Studies on the species level variation of selected coccolithophores Markus Geisen University College London, Geological Sciences Department, Gower Street, London WC1E6BT, UK The Natural History Museum, Palaeontology Department, Cromwell Road, London SW7 5BD, UK Degree: Ph.D. Geology Supervisors: Dr. Jeremy R. Young, The Natural History Museum Dr. Paul R. Bown, University College London ProQuest Number: U643698 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest. ProQuest U643698 Published by ProQuest LLC(2016). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code. Microform Edition © ProQuest LLC. ProQuest LLC 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106-1346 A bstract 2 Abstract The oceans cover roughly seventy percent of the surface of the earth. With few exceptions minute photosynthetic primary producers like diatoms, dinoflagellates, silicoflagellates and coccolithophores inhabit the upper 200 m of this vast expanse. This phytoplankton forms the base of the marine food chain and plays an important role in geochemical cycles. Knowledge about species level biodiversity and spécia­ tion thus is important to understand marine ecology and biogeochemistry. Amongst the mentioned groups coccolithophores appear to be the ideal test group since their biomineralised periplasts - the coccoliths - provide a rich suite of qualitative and quantitative morphological characters and a uniquely extensive fossil record. In ad­ dition to this extant coccolithophore species can be grown in culture and hence are available for molecular genetic studies and cytological research. Combining data from both palaeontology and biology hence allows for a more detailed interpreta­ tion of coccolithophore biodiversity, evolution and spéciation. For the CODENET project (the EC funded Coccolithophorid Evolutionary Biodiversity and Ecology Network) extant species with seemingly global occur­ rences - spanning the biodiversity of coccolithophores - were selected and different case studies were carried out on them to elucidate their species level biodiversity. Here we present the results and discuss tentative models of spéciation for the coc­ colithophores in general. Following a brief introduction the second chapter (Methods) deals with sampling for both life and fossil coccolithophores and introduces culture techniques as well as biometrical methods used. Chapter 3 (Results) is divided in four parts - in part 1-3 detailed results from three CODENET species will be presented, mainly dealing with their morphological variability and physiology, but also with their evolution­ ary history. Part 4 is a published research paper in which the novel phenomenon of cryptic spéciation is demonstrated for the first time in the coccolithophores. This paper equally highlights the importance of studies on living species to achieve a better understanding and interpretation of coccolithophore evolution, diversity and spéciation. Chapter 4 (Discussion) comprises a comprehensive review about species level variation in all the CODENET key species. Here we tie together the various sources of data obtained during the project and introduce models of spécia­ tion for the coccolithophores. Further published manuscripts - both dealing with methods used in this study, but also supplementary data important for this thesis are given in an appendix. Aknowledgements Acknowledgements - A narration Work for this thesis started April 1998 with my move from Bochum University - where I graduated as a geologist - to the Natural History Museum (NHM) in London. This was not my first visit to the NHM - in fact I had been there just a year earlier using the biometrical routines that Jeremy Young had developed for work on my then beloved coccolithophore species Watznaueria barnesae from the Hauterivian. Being in need for a morphometrician for his Training and Mobility of Researchers (TMR) network Jeremy put his faith in me and subsequently offered me a position. This network - the aptly abbreviated CODENET - consisted out of eight European large scale facilities or universities with specialists in the fields of research that were targeted. As each of the institutes had the possibility to hire a post-doc eight so called young visiting researchers formed the core team. This team consisted of Ian Probert (Univ. Caen), Sabrina Renaud (ETHZ Zurich), Mario Cachao (Univ. Lisbon), Kees van Lenning (CSIC Barcelona), Alberto Garcia- Saez (AWI Bremerhaven), Hanno Kinkel (NIOZ), Patrizia Ziveri (Free Univ. Amsterdam) and myself. Some of us were lucky and so we got to know each other on the International Nannoplankton association meeting in Puerto Rico in early 1998. Tales of fabulous, albeit non-alcoholic drinks has it from there... Work really started in April and one of our first tasks was the identification and preparation of a communal sample set. This work was done in the course of several workshops in Zurich by a number of people namely Jorg Bollmann (ETH Zuric), Patrizia Ziveri, Jorijntje Henderiks (ETH Zurich), Sabrina Renaud and Mario Cachao. From there I still vividly recall the time Jorg spent on introducing me to his new SEM. What I learned from Jorg came in handy as the Electron Microscopy and Mineral Analysis (EMMA) unit at the NHM had just purchased a brand-new high specs SEM that soon became my very own toy. Chris Jones and Alex Ball from the EMMA unit did not only maintain this (and other) machines to superb standards, but they proved to be real experts in the field of microscopy whenever a tricky pro­ cedure was required to get the best out of the machine. I think the micrographs in the thesis speak for themselves and are a testimony to their skills. Later this year I went on my first oceanographic cruise around the Canary Islands on the German RV Meteor. In Claudia Sprengel (then Univ. Bremen, now AWI Bremerhaven) I found a specialist, happy to introduce me to the field of coccolitho­ phore sampling at the high seas. We turned out to become close friends over the years and have been a real “Dream Team” working together on cruises and are now sharing an office at the AWI. Aknowledgements It was in the late summer of 1998 that I first had the chance to participate in one of the famous Blagnac meetings. Although I had a pretty good idea what to expect - from images that is - the beauty of the place, its suitability for scientific and private discussion until the early morning hours, and the hospitality of the owners - Dorine and Jan van Hinte - really blew me away. Blagnac has become an annual experience since then and 1 really miss the windowsill Ian and myself used to sit on in the morning to get over our hang-over. After a nice meeting, organised by Hanno Kinkel on Texel at the NIOZ in early 1999, a series of cruises followed. One was a short test bed trip for sampling techniques for which we hired the RV Andromeda from the Portuguese army and in which nearly all post-docs participated. Although Mario did an expert job on organising the trip he nevertheless refused to partake - allegedly due to his sea­ sickness. Having been on the ship, or boat one should really say, 1 guess Mario had the right approach. The methods and sampling protocol developed there were then used onboard the RV Hesperides in the Alboran Sea by a competent team consisting of Alexandra Broerse (Free Univ. Amsterdam), Kees van Lenning, Andy Howard (UCL) and the author. LIuisa Cros (CSIC Barcelona), whose taxonomic skill has been a great help throughout the project, provided bed and breakfast upon our return and an unforgettable tour around Barcelona late at night. This turned out to be our most successful trip and upon my return with the living samples Ian Probert shared his broad knowledge on culturing phytoplankton with me. Many trips from London to Caen should follow and Ian and myself probably deserve the “Seamiles Gold Card” for travelling with Brittany ferries. The head of lab in Caen, Chantai Billard and her colleague Jaqueline Fresnel have been fantastic hosts providing me with plenty opportunities for splendid working dinners. Later in the year Masanobu Kawachi and Marie-Helene Noel invited Patrizia, Jeremy, Ian and myself over to the National Institute for Environmental Sciences (NIES) in Tsukuba, Japan. He proved to be an excellent host and introduced us to the Japanese way of life. Under his expert guidance we had the chance to obtain samples from a small volcanic island off Tokyo Bay, which blew up later in the year. The year 2000 saw the Mid-term-Review of our project at the NHM - including a rather picturesque Them se boat trip involving loads of drinks... Later in the year 1 had the change to meet with Claudia and with Babette Bockel (Univ. Bremen) on a small meeting organised by Karl-Heinz Baumann (Univ. Bremen). The INA meeting in Bremen followed immediately afterwards and Claudia and Babette had the courage to allow a number a British colleagues to stay in their apartments. These were busy weeks - shortly after the INA meeting Claudia and myself left for Namibia for an oceanographic cruise in the South Atlantic. My culture experiments started late in the project and after my initial success with two of the selected species 1 managed to interest Blair Steel - a friendly, hard working and hard partying Scotsman - to perform further experiments for his mas­ ters thesis at UCL. Sharing my office at the NHM and the same taste as far as bever­ Aknowledgements ages are concerned we quickly became friends and I am happy that Blair since then took up a PhD studentship with Michal Kucera at Royal Holloway.