Okefenokee Swamp. Initial work has focused in morphometric characters, with subsequent genetic analysis underway. The Fundulus lineolatus complex includes both eastern and western forms with only one population of the western form found in the study area. Members of the F chrysotus complex includes F. cingulatus and F. rubrifrons, as well as the more abundant F. chrysotus. Fundulus cingulatus is found in the southeastern portion of the study area in the Alapaha River basin and the Okefenokee Swamp, and F. rubrifrons consists of a single population from the Alapaha River Basin in southern Lanier County. Fundulus chrysotus, while the most abundant species in the complex, is restricted primarily to the Withlacoochee River Basin.

1:30 DOMINANT BEHAVIOR MUTANTS FROM THE HERMAPHRODMC VERTEBRATE MODEL FISH, KRYPTOLEBIAS MARMORATUS, Garrett L. Carter * and B.C. Ring, Valdosta State University, Valdosta, GA 31698. The mangrove killifish (Kryptoiebias marmoratus) is a self-fertilizing vertebrate that produces clonal isogenic lines suitable for molecular genetic studies. Through a forward genetic dominant screen (ENU mutagenesis: n=50 Fl fish), eight behavioral mutants were identified as exhibiting bold (lag-time) and/or aggressive (mirror test) behaviors via filming experiments. Three of these mutants descended from the same P mutated fish, therefore, 6 different dominant behavioral mutant alleles were identified. To confirm the behaviors were heritable, 72 F2 fish were reared from the original 8 Fl mutant parents and re-filmed. All F2 fish displayed Mendelian patterns of inheritance of the dominant behavioral traits. These mutants are currently under selection to produce true breeding clonal stocks into the F3 generation for future characterization at the neurophenomic level. Here we describe initial characterization through filming and statistical analysis. Behavioral mutants identified in this screen are useful for characterizing conserved behavior loci that may be applicable to behavioral syndrome research across the animal kingdom. This research was supported by NIH Grant # R15HD060017 from the Eunice Kennedy Shriver National Institute of Child Health & Human Development.

1:45 MITE AND DOMATIA DENSITY IN TWO FOREST TYPES IN WEST-CENTRAL GEORGIA, Skylar C. Kirk *, J.A. Barone, J.R. Harrell, M.A. Robinson, C.N. Allen, J.L. Burston, D.J. Ellis, J.H, Gilmore II, B.L. Holloman, J.D. Huffman, B.C. Long, A. McIntosh, B.J. Philpot. W.D. Rogers, J.M. Santos, S. Silvis, AD. Skillman and B.M. Truett, Columbus State University. Columbus, GA 31907. Plants and mites frequently engage in a mutualism in which plants provide domatia for predaceous and fungivorous mites, while mites provide protection against herbivores and pathogenic fungi. We examined the densities of mites and leaf domatia in two forest types in west central Georgia: warm temperate forest and long-leaf pine turkey oak forest. We expected to find a higher density of domatia in the relatively nutrient-poor long-leaf pine turkey oak forest than the nutrient-rich warm temperate forest. We also compared our domatia frequencies to other studies. There was no significant difference in the average number of domatia per leaf between warm temperate forests and long-leaf pine turkey oak forest, nor was there a difference between mite densities. However, there was a significant difference in the average leaf size between the two forest types. A significant difference was noted in domatia types across the two sites. Variability across species could be the cause of no significant difference between the two forest types. Our numbers were significantly lower than five other sites around the world.

2:00 A TEST OF THE MULTIPLICATIVE RISK MODEL USING A FRESHWATER FOOD-WEB FRAGMENT. Samantha J. Worthy *, A.L. Bullock, Z.R. Diener, A.U. Edwards, O.Y. Jackson, J.M. Joiner, M. Junious, J.E. Pitts, A.P. Shields, J.T. Skariah. V.C. Staples and C.B. Ruehl, Columbus State University, Columbus, GA 31907. Interactions between multiple predators may result in risk reduction or risk enhancement for prey. Predators that interfere with each other slow predator-prey encounter rates and reduce the risk of predation for prey. Conversely, prey may shift habitat use in response to one predator, which enhances their risk of predation by making them more vulnerable to another predator. We tested the multiplicative risk model for emergent multiple predator effects on the mortality of freshwater pulmonate snails (Physa acuta) using giant water bugs (Belostoma flumineum) and crayfish (Procambarus zonangulus) as predators. Treatments consisted of either one giant water bug, one crayfish, or an individual of each predator. Analysis of variance followed by Tukey's post-hoc test revealed that snail mortality in crayfish tanks (76%) was less than mortality in water bug tanks (98%), but mortality in combined predator treatments was intermediate (95%). A multiplicative risk model would predict 99% mortality in combined predator treatments based on mortality in single treatments. Therefore, combining predators resulted in risk reduction for snails likely from interference competition between giant water bugs and crayfish.

2:15 AN ASSESSESSMENT OF POLLINATION SUCCESS BY NATIVE BEES IN NORTH GEORGIA APPLE ORCHARDS, Catherine G. Schlueter *, N.G. Stewart and M.A. Schlueter. Georgia Gwinnett College, Lawrenceville, GA 30043. Most commercial apple orchards rely on European Honeybees (Apis mellifera L.) for pollination of their apple trees. Recent concerns over the declines in honeybee populations and increasing expenses to rent honeybee hives has generated a strong interest in identifying native insect pollinators, which can replace or supplement the honeybee. In this study, an assessment of native bee pollination success was examined. At Mountain View Orchards (McCaysville. GA), ten apple trees (Malus domestica Borkh.) were selected. On each tree, two similar branches (e.g., similar bud numbers and length) were identified. A netting enclosure, which excluded honeybee-size and larger bees, was place over one of the selected branches in March 2012. The other branch (control) was left uncovered. All ten apple trees produced blossoms on both control and experimental branches. In August, apples were collected from both the control and experimental branches. Similar numbers of apples were produced on each tree; however, one of the experimental branches produced no apples. The apples were weighed, their circumferences measured, and their seeds counted. Two-tailed T-tests compared apple weight (t = 1,305, p = 0.2038), apple circumference (t = 1.243, p = 0.2253) and seed number (t = 1.482, p = 0.1507) between control and experimental branches. Statistical analyses indicated that there were no differences between the control and experimental groups in any of these measurements. The most common native pollinators captured in pan traps within the netting enclosure were Andrena crataegi and Andrena carlini. Therefore, native bees are effective pollinators in commercial apple production. Native bees provide a natural and sustainable agricultural alternative to the declining honeybee.

2:30 AN EXAMINATION OF RURAL, SUBURBAN, AND URBAN WATER QUALITY IN GEORGIA, COSTA RICA, AND COLOMBIA, Jose O. Castano * and M.A. Schlueter, Georgia Gwinnett College, Lawrenceville, GA 30043. This study examined the water quality of 26 different streams and rivers in Georgia-USA, Costa Rica, and Buenaventura-Colombia to evaluate the effect of human populations on these waterways. Streams and rivers were sampled in: (a) rural areas with large natural areas and farms. (b) suburban areas with predominantly residential housing and less than 30% vegetation, and (c) urban areas with mostly paved roads and large commercial areas. Specific water quality indicators gathered from biological, physical, and chemical results were used to grade each site using North American water quality assessment methods. Macroinvertebrates, used in the biological assessment, were sampled using a D-net and a seine net in three riffles and three pool areas per site. The chemical and physical analyses tested for temperature, water flow, dissolved oxygen. pH, ammonia, nitrate, turbidity, phosphate, copper, lead, and mercury. There was a significant difference (F = 8.12, p = 0.0024) in the biological assessment between urban streams (mean biological index = 5.5), suburban streams (mean biological index = 10.8), and rural streams (mean biological index =16.2). Sensitive macroinvertebrate groups such as stoneflies (Plecoptera) and riffle beetles (Coleoptera) were abundant in rural areas in all three countries. High dissolved oxygen levels correlated (r=0.557, p=0.003) with high diversity of macroinvertebrates (high biological index). Trace levels of mercury (5 ppb) were found in some Costa Rican and Colombian rivers. In all three countries, rural sites had higher dissolved oxygen levels, and lower ammonia and phosphate levels compared to suburban and urban sites. This study found water quality conditions were worse in urban and suburban areas in all three countries due to pollutants and other negative factors (e.g., sedimentation) introduced through human activity.

2:45 MASON BEE (MEGACHILIDAE:OSMIA) ABUNDANCE AND DIVERSITY IN NORTH GEORGIA APPLE ORCHARDS FROM 2010-2012: THE ROLE OF OSMIA DURING PREMATURE APPLE BLOOM CONDITIONS, Nicholas G. Stewart * and M.A. Schlueter, Georgia Gwinnett College, Lawrenceville, GA 30043. Native mason bees (Osmia species) provide low-cost, sustainable pollination services more efficiently than honeybees. For instance, 250 metallic blue Osmia lignaria females pollinate equivalently to 2.4 honeybee hives (16.000-50.000 bees). Furthermore. Osmia are easy to attracted, maximize and transplant artificially within and between orchards. Unlike the most abundant native apple pollinators, the mining bees (Andrena), mason bees were the earliest emerging bees in 2010-2012. Typically, Osmia actively forage for brood provisions amidst a seasonal period devoid of floral resources in apple orchards, forcing constant migratory behavior as they search out flowers until the bloom. In 2010, we collected 9 mason bees from 5 species during the typical apple bloom spanning mid-April through early-May. The subsequent aberrant bloom periods during two years following 2010 were progressively premature. The 2011 bloom began in late-March and ended early-April, before apple blooms begin under traditional spring conditions. As a result, an Osmia abundance spike was recorded--jumping from 9 to 39 specimens. In 2011, the onset of the bloom occurred around March 2nd and was complete before April--the earliest bloom on record throughout the Eastern Seaboard. With over 232 mason bees collected, representing 13 of the 19 species known to occur in all of Georgia. Osmia abundances hit an all-time high for apple orchards in our study. Our findings indicate that mason bees may be optimal safe-guards for early apple blooms. While typical native pollinators are reduced during premature bloom conditions, native pollination deficiencies can be mitigated in apple orchards by Osmia-maximization--thereby further justifying the use of sustainable native pollination-systems.

3:00 Break

3:15 COSTS AND BENEFITS OF CERATOMIA CATALPAE CHEMICAL DEFENSE, Audrey Barrett * and E. Lampert, University of North Georgia, Oakwood. GA 30566. Sequestration of consumed plant compounds is a defense used by many insect herbivores. One compound, catalpol, is sequestered by several herbivore species, rendering them unpalatable to predators. However, catalpol sequestration has been shown to weaken immune response, and reduce digestive effeciency. Here we test whether catalpol sequestration is costly or beneficial to the catalpa specialist Ceratomia catalpae. First, respirometry was used to compare C[O.sub.2] production as larvae consumed catalpol throughout development. If catalpol sequestration is costly, we predicted reduced C[O.sub.2] production as larvae continuously consumed catalpol as they developed; however, we found no such relationship in our group of larvae. Next, we exposed predatory Solenopsis sp. ants to C. catalpae samples to determine if catalpol sequestration deterred the ants. We found that gut and hemolymph samples were highly deterrent compared to a control and plant extract. Our results show that catalpol sequestration is highly beneficial to this herbivore species, while any cost of sequestration is negligible.

3:30 POPULATION GENETICS OF THREE CRAB SPECIES ALONG THE SOUTHEASTERN ATLANTIC COAST **, S.D. Mannix *, A.E. Hammak. A.L. Coleman. J.M. Reichmuth and A.L. Abdulovic-cui, Augusta State University, Augusta. GA 30904. The Blue Crab (Callinectes sapidus), fishery is the second largest seafood industry in Georgia. It is both economically and ecologically important. Blue Crabs are commonly found along with other ecologically important species, including Callinectes similis and Arenaeus cribrarius. The aim of our research is to study the genetic diversity among these different species. We will sequence several mitochondrial loci from each crab species by using the already sequence DNA of the Blue Crab. This DNA will help us to develop primers used for comparison. A lack of genetic diversity in the three species could indicate an unhealthy ecosystem. Suppression of diversity may be caused by the natural removal of genes from predation, or it could indicate that the species genes are becoming fixed by over fishing. Currently, we are collecting crabs, using a monofilament and bag seine on two different beaches, Tybee Island GA and Hunting Island SC. These islands differ in population dynamics. Tybee is a very urbanized area while Hunting Island is left semi-un-touched. We are extracting DNA from crab limbs stored in ethanol following standard molecular methods. The genetic diversity of the ecosystem will be based on the difference in genes of the crab species. The more differences the healthier the ecosystem.

3:45 SPADIX FUNCTION IN THE JACK-IN-THE-PULPIT. ARISAEMA TRIPHYLLUM. Sabrina M. Jones *, F.S. Corotto, M.S. Davis and A.R. McCaskill, University of North Georgia, Dahlonega, GA 30597. Aroids are perennial herbs that are characterized by inflorescences with a rod-shaped spadix surrounded by a vase-like spathe. A prominent aroid in Georgia is the Jack-in-the-Pulpit. Arisaema triphyllum. In this study, we assessed the role of the spadix in attracting insect visitors to A. triphyllum. Two study sites near Dahlonega. GA. were chosen: one along an unnamed first-order stream and the other along Cane Creek (34[degrees]33'02"N; 84[degrees]03'46"N; 34[degrees]31'03"N; 84[degrees]00.13"W). Plants received either ablation of the distal appendix (n = 40), removal of the spadix tip (n = 30), or a sham ablation (n = 31). Treatments were assigned by an Excel random number generator. Each treated plant had a 5 mm x 20 mm Agralan pot plant sticky trap placed at the back of the spathe chamber to collect visitors. Inflorescences were collected at senescence. Despite the treatment applied, the number of Diptera captured was not affected. In contrast, ablation reduced the number of Collembola captured to just 29% of what was found in the other two treatments (interaction of taxa and treatment after square root transformation: [F.sub.10,480] = 2.761, P = 0.003). Other taxa were poorly represented. Pollination in A. triphyllum has previously been attributed to fungus gnats and the thysanopteran. Heterothrips arisaemae Hood. Our results suggest that Collembola, which do not fly, may play a role in pollination, perhaps within clustered plants in which long-distance travel is not necessary.

4:00 EFFECT OF LAKE LANIER WATER QUALITY ON THE SURFACING FREQUENCY OF RED-EARED SLIDER TURTLES, TRACHEMYS SCRIPTA ELE-GANS (WIED-NEUWIED) **, T.J. Pass *. R.C. Fuller and M.D. Horton, North Georgia College & State University, Dahlonega, GA 30597. Polluted waters have been shown to cause physiological distress in animals, including aquatic turtles that must surface to exchange gases. The rate of surfacing offers a simple method of quantifying behavioral responses to environmental stressors. The purpose of this study was to assess the frequency of turtles surfacing when held in water collected from eleven sites in Lake Lanier, Georgia and tributaries of that reservoir. Each water collection site was monitored for environmental parameters (e.g., temperature, pH, biological oxygen demand, chemical oxygen demand, hardness, fecal coliform counts, and turbidity). Three adult turtles, tagged for identification using colored pipe cleaners wrapped around the carapace and plastron, were housed in individual aquaria containing 20-liters of water from each of the eleven sites. These were placed in a greenhouse with controlled temperature settings. Three turtles were placed in one aquarium that served as the experimental set-up and three in a separate aquarium to serve as control. The breathing frequency of the turtles was recorded using digital videography for one hour and viewed for analysis. To determine the significance in the breathing frequencies between set-ups, and the environmental parameters between sites, analysis of variance was used.

4:15 EFFECTS OF TEMPERATURE, pH. AND SUBSTRATE CONCENTRATION ON CELLOBIASE ACTIVITY FROM ENZYMES ISOLATED FROM COMMON AND GEORGIA-NATIVE MUSHROOMS **. Mary L. Calderon *, P.T. Arnold and J.C. Schroeder. Young Harris College, Young Harris, GA 30582. Fungi and bacteria use the enzyme cellobiase ([beta]-glucosidase) in order to help break down cellulose from plant cell walls to obtain glucose. The cellobiase enzyme was examined under several conditions, including different temperatures and pH values, to determine the optimal environment for enzymatic activity. Enzymes were extracted from different mushroom species (common and Georgia-native) to deduce their ability to break down an artificial substrate (p-nitrophenol glucopyranside). Initial findings using a purified form of cellobiase suggest that the enzyme forms product (p-nitrophenol. which can be detected under basic condition by absorbance at 410nm) at the fastest rate when conditions are 37[degrees]C or pH 5.0. Enzymes isolated from mushrooms were further characterized using Lineweaver-Burk analysis to determine maximum velocity ([V.sub.max]) and substrate affinity ([K.sub.m]) at optimal conditions. Other initial findings led to the hypothesis that enzymatic activity of mushrooms will vary greatly among the different species of mushroom examined. As this is likely to be due (at least in part) to varying levels of enzyme among mushroom samples. [K.sub.m] values of the mushroom enzymes will be compared.

4:30 EFFECTS OF DIETARY FLAVONOIDS ON CYP1A1-LUCIFERASE REPORTER ASSAY ACTIVITY **, Mary E. Maxwell * and J.C. Schroeder, Young Harris College. Young Harris, GA 30582. The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor involved in the regulation of multiple cellular pathways, including transcription of the cyplal gene. While many AHR agonists are known carcinogens to which humans are commonly exposed, dietary constituents (including flavonoids) that have chemo-preventative properties have been found to act as antagonists of the AHR pathway. A chemo-preventive approach may be effective in decreasing the incidences of many human cancers by incorporating a dietary regimen that includes a number of these naturally occurring AHR antagonists. Kaempferol, apigenin, resveratrol, and hesperitin are all common flavonoids isolated from various plant materials. Benzo[a]pyrene (B[a]P) and 3-methylcholantherine (3-MC) are both known agonist of the AHR. Cultured hepatocytes will be treated with B[a]P or 3-MC alone or in combination with one of the flavanoids listed to determine their protective effects on AHR activation. This activation will be determined by measuring luciferase activity of the pGudLuc reporter gene, which has been stably transfected into the hepatocyte cell line used in this experiment. Funded by the Young Harris College Biology Research Initiative.

4:45 POPULATION CHARACTERISTICS AND HABITAT PREFERENCES OF A STATE-ENDANGERED CRAYFISH CAMBARUS PARRISH' IN THE UPPER HIWASSEE RIVER **. Kacey R. Miller *. A.M. Johnson and J.G. Davis, Young Harris College. Young Harris, GA 30582. Crayfishes are keystone species in headwater aquatic ecosystems responsible for processing organic material, increasing nutrient availability and engineering complex benthic stream habitat. This study defined population characteristics and habitat preferences of a state-endangered, understudied species, Cambarus parrishi in the upper Hiwassee River watershed of northeast Georgia. Crayfish were collected at seven sites over one year. Multiple habitat parameters including substrate size, depth, water velocity, and stream roughness were measured at a microhabitat scale. Correlation analysis identified habitat variables associated with C. parrishi presence which were incorporated into logistic regression models to predict probability of presence at available microhabitats. C. parrishi prefer habitats with slower water velocities, cobble substrates and shallow depths. Due to low incidences of capture (n=46), data on reproduction was limited. Length-frequency histograms were constructed to assign ages to sampled individuals to allow for calculation of annual growth rate and estimate mortality rate of the population through a catch-curve regression model. Crayfish older than two years of age were rare (n=6), and estimated annual mortality rate of the population was 25% (P<0.001; [R.sup.2] = 0.90). This study provided essential habitat information and population metrics that will aid in developing monitoring and targeted conservation strategies for this species.

* Denotes student presenter

** Denotes student "in progress" research
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Publication:Georgia Journal of Science
Article Type:Conference notes
Geographic Code:1U5GA
Date:Mar 22, 2013
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