Life cycle evolution and systematics of Campanulariid hydrozoans
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2004 The purpose of this thesis is to study campanulariid life cycle evolution and systematics. The Campanul...
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Massachusetts Institute of Technology and Woods Hole Oceanographic Institution
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ftwhoas:oai:darchive.mblwhoilibrary.org:1912/1857 2023-05-15T15:44:15+02:00 Life cycle evolution and systematics of Campanulariid hydrozoans Govindarajan, Annette F. 2004-09 application/pdf https://hdl.handle.net/1912/1857 en_US eng Massachusetts Institute of Technology and Woods Hole Oceanographic Institution WHOI Theses https://hdl.handle.net/1912/1857 doi:10.1575/1912/1857 doi:10.1575/1912/1857 Hydrozoa Life cycles Thesis 2004 ftwhoas https://doi.org/10.1575/1912/1857 2022-05-28T22:57:22Z Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2004 The purpose of this thesis is to study campanulariid life cycle evolution and systematics. The Campanulariidae is a hydrozoan family with many life cycle variations, and provide an excellent model system to study life cycle evolution. Additionally, the unique campanulariid Obelia medusae may have been "re-invented" from ancestors without medusae. Chapter 1 reviews campanulariid life cycles and taxonomy. Chapter 2 presents a phylogeny based on 18S rDNA, calmodulin, L6S rDNA and cytochrome c oxidase I (COI). Ancestral life cycles are reconstructed using parsimony. Medusa loss is common, and Obelia may derive from ancestors with typical medusae. Taxonomic results are discussed in Chapter 3. Bilardia, a nominal campanulariid, appears phylogenetic ally distant, while Bonneviella spp. (Bonneviellidae), are nested within the Campanulariidae. Campanulariid genera are not monophyletic. Orthopyxis integra and elytia gracilis may represent cryptic species, while Obelia longissima may be cosmopolitan. Chapter 4 investigates Obelia geniculata phylogeography. Japanese and North Atlantic 16S rDNA and COI sequences are calibrated against the opening of the Bering Strait. Substitution rates are faster than in anthozoans and comparable to non-cnidarian invertebrates. Comparison of Pacific and Atlantic sequences suggests cryptic species exist. Finally, hydroids in New Brunswick, Canada and Iceland may have survived the last glaciation. Funding for my thesis was provided by WHOI Academic Programs, an NSF PEET grant to Cliff Cunningham (DEB-9978131), WHOI Ocean Ventures Fund, the Society for Integrative and Comparative Biology, WHOI Biology, and the MIT-Italy club. Thesis Bering Strait Iceland North Atlantic Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) Bering Strait Canada Medusa ENVELOPE(157.417,157.417,-79.633,-79.633) Pacific Woods Hole, MA |
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Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) |
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ftwhoas |
language |
English |
topic |
Hydrozoa Life cycles |
spellingShingle |
Hydrozoa Life cycles Govindarajan, Annette F. Life cycle evolution and systematics of Campanulariid hydrozoans |
topic_facet |
Hydrozoa Life cycles |
description |
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2004 The purpose of this thesis is to study campanulariid life cycle evolution and systematics. The Campanulariidae is a hydrozoan family with many life cycle variations, and provide an excellent model system to study life cycle evolution. Additionally, the unique campanulariid Obelia medusae may have been "re-invented" from ancestors without medusae. Chapter 1 reviews campanulariid life cycles and taxonomy. Chapter 2 presents a phylogeny based on 18S rDNA, calmodulin, L6S rDNA and cytochrome c oxidase I (COI). Ancestral life cycles are reconstructed using parsimony. Medusa loss is common, and Obelia may derive from ancestors with typical medusae. Taxonomic results are discussed in Chapter 3. Bilardia, a nominal campanulariid, appears phylogenetic ally distant, while Bonneviella spp. (Bonneviellidae), are nested within the Campanulariidae. Campanulariid genera are not monophyletic. Orthopyxis integra and elytia gracilis may represent cryptic species, while Obelia longissima may be cosmopolitan. Chapter 4 investigates Obelia geniculata phylogeography. Japanese and North Atlantic 16S rDNA and COI sequences are calibrated against the opening of the Bering Strait. Substitution rates are faster than in anthozoans and comparable to non-cnidarian invertebrates. Comparison of Pacific and Atlantic sequences suggests cryptic species exist. Finally, hydroids in New Brunswick, Canada and Iceland may have survived the last glaciation. Funding for my thesis was provided by WHOI Academic Programs, an NSF PEET grant to Cliff Cunningham (DEB-9978131), WHOI Ocean Ventures Fund, the Society for Integrative and Comparative Biology, WHOI Biology, and the MIT-Italy club. |
format |
Thesis |
author |
Govindarajan, Annette F. |
author_facet |
Govindarajan, Annette F. |
author_sort |
Govindarajan, Annette F. |
title |
Life cycle evolution and systematics of Campanulariid hydrozoans |
title_short |
Life cycle evolution and systematics of Campanulariid hydrozoans |
title_full |
Life cycle evolution and systematics of Campanulariid hydrozoans |
title_fullStr |
Life cycle evolution and systematics of Campanulariid hydrozoans |
title_full_unstemmed |
Life cycle evolution and systematics of Campanulariid hydrozoans |
title_sort |
life cycle evolution and systematics of campanulariid hydrozoans |
publisher |
Massachusetts Institute of Technology and Woods Hole Oceanographic Institution |
publishDate |
2004 |
url |
https://hdl.handle.net/1912/1857 |
long_lat |
ENVELOPE(157.417,157.417,-79.633,-79.633) |
geographic |
Bering Strait Canada Medusa Pacific |
geographic_facet |
Bering Strait Canada Medusa Pacific |
genre |
Bering Strait Iceland North Atlantic |
genre_facet |
Bering Strait Iceland North Atlantic |
op_source |
doi:10.1575/1912/1857 |
op_relation |
WHOI Theses https://hdl.handle.net/1912/1857 doi:10.1575/1912/1857 |
op_doi |
https://doi.org/10.1575/1912/1857 |
op_publisher_place |
Woods Hole, MA |
_version_ |
1766378558170595328 |