Oral Presentations

Do river-reservoir interfaces serve as surrogate nurseries for floodplain-dependent riverine ?

Matthew R. Acre*1,2, Timothy B. Grabowski2,3 , Nathan G. Smith4

1Department of Natural Resources Management, Texas Tech University 2Texas Cooperative and Wildlife Resource Unit, Texas Tech University 3U.S. Geological Survey 4Texas Parks and Wildlife, Inland Fisheries Division

Keywords: river-reservoir interface, larval fishes, assemblages

Anthropogenic modification to riverine systems has reduced access to important off-channel nursery habitats. Some utilize these floodplain habitats during early life history. The river-reservoir interface (RRI), a transitional zone between lentic and lotic habitats, may provide surrogate nursery habitats for these species. We sampled ichthyoplankton assemblages in riverine and RRI off-channel and main channel habitats in the Trinity River system of east Texas to compare species composition and abundance in these different habitat types and evaluate the influence of abiotic and physicochemical characteristics on ichthyoplankton assemblages. Ichthyoplankton was sampled using light traps and paired push nets deployed off jet-powered kayaks during February-July 2013 and 2014. Over 30,000 larval fishes were collected, representing 11 taxa. A few taxa were dominant at all sites, however, less common ichthyofauna such as moronids, centrarchids, and Freshwater Drum were captured more frequently in RRI habitats. In general, larval fish abundance, species richness, and species diversity, were greater in the RRI off-channel habitats than other habitat types. The duration and size of connection to the main channel best explained species richness, diversity, and overall abundance in RRI off-channel habitats. Our results suggest RRI habitat may serve as a surrogate nursery for some species.

Genetic Structure of Striped Bass in the Southeastern United States and Effects from Stock Enhancement

Andrew Anderson*1, Michael R. Denson2, Tanya L. Darden2

1Department of Biology, Texas A&M University 2South Carolina Department of Natural Resources

Keywords: population genetics, fisheries management, stock enhancement

It is necessary to understand the genetic relationships of Striped Bass Morone saxatilis populations within and between watersheds to identify appropriate management units. Determining temporal changes in genetic relationships as well as the genetic diversity of the populations is important in understanding how stock enhancement may have and continues to influence populations units. A suite of 12 microsatellites was used to evaluate patterns of Striped Bass gene flow both spatially and temporally across watersheds in the southeastern United States. Populations from the study watersheds were genetically diverse with the exception of the Savannah River which is recovering from a major population decline. Striped Bass in the Roanoke and Cape Fear rivers, North Carolina, represented a single population, most likely due to historical transfer stocking across the state from Roanoke River stock. Watersheds in South Carolina contained genetically distinct Striped Bass populations, although the difference between Striped Bass populations in the Ashepoo-Combahee-Edisto (ACE) and Santee- Cooper watershed has decreased over the past 15 years, likely due to the stocking of Santee-Cooper fish into the ACE Basin. Conversely, supportive breeding of the Santee-Cooper system has helped to maintain genetic diversity of the population. Striped Bass populations in the southeastern U.S. are good examples of the positive and negative effects of stock enhancement that must be considered and monitored when implementing or assessing a stock enhancement program.

Occupancy, density, and dispersal of a critically endangered lizard on a small island

Nicole Angeli*1, Ian Lundgren2, Clayton Pollock2, Zandy Hillis-Starr2, Lee A. Fitzgerald1,3

1Department of Wildlife and Fisheries Sciences, Texas A&M University 2Buck Island Reef National Monument, U.S. National Park Service 3Applied Biodiversity Sciences, Texas A&M University

Keywords: Ameiva polops, translocations, monitoring, population estimation, occupancy, hierarchical Bayesian models

Monitoring is a key component of translocation projects. The critically endangered St. Croix Ground Lizard (Ameiva polops) declined on mainland St. Croix due to mongoose and rat predation. To augment its populations, fifty-seven were translocated to Buck Island, St. Croix in 2008. With the goal of estimating the current size and extent of the population, we made visual counts of unmarked animals by multiple observers at an array of sites throughout Buck Island. The 61 observation sites covered 12% of the island, and were surveyed 3 times between March and May 2013. We used count data and habitat variables to estimate island-wide occupancy and to draw correlations among habitat variables and abundance. By May 2013, A. polops occupied 59% of the entire island. Over five years, the population increased at least four-fold from 57 to 1473 (CI: 940- 1802). After accounting for detectability and distance from the release site, models showed lizard abundance was correlated with temperature and habitat structure. We suggest that future translocations of A. polops to other locations are feasible and would be a worthwhile conservation and restoration strategy for this species.

Hawaiian shell game: surveying cryptic species with PCR (Undergraduate)

Brenda Bennett*1, Jessica Williams*1, Sharon Furiness1, Christopher E. Bird1

1Department of Life Sciences, Texas A&M University, Corpus Christi

Keywords: PCR, cryptic species, limpets, morphologic

Positive identification of morphologically similar species can be difficult, even by trained experts. Larvae of many marine species are very similar, and in some cases, even the adults are difficult to decipher. We are interested in deciphering between two siblings, endemic limpet species in the Hawaiian Islands, Cellana exarata and C. sandwicensis. Typically, the adult limpets are identifiable to the species level, but on Mokupāpapa, they are phenotypically indistinguishable. Using all known Cellana COI haplotypes, we designed several custom PCR primers whose terminus aligns to a diagnostic SNP, indicative of species identity. We tested the specificity and sensitivity of several primers using 50 unique haplotypes per species, and identified the best primer set for each target species. Finally, 58 unidentified limpets were collected from Mokupāpapa in a stratified random design by shore level and subjected to the PCR test. All limpets but one were identified as C. exarata. Our results, combined with a complete population census, indicate that C. sandwicensis does not have an established population on Mokupāpapa. Rather, the island is being repeatedly colonized from the southeastern island of Mokumanamana.

Mosquito movement in the urban environment: a stable isotope mark-capture study

Emily Boothe*1, Gabriel Hamer1, Mark Johnsen2

1Department of Entomology, Texas A&M University 2Brazos County Health Department

Keywords: mosquitoes, mark-capture, Culex quinquefasciatus, Aedes albopictus, stable isotopes

To better control populations of mosquitoes and break the transmission cycle of vector-borne diseases, it is crucial to understand the dispersal of female mosquitoes. We performed a stable isotope mark- capture study, focusing primarily on Culex quinquefasciatus and Aedes albopictus, to facilitate mechanisms to measure mosquito dispersal. Stable isotope enrichment is a non-invasive approach to quantifying dispersal and marks individual mosquitoes for the duration of their adult life. Naturally breeding mosquitoes were marked by enriching their larval habitat with 13C-glucose or 15N-potassium nitrate at two different locations (~0.5km apart) in south College Station, Texas. Eighty CDC light, gravid, and BG Sentinel traps were set up each week within a two kilometer radius of each of the enriched larval habitats for capture of marked mosquitoes. In total 720 tra p nights were completed from July to August 2013. Although stable isotope results for enriched female mosquitoes is still pending, of the 568 pools tested, twelve were successfully marked with 13C and eleven were marked with 15N. This study provides a greater understanding of the dispersal of arthropod vectors capable of transmitting diseases in urban environments. It also demonstrates the ability to use stable isotope enrichment as a means to study the biology of mosquitoes.

Getting in shape? A geometric morphometric study of body shape divergence within two sympatric fish species (Atherinopsidae and Goodeidae)

Luke Bower*1, Kimberly L. Foster2, Kyle R. Piller2

1Department of Wildlife and Fisheries Sciences, Texas A&M University 2Department of Biological Sciences, Southeastern Louisiana University

Keywords: geometric morphometrics, selection, phenotypic plasticity, fish

An important area of interest in evolutionary biology is the relationship between phenotypes and heterogeneous environmental gradients. At the population level, morphological trait divergence is the product of genetic differentiation and/or phenotypic plasticity via natural selection. These plastic morphological traits in concordance with habitat differences can result in divergent character selection of adaptive phenotypes. Steady-unsteady swimming performance model predicts the impacts of natural selection on morphology and locomotion abilities for fishes inhabiting different flow gradients. In this study, geometric morphometrics was used to explore the body shape divergence between lentic and lotic habitats for two unrelated fish species (Chirostoma jordani and Goodea atripinnis). Both species displayed strong body shape divergence between the lake related to swimming performance within lentic and lotic habitats, supporting the steady swimming hypothesis. The morphology of head and mouth regions for both species may be related to differences in prey or environmental differences within each habitat type, but additional research is needed to disentangle the main driving forces behind the morphological divergence. These results are consistent with the evolutionary hypothesis that divergent habitats drive intraspecific diversification, and are important for predicting adaptive responses of freshwater fish species to divergent habitats and anthropogenic stream modification.

Interactive effects of prescribed fire and grazing on invasive grass abundance and woody brush encroachment in a south Texas coastal prairie

Michele Clark*1, William E. Rogers1, Carissa L. Wonkka1, Terry L. Blankenship2

1Department of Ecosystem Science and Management, Texas A&M University 2Rob and Bessie Welder Foundation

Keywords: invasion, restoration ecology, invasive species management, prescribed fire

Developing effective restoration techniques for coastal prairies degraded by woody encroachment and invasive introduced grasses requires an understanding of two fundamental ecological processes: fire and grazing. Prescribed fire and grazing are recommended for suppressing non-native species that are functionally distinct from the native prairie they invade. However, in south Texas, exotic C4 grasses (Bothriochloa ischaemum and Dichanthium sericeum) invade native C4 prairies. Comprehensive examination of non-native grass response to fire and grazing is needed, given the functional similarity of the natives and non-natives in this system.

We established a full-factorial, completely randomized experiment on an encroached prairie in south Texas to examine the interactive effects of seasonal prescribed fire and ungulate grazing on invasive grass abundance, herbaceous community diversity, and woody vegetation density. We randomly assigned six treatments to 36 10mX10m plots including: i.) summer burned and fenced ii.) summer burned and unfenced iii.) winter burned and fenced iv.) winter burned and unfenced v.) unburned and fenced vi.) unburned and unfenced. Results from vegetation sampling conducted two months after treatment applications suggest that summer prescribed fire may decrease shrub height and canopy cover and increase total stem counts across all shrub species. Percent utilization was similar in both summer burned and unfenced (grazed) plots and unburned fenced plots. Assessing plant community responses in subsequent growing seasons and comparing vegetative responses to summer vs. winter prescribed fire will reveal whether certain seasons of fire are more effective at controlling re-sprouting shrubs and invasive grasses.

Chagas disease ecology in Texas: a look at geographic distribution of vector species and parasite strains

Rachel Curtis*1, Edward J. Wozniak2, Gabriel L. Hamer3, Sarah A. Hamer4

1Department of Veterinary Integrative Biosciences, Texas A&M University—Galveston 2Zoonosis Control Branch, Texas Department of State Health Services 3Department of Entomology, Texas A&M University 4Department of Veterinary Integrative Biosciences, Texas A&M University

Keywords: disease ecology, Trypanosoma cruzi, Chagas disease, GIS Chagas disease affects humans and animals throughout the Americas, causing a spectrum of outcomes in hosts ranging from asymptomatic infection to acute death caused by cardiac malfunction. The causative disease agent is Trypanosoma cruzi, a vector-borne protozoan parasite comprised of seven distinct genetic strain types that each have unique ecological and epidemiological relationships. Competent vectors of T. cruzi are hematophagous Triatominae (Reduviidae, Hemiptera), commonly known as “kissing bugs.” Though there is a general lack of knowledge and recognition of this disease system in Texas, recent publications and disease reporting requirements have created a surge of raised awareness throughout the state. Our objective is to delineate the current geographic distribution of kissing bug species and parasite strains across Texas. These baseline data will benefit public and veterinary health protection efforts and afford comparisons with Chagas disease ecology in regions of endemicity across Latin America. The main method we have employed for sample collections is a public education outreach and citizen science initiative, through which the citizens across Texas submit kissing bugs to our laboratory. We have established georeferenced points of kissing bug presence, T. cruzi infection prevalence, and T. cruzi strain types. We will present current distribution maps, T. cruzi infection prevalence, and strain type data from a subset of the approximately 1200 kissing bugs collected in 2013. Our approach to elucidating the natural history of kissing bugs and T. cruzi aims to establish a strong base for using landscape epidemiology techniques to model Chagas disease ecology in Texas.

Legal and illegal wildlife trade: the case of export quotas and pet birds in Peru

Elizabeth Daut*1, Patricia Mendoza2, Donald J. Brightsmith3, Markus J. Peterson3

1Department of Veterinary Pathobiology, Texas A&M University 2Wildlife Conservation Society—Peru 3Texas A&M University

Keywords: wildlife trade, Peru, quota, pet birds

Entwined legal and illegal wild-animal markets complicate trade regulation and generate debate regarding the perceived costs and benefits of wildlife trade, prompting calls from some conservationists for wildlife-trade bans. We examined bird trade in Peru as a case study to explore the relationship between a legal export quota system for the international market, and illegal trade to fill demand for pet birds from domestic consumers. We specifically evaluated the hypotheses that (1) legal export quotas encourage illegal domestic trade, and (2) authorities view quota-listed species differently from non- quota listed species in the illegal domestic markets, and thereby confiscate less quota-listed species. To assess the trade, we recorded the species and number of individuals of quota and non-quota birds for sale in animal markets located in nine Peruvian cities , and compared these values to those recorded in government seizures (March 2007 - July 2011). Over 35,000 birds of 130 native species were recorded for sale; 33% of the species had published export quotas. Parrots were the most abundant individuals in the animal markets and seizures, but typically represented only 10% of annual quotas. Our descriptive analyses indicate that illegal domestic trade of native birds is common in Peru and appears to occur regardless of the nation’s export quota system. Predictors of abundance in Peru’s bird trade, such as body size, wild-range abundance, distribution, color, as well as quotas, are still being evaluated using multiple linear regression.

Spatial variation in aquatic food-web structure in an anthropogenically impacted arid-land river Jessica East*1, Allison Pease1

1Department of Natural Resources Management, Texas Tech University

Keywords: aquatic foodweb, stable isotopes, fish community structure

Anthropogenic influences have been shown to disrupt natural longitudinal patterns in riverine food-web structure. The Pecos River is impacted by threats common in semi-arid regions including increased salinity, diminished discharge, altered flow regime, and conversion of watershed land for human uses. We used stable isotope analysis to characterize trophic positions of species and assemblage-wide resource use at twelve sites along the main stem of the Pecos River in New Mexico and Texas. Stable isotope ratios revealed different sources of carbon supporting fish production along the longitudinal fluvial gradient. Nitrogen isotopes elucidated variation in trophic position among species. For example, the coastal nonnative killifish, Fundulus grandis appears to feed at a higher trophic level than the native killifishes, F. zebrinus and Lucania parva. In addition , it appears that anthropogenic inputs are enriching baseline nitrogen isotopic ratios in part of the river. Furthermore, assemblage-wide trophic niche breadth was found to be greatest in less degraded sites with higher fish species richness. Characterizing changes in food-web structure in relation to natural and anthropogenic factors is important for habitat assessment, stream restoration, and management and conservation strategies.

Sexual selection on female ornaments in the sex-role-reversed Gulf pipefish (Syngnathus scovelli)

Sarah Flanagan*1, James B. Johnson2, Emily Rose2, Adam G. Jones2

1Department of Biology, Texas A&M University 2Texas A&M University

Keywords: evolution, complex traits, selection gradients

Understanding how selection acts on traits individually and in combination is an important step in deciphering the mechanisms driving evolutionary change. Sexual selection usually acts on complex ornaments in males, but in sex-role-reversed species female traits can be sexually selected. The Gulf pipefish, Syngnathus scovelli, is a sexually dimorphic, sex-role-reversed species in which females display an ornament and compete for access to choosy males. Here, we used a laboratory-based mesocosm experiment to quantify pre- and post-mating selection on the female ornament. Selection differentials and gradients on female traits including ornament area, ornament number, and body size were calculated for three episodes of selection related to female reproductive success (number of mates, number of eggs transferred, and number of surviving embryos). Selection was strong on both ornament area and ornament size, and the majority of selection occurred during the pre-mating episode of selection. Additionally, a comparison of the multivariate selection gradient and the phenotypic covariance matrix indicated that selection was not limited by a lack of favorable trait combinations. Although we found no major tradeoffs between pre- and post-mating episodes of selection, sexual selection appears to favor either many bands or larger bands in female Gulf pipefish.

Conservation Status of Freshwater Fish in Central Mexico and the Effect of Introduced Species

Pablo Gesundheit*1, Constantino Macías2

1Department of Wildlife and Fisheries Sciences, Texas A&M University 2 Departamento de Ecología Evolutiva, Instituto de Ecología, UNAM Keywords: fish, aquatic systems, conservation, introduced species

Central Mexico is a densely populated area with high freshwater fish endemicity. Its aquatic systems have been severely disturbed, which has resulted in a severe decline in the native freshwater fish fauna. Species introductions are presumably one of the ways in which aquatic systems have been disturbed. I present a general overview of the conservation status of the fish fauna in the area and an analysis of the effects of introduced species on the native communities. Water physicochemical parameters were recorded and the fish communities sampled in a set of localities within the area. I identified species as native or introduced and estimated the original composition of the sampled communities using historical records. I then calculated the taxonomic integrity of the communities, defined as the proportion of native species present out of the total expected. I graded the water parameters and aggregated them into an index of water quality. I analyzed water quality and number of introduced species as variables in a General Linear Model (GLM) using taxonomic integrity as a response variable to determine if there is a statistical effect of introduced species on native community integrity. I calculated numerical descriptors that show that a great amount of the fish faunal diversity in this area of the country has been lost. The results from the GLM suggest that both water quality and introduced species have had an effect on the native populations and communities. I point to possible directions of future analysis and offer succinct recommendations.

Rapid Radiations and the Problem of Delineating Species

Melissa Giresi*

Department of Biology, Texas A&M University

Keywords: morphology, genetics, phylogenetics

There are a multitude of examples of rapid evolutionary radiations across. These diverse assemblages of closely related organisms present a challenge for taxonomists, particularly when phenotypic and genotypic evidence are discordant. This presentation will utilize a few examples of rapidly evolved assemblages to assess current methods of species delineation. Included in this presentation will be a brief discussion regarding utility of the COI gene in species 'barcoding'. The aim of this presentation is to spark discussion regarding how we currently define relationships among species and how to better understand relationships among species using integrative methods.

Predicting the mosquitoes and animals involved in Rift Valley fever virus transmission in the United States

Andrew J. Golnar*1, Gabriel L. Hamer1

1Department of Entomology, Texas A&M University

Keywords: mosquito, infectious disease, invasive, transmission ecology Rift Valley fever virus (RVFV) is a mosquito-borne virus in the family Bunyaviridiae that has spread throughout continental Africa to Madagascar and the Arabian Peninsula. The establishment of RVFV in North America would have serious consequences for human and animal health in addition to a significant economic impact on the livestock industry. Data on RVFV vector competence, vertebrate host competence, and mosquito feeding patterns were combined to quantitatively approximate the vector and vertebrate force of infection, defined as the relative contribution of the mosquito or vertebrate host to pathogen transmission. Results implicate several Aedes spp. mosquitoes and vertebrates in the order Artiodactyla as important hosts for RVFV transmission in the U.S. Moreover, the risk for different pathways of introduction were quantified to spatially predict the propagule pressure exerted on the U.S. from RVFV endemic regions within Africa and the Arabian Peninsula.

Nothing in an otherwise ideal system: the lack of host-associated differentiation (HAD) in the non- model cranberry fruitworm, Acrobasis vaccinii

Kyle Harrison*1, Raul R. Medina1, Zsofia Szendrei2, Caesar Rodriguez-Saonia3

1Department of Entomology, Texas A&M University 2Department of Entomology, Michigan State University 3Department of Entomology, Rutgers University

Keywords: host-associated differentiation (HAD), cranberry fruitworm (Acrobasis vaccinii), cranberry, blueberry

Genetically distinct herbivorous insect lineages can form when each lineage is in association with a different host-plant species, a special case of ecological speciation referred to as host-associated differentiation (HAD). The frequency and circumstances surrounding HAD have not yet been fully characterized. This is especially true of agricultural systems. However, it is thought that certain characteristics within a system increase the probability that HAD will occur. These characteristics include relatively long-standing evolutionary relationships between insects and their host-plants, endophagous feeding by insects of their host-plants, and allochrony in host-plant phenologies. We assessed status of these characteristics as well as the presence of HAD in an agricultural system involving Acrobasis vaccinii (Lepidoptera: Pyralidae) associated with blueberry and cranberry. Despite finding the characteristics that usually co-occur with HAD within our study system, we did not find the genetic signature of HAD in A. vaccinii. These findings suggest that the interaction between the characteristics which explain HAD are more complex than previously suspected.

Genetic diversity comparison among domestic and feral populations of channel catfish in Tamaulipas using microsatellite markers

Ana Lara*1, Ana M. Sifuentes-Rincón1, Pascuala Ambriz-Morales1, Xochitl F. De La Rosa-Reyna1, Hector H. Gojón-Baez2, Gaspar M. Parra-Bracamonte1

1Center of Genomic Biotechnology/IPN 2Coomité Sistema - Producto Bagre Tamaulipas

Keywords: microsatellite, DNA markers, genetic variability

Channel catfish (Ictalurus punctatus) is an important species for aquaculture. Its native distribution includes rivers in the state of Tamaulipas, Mexico. Since 1976, farms for commercial purposes began operations. It is unknown, however, if fish have suffered of genetic diversity loss since first domestic populations were established, which is a subject of major concern. Nor are there records on genetic diversity and dynamics for feral populations. In the present work, we report a comparison of genetic diversity among of six domestic and five feral fish populations (n= 262) using 13 microsatellite markers. Markers were polymorphic with allele count ranging from 24 to 60. Only one feral population was found to be under Hardy-Weinberg Equilibrium. Mean observed heterozygosity was 0.877 and 0.894 for feral and domestic populations, respectively, while expected heterozygosity varied from 0.855 to 0.842. No significant differences were found when comparing these values. However, genic diversity showed significant differences between feral and domestic groups (0.882 vs. 0.852). Inbreeding coefficient was also significant (0.016 vs. -0.045) suggesting heterozygous excess in domestic populations. Allele range varied among loci and populations, however, a clear tendency to a wider range was observed for feral populations. Number of private alleles was interestingly higher for feral populations. These results suggest a loss of genetic diversity due to domestication, which is consistent with previous reports for other species and could have implications for future management of natural and aquaculture resources.

Alternative IPM methods in the fall for Varroa mite control in East Texas apiaries (Undergraduate)

Alejandro Martinez*1, Juliana Rangel-Posada1

1Department of Entomology, Texas A&M University

Keywords: Apis mellifera, honey bee, IPM, Varroa destructor

The ectoparasitic mite Varroa destructor is the major pest of the honey bee (Apis mellifera), as high mite levels cause colonies to collapse and die. Prophylactic treatment of Varroa using pyrethroid and organophosphate chemicals over the last two decades has caused mites to develop resistance to these chemicals, causing higher maintenance and treatment costs for beekeepers, and a reduction in the number of colonies available for crop pollination. Thus alternative methods for Varroa control need to be implemented. In this study, we tested the therapeutic effects of three different IPM methods for Varroa control in two apiaries in East Texas. Each of 24 colonies belonged to either an untreated control group, or to groups in which we either caged the queens, treated colonies with powder sugar, or treated with thymol (active ingredient in ApiLife Var®). We monitored Varroa levels for 54 days from each colony using the standard “powder sugar shake” or the “24-hour sticky board” method. Powder sugar shake mite counts showed significantly lower levels of Varroa in all colonies treated with all IPM methods compared to untreated controls. Conversely, sticky board mite counts showed no statistical difference in mite counts based on IPM treatments compared to untreated controls. Our results suggest that (1) the powder sugar shake method is a more efficient method for Varroa monitoring than the 24- sticky board method; and (2) alternative IPM methods are effective in the Fall and serve as a promising new avenue for non-chemical control of this major honey bee pest.

Mating patterns of dusky dolphins (Lagenorhynchus obscurus) off Kaikoura, New Zealand

Dara Orbach*1, Bernd Würsig1

1Department of Marine Biology, Texas A&M University—Galveston

Keywords: mating, behavior, dolphin, competition

Mating behaviors are poorly described for most cetacean species and are generally limited to anecdotal reports with inadequate quantitative data or studies of captive animals with restricted inter-sexual interactions. Dusky dolphin (Lagenorhynchus obscurus) mating events occur frequently off Kaikoura, New Zealand in good water visibility. We determined the number, duration, and frequency of copulation events and sex-specific mating behaviors of wild dusky dolphins. Boat-based focal group follows were conducted during the peak breeding season (October – January) in 2011-2012 and 2013-2014. We video-recorded the behaviors of 91 mating groups and 960 copulation events. The mean follow duration was 13 minutes (S.E. ± 1.15, n= 91). Groups spent 92.6% of their time at the surface of the water. Males and females copulated with several individuals in belly-to-bell y contact. The male was inverted during all copulations and pushed the female against the surface of the water during 87% of copulation events. Mating interactions generally consisted of five adult males chasing one sexually mature female (S.E. ± 0.33, n= 90). Copulation events were brief (4.57 seconds, S.E. ± 0.26, n= 90) and occurred once per minute. On average, 1.3 presumed males were within one body length of the copulating pair (S.E. ± 0.09, n= 90). Males competed with each other for a close spatial position near the female. Females exhibited apparent evasive maneuvers that potentially enabled them to exercise mate choice. The observed mating behaviors are consistent with male scramble competition, where the most maneuverable or proximate males gain copulation opportunities with a female.

Diversity and evolutionary patterns of mollies

Maura Palacios Mejia*1, Lenin Arias Rodriguez2, Gary Voelker1, Mariana Mateos1, Michael Tobler3

1Department of Wildlife and Fisheries Sciences, Texas A&M University 2 Division Academica de Ciencas Biologicas, Universidad Juarez Autonoma de Tabasco 3 Department of Zoology, Oklahoma State University

Keywords: phylogenetics, ecology & evolution, freshwater fish, speciation

Mollies are a group of livebearing freshwater fishes distributed from the southeastern United States to northern Colombia. This region contains areas of past and ongoing geological activity in addition to climatic events and studying this group would provide a better understanding of the evolution of the region. In addition, species of the group represent model species for understanding biological and evolutionary processes but the evolutionary relationships have not been thoroughly resolved for an evolutionary baseline. Here we aim to establish a robust phylogeny for the group, explore biogeographical patterns of mollies, and provide insight to the of the group. We conduct molecular phylogenetic analyses of two mitochondrial and seven nuclear genes using maximum likelihood and bayesian methods. We conduct ancestral area reconstruction and dispersal/ vicariance analyses to assess past historical events. Calibrated species trees are also estimated to check for gene tree vs. species tree discordance. The results support the monophyly of mollies in accordance to a previous study but exclude “mollies” from the Caribbean. Two major groups are defined, the sailfin clade and the shortfin clade, that agree with morphology and behavior. The sailfin clade speciation events suggest allopatric speciation as a result of Pliocene volcanics. The shortfin clade is composed of two main clades: the sphenops and the mexicana complexes. Both complexes have vicariant and ecological speciation events. Collectively, the phylogeographic patterns observed in mollies indicate signatures of the geologic and cyclical changes across their distribution in addition but to ecological forces driving the diversification of the group.

Hawaiian ‘opihi populations are partitioned by island

Kelly Pennoyer*1, Adam Baker1, J. Derek Hogan2, Robert J. Toonen1, Christopher E. Bird2

1Department of Life Sciences, Texas A&M University—Corpus Christi 2 Hawaii Institute of Marine Biology, University of Hawaii

Keywords: microsatellite, genetic connectivity, fisheries, marine management

The Hawaiian limpet fishery, locally known as ‘opihi, crashed ~100 years ago and has exhibited no signs of recovery. In order to inform a spatial management strategy for ‘opihi and other coastal species, we investigated the population genetic structure of ‘opihi makaia‘uli Cellana exarata, using six microsatellite markers. Adult C. exarata were collected from six locations on five islands in both the Main Hawaiian Islands (MHI) and the Northwest Hawaiian Islands (NWHI). As with previous work with mtDNA, isolation by distance was observed, the NWHI sites exhibited the lowest genetic diversity, and the MHI and NWHI were significantly differentiated. Unlike previous mtDNA work, there was statistically significant population genetic partitioning among all islands sampled (Dest = 0.006 – 0.894). While slight, genetic differentiation was detected between Maui and Molokai, which was part of a larger island, Maui Nui, as recently as the last glacial maximum. To better assess ongoing genetic exchange we analyzed kinship relationships, and found the NWHI populations exhibited inbreeding. Overall, the fine-scale population structure exhibited in C. exarata highlights the importance of localized, community-based initiatives in managing marine resources.

Males are from Mars, females are from Venus… and Earth?

Meaghan Pimsler*1, Sing-Hoi Sze2, Corbin D. Jones3, Max J. Scott4, Shuhua Fu2, Jeffery K. Tomberlin1, Aaron M. Tarone1

1Department of Entomology, Texas A&M University 2Department of Computer Science, Texas A&M University 3Department of Biology, University of North Carolina 4Department of Genetics, North Carolina State University

Keywords: entomology, sex-determination, monogeny, transcriptome

Chrysomya rufifacies (Diptera: Calliphoridae) is a species of blow fly invasive to the New World. Unlike other flies which have heteromorphic sex chromosomes and a sex determination system based on embryonic genotype, C. rufifacies has homomorphic sex chromosomes and a monogenic system of sex determination in which the sex of her offspring is a phenotype of the mother. Based on QTL mapping, tissue exchange, and proteomics studies, female-producing (thylegenic) females are heterozygote- dominant for a protein produced in the germ-line and incorporated into the soma of the eggs that predetermines the sex of the offspring. At present, hybridization studies suggest the presence of sex- lethal and daughterless homologues in this species. In other species, a transformer homologue is also an important part of the sex-determination cascade. A de novo transcriptome assembly using Illumina HiSeq data was completed to compare patterns of gene expression between males, male-producing (arrhenogenic) females, and thylegenic females. Homologues to most of the genes identified in studies of the sex-determination cascades of Drosophila melanogaster (Diptera: Drosophilidae) have been assembled, though transformer is a notable exception. Homologues to blow fly transformer sequences have been identified, though it appears to be evolving very quickly. In addition, there are clear patterns of male, thylegenic, and arrhenogenic gene expression and splicing. This mode of monogeny, especially in the absence of transformer, is distinct within the flies. Discussion of pertinence of these findings to the evolution of sex determination and application to forensic entomology follows.

Visceral leishmaniasis in India: modeling alternative control strategies using systemic insecticides orally administered to cattle

David M Poché*1, Hsiao-Hsuan Wang1, Rajesh B. Garlapati2, William E. Grant1

1Department of Wildlife and Fisheries Sciences, Texas A&M University 2Genesis Laboratories, Inc.

Keywords: visceral leishmaniasis, sand flies, systemic insecticides

Visceral leishmaniasis (VL) is the second (behind malaria) most deadly parasitic vector-born disease worldwide, resulting in over 500,000 cases and 50,000 deaths globally. Approximately 60 percent of these cases occur in Northern India and bordering regions of Nepal and Bangladesh, where the disease is spread by sand flies (Phlebotomus spp.) that take blood meals from hosts (including livestock and humans), lay eggs in organic matter, particularly feces, upon which the larvae feed, pupate, and subsequently emerge as adult flies, completing the life cycle. Recent research in Northern India has indicated that systemic insecticides orally administered (once) to cattle can kill 100% adult flies feeding on insecticide-treated cattle and 100% larvae feeding on feces from insecticide-treated cattle. To evaluate the potential efficacy of large scale systemic insecticide treatment, we are developing a quantitative model representing transmission of leishmania donovani (the pathogen causing VL) among the various sand fly life stages (egg, larva, pupa, adult), cattle, and humans in a typical rural village in the state of Bihar, India. We plan to simulate a variety of control strategies in which we will vary the season and frequency of treatment as well as the proportion of cattle treated. We hypothesize that the potential to reduce the number of human VL cases will depend on coordination of the timing of treatments with particular phases of the sand fly life cycle. Here we present the conceptual model of the system of interest, which will form the basis for development of the quantitative model.

Small rodent species as reservoirs for tick-borne pathogens in East-Central Texas

Jaime Rodriquez*1, Adrian Castellanos1, Lisa Auckland2, Jessica E. Light1, Sarah Hamer2

1Department of Wildlife and Fisheries Sciences, Texas A&M University 2Department of Veterinary Integrative Biosciences, Texas A&M University

Keywords: tick, vector, disease, pathogen

Tick-borne diseases are emerging worldwide, causing significant illness and death in human and animal populations. The southern United States is an area of particular concern for tick-borne disease emergence due to high tick species diversity and longer periods of seasonal tick activity. Wild rodent species are important in the ecology of many tick-borne diseases due to their ability to feed ticks and serve as reservoirs for pathogens. Using a longitudinal study design, I explored the temporal dynamics and degree to which wild rodents are involved in tick-borne disease systems at a field site in east-central Texas. For nineteen months, small mammals were live-trapped two nights per month and subjected to blood and ear biopsy collections; drag sampling also was performed monthly to collect ticks. All captured mammals were checked for the presence of ticks, which were removed for diagnostic testing. Preliminary data from 943 small mammals of four species (Peromyscus leucopus, Sigmodon hispidis, Reithrodontomys fulvescens, and Baiomys taylori) suggest that peaks of larval and nymphal tick activity occur in the fall, when both Ixodes scapularis and Amblyomma species were found. Tick infestation of rodents was rare; 2.33% of rodents (22 of 943) harbored ticks at the time of capture (75.5% A. americanum; 20.4% A. maculatum; 1% D. variabilis; 3.1% I. scapularis). Pathogen infection prevalence was low, with Borrelia miyamotoi and Borrelia lonestari detected.

Identifying target genes responsible for mating system variation in two pipefish species using whole brain transcriptomes

Emily Rose*1, Adam G. Jones2

1Department of Biology, Texas A&M University 2Texas A&M University

Keywords: sexual selection, mating system variation, next generation sequencing, pipefish, brain transcriptomes

The family , which includes seahorses, pipefishes, and seadragons, provides an excellent system for studying mating system variation with species ranging from monogamous to polyandrous and polygnandrous. We chose to study changes in gene expression levels in the brains of the monogamous Messmate pipefish, haematopterus, and the polyandrous Gulf pipefish, Syngnathus scovelli, to identify target genes responsible for mating system variation. Using Illumina next generation sequencing, we sequenced whole brain transcriptomes from females, non-pregnant males and pregnant males to determine the differential expression levels of genes in the brains of these two pipefish species. We looked at gene expression differences across the two species and between sexes within each species, as well as between brooding and non-pregnant males within and across species. I will be presenting gene expression patterns and rates of molecular evolution for two target genes, arginine vasotocin and isotocin, that have previously been shown to affect partner preference formation, pair bonding, and paternal care in other fish species.

Stressed plants and herbivores: exploring the mechanisms of drought's impact on plant-insect interactions

Warren Sconiers*1, Micky D Eubanks1

1Department of Entomology, Texas A&M University

Keywords: drought, insects, plants, amino acids, carbohydrates, performance

Drought is predicted to become more prevalent in the future and will dramatically impact plant-insect interactions. Water-deficit stress in plants increases concentrations of amino acids and carbohydrates, as well as toxic allelochemicals. These changes may lead to greater abundances of insect herbivores leading to pest outbreaks in agricultural and natural ecosystems. Since the 1960s, over 500 studies and several long-standing hypotheses have attempted to predict the behavior and abundance of insect herbivores on water stressed plants. Despite this intensive effort, we cannot accurately predict herbivore response to water stressed plants. With increased drought following climate change, it is critical that we understand how insect herbivores respond to water stressed plants in order to formulate proper management strategies for agricultural and natural ecosystems.

In this study we attempted to determine the mechanisms that influence herbivore response to water- stressed plants through a meta-analysis of relevant literature. Our analysis composed of studies that reported data on herbivore performance and stress-induced increases in nutrients and allelochemicals. We found that the degree of change in nutrients and allelochemicals in response to water stress varies greatly between plant families. For insects, performance varied significantly between families, diet breadth, and feeding physiology. When herbivores fed on stressed plants, their performance depended upon the magnitude of increase in nutrients and depended less on allelochemicals. Overall, we found that stress-induced changes in nutrient concentrations are the most important factor in determining herbivore performance on water stressed plants.

Comparing political economy of management strategies in commercial and recreational marine fisheries

Erin Simmons

Department of Wildlife and Fisheries Sciences, Texas A&M University

Keywords: bioeconomics, fisheries, models, marine

The threat of overfishing extends well past the health of an individual species: overfishing also affects the livelihood of fishermen, as well as the local economy within which they operate. As valuable economic resources, marine fish stocks will continue to be harvested but the methods by which harvesting is performed require significant changes to address this issue of overfishing. It is important to understand both the economic and political implications of putting forth management plans and under what conditions favorable (or unfavorable) reactions will occur within the fishing community. I propose to address the following questions: (1) how do management strategies interact, (2) does the order of their implementation matter, and (3) how does decision-making by fishermen differ between recreational and commercial fisheries in response to management? The proposed model will be a simulation model based on that of Smith et al. (2010), which models commercial fisherman choice in response to implementation of a single management strategy, marine reserves. The scope of my model will be expanded to include not only recreational and commercial fishing sectors, but also both marine reserves and individual transferable quotas (ITQ’s). Understanding fisherman choice is necessary to “market” a management plan and gain their cooperation, but assuming that the same decision tree applies to both recreational and commercial fishermen would be a mistake. Developing models that include fishery sectors, fisherman opinion, and alternative management strategies will increase our understanding of the system as a whole.

Mate choice in a hybrid zone: chemical and visual preferences of male swordtails, Xiphophorus malinche

Mattie Squire* and Gil Rosenthal

Department of Biology, Texas A&M University

Keywords: mate choice, behavior, communication

Species recognition via various cues, including chemical and visual cues, is extremely important when it comes to animals’ mating preferences and subsequently, mate choice and reproductive fitness. Multivariate cues may be especially important; an animal may rely on multiple cues presented simultaneously when choosing whom to mate with. Hybrid zones represent a breakdown in species recognition; heterospecifics may mate if certain cues are missing. In the Xiphophorus malinche/X. birchmanni hybrid zone of the Sierra Madre Oriental of central Mexico, anthropogenic disturbance has led to this species recognition breakdown: chemical pollutants in the water have been found to block the olfactory receptors of these fish, leaving them to choose mates based mostly on visual cues. Past research in the lab has found that females of both species tend to favor the visual cues of male X. birchmanni. In addition, another study found that X. birchmanni males also tend to choose the chemical cues of X. malinche females over those of conspecifics. This complex array of preferences highlight the need to understand both male and female multivariate preferences in order to determine the fate of these species and the hybrid zones they form. In this study, we set out to determine both the chemical and visual preferences of X. malinche males, so that we may complete the preference picture. Here, we found that X. malinche prefer conspecific chemical cues, and like X. birchmanni, have no preferences for female visual cues. This creates an interesting asymmetry in preferences between these species that will inform future work.

Estimating effects of land cover configuration at multiple scales on habitat for an endangered toad

Michael Treglia

Department of Wildlife and Fisheries Sciences, Texas A&M University

Keywords: conservation, herpetology, land cover change, land use

Understanding influences of environmental characteristics at multiple spatial scales on biodiversity is critical for developing effective long-term conservation strategies. For example, management actions implemented at small scales, in and around habitat, often provide short-term benefits, but must be repeated for long-term effectiveness because processes that degrade habitat are often driven by properties of the larger landscape. This study is focused on the endangered Arroyo Toad (Anaxyrus californicus), which is a habitat specialist that relies on open, sandy streams and the surrounding floodplains for most of its life. A number of factors have contributed to declines of this species, including habitat degradation associated with altered hydrologic flows, invasive vegetation, and exotic predators. I used fine-scale distribution models and land cover data to analyze the relative influences of land cover configuration at a small scale, around streams, and at a larger scale, of entire watersheds, on habitat for Arroyo Toads. My results suggest that it is important to take both scales into account when implementing conservation strategies for this species. Furthermore, the general approach can be applied to other species in various ecosystems to help inform conservation and management actions in a broader context.

Settlers of the Ice Age: Terminal Pleistocene Human Settlement Strategies for the Midsouth United States

Jesse Tune

Department of Anthropology, Texas A&M University

Keywords: archaeology, Pleistocene, human migration

Anderson and colleagues (2011) have proposed a model of technological and social change during the Pleistocene/Holocene Transition in the Midsouth United States. This model predicts that the Younger Dryas (YD) climate event played a causal role in demographic collapse and/or reorganization in the region. Other researchers (Eren 2012; Holliday and Meltzer 2010; Meltzer and Holliday 2010; Straus and Goebel 2011) contend there is a lack of evidence for such restructuring, as well as a lack of evidence indicating significant ecological changes even occurred in the Midsouth during the YD. The research I present here addresses this debate by assessing the evolution of stone tool technology throughout the Pleistocene/Holocene Transition. Specifically, I will evaluate whether diachronic change in technological organization was ecologically driven, or was the result of settling-in processes as people became increasingly familiar with the surrounding landscape and local resource distribution.

Landscape fragmentation disrupts population dynamics and phenology

Danielle Walkup*, Lee A. Fitzgerald

Department of Wildlife and Fisheries Sciences, Texas A&M University

Keywords: fragmentation, phenology, Sceloporus arenicolus

Fragmentation alters biotic and abiotic characteristics of landscapes, variously affecting the size and distributions of species’ populations. Landscape fragmentation can disrupt the demography of populations and may also affect phenology of species’ life cycles, depending on their life history. Fragmentation is predicted to negatively impact habitat specialists because of perturbations to their specific habitat requirements. For example if individuals encounter barriers to movements or difficulties finding mates or nesting sites, we may expect differences in population sizes, dynamics, and structure. During five breeding seasons (2009-2013), we captured eight species of lizards on trapping grids located in unfragmented and fragmented dunelands in the Mescalero Sands ecosystem in southeastern New Mexico. One species, Sceloporus arenicolus (dunes sagebrush lizard), is a habitat specialist endemic to this ecosystem, the other species are generalists found across the western United States. Using a two- way ANOVA, we examined the effect of landscape condition and year on each species’ capture rates. To test for effects of fragmentation on demography among species, we applied goodness-of-fit tests using expected frequencies computed from the average demographic structure observed on unfragmented grids. Capture rates of S. arenicolus decreased in fragmented sites; the other species responded variably (increasing, decreasing, or remaining the same). Several species, including S. arenicolus, exhibited a disruption in phenology and showed disparate demographic proportions on fragmented grids with juveniles, males and females being over or under represented. The pattern indicates population reduction due to fragmentation causes severe alterations of population dynamics of habitat specialists in this system.

Ecological niches as underlying mechanisms of L. olivacea female alternative reproductive tactics

Kathryn Wedemeyer*1,2, Pamela T. Plotkin2,3, Joseph Bernardo1,2

1Department of Biology, Texas A&M University 2Marine Biology Graduate Interdisciplinary Program, Texas A&M University 3Department of Oceanography, Texas A&M University

Keywords: stable isotope analysis, reproductive tactics, ecological niches, behavioral ecology, sea turtle

Alternative reproductive tactics (ARTs) are a model system for studying the evolution of variation and are well studied in males, characterized by color and/or size, morphology, behavior (i.e. territorial vs. sneaker males), etc. By contrast, female ARTs are poorly studied and many open questions remain: What selection pressures cause divergent female behavior and/or morphology? Do morphological and reproductive behavioral differences evolve as a result of sexual selection, which then impacts other life history aspects, such as feeding? Or does natural selection create feeding dimorphisms that in turn shape morphological and reproductive behavioral differences? Our study explores phenotypic variation and ecological niches as underlying mechanisms of female alternative reproductive tactics in a novel, model system. Olive ridley sea turtles, Lepidochelys olivacea, exhibit strikingly divergent female reproductive tactics. In the same population, some nest synchronously en masse (arribadas) on a few, distinct, beaches whereas others nest solitary on multiple beaches over thousands of kilometers of coastline. L. olivacea are the only sea turtle species known to exhibit these ARTs, which were not formally recognized until 2002. Virtually nothing is known about why or how they occur. We hypothesize that L. olivacea female alternative reproductive tactics (solitary vs. mass-nesting behaviors) relate to an ecological dimorphism - differential foraging strategies (neritic vs. pelagic). We are investigating this idea in the Eastern Pacific using morphometrics, stable isotopes (δ15N and δ13C) and satellite tracking.

Variability of mesophyll conductance to CO2 and coordination of physiological traits in loblolly pine (P. taeda L.)

Elizabeth S. Wilson*1, Jason B. West2, Jason G. Vogel2, Madison Wigley2

1Department of Ecosystem Science and Management, Texas A&M University 2Texas A&M University Keywords: ecophysiology, plant physiology, stable isotopes, hydraulic conductance

Climate change will likely affect the productivity of forests through changes in precipitation and moisture availability. An important measure of a plant’s ability to assimilate carbon in photosynthesis with limited water loss, water use efficiency (WUE), is assessed through the use of carbon stable isotopes by the Farquhar model. However, recent work has shown that mesophyll conductance to CO2 (gm) changes in response to environmental conditions, and the simplified model does not take into account this variability. Variation in this parameter could decrease the effectiveness of the stable isotope tool. This study, conducted in a greenhouse, examined the effects of drought on gm and other physical and biochemical traits in three clones of loblolly pine (P. taeda L.).

There were not significant effects of water treatment and clone on gm, suggesting that the simple Farquhar model is an appropriate tool for using carbon isotopes as a proxy for WUE in loblolly pine. We report on the relationship between the carbon isotopic composition of soluble sugars and a set of other physiological traits in the three clones studied that are evidence for patterns of plant response to drought and the implications for management of pine forests in a changing climate.

Testing bottom-up and top-down processes in ecological communities

Can Zhou*1, Masami Fujiwara1

1Department of Wildlife and Fisheries Sciences, Texas A&M University

Keywords: bottom-up, top-down, community ecology, cointegration

Bottom-up (resource controlled) and top-down (predator controlled) processes are the two widely used ecological concepts to represent species interactions in ecological communities. Previous studies took a correlation approach to resolve these two types of processes in natural communities. Here, we show three common situations, namely non-stationarity, misalignment of times series and complex community structure, that imperil inferences from the correlation approach. In this paper, from the respective of factor analysis, we define a top-down process as one where the influence of species interaction only flows from a higher trophic level to a lower trophic level, and vice versa for a bottom-up process. The new statistical method employed in this study is called a cointegration method. Together with the concepts defined above, the cointegration method can be used to analyze non-stationary and misaligned multi-dimensional time series data to resolve complex community structure, which is often partially observed. Then, we use Gulf of Mexico SEAMAP (Southeast Area Monitoring and Assessment Program) survey data as an example to illustrate the testing procedure.

The effects of endophytic Chaetomium fungus on herbivores

Wenqing Zhou*1, James Starr2, Gregory Sword1

1Department of Entomology, 2Department of Plant Pathology & Microbiology, Texas A&M University

Keywords: endophyte, nematode, cotton plant, cotton aphid.

Chaetomium fungi have been reported to have anti-insect and anti-fungal properties. Chaetomium species have been recognized as antagonists against fungal plant pathogens such as Aspergillus flavus. Chaetomium metabolites (i.e., chetomin, chetocin, cochliodinol, etc) have been reported to negatively affect both insects and nematodes. We evaluated an endophytic Chaetomium sp. strain isolated from cotton plants in Texas for its effects against both nematodes and insect herbivores when present as an endophyte in greenhouse trials. When re-introduced into cotton as an endophyte, the Chaetomium isolate enhanced early plant growth and negatively affected root-knot nematode (Meloidogyne incognita) reproduction. The potential for anti-insect effects of the endpophytic Chaetomium isolate was examined in feeding assays using phloem-feeding aphids (Aphis gossypii).

Graduate Poster Presentations

Impact of red imported fire ants on small mammals, ticks and tick-borne pathogens

Adrian Castellano*1, Sarah A. Hamer2, Katelyn M. Wagner3, Gabriel L. Hamer4, Michael E. Morrow5, Pete D. Teel4, Micky D. Eubanks4, Jessica E. Light1

1Department of Wildlife and Fisheries Sciences, Texas A&M University 2Department of Veterinary Integrative Biosciences, Texas A&M University 3Department of Zoology, Michigan State University 4Department of Entomology, Texas A&M University 5U.S. Fish and Wildlife Service

Keywords: mammals, ticks, disease ecology

Ticks are important vectors of pathogens that impact both animal and human health, making them and their ecological interactions an important scientific concern. In the southeastern United States, small mammal and tick populations are affected by the prevalence of red imported fire ants (RIFA; Solenopsis invicta), an invasive predator that consumes both vertebrate and invertebrate species. Our objective was to elucidate the impact of RIFA on tick-borne disease systems. Two field sites in Texas were assessed for the ecological relationships among small mammals, ticks, tick-borne pathogens, and RIFA. Untreated and treated plots (to suppress RIFA populations) were sampled monthly using Sherman live traps and tick drag sampling to determine mammal and tick density and collect specimens for pathogen testing. Field samples were processed in the lab to detect tick- borne pathogens in the genera Borrelia, Ehrlichia, and Rickettsia. After seven months of trapping, we have captured over 600 mammals of six species, the most abundant being the hispid cotton rat, Sigmodon hispidus. The most common tick species encountered was the Gulf Coast tick, Amblyomma maculatum. We have detected at least three human tick-borne pathogens at low prevalence within ticks and rodents: Borrelia burgdorferi (agent of Lyme disease), B. miyamotoi (agent of relapsing fever), and Rickettsia parkeri (agent of American tick bite fever). Preliminary data indicate that treatment plots (where RIFA populations are suppressed) have higher densities of small mammals and ticks relative to control plots, suggesting that RIFA may be impacting the ecology of tick-borne disease transmission at these study sites.

A beloved and hated species, the channel catfish (Ictalurus punctatus), why to study conservation genetics in a successful species?

Xochitl De La Rosa*1, Ana M. Sifuentes-Rincón2, Gaspar M. Parra-Bracamonte2, Williams Arellano-Vera2, Luis Hurtado3

1Department of Wildlife and Fisheries Sciences, Texas A&M University 2Center for Genomics Biotechnology 3Texas A&M University

Keywords: channel catfish, aquaculture, genetic diversity

The channel catfish is the most important freshwater aquaculture species in the US and constitutes an important growing aquaculture industry in northeast Mexico. In Mexico, channel catfish farming started in the 1970s with stocks originated from the US. Historically, the natural distribution area of channel catfish was restricted to the Northeast of Mexico. Nowadays, channel catfish is beyond its natural distribution range and is reported as exotic to new environments. The enhancement of the aquaculture in Mexico without alterations to local diversity is fundamental. In this point, aquaculture and conservation of the natural populations converge in the importance of channel catfish assessment. We characterized genetic stocks of the channel catfish using microsatellites, including two broodfish stocks raised in Mexico, three grow-out farm populations, and one domestic strain raised in the US. A total of 154 fin-clip samples were amplified with 13 microsatellites. Individuals were successfully assigned to their corresponding genetic stock using two Bayesian methods: STRUCTURE and GENECLASS. This information will aid to identify genetic make up of populations that inhabit Mexico. Our final aim is to provide information that help prevent erosion of the genetic diversity of channel catfish.

Investigating evolutionary novelties: the origin of the seahorse tail

Laura W. Edelstein*1, Adam G. Jones1

1Department of Biology, Texas A&M University

Keywords: developmental evolution, seahorse, morphology

Studies investigating evolutionary novelties shed light on the developmental and evolutionary origins of intriguing morphological innovations. Most bony fish rely on their muscular tail as a source of power for locomotion, but seahorses have a novel prehensile tail that lacks a caudal fin and allows for grasping the substrate. This morphological innovation is not present in most other syngnathids (e.g. pipefish and seadragons), raising evolutionary questions as to how the unique seahorse tail arose from a common ancestor lacking a prehensile tail. Moreover, the development of the prehensile tail during embryonic gestation within the father’s pouch makes it an ideal trait to study in order to answer questions as to how novel traits arise. My research investigates the development of syngnathid tails, both the prehensile tail in seahorses and the more typical teleost tail of the pipefish. I am conducting a morphological developmental time series throughout the duration of male pregnancies in both a seahorse species, Hippocampus zosterae, and a pipefish species Syngnathus scovelli. I will also use next- generation RNA sequencing technology to investigate differential gene expression and identify candidate genes involved in syngnathid tail development at the same developmental stages as the morphology series. This will identify both the intraspecific and interspecific changes in gene expression during syngnathid tail development, thereby shedding light on how the evolutionary novelty of the seahorse prehensile tail evolved.

Sex, ecology, and the genome: how a novel sex determination mechanism interacts with genome evolution during ecological speciation in the gall wasp Belonocnema treatae

Carl Hjelmen*1, James R. Ott2, Scott P. Egan3, J. Spencer Johnston1

1Department of Entomology, Texas A&M University 2Department of Biology, Texas State University 3Department of Ecology and Evolutionary Biology, Rice University

Keywords: genome, speciation, sex determination, isolation

Genome size can vary by orders of magnitude between species. However, within species variation between populations and between individuals has received much less attention, despite growing evidence of its prevalence in nature. We investigated genome size variation in the haplodiploid and cyclically parthenogenic gall wasp Belonocnema treatae. B. treatae hosts on different species of live oaks (Quercus) in southeastern United States where it appears to form locally adapted populations on specific host species. Due to its particularly peculiar life history characters and ecology, we asked whether there were differences between genome sizes among populations and individuals based on sex, host plant, generation (sexual or asexual), and geographic region. Not surprisingly, we found differences among sexes in the sexual generation consistent with haplodiploidy, but we also found differences between females from the sexual and asexual generations. Moreover, we found differences among host-associated populations within geographic regions and, more generally, between geographic regions. Our results suggest changes in genome size associated with ecology and point to a novel sex determination system not previously documented.

Evaluating the infestation and dispersal risks of the southern pine beetle using a landscape framework that integrates spatial and temporal data Ordom Huot*1, Billy Hales2, Adrian Fisher1, Chase Jennings2, Maria Tchakerian1, and Robert N. Coulson1

1Department of Entomology, Texas A&M University 2Department of Geography, Texas A&M University

Keywords: southern pine beetle, infestation, loblolly pine, cut and leave method

The southern pine beetle (SPB) is a destructive pest of several pine species in the southern US. To determine effective control protocols against infestations, we examined documented cases of SPB infestation in the Homochitto National Forest in Mississippi, USA. Data was procured from a 2012 excerpt of SPB Information System (SPBIS) containing reports of SPB infestations in the Homochitto National Forest. This data was used to first determine probable hosts of southern pine beetles based on age and species composition. Of particular interest were those stands composed of 50% or greater loblolly pine over the age of 25 years. Buffers with radii of 100, 200, 400, and 600 meters were used to determine recurrence rates after the application of the cut and leave method based on their distance from the epicenter of the treated infestation. Our results show several main points: the risk of SPB attack and pattern of attack depend on host tree availability; the closer the proximity of a buffer to the initial infestation, the greater the host tree composition of the given buffer. SPBs showed patterns of long distance dispersal based on documented recurring infestations. Most notable among these patterns of dispersal was that there were far more recurring infestations in buffers farther from the initial infestation. This pattern of dispersal may represent an evolutionary adaptation by SPBs to overcome the carrying capacity of their local ecosystem, thereby reducing competition for resources, increasing the availability of host plants, and providing more space for population growth.

Sexual selection and trait introgression across a natural swordtail hybrid zone (Teleostei: Xiphophorus)

Gastón Jofre*1, Rongfeng Cui1,2, Molly Schumer1,2,3, Peter Andolfatto2,3, Gil G. Rosenthal1,2

1Deparment of Biology, Texas A&M University 2Centro de Investigaciones Científicas de las Huastecas "Aguazarca" 3Department of Ecology and Evolutionary Biology, Princeton University

Keywords: hybridization, sexual selection, mate choice, introgression, evolutionary dynamics, Xiphophorus

Clinal hybrid zones, where one species transitions to another over a spatial gradient, are amenable to powerful tests of evolutionary hypotheses by comparing cline widths among traits and genetic markers. Sexual selection by mate choice can drive both the evolution of novel traits or the loss of an existing one, and gene flow can generate introgression of specific genes. We will study how these two processes affect specific sexually dimorphic traits in natural hybrid zones between the livebearing fish Xiphophorus malinche and X. birchmanni along an altitudinal gradient in the foothills of the Sierra Madre Oriental in Hidalgo, Mexico. We will characterize phenotypic clines by quantifying both male sexually-dimorphic morphology and female mating preferences for morphological traits upstream to downstream in at least seven localities. To estimate genome-wide genotypic clines, I will use multiplexed shotgun genotyping (MSG) to identify soft ancestry calls in sampled individuals, corresponding to X. birchmanni or X. malinche. By comparing cline width in morphological traits relative to cline width in genome-wide ancestry, we can estimate the magnitude and direction of selection on these traits across the hybrid zone. We can then compare this estimate of selection with that predicted by clinal data on mating preferences. We can also compare cline width for morphological traits with that for candidate gene regions associated with these traits.

Genome sequencing of Spiroplasma strains from Drosophila flies and genomic comparison with previously sequenced insect and plants related strains

Humberto Martinez Montoya1*, Mariana Mateos1, Rodolfo Aramayo2

1Wildlife and Fisheries Sciences, Texas A&M University 2Biology department, Texas A&M University Keywords: Spiroplasma, genome, next generation sequencing, annotation

Associations between heritable endosymbiotic bacteria and arthropods are ancient and taxonomically diverse. The nature of such associations includes reproductive parasitism, as well as nutritional and defensive mutualisms. Spiroplasma are wall-less bacteria (Class Mollicutes) associated with plants and arthropods. Several members of the genus Drosophila harbor maternally transmitted strains of Spiroplasma, which are fastidious to culture outside the host. Several of these Spiroplasma strains are male killers, and several strains confer resistance or tolerance against natural enemies of Drosophila. Spiroplasma strains associated with Drosophila fall within four major clades that represent independent invasions of Drosophila (i.e., clades poulsonii, citri, ixodetis, and tenebrosa). Partial or complete genome sequences have been reported for seven Spiroplasma strains, but none of them are Drosophila-related. Herein we present the first annotated genome draft of a Spiroplasma associated with Drosophila flies. Herein we present the first annotated genome draft of a Spiroplasma associated with Drosophila flies. Spiroplasma hyd1 (poulsonii), a strain that enhances survival of Drosophila hydei flies against parasitism by the wasp Leptopilina heterotoma, additionally we present several preliminary sequences of Spiroplasma moj (citri), a strain related to Drosophila mojavensis. In both cases a paired-end library was constructed and sequenced on Illumina Hi-Seq. For S. hyd1, approximately 1000 ORFs were detected, many of which exhibit similarity to known and hypothetical protein-coding genes of Spiroplasma. Genomic comparison was performed against all previously Spiroplasma strains sequenced, S. citri, S. melliferum KC3, S. melliferum IPMB4A, S. taiwanese CT-1, S. syrphidicola and S. chrysopicola.

Trophic Ecology of Osteolaemus Species

Nicole Smolensky

Department of Wildlife and Fisheries Sciences, Texas A&M University

Keywords: Cameroon, stable isotopes, food web structure, ontogenetic niche

Crocodilians are mobile top predators in their environments and can serve as energy and nutrient couplers of terrestrial and aquatic habitats. They undergo ontogenetic niche shifts in habitat and trophic ecology occupying both prey and predators roles as they grow. Few studies have integrated their ontogenetic niche shifts with their functional roles as nutrient vectors across terrestrial and aquatic systems. I investigated this aspect in dwarfed species of crocodile, Osteolaemus tetraspis and O. osborni, that occur in Cameroon Africa. I used stable isotope analyses of carbon and nitrogen to compare the trophic position of these species in a large river vs. small tributaries. I collected samples from plants, detritus, dominant primary and secondary consumers and constructed δ13C- δ15N bi-plots and Bayesian mixing models to explore the trophic positions and terrestrial vs. aquatic basal sources supporting these crocodiles. In large rivers and small tributaries there was little variation in the nitrogen isotope ratios between yearling, sub-adult and adult crocodiles with their trophic positions similar to predatory fish but not above them. There was significant positive correlation in the carbon isotope ratios with size such that larger crocodiles had higher δ13C isotope ratios which were found in terrestrial prey while smaller crocodiles had lower δ13C isotope ratios found in aquatic prey. These results suggest that Osteolaemus species occupy similar trophic positions in large and small tributaries and that larger individuals are more likely to transfer nutrients between terrestrial and aquatic systems than smaller individuals.

Effect of nutrient availability and competition control on end of rotation C, N, and P accumulation and retention in loblolly pine forests in north-central Florida

Ignacie Tumushime*1, Dr. Eric J. Jokela2, Dr. Jason G. Vogel1

1Department of Ecosystem Science and Management, Texas A&M University 2University of Florida

Keywords: fertilization, weed control, nutrient accumulation, nutrient retention

The end of rotation effects of fertilization and weed control on C, N, and P accumulation and retention was examined for a managed loblolly pine (Pinus taeda L.) forest in central Florida. The objective of this study was to determine the effect of fertilization with different nitrogen and phosphorus fertilizers (diammonium phosphate (FDAP; 250 kg N ha-1, 90 kg P ha-1); triple superphosphate (FTSP; 200 kg N ha- 1, 90 kg P ha-1)), weed control (W) and the combined application of these treatments (FDAPW or FTSPW) on C accumulation, and N and P accumulation and retention for a managed forest. The soils at the site are classified as sandy, siliceous, hyperthermic Ultic Alaquods. The forest was harvested at age 25 years and tree and understory biomass sampled. The forest floor and four soil depth intervals (0-10 cm, 10-20 cm, 20-50 cm, and 50-100 cm) were also sampled. FDAPW and FTSPW significantly increased total aboveground biomass by 20% and 18%, respectively, above the control. These combined treatments also had greater accumulation of N and P than the control in plant tissues, but not for the forest floor. For plant tissues, the type of fertilizer was not significant for any treatment although nutrient concentrations were increased by all fertilizer combinations. Soil extractions of NH4+ and NO3- (KCl) and PO43- (Mehlich III) indicated few significant differences among treatment except for PO43-, which was significantly greater in the FDAPW than the FTSPW treatments in the 20-50 cm soil layer. This suggests greater PO43- movement to deeper depths with the use of DAP than TSP, which might indicate varying levels of P retention. Ongoing mass balance analysis is being used to determine how intensive silvicultural treatments will affect N and P retention at this site.

Species delimitation based on the limits of climate and morphology in paleontology: a geometric morphometric analysis of Chrysemys picta plastrons

Wesley Vermillion*1, P. David Polly1

1Department of Geosciences, Indiana University—Bloomington

Keywords: geometric morphometrics, turtles, climate change, morphology

Aquatic turtles have great promise as paleoclimatic indicators. Their ectothermic physiology gives them sharp geographic boundaries defined by winter cold, and their freshwater environment and diet give the istopic signature in their bones a clear relationship to the signature of precipitation within their environment. The North American pond turtle, Chrysemys picta, originated in the Miocene and persists to the present day, with its northern boundary following isothermic lines around New Brunswick, along the northern Great Lakes, and into southern Saskatchewan and Manitoba. This species is not homogenous; however, it is divided into four subspecies C.picta picta (Atlantic seaboard), C. p. marginata (Midwest), C. p. bellii (upper Great Plains and northwoods), and C. p. dorsalis (southern Mississippi River drainage). The latter group has an entirely different climatic regime and has been considered a distinct species by many authors.

The possibility of distinguishing these four phylogeographic groups, especially, C. p. dorsalis, based on its shell, was examined in this study. Seventeen landmarks were taken on the plastrons of individuals within each of the four subspecies. A Principal Component Analysis of the Procrustes superimposed landmarks shows morphological variation within C. picta is determined by subspeciation. Differentiation of subspecies accounts for ~8% of the total morphological variation. C. picta picta was determined to be marginally more similar to C. dorsalis than to the other subspecies. Compared to morphological differentiation between subspecies, there is considerable within group variation. While there are phenotypic differences between subspecies, a reasonable sample size is necessary to distinguish them. Future work tracing the differentiation of C. picta in relation to the climatic transition from Miocene to Quaternary will have to be based on more than individual specimens.

Payments for Ecosystem Services: Landholder Perspectives and Decisions

Margot Wood

Department of Wildlife and Fisheries Sciences, Texas A&M University

Keywords: tropical ecology, mammals, environmental policy, payment for ecosystem services

Costa Rica has had its share of land conversion to agriculture, reaching its peak in the 1970’s. Current government payments for ecosystem service (PES) policies, in place since 1997, strive to accomplish the goal of aiding in water, biodiversity, scenic beauty and carbon protection. PES participants that live in the Sistema Nacional de Areas de Conservacion designated biological corridors are given funding priority because these regions are considered essential for connecting segregated wildlife populations held in the National Parks. The purpose of the study is to assess the ecological function of the Paso de Las Nubes biological corridor. The goal of these biological corridors is to promote conservation of biodiversity and sustainable use of natural resources. Although forest cover has been described in these corridors, there have been few studies on the actual ecological function of the corridors. There are three components to this study; (1) To determine the influence of the PES program on land use change in the Paso de Las Nubes corridor during the two separate “periods” of the program (from 1997-2000 and from 2001-current day). This will be accomplished through a land use change analysis. (2) Next, determine why mammals choose specific habitats and how these habitats impact movement in the corridor. (3) Lastly, quantify the biological conservation potential of the various land use treatments within this corridor. This study will provide valuable information for the future of geographic PES targeting, non-human species resource use, and conservation value of biological corridor in multifunctional landscapes.

Effect of climate change and forest management on wood mass loss in a southeastern US loblolly pine forest

Yang Zhang*1, Jason Vogel1, Jason West1

Department of Ecosystem Science and Management, Texas A&M University

Keywords: fertilization, climate change, wood mass loss The productivity of managed pine forests in the southeastern US has been improved in part through nutrient management over the past 50 years. Although significant uncertainty exists, climate change may drive a reduction of rainfall of 10%-30% by 2080 for the region. This reduced precipitation may interact with fertilization to affect forest productivity and carbon balance. In this study, we analyzed the mass loss of southern pine wood and the accumulation of soil ammonium and nitrate under a factorial combination of two treatments: soil moisture (30% throughfall removal) and nutrient addition (224 kg/ha N, 64 kg/ha P and 67 kg/ha K). Our results showed that after 6 months the substrate mass loss by microbes under throughfall removal, irrespective of fertilization treatment, was lower compared to the wood mass loss under control. After one year, both fertilization and throughfall removal decreased microbial decomposition (decreased k value). Increased N pools, primarily nitrate, corresponded to decreased microbial decomposition. Our results indicate that future drought and fertilization may cause slower substrate decomposition by microbes but higher substrate mass loss by termites.

Undergraduate Poster Presentations

The Impact of Stressed Cotton Plants on Aphids

Katherine Bass*1, Warren Sconiers2, Micky Eubanks2

1Zoology, Texas A&M University 2Department of Entomology, Texas A&M University

Keywords: aphids, plants, drought, plant-insect interactions

Climate change is predicted to increase the occurrence of drought in the future, which could impact plant-insect interactions. When plants experience water deficits, they become stressed and their physiology changes. Stress can cause them to be smaller, grow fewer leaves, and have a higher abundance of nutrients. Crop pests, such as aphids, ingest phloem from plants for nutrients to grow and develop. With the increase of nutrients in plants due to stress, aphids living on plants could become more abundant and decrease crop production for industries.

In this experiment, we tested the impact of stressed cotton plants on aphids. We used three treatments: control (watered regularly), pulsed stress (watered infrequently), and continuous stress (which were not watered once the experiment began). These plants were kept in a greenhouse and monitored over five weeks. We found that there were significantly fewer aphids on the continuously stressed plants, but aphids were similar in abundance on the pulse stressed and control groups. The number of alates, aphids with wings, also varied with different treatments. The control group had the highest abundance of alates and the continuously stressed group had the lowest abundance. Alates normally form due to low plant quality or overcrowding on a plant and signifies the need for aphids to disperse. The variation of alates on different treatments was likely due to the level of overcrowding and not plant quality. Overall, aphid and alate abundance appeared to be highly dependent on the level of plant stress.

Interspecies genetic determination of the massasauga distribution in Texas

Anna Blick*1, Wade Ryberg2, Johanna Harvey2, Toby Hibbitts2, Gary Voelker2

1Zoology, Texas A&M University 2Texas A&M University

Keywords: phylogeography, herpetology

The Massasauga (Sistrurus catenatus) is a grassland specialist that formerly occurred from Arizona to New York. Currently its populations have become fragmented due to various reasons including: desertification due to overgrazing and climate change in the south west, agriculture in the Great Plains and habitat succession in the Midwest due to human control of fires and floods. Three subspecies have been described based on genetic structure, morphological variation, and geographic isolation. Recent genetic findings distinguish the geographically isolated eastern subspecies (Sistrurus catenatus catenatus) from both the western (Sistrurus catenatus tergeminus) and desert subspecies (Sistrurus catenatus edwardsii), but poor genetic sampling and a lack of geographical barriers have impeded the distinction among the western (S. c. tergeminus) and desert (S. c. edw ardsii) subspecies. Lack of sampling within Texas, the only state where S. c. tergeminus and S. c. edwardsii co-occur, has prevented clear determination of taxonomic relationships and inter-species dynamics. Here, we aim to elucidate this relationship via increased sampling and molecular methods. We have increased known sampling, adding 17 counties in Texas (n=40), and several more localities in Oklahoma, Kansas, and New Mexico (n=14). Using 2 independent molecular loci (1 mitochondrial DNA and 1 nuclear DNA locus), we will determine subspecies dynamics and use this information to make recommendations for current and future conservation efforts targeting this species.

Engaging local communities to protect bats through conservation education activities in a transboundary biodiversity corridor

Patricia Citlally Jimenez*1, Jane M. Packard1, Michael Petriello2, Emma P. Gomez Ruiz1

1Department of Wildlife and Fisheries Sciences, Texas A&M University 2Applied Biodiversity Science, Texas A&M University

Keywords: conservation education, theatre, biodiversity education

A key step in any bat conservation strategy includes engaging local communities to protect species in the region. Bats are potentially effective ambassadors for elementary school enrichment activities. The problem lies with availability of materials, which are spread across many sources, challenging educators to find what is available. We addressed this problem by collating available materials, making them accessible on the web, while also finding better ways to engage students. We evaluated: (1) how effectively existing bat conservation materials address essential knowledge and skills needed by educators, and (2) which interactive activities (venues) are more readily obtainable: videos, hands-on, or role-drama. A network of people with knowledge of bat educational materials were contacted, starting with key actors in Bat Conservation International, and snow balling to others who were recommended. Educational materials were collated (n = 24), sorted within venue categories, and scored for essential skills and knowledge. All materials were assembled in an electronic binder, and posted online for easy access through the Biodiversity Stewardship Lab website. The materials gathered consisted of 55% videos, 38% hands-on, and 5% role-drama/stories. The subject matter included: 27% Arts, 25% Science, 16% Language Arts, 22% Social Sciences, 5% Mathematics, and 5% Performance. Since most activities were passive video or individual hands-on, we recommend more interactive role-drama adaptations of stories. Although existing materials address a variety of essential skills and knowledge used by educators, the effectiveness of role drama in engaging students of high priority bat conservation regions needs to be further investigated.

Post-fire response of understory bryophytes in association with vascular plants in the lost pines ecosystem of central Texas

Ingrid Karklins

Department of Ecosystem Science and Management, Texas A&M University

Keywords: bryophyte-vascular plant assemblages, post-fire succession, Bastrop Lost Pines ecosystem

Non-vascular bryophytes, which are usually first-responders, have generally not been included in post- fire vascular plant research and may be an important element in the fire-recovery process. This study expands the work of past studies of forest succession after fire by combining vascular and non-vascular community fire-response interactions in a comprehensive evaluation of understory response to the Bastrop Fires of 2011. Approximately two years after the fire, I quantified herbaceous and non-vascular plant cover in both heavily burned and unburned riparian and upland areas in two adjacent watersheds of the unique Bastrop Lost Pines Ecosystem to identify recognizable post-fire plant assemblage patterns. I also measured soil moisture and estimated ground cover percentages of litter, bare ground and rock. Preliminary results demonstrate clear differentiation in species presence. Vascular plant species diversity and abundance was higher in burned areas while bryophyte presence in burned areas was primarily limited to a limited number of early disturbance species. Bryophyte diversity was higher in unburned areas than unburned areas while vascular plant diversity and abundance was low in unburned areas. Overall, burned areas were dominated by both vascular and non-vascular species commonly associated with disturbance. Results of this study will offer inferences into interactions between bryophytes and vascular plants and the role these interactions play in ecosystem recovery processes.

Habitat preference in small mammals

Rebecca Langley*1, Margot A. Wood2, Dr. Thomas E. Lacher2, Pablo José3

1Department of Bioenvironmental Sciences, Texas A&M University 2Department of Wildlife and Fisheries Sciences, Texas A&M University 3Universidad Nacional Costa Rica-UNA

Keywords: biodiversity, mammal, wildlife, habitat

Small mammals, especially rats and mice, have long been considered pests when found in urban areas. I analyzed the habitat preferences of small mammals in Costa Rica in order to determine if the mammals favor urban or wild environments. While there have been similar studies performed, their focus tends toward areas with a heavy anthropogenic influence, as opposed to the protected rainforest area I surveyed. I analyzed four different habitat types within the Children’s Eternal Rainforest in Costa Rica. These habitat types included unlogged forest, selectively logged forest, an urban area, and a tree plantation. I set 100 traps for three nights in each habitat area and recorded the coordinates of each mammal caught. This study could provide insight into areas that are suitable for small mammals in order to create an effective conservation strategy.

Variation in aggressive behaviors in the blue-striped pipefish, Doryrhamphus excisus

Caitlin Leslie*1, Emily Rose2, Adam Jones2

1Department of Biology, Texas A&M University—College Station 2Texas A&M University—College Station

Keywords: pipefish, behavior, aggression, social systems

To date, little is known about the blue-striped pipefish, Doryrhamphus excisus, a member of the Syngnathidae family, which includes seahorses, pipefish, and seadragons. This reef-dwelling species of pipefish has been assumed to be monogamous due to their monomorphic coloring across sexes and being consistently found in pairs in the wild. However, no experimental studies of the D. excisus social system have been published. We set out to study the social system of the blue-striped pipefish, and in the process discovered the predominance of intrasexual aggression in this species. We performed one- on-one aggression trials using inter- and intrasexual pairs to quantify variation in aggression and identify potential causes of this variation. Overall, while very little aggression was observed in the intersexual trials, we found that same-sex pairs demonstrated several aggressive behaviors, including posing, flicking, and chasing.

Settlers of the Ice Age: Terminal Pleistocene Human Settlement Strategies for the Midsouth United States

Judith A. Melton*1, Jesse W. Tune1

Department of Anthropology, Texas A&M University

Keywords: archaic, lithic technologies, paleoenvironment

The Midsouth United States has a rich and diverse archaeological record representing continual human occupation in the region since the terminal Pleistocene. During that time both the environment and human behaviors underwent various scales of change. An ecological model of human occupation was constructed based on analysis of two contemporary archaeological sites within the Cumberland River basin. Temporally diagnostic artifacts were used to reconstruct site occupation histories based on existing regional chronologies. The Stratton site is located along a major stream in Kentucky, while the Magnolia Valley site is in an upland setting in Tennessee. The two sites likely represent different components of regional settlement strategies. Ecological data was compiled from existing paleoenvironmental literature. The archaeological and environmental datasets were correlated to establish an ecological model of regional human occupation.

Multiple paternity analysis of a hybrid zone

Janae Rapp*1, Mattie K. Squire1, Gil G. Rosenthal1

1Department of Biology, Texas A&M University

Keywords: hybrid, polyandry, Xiphophorus, sexual selection

Hybridization is an important evolutionary process. Studies of hybrid zones can illustrate mechanisms that maintain the hybrid zone or mechanisms which lead to further introgression. Natural hybrid zones of the swordtail genus Xiphophorus form between X. malinche and X. birchmanni; these species are live bearing, internally fertilizing fish, and the females of both species are known for mating several times with several males (polyandry) in any reproductive session. Polyandry is an important phenomena, and has been shown to increase genetic diversity and increase the opportunity for sexual selection. To analyze levels of multiple paternity, offspring and parents will be genotyped with microsatellite markers, which are highly variable short tandem repeats of DNA that allow for easy paternity assignment. Using the program GERUD, I will assess paternity and determine the number of sires for each female’s brood of offspring. I expect, like parental species, hybrid females will display a high level of multiple paternity. By studying the level of multiple paternity in this hybrid zone, consequences of polyandry, such as increased opportunities for sperm competition or other mechanisms promoting postcopulatory sexual selection, can be studied in this system in the future.

Monitoring the endangered Mexican long-nosed bat (Leptonycteris nivalis) at a maternity cave in Nuevo Leon, Mexico

Rachel Saker*1, Emma P. Gomez1

1Department of Wildlife and Fisheries Sciences, Texas A&M University

Keywords: population, dynamics, monitoring, monitor, bats, chiroptera, endangered, species, wildlife, IUCN, red list, animal, science, maternity, cave, karst, speleobiology, fauna, ecology, agave, migration

Mexican long-nosed bats (Leptonycteris nivalis) are a desert and forest dwelling cave bats that range from central Mexico to southwestern United States. L. nivalis is an endangered species with dramatic population declines from habitat loss and roost disturbance. L. nivalis are important desert pollinators. Mainly females migrate north following the bloom of century plants (Agave spp.). They give birth in specific maternity roost caves during summer. There are only two known maternity roost for L. nivalis: El Infierno Cave, La Camotera, Nuevo Leon, and Mt Emory Cave, Big Bend National Park, Texas. These caves are crucial and monitoring the populations there is an important tool for understanding the species’ fitness. This study was conducted during May & June 2013. The main objectives were to determine the migration’s arrival time, record nightly emergenc e activity, estimate population size, and assess the colony’s reproductive condition. In early summer, only three L. nivalis were netted and few bats were counted. During mid-summer the visual count increased tenfold and 20 L. nivalis were netted. The sudden peak in activity indicates the L. nivalis colony did not arrive until mid-summer. The arrival time this year was much later than times recorded in previous years. Drought conditions may have indirectly delayed the bats’ migration by affecting the agave bloom, thus limiting the locally available food.

Effects of diet on female preference in Xiphophorus malinche

Michael Stanley*1, Pablo J. Delclos1, Gil G. Rosenthal1

1Department of Biology, Texas A&M University

Keywords: mate choice, diet, olfactory cue, swordtail

In nature it is beneficial for females to mate with males who will provide their offspring with the best chance of survival. So, female preferences are often sensitive to male condition. However, mate choice may also be influenced by the female’s condition. While females should prefer males in better condition, the strength of this preference may be affected by the female’s nutritional state. We tested the preference strength of well-fed and starved females to chemical cues produced by well-fed and starved males in the swordtail fish, Xiphophorus malinche. In their natural setting, X. malinche live in environments of seasonally fluctuating resource availability. In cases where access to resources is low, male nutritional condition is likely to be used by females as a strong indicator of quality. We therefore expect females deprived of food to have a stronger preference for chemical cues of well-fed males than females who have been maintained on a more substantial feeding regimen. While a similar study has been conducted previously in a sister species, X. birchmanni, these two species often hybridize, and in order to better predict hybrid behavior it is important to have a firm understanding of behavior in both of the parental species. Furthermore, X. malinche typically live in more depauperate environments in which resource availability is lower than in X. birchmanni habitats. Therefore, we might expect different evolutionary trajectories to emerge regarding this behavior in female mate choice.