Biology Commons^™

A Biodiversity Survey Of The Soil Crusts Of The Geographically Isolated San Nicholas Island, California, Usa And Description Of Species In Three Genera (Atlanticothix, Pycnacronema, Konicacronema) Previously Restricted To Brazil Using A Polyphasic Approach To Cyanobacterial Taxonomy, Brian Jusko

Masters Theses

San Nicholas Island, California, USA is a geographically-isolated island that experiences a semiarid climate and exhibits significant topographic and geologic diversity. Access to the island is restricted to the public and, as a result, only one previous study has been done on the algal biodiversity of its biological soil crusts. The previous study used morphology as the sole basis of species identification, and it was the aim of this study to corroborate and expand upon the results by including molecular data. Using 16S rRNA and 16S–23S ITS sequences and phylogenetic analyses, a diverse set of taxa were identified and are …

Bloom Or Bust: Search For Phytoplankton Community Drivers Using Long-Term Time-Series Observations And Field Measurements In A Model Great Lakes Estuary, Jasmine Mancuso

Masters Theses

As sentinels of climate change and other anthropogenic effects, freshwater lakes are experiencing ecosystem disruptions at every level of the food web, beginning with the phytoplankton. One of the major threats to waterbodies around the world are cyanobacterial harmful algal blooms (HABs) resulting from anthropogenic eutrophication and exacerbated by climate change. Muskegon Lake, a drowned river mouth Great Lakes estuary on the east coast of Lake Michigan, is no exception and was declared an Area of Concern by the EPA in 1987 with nuisance algal blooms cited as a beneficial use impairment. Using long-term data and additional 2019 sampling, we …

Revision Of The Synechococcales (Cyanobacteria) Through Recognition Of Four Families Including Oculatellaceae Fam. Nov. And Trichocoleaceae Fam Nov. And Seven New Genera Containing 14 Species, Truc Mai

Masters Theses

A total of 48 strains of thin, filamentous cyanobacteria in the Synechococcales were studed by sequencing 16S rRNA, rpoC1, and rbcLX gene fragments. A subset of these were carefully characterized morphologically. Bayesian analysis of the 16S rRNA gene data in a large alignment of Synechococcales (345 OTU's) was in agreement with the phylogeny based on the rpoC1 gene for 59 OTU's. Both indicated that the large family-level grouping formerly classified as the Leptolyngbyaceae could be further divided into four family-level clades. Two of these family-level clades have been recognized previously as Leptolyngbyaceae and Prochlorotrichaceae. The Oculatellaceae fam. prov. and Trichocoleaceae …

Cyanomargarita Gen. Nov. (Nostocales, Cyanobacteria): Convergent Evolution Resulting In A Cryptic Genus, Sergey Shalygin

Masters Theses

Two populations of Rivularia-like cyanobacteria were isolated from ecologically diverse and biogeographically distant sites. One population was from an unpolluted stream in the Kola Peninsula of Russia, whereas the other was from a wet wall in the Grand Staircase-Escalante National Monument, a desert park-land in Utah. Though both were virtually indistinguishable from Rivularia in field and cultured material, they were both phylogenetically distant from Rivularia and the Rivulariaceae based on both 16S rRNA and rbcLX phylogenies. The new putative cryptic genus Cyanomargarita, with proposed type species C. melechinii sp. nov., and additional putative species C. calcarea are described herein. A …

Toxin Production And Population Dynamics Of Gloeotrichia Echinulata With Considerations Of Global Climate Change, Sarah Stamann

Masters Theses

Global climate change has been identified as a driver for increasing cyanobacteria blooms world-wide. Blooms of the cyanobacterium, Gloeotrichia echinulata, (hereafter, G. echinulata) have been observed in Silver Lake (Oceana County, MI), often forming dense surface scums. This organism is known to produce the hepatotoxin, microcystin- LR, and its growth is linked to phosphorus accumulation from sediment and temperature.

A series of experiments at ambient and elevated temperatures (+2° and +6°above ambient) with sediment from four locations in Silver Lake with varying phosphorus concentrations were conducted to examine the effect of these variables on G. echinulata growth. These …