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Full-Text Articles in Biology

Community Structure And Ecological Specialization In Plant-Ant Interactions, Paola Barriga Dec 2012

Community Structure And Ecological Specialization In Plant-Ant Interactions, Paola Barriga

Graduate Theses and Dissertations

Positive associations among species have contributed to the maintenance of biodiversity. These interactions are typically studied in pairwise fashion where two interacting organisms are the focus. This dissertation uses network theory to analyze positive plant-ant associations in three Neotropical forests. Obligate plant-ant mutualisms were used, where plants host the ants in domatia and provide food bodies while the ants protect the plants and can feed them. A network approach was used to depict all obligate plant-ant interactions within a community. The main questions asked at the community level were: 1) Do network structure and levels of specialization change geographically and, …


The Spatial Games: Investigating The Spatial Distribution Of Anax And Select Prey As A Function Of Predator-Prey Interactions, Shane Elizabeth Johnson, Nene Kumashe Ugbah Jun 2012

The Spatial Games: Investigating The Spatial Distribution Of Anax And Select Prey As A Function Of Predator-Prey Interactions, Shane Elizabeth Johnson, Nene Kumashe Ugbah

Biological Sciences

Our study investigated the spatial distribution and movement behavior of predatory dragonfly larvae (Anax) and of two prey types: mosquito larvae and amphipods. Predator-prey interactions have important consequences for the population dynamics of both predator and prey groups and these interactions can shape community structure. We measured behavior of each prey type in the presence of the Anax predator and the behavior of the predator in the presence of these alternative prey types. Observations were made in five-gallon aquaria where a grid pattern allowed us to track the number of moves made by individuals. We compiled data from …


Early Embryology Of The Insect Oligotoma Saundersii (Embiidina) Using Targeted Genes As Developmental Landmarks, Omar Doria May 2012

Early Embryology Of The Insect Oligotoma Saundersii (Embiidina) Using Targeted Genes As Developmental Landmarks, Omar Doria

Theses and Dissertations - UTB/UTPA

Embiidina, or "webspinners", is a small, sexually dimorphic, polyneopterous insect order and is the only order to spin silk throughout their life cycle. Unique morphological features and the phylogenetic position of Embiidina make it an attractive subject for study of the evolution and development of the insect body plan and the origin of novel morphological features. Oligotoma saundersii is easily cultured and a viable laboratory organism. It has a fairly standard short-germ embryogenesis process requiring 453 hours at 28°C with progressive development beginning in the anterior region. Preliminary work on targeted developmental genes has yielded small portions of seven genes. …


Externally-Expressed Fluorescence Across Sexes, Life Stages, And Species Of Spiders, Erin Brandt Jan 2012

Externally-Expressed Fluorescence Across Sexes, Life Stages, And Species Of Spiders, Erin Brandt

Dissertations and Theses

Although all spiders possess fluorophores in their hemolymph, the expression of external fluorescence is much more restricted. The purpose of this study was to evaluate differences in externally-expressed fluorescence between sexes, life stages, and species of spiders. To approach this question, we developed novel instrumentation to capture fluorescence with photographs of our specimens. We paired these fluorescence measurements with spectrometer measurements to attempt to determine the role that fluorescence plays in the overall coloration in spiders. The study was divided into four sections. First, we examined how fluorescence varies in sexes and life stages in Misumena vatia, an ambush predator …


Empirical And Conceptual Approaches To Life-History Trade-Offs: The Size And Number Of Offspring In Broods Of A Parasitoid Wasp, Yoriko Saeki Jan 2012

Empirical And Conceptual Approaches To Life-History Trade-Offs: The Size And Number Of Offspring In Broods Of A Parasitoid Wasp, Yoriko Saeki

Theses and Dissertations--Biology

Trade-offs in resource allocation underlie key life history traits of organisms. My dissertation focuses on the size-number trade-off in clonal broods of offspring using the polyembryonic wasp, Copidosoma bakeri parasitizing immature stages of the moth Agrotis ipsilon. I aim to characterize responses of wasp brood size and individual body mass by manipulating the environments in order to understand the allocation pattern in the size number trade-off. In reviewing the functional forms of trade-off relationships in relation to resource constraints, I distinguish among three main trade-off types based on graphical representations of the relationship between the trade-off variables: linear, convex …