Ecology and Evolutionary Biology Commons^™

Exploring The Sulfide Tolerance Of Ectosymbiotic Niphargus Amphipods From The Frasassi Caves, Central Italy, Jan Bauermeister, Karoline Assig, Sharmishtha Dattagupta

International Journal of Speleology

Two species of the crustacean amphipod genus Niphargus inhabit the sulfidic groundwaters of the Frasassi caves in central Italy, and both harbor filamentous, sulfide-oxidizing Thiothrix ectosymbionts. As sulfide is toxic to most aerobic organisms, it appeared possible that the ectosymbionts could help their Niphargus hosts with detoxification processes. In this study, mortality due to sulfide was compared between Niphargus individuals with ectosymbionts and individuals whose ectosymbionts had been killed by antibiotic treatment. Both Frasassi-dwelling Niphargus species revealed exceptionally high tolerances to sulfide compared to other amphipod species studied so far. Niphargus individuals without viable ectosymbionts tolerated sulfide levels exceeding those ...

Reexamination Of Herpetofauna On Mormon Island, Hall County, Nebraska, With Notes On Natural History, Keith Geluso, Mary J. Harner

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

The Platte River in central Nebraska, USA, was historically surrounded by mixed grass and tallgrass prairies and wet meadows, but many of those habitats were lost or altered during the last century with unknown effects on animals that reside in them. Researchers first surveyed herpetofauna on part of a large island preserve in the Platte River, Mormon Island, Hall County, Nebraska, in 1980 when the land was protected for conservation. They documented 10 species, including three species of amphibians and seven species of reptiles. We inventoried herpetofauna after 30 years of conservation management on Mormon Island and adjacent Shoemaker Island ...

Euryhalinity In An Evolutionary Context, Eric T. Schultz, Stephen D. Mccormick

EEB Articles

This chapter focuses on the evolutionary importance and taxonomic distribution of euryhalinity. Euryhalinity refers to broad halotolerance and broad halohabitat distribution. Salinity exposure experiments have demonstrated that species vary tenfold in their range of tolerable salinity levels, primarily because of differences in upper limits. Halotolerance breadth varies with the species’ evolutionary history, as represented by its ordinal classification, and with the species’ halohabitat. Freshwater and seawater species tolerate brackish water; their empirically-determined fundamental haloniche is broader than their realized haloniche, as revealed by the halohabitats they occupy. With respect to halohabitat distribution, a minority of species (<10%) are euryhaline. Habitat-euryhalinity is prevalent among basal actinopterygian fishes, is largely absent from orders arising from intermediate nodes, and reappears in the most derived taxa. There is pronounced family-level variability in the tendency to be halohabitat-euryhaline, which may have arisen during a burst of diversification following the Cretaceous-Palaeogene extinction. Low prevalence notwithstanding, euryhaline species are potent sources of evolutionary diversity. Euryhalinity is regarded as a key innovation trait whose evolution enables exploitation of new adaptive zone, triggering cladogenesis. We review phylogenetically-informed studies that demonstrate freshwater species diversifying from euryhaline ancestors through processes such as landlocking. These studies indicate that some euryhaline taxa are particularly susceptible to changes in halohabitat and subsequent diversification, and some geographic regions have been hotspots for transitions to freshwater. Comparative studies on mechanisms among multiple taxa and at multiple levels of biological integration are needed to clarify evolutionary pathways to, and from, euryhalinity.

The Effects Of Refuge On Escape Responses Of Two Caribbean Goby Species, Russell P. Dauksis

Senior Honors Projects

The Effects of Refuge Abundance on Escape Responses of the Bridled Goby (Coryphopterus glaucofraenum)

Russell P. Dauksis

Major

Marine Biology

Advisor

Dr. Graham Forrester

Advisor Department

Natural Resources Science

Date

5-2012

Keywords

Escapology, marine ecology, functional morphology, animal behavior, predator-prey interactions, Bridled Goby, Coryphopterus glaucofraenum

Abstract

Interactions between predators and prey species are arguably the most pervasive and important events in ecology. Predators have strong effects on the distribution and abundance of prey in virtually all environments. In the long-term, it is therefore hardly surprising that selective mortality imposed by predators has shaped a wide array of prey behaviors that ...

Effects Of Non-Surface-Disturbing Restoration Treatments On Native Grass Revegetation And Soil Seed Bank Composition In Cheatgrass-Invaded Sagebrush-Steppe Ecosystems, Alexandra D. Reinwald

All Graduate Theses and Dissertations

The conversion of sagebrush-steppe communities of the Great Basin into cheatgrass-dominated communities is one of the most dramatic ongoing land conversions in North America. Although restoration of these communities is a high priority to landowners and land management agencies, restoration of native vegetation is difficult. Several restoration treatments intended to increase the success of aerially‐seeded perennial grasses in cheatgrass-invaded sagebrush ecosystems were assessed to determine their effects on perennial seedling emergence and soil seed bank density and composition. Assessed restoration treatments were: 1) vegetation manipulation (sagebrush thinning and prescribed burning); 2) imazapic herbicide application; 3) seedbed amendments (aerial seeding ...

A Multi-Scale Investigation Of Factors Limiting Bull Trout Viability, Tracy Bowerman

All Graduate Theses and Dissertations

Effective conservation strategies for imperiled species require an understanding of processes that influence fitness throughout the organism's life cycle and across the range of habitats needed to complete that cycle. I evaluated factors that affect population viability of bull trout Salvelinus confluentus, a threatened freshwater char species, throughout individual life stages and over the entire life cycle. I assessed the relationship between bull trout egg incubation success and environmental variables. Egg survival was negatively related to the percent of fine sediment in redds and positively related to hydraulic conductivity and the strength of downwelling. Next, I quantified juvenile bull ...

Forest Recovery, Nutrient Cycling And Carbon Sequestration In A Southern Appalachian Spruce-Fir Forest, Patrick T. Moore

All Graduate Theses and Dissertations

In order to fully understand the magnitude of the benefits that forests provide, it is crucial to understand the full suite of ecosystem services that they offer. A southern Appalachian red spruce-Fraser fir forest was intensively analyzed using a variety of methodologies to determine the nature and quantity of some of these services. Many hypotheses exist regarding the future of these spruce-fir forests, which were heavily disturbed by the non-native balsam wooly adelgid during the 1980s. Direct measurements over the course of a decade assessed these hypotheses and indicate that this forest is recovering structure and function. The forest is ...

Colonization Of Subterranean Habitats By Spiders In Central Europe, Vlastimil Růžička, Petr Šmilauer, Roman Mlejnek

International Journal of Speleology

Using data from the Czech Republic, we studied the distribution of spiders in soils, crevice systems, scree and caves, i.e. subterranean habitats at depths spanning from 10 cm to 100 m. In total, we found 161 species. The number of species declines with increasing habitat depth, with a major drop in species richness at the depth of 10 meters. Thirteen species exhibit morphological adaptations to life in subterranean habitats. At depths greater than 10 meters, spider assemblages are almost exclusively composed of troglomorphic species. We propose a hypothesis of evolution of troglomorphisms during Quaternary climatic cycles.

Parental Provisioning In The Face Of Pathogenic Presssures: Contributions To Offspring In A Social Insect, The Dampwood Termite (Zootermopsis Angusticollis), Andrielle N. Swaby

Biology Master's Theses

Social insects (i.e. ants and termites) are excellent candidate species to address questions about parental provisioning in the face of pathogenic constraints. Parental investment theory holds that adults that anticipate the future needs of their offspring based on their current surroundings and conditions will allocate resources to their young accordingly. The specific focus of this research is trans-generational immunity, the phenomenon whereby parents provision their offspring with raw materials that confer their progeny protection against pathogenic microbes. Using the dampwood termite, Zootermopsis angusticollis, I tackled the question of whether parents contribute differently to offspring in the face of different ...

The Effects Of Fire On The Vernal Herbs Of An Eastern Mesic Forest, David Randolph Kem

Masters Theses & Specialist Projects

The effects of fire on vernal herbs of the mesic forests of eastern North America are poorly understood. I studied the influence of prescribed fire on species richness, abundance of rare and common species, and density of exotics in the vernal herbaceous layer. To determine these effects, three sites in central Kentucky were surveyed prior to and following one of three treatments: spring burn, winter burn, or negative control. I conducted low-intensity spring burns in April 2010 and winter burns in February 2011. I used chi square analyses to test for changes in species richness, abundance of rare species, abundance ...

Federal Conservation Spending Allocated By Agency, Emily Clare Manneschmidt

University of Tennessee Honors Thesis Projects

No abstract provided.

How Do Prey Refuges Affect Predator-Prey Interactions?, Justin Vendettuoli

Senior Honors Projects

While it is well known that predators eat their prey, prey that avoid predation risk can also incur substantial fitness costs through risk-induced changes in survival and reproduction, growth, and morphology. Changes in prey that occur without the predator physically consuming the prey are referred to as ‘non-consumptive effects’. One way to reduce the risk of predation is to use a refuge. While refuge use may reduce predation risk, however, it may also be costly to the prey. These costs may include within-refuge competition for resources, which can alter prey population dynamics, coexistence, and metapopulation dynamics. While these costs may ...

Limnological Assistance For Lake Mead National Recreation Area: Quarterly Report, Period Ending September 30, 2012, Margaret N. Rees

Limnological studies

Continuation of Project 1

• The research effort titled Growth of adult quagga mussels within Las Vegas Wash/Las Vegas Bay is ongoing.

Continuation of Project 2

• Additional content was contributed to the future NPS-funded U.S. Geological Survey Circular ‘state-of-the-science’ report for Lakes Mead and Mohave. UNLV performed a new co-editing and coordinating task related to this product as the major focus of this quarter’s effort; the master version of this report is on schedule for delivery to the editorial team during the first week of October 2012.

Modification Activities:

Extended Short-term Continued Limnological Assistance

Quagga Mussel Objectives:

• Most ...

Positive Relationships Between Association Strength And Phenotypic Similarity Characterize The Assembly Of Mixed-Species Bird Flocks Worldwide, Hari Sridhar, Umesh Srinivasan, Robert A. Askins, Julio Cesar Canales-Delgadillo, Chao-Chieh Chen, David N. Ewert, George A. Gale, Eben Goodale, Wendy K. Gram, Patrick J. Hart, Keith A. Hobson, Richard L. Hutto, Sarath W. Kotagama, Jessie L. Knowlton, Tien Ming Lee, Charles A. Munn, Somchai Nimnuan, B. Z. Nizam, Guillaume Péron, V. V. Robin, Amanda D. Rodewald, Paul G. Rodewald, Robert L. Thomson, Pranav Trivedi, Steven L. Van Wilgenburg, Kartik Shanker

Biology Faculty Publications

Competition theory predicts that local communities should consist of species that are more dissimilar than expected by chance. We find a strikingly different pattern in a multicontinent data set (55 presence-absence matrices from 24 locations) on the composition of mixed-species bird flocks, which are important sub-units of local bird communities the world over. By using null models and randomization tests followed by meta-analysis, we find the association strengths of species in flocks to be strongly related to similarity in body size and foraging behavior and higher for congeneric compared with noncongeneric species pairs. Given the local spatial scales of our ...

Amphibian Occupancy And Functional Connectivity Of Restored Wetlands In The Missouri River Floodplain, Michelle L. Hellman

Dissertations & Theses in Natural Resources

Wetland decline may threaten many taxa including shorebirds, amphibians, and fish. As agencies increase restoration of wetland habitat, monitoring is crucial to inform the process. Permeable skin sensitive to water quality and biphasic life histories requiring both terrestrial and aquatic habitat make amphibians good indicators of wetland health. I modeled amphibian occupancy in restored Missouri River bends to determine habitat characteristics associated with the presence of amphibians.

Occupancy modeling acknowledges imperfect detection and allows the inclusion of detection covariates. To assess detection I examined two methods currently used to assess anuran occupancy in wetlands, aural anuran surveys and tadpole dip-netting ...

Parasitoid Infestation Changes Female Mating Preferences, Oliver M. Beckers, William E. Wagner

Faculty Publications in the Biological Sciences

Females often adjust their mating preference to environmental and social conditions. This plasticity of preference can be adaptive for females and can have important consequences for the evolution of male traits. While predation and parasitism are widespread, their effects on female preferences have rarely been investigated. Females of the cricket Gryllus lineaticeps are parasitized by the parasitoid fly Ormia ochracea. Infestation with fly larvae substantially reduces female life span and thus reproductive opportunities of the cricket. Both female G. lineaticeps and flies orient to male song and both prefer male songs with faster chirp rates to songs with slower chirp ...

Review Of The Purple Amole Chlorogalum Purpureum (Agavaceae): A Threatened Plant In The Coast Ranges Of Central California, Christopher P. Kofron, Connie Rutherford, Elizabeth R. Clark, Darlene Woodbury, Jody Olson, Robert F. Holland

Bulletin of the Southern California Academy of Sciences

The purple amole Chlorogalum purpureum (Agavaceae) is a bulbous, perennial soap plant endemic to central California and listed as threatened under the U.S. Endangered Species Act since 2000. Chlorogalum p. purpureum occurs in the rain shadow of the Santa Lucia Range on Fort Hunter Liggett, south Monterey Co., and on Camp Roberts, north San Luis Obispo Co. Chlorogalum p. reductum occurs in the rain shadow of the La Panza Range in central San Luis Obispo Co., mostly on Los Padres National Forest and with potential for a substantially larger occupied area on private land. We review and enhance the ...

Recent Mass Mortality Of Strongylocentrotus Purpuratus (Echinodermata: Echinoidea) At Malibu And A Review Of Purple Sea Urchin Kills Elsewhere In California, Gordon Hendler

Bulletin of the Southern California Academy of Sciences

Mass mortalities of intertidal purple sea urchins, Strongylocentrotus purpuratus occurred at Malibu Lagoon State Beach, California, in 2010 and 2011. Both events followed the first heavy rain of the season, and coincided with an illegal breaching of the lagoon. Osmotic shock from low-salinity lagoon water, the likely cause of death, may have acted jointly with stress from exposure during especially low tides. Comparable die-offs of purple sea urchins have occurred at other localities after exposure to brackish water or thermal shock. Annually recurring lagoon ruptures at Malibu, combined with predation by western gulls, can have a profound impact on the ...

Fishery-Dependent Estimates Of Growth, Development, And Reproduction In Gulf Corvina (Cynoscion Othonopterus), Katie E. Gherard, Brad E. Erisman, Octavio Aburto-Oropeza, Kirsten Rowell, Larry G. Allen

Bulletin of the Southern California Academy of Sciences

Gulf corvina, Cynoscion othonopterus, is a vital component of commercial fisheries in the northern Gulf of California, but a lack of information on life history parameters have thus far prevented a comprehensive stock assessment. In this project, 530 specimens of Gulf corvina were collected from commercial gill net fisheries in the Colorado River Delta region in Sonora, Mexico, to characterize population structure, age and growth patterns, age and size at sexual maturity and batch fecundity of Gulf corvina. Fish ranged from 145 mm to 1013 mm in total length and from 1 to 8 years of age. Von Bertalanffy growth ...

Is Your Immunity Compromised By Being Nice To Your Bacteria? Insights From A Social Amoeba, William E. Callison

Undergraduate Research Symposium

Eukaryotes are dependent on beneficial microbes, but can be killed by harmful ones. How have they evolved responses that protect themselves from harmful bacteria while coddling the beneficial ones? An ideal system for investigating this relationship is the eukaryote social amoeba Dictyostelium discoideum because some clones carry commensal bacteria through the social state to use as future seed corn, while others do not. Most of its life, D. discoideum amoeba consume bacteria and divide by binary fission. Under starvation, amoebae aggregate into a multicellular body which crawls to light, then forms a fruiting body of 20% dead stalk cells and ...