Ecology and Evolutionary Biology Commons^™

A Molecular Framework Phylogeny For Ptilotus (Amaranthaceae), Timothy A. Hammer

Biological Sciences Theses & Dissertations

Ptilotus (Amaranthaceae) is an Australian genus with over 100 species, most of which occur in arid Western Australia. Ptilotus has been a taxonomically difficult genus; despite rigorous morphological studies into the genus over many years, previous workers have found it difficult to delimit infrageneric groups due to inconsistent morphological variation. With the goal to establish a phylogenetic framework for the genus, 100 taxa were sampled, including 87 Ptilotus spp., and the ITS nrDNA and matK cpDNA were sequenced. The phylogeny was reconstructed using Bayesian, maximum likelihood and maximum parsimony analyses on separate and concatenated datasets. Morphological characters were assessed and …

Predictors Patterns And Processes Of Extinction Risk In Porgies And Seabreams (Family: Sparidae), Mia Theresa B. Conteros

Biological Sciences Theses & Dissertations

A variety of human-induced changes are having profound impacts on the marine environment, and no area on the planet remains unaffected by the detrimental effects of our activities. These stressors can potentially lead to synergistic effects, causing accelerated biodiversity loss and diminished ecosystem functioning. Identification and understanding of the factors that drive species to heightened risk of extinction are important goals in conservation.

The Sparidae are commercially important and ecologically complex marine fishes; global extinction risk assessments using the IUCN Red List of Threatened Species methodology show that 9% (13 species) have increased vulnerability to population declines from intense fishing …

The Role Of Chemical Attractants In The Use Of Tick Traps For Life Stages Of Tick Species Ixodes Scapularis, Dermacentor Variabilis And Amblyomma Maculatum, Pamela C. Kelman

Biological Sciences Theses & Dissertations

Amblyomma maculatum, Ixodes scapularis and Dermacentor variabilis are three of the hard-bodied ticks found in the United States. This study explored three aspects of the appetence process of these tick species: attraction, desiccation survival, and locomotive activity. The first portion of this work was to improve one of the standard methods used for collecting ticks from the environment, the tick trap. To determine the attractants needed to capture all life stages of the three chosen species of ticks in the field using tick traps, a series of experiments were conducted using laboratory-reared larval, nymphal and adult A. maculatum, I. scapularis …

The Ecological Impact Of Casitas On Caribbean Spiny Lobster (Panulirus Argus) Populations In The Florida Keys, Fl, (Usa), Benjamin C. Gutzler

Biological Sciences Theses & Dissertations

Casitas are artificial structures placed on the seabed by fishermen to aggregate Caribbean spiny lobsters (Panulirus argus) for ease of capture. Some researchers suggest that they may also enhance lobster populations in shelter-limited environments. Conversely, aggregation of lobsters within casitas may be detrimental to the population if the nutritional condition or mortality of lobsters is poorer in casitas than in natural shelters. Small juvenile lobsters may be at particular risk because their foraging range is smaller and they are more readily preyed upon than larger lobsters. If so, then casitas placed in lobster nurseries may function as "ecological traps"; wherein …

Phylogeny And Biogeography Of The Family Haemulidae Based On A Multigene Approach, Millicent D. Sanciangco

Biological Sciences Theses & Dissertations

Haemulids are one of the most ecologically and commercially important groups of near-shore fishes. They are very diverse, with 145 putative species belonging to 18 genera. The phylogenetic relationships of the genera within the haemulids, however, are uncertain and the limits and relationships with other percomorphs are undefined.

Here, I present the first comprehensive phylogenetic hypothesis for the family based on a combined dataset of five genes (4731 bp; 16 genera, 56 species). Results show strong support for a monophyletic Haemulidae with the inclusion of the former inermiids. However, results of the analyses call into question the monophyly of a …

Benthic And Planktonic Microalgal Community Structure And Primary Productivity In Lower Chesapeake Bay, Matthew Reginald Semcheski

Biological Sciences Theses & Dissertations

Microalgal populations are trophically important to a variety of micro- and macroheterotrophs in marine and estuarine systems. In Chesapeake Bay, microalgae facilitate the survival and development of ecologically and economically relevant fauna, including shellfish and finfish populations. While regarded as significant components of coastal environments, microphytobenthic communities are historically understudied. In Chesapeake Bay, the importance of phytoplankton to the ecosystem is understood, but the contribution of microphytobenthos remains unclear. This project surveys intertidal microphytobenthic communities, in relation to phytoplankton communities, around lower Chesapeake Bay describing the taxonomic makeup of these populations, coupled with quantification of cell abundance, biomass, and primary …

Determination Of The Ecological Condition Of Benthic Communities Affected By Polycyclic Aromatic Hydrocarbons In The Elizabeth River, Chesapeake Bay, Usa, Adam M. Webb

Biological Sciences Theses & Dissertations

The Southern Branch of the Elizabeth River, a tributary of Chesapeake Bay, has historically been polluted with hydrocarbon based industrial by-products. My study compared benthic community condition from two locations in the Southern Branch: the subtidal region near Money Point, historically affected by pollution of polycyclic aromatic hydrocarbons (PAHs), to a subtidal region near Blows Creek on the opposite shore that is putatively designated as unimpacted by P AH contamination. Samples from both study sites in the Southern Branch were compared to the benthic community condition of samples from the same habitat type designations collected as part of the Chesapeake …