Publication Date

2015

Document Type

Honors Thesis

Department

Biological Sciences

Keywords

Biodiversity-New England, Microorganisms, Biotic communities-New England, Bog ecology, Marine microbial ecology, Microbes, Marine, Bog

Abstract

I. Microbes are important to the Earth. Their existence assists in the maintenance of oceanic crusts and contributes to the success of macro-organisms such as plants and animals. This study analyzes key players in the marine planktonic food web. Here, we seek to examine the change in ciliate communities following copepod grazing. In order to do this, we conduct several microcosm experiments meant to simulate the natural environment. We then use Denaturant Gradient Gel Electrophoresis to obtain an image of the impact of copepods and incubation on ciliate communities. Two clear patterns emerge from these experiments: first, we observe a replicable change within the ciliate community after incubation. Second, we describe a trend of decreasing abundance of aloricate (naked) ciliates within the treatments with copepods as compared to the controls, and a gradual increase in the abundance of loricate (shelled) ciliates. This observation supports the idea that copepods are prey selective on certain ciliates. Here we provide more information on the interactions between members of the planktonic food web and highlight the importance of studying such interactions. II.Testate Amoebae are very important organisms in their environments. Their presence in low pH environments assists in regulating important abiotic and biotic factors. Testate amoebae are also the leading competitors in their environments. In this study, we examine the relationship between testate amoebae and an unknown flagellate swimming inside the tests (shells) of amoebae. We use whole genome amplification to isolate DNA from our samples and identify the flagellate species. We also set out to gather a qualitative assessment of the presence and absence of the interactions amongst the testate amoebae and the flagellate, and to infer their relationship by examining characteristics of the species found. After searching for literature on this interaction, we see that after over 200 years of testate amoebae research, no other study has documented this interaction. Along with this, after numerous whole genome amplifications, we suspect that the flagellate is a cercozoan species, but this is difficult to discern, as testate amoebae cannot be cultured axenically.

Language

English

Comments

75 pages : illustrations (some color), color maps. Honors project-Smith College, 2015. Includes bibliographical references (pages 73-74). Contents: I. Changing parameters and the global environment: microcosm experiments -- II. A qualitative assessment of the presence of flagellates in testate amoebae in New England bogs and Acadia National Park.

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