Chapter 4 introduction 585
Carmelo R. Tomas
Chapter 5 ^Jlie f-^ianbtonic fYjarine ^dlaqeliatei Jahn Throndsen
General Considerations 592 Algal Flagellate Characteristics 594 Flagellate Terminology 600 Phytoflagellate Taxanomy 602 Phytoflagellate Systematics 602 Chromophyta 605 Cryptophyceae 605 Raphidophyceae 612 Chrysophyceae 616 Dictyochophyceae 626 Prymnesiophyceae-Haptophyceae (Exclusive of Coccolithophorids) 633 Chlorophyta 645 Euglenophyceae 645 Prasinophyceae 651 Chlorophyeae 664 Zooflagellates (Phylum Zoomastigophora) 671 Choanoflagellidea 671 Kinetoplastidea 680 Ebriidea 685 Techniques 686
Preparing Samples for Observation 688 Cultivation for Identification 694 Preparation of Samples for Further Studies 697 Specific Problems to Avoid 698 Common Flagellate Synonyms 699 Glossary 702
Index of Flagellate Taxa 708 References 715
(Chapter 6 WoJe m C^occo (ithoplioricls 731 Berit R. Heimdal
General Characteristics 742
Terminology and Morphology 744
Problems in Studying Recent Coccolithophorids 749
Outline for Classification and Arrangement of Genera 752 Systematic Descriptions 755 Holococcolithophorids 755 Heterococcolithophorids 773 Common Coccolithophorid Synonyms 816 Index of Coccolithophorid Taxa 819 References 821 Glossary 832
This volume is a reprinted version of the two volume series previously published as "Marine Phytoplankton: A Guide to Naked Flagellates and Coccolithophorids" Academic Press, 1993, and "Identifying Marine Diatoms and Dinoflagellates" Academic Press, 1996. It achieves one of the original project objectives of providing in one volume, updated information required for the identification of marine phytoplankton. The response to both volumes was gratifying and confirmed our belief that there was a need for information of this kind. The reprinting of this literature allowed us an opportunity to combine both book texts, to correct errors, and to offer the complete text in a soft-bound format. While the discipline has not stood still since the first publishing, a complete revision was not possible at this time. Therefore, we urge users of this literature to review the latest journal publications for recent changes. The historical literature is well represented in the reference lists following each chapter and should suffice for returning to original descriptions.
The organization of this book was made with the broadest of outlines to accommodate the specific needs of the contributors—each had their own preference as to how the chapters should be designed. As a result, the reader will recognize that certain elements are common to all chapters. A general introduction, terminology list (in one case illustrated), numerous line drawings as well as SEM and TEM photomicrographs, cryptic descriptions giving essential characters, a synonymy list, index taxa, and extensive reference citations accompany each chapter. Since the material of each chapter varied, a flexible approach was required. Thus readers will find differences in format from chapter to chapter accommodating these differences. I hope this will not be too distracting and that the users will freely move from chapter to chapter with little difficulty.
For the most part, the illustrations are unique and have been produced for this publication. Photographs loaned for inclusion here are noted as are figures taken after published drawings. All original authors were contacted for approval prior to publication of the book. In some instances there are unlabeled illustrations as in a plate series in the Dinoflagellate chapter. These figures, appearing in silhouette, were purposely unlabeled forcing the users to match the silhouette with the corresponding line drawings appearing in the other plates of that chapter. In this manner, the authors of this chapter hoped to encourage researchers to use cell shape and outline as one of the important diagnostic tools in accurate identification of species. This was a deliberate challenge and not an oversight in labeling illustrations.
All chapters have special guides for identification. In the Diatom chapter, there are numerous keys, list of characters, and tables comparing species to aid the researcher in distinguishing between similar species. In the Coccolithophorid chapter, there are comparisons of similar or problem taxa, which is of particular help with closely related confusing species. In the Flagellate chapter, there is a diagnostic "What to Look For" outline which can serve as a quick reference in narrowing the appropriate class, while in the Dinoflagellate chapter, the illustrated terminology section is oriented at showing the various features used in identifying species. Again, this reflects the preference of the authors. Of particular note, all readers should be aware of the Taxonomic Index that appears near the end of the Diatom Chapter. In this section, a new genus, new names and new taxa as well as novel nomenclatural combinations, are presented. AH nomenclatural novelties were validated in the original publications in, Tomas, C. (ed.), "Identifying Marine Diatoms and Dinoflagellates," Academic Press, 1996 and Tomas, C. (ed.), "Marine Phytoplankton: A Guide to Naked Flagellates and Coccolithophorids," Academic Press, 1993. Additionally, common synonyms are presented at the end of each chapter. The most recently presented valid name is given with the others as equal synonyms including the full author citation.
A word of caution should be mentioned regarding distributions of species. The common feeling was that distributional information was to be given along broad climatic zones such as temperate waters, arctic or antarctic, subtropical, tropical oceans. In some instances, specific locations are mentioned, primarily because the species illustrated may have first been described from that region. The lack of a location reference for any species should not be construed as denoting the absence of that species from a region. Also, it would be impossible to cover all species of marine phytoplankton. The species chosen for description were selected to give a good representation of the commonly important species as well as enough different species as to give a full spectrum of characters to be found in the phytoplankton. The definitive book covering all phytoplankton species in the sea will probably never be realized.
As a final word, I would like again to restate my gratitude to my author/colleagues who devoted considerable effort in creating, revising, and modifying this literature. Without their full commitment, support, and patience this work could not have been completed. Numerous other colleagues also have assisted including those at the Zoological Station of Naples, Italy, the Florida Marine Research Institute, and the students of the International Phytoplankton Course, who have suggested modifications and corrections. Dr. Paul Silva gave invaluable assistance in matters regarding nomenclature. A special word of thanks is due to the editorial staff at Academic Press that has endured numerous modifications, delays, and revisions yet was supportive of the combined book project. Finally, I wish to acknowledge the continued effort and encouragement of my wife Cele, who throughout the various versions of these books has been the constant support without which this work would not have been completed.
The diatoms have been studied for almost 300 years. A multitude of monographs and floras covering smaller and larger areas has been published, and the exact number of thousands of species distributed can hardly be given. Although the marine planktonic diatoms probably constitute a smaller fraction of the total number of species described, we are still dealing with some thousands of species. The elaborately and intricately ornamented siliceous diatom frustule was a challenge to the first transmission electron microscopist in the 1940s, and in the 1960s scanning electron microscopy was introduced in diatom studies providing even better insight into the structure of the diatom cell. This information led to new combinations of species, rejection of species, and description of taxa of all taxonomic categories. The thousands of species, the hundreds of years of studies, the clarification of intricate structures and relationships between taxa obtained by electron microscopy, and the confusion caused by introduction of new names may explain the length of the present chapter.
The history and development of the diatom chapter coincide with the rest of the project, starting with a simple text in 1976, mainly based on the authors' own research. The basis for a manuscript was therefore at hand when the possibility to publish the course notes as a book started to materialize in 1989. The first draft for a complete text was ready for the editor's corrections at the end of 1991 and was returned to the authors at the end of 1992. This version went back to the editor in April-May 1993, to be returned to the authors 1 year later. In April 1994, the editor and the senior author sat together for a short week to finally prepare a manuscript ready to submit to Academic Press.
Diatom research fortunately did not stand still between the start and the final step of the preparation of the diatom chapter. Efforts were made to incorporate, although to a limited extent, literature published in 1992-1994, but with the qualification that time and space did not permit a detailed treatment. During the last years of preparation nomenclatural problems related to the diatoms under study came to our notice. Thanks to Dr. Paul C. Silva as the nomenclature specialist on algae, most of the problems have been solved. New taxa and nomenclatural combinations having their first appearance in this chapter will hopefully be dealt with in detail in future publications.
The authors are grateful to Tyge Christensen for correction of the latin, to Paul Silva for his patience with the senior author's numerous questions, to Greta Fryxell for comments on Pseudo-nitzschia and Thalassiosira, to Frithjof Sterrenburg for comments on Pleurosigma, and to Bo Sundstrom for letting us copy his Rhizosolenia drawings. Carmelo Tomas is especially thanked for his editorial assistance; his initiative and sustained effort fulfilled the senior author's long-dreamt dream to get literature prepared for the International Phytoplankton Courses formally available to a greater audience. E. Paasche and Carina Lange carefully read and commented on parts of the manuscript; Berit Rytter Hasle assisted with the preparation of the line drawings, and the electron micrographs were made at the Electron Microscopical Unit for Biological Sciences at the University of Oslo.
The project was supported by grants from the Norwegian Fisheries Research Council (1202-203.075 to E.E.S.), and from the Norwegian Research Council for Science and the Humanities (457.90/027 to E.E.S., 457.91/001 and 456.92/006 to G.R.H.). The senior author expresses gratitude to the Department of Biology, University of Oslo, for financial support and also for continued working facilities after retirement.
Advances in microscopy have furthered our ability to differentiate genera and species based on morphology and cytology. Concurrent with these advances in equipment and technique were individual studies that clarified useful characters; for example, E. Balech's recognition and characterization of sulcal and cingular plates; D. Wall's, B. Dale's, and L. Pfiester's characterization of life-cycle stages; H. Takayama's characterization of apical grooves or what B. Biecheler described as acrobases; J. Dodge's characterization of apical pore complexes; and F. J. R. Taylor's synthesis and interpretations on dinoflagellate taxonomy, biology, and evolution. These scientists are counted among my heroes. In the future, there will be more heroes who will have worked on optical pattern recognition, biochemical systematics and molecular probes, and other new avenues to identify species and relatedness among species.
My deepest respect and appreciation go to my Norwegian colleagues to whom I am indebted for inviting me to be an instructor and for sharing their knowledge, wisdom, kindness, and sense of humor with me. To Dr. Karl Tangen of OCEANOR, my collaborator, I offer special thanks. To my friend and mentor, Dr. Enrique Balech of Argentina, I offer my sincerest appreciation for teaching me to see beyond what is obvious and to interpret plate patterns and species differences. To Dr. Jan Landsberg (Florida Department of Environmental Protection, Florida Marine Research Institute) and Julie Garrett (Louisiana State University) I offer my gratitude for encouraging and helping me to complete this project. To the editor of this series, Dr. Carmelo Tomas, I express my gratitude for his patience, resolve, and continued friendship. I also thank and acknowledge Dr. Earnest Truby (Florida Department of Environmental Protection, Florida Marine Research Institute) and Dr. Elenor Cox and Clarence Reed (Texas A&M University) for the loan of their exceptional, unpublished scanning electron micrographs of armored species that were used to draw some of the composite illustrations in the plates. Julie Garrett provided most of the scanning electron micrographs of apical pore complexes. Consuelo CarbonellMoore (Oregon State University) shared her knowledge of the Podolampaceae with me and is credited for photographs in Plate 7. Llyn French (Florida Department of Environmental Protection, Florida Marine Research Institute) assisted in preparation of the plates and provided artistic advice. Diane Pebbles, a biological illustrator and artist, provided 80% of the species illustrations, many of them original drawings based on scanning electron micrograph images. Her work increases the value of this chapter. Dr. Haruyoshi Takayama (Hiroshima Fisheries Experimental Station) provided all the photographs of apical grooves in Plates 1 and 2.
Among today's experts in flagellate taxonomy, the electron microscope has become an indispensable tool for identification of the species. However, the light microscope still remains the main instrument for routine use, and in many cases electron microscopy is merely used to verify identifications already made with conventional light microscopy. For most phytoplankton ecologists, however, the light microscope remains the only accessible equipment for taxo-nomic identification.
My account of marine planktonic flagellates (excluding dinoflagellates) is an introductory guide to this group and is based primarily on observations using the light microscope. The number of species illustrated for each genus is limited to presumably the most characteristic ones. Within genera such as Chrysochromulirta (Prymnesiophyceae) and Pyramimonas (Prasinophyceae) large numbers of species need electron microscopy for reliable identification. In these cases, reference to features observed using both light and electron microscopy is given. Whenever possible the original description should be consulted, as all later ones depend on the interpretation of the first. Emended diagnoses and descriptions, however, are very important for an up-to-date identification. The variation in morphology common within one flagellate species makes it desirable to give several illustrations, but for practical reasons only one illustration for each species is included here.
When dealing with flagellates, as with other types of plankton, personal experience with each taxon is most important for practical work. The variation within the species required for determining the typical cell shape can be observed by using culture techniques or studying the species during boom conditions. It should be noted, however, that some species vary in appearance with growth condition (such as the number of cells in the Oltmatinsiella colonies; Carmelo Tomas, personal communication).
The systematics of marine flagellates is presently in a dynamic state. The contents of the plates presented here were fixed to a classification system that becomes further modified as time goes on. The contents of this chapter have,
Karen A. Steidinger within practical limits, been updated to accommodate recent systematic revisions.
I am indebted to colleagues at the Institut for Sporeplanter, Copenhagen University; Tyge Christensen for providing Latin diagnoses and critically commenting upon the etymology of terms in the glossary, and 0jvind Moestrup, Helge A. Thomsen, and Jacob Larsen for comments on the manuscript. David Hill, School of Botany, University of Melbourne, Australia, commented on the cryptophycean systematics.
]. Throndsen upter 6
Coccolithophorids, characterized by an outer covering of calcified scales or coccoliths, present special problems in identification due to the small cellular and coccolith size, often requiring observations with electron microscopes for reliable identification. However, species that are larger and/or have characteristic gross morphologies, like Discosphaera tubifer and Scyphosphaera apsteinii, can be readily identified during routine analysis of water samples with light microscopy. Morphological details of coccolith structure of smaller cells are discernible only under the best optical conditions. Thus, difficulties may be encountered if species like Emiliania huxleyi and smaller cells of Gephyrocapsa oceatiica are present in the same sample. Use of an oil immersion objective and a total magnification of 800-1000 times should allow clear distinction between these species.
My chapter provides an introductory guide to the coccolithophorids. It presents the key literature, which is scattered in numerous publications. The text includes systematic descriptions and line drawings of a number of species as examples of the presumably most common ones encountered in marine samples. The chapter also includes species-related information such as synonyms, characteristics for identification, and distribution.
Several colleagues have kindly read parts of this chapter in manuscript form. This has been a great help. Among the many individuals to whom personal thanks are due, I wish to especially mention the late K. R. Gaarder, who introduced me to the coccolithophorids and so greatly enriched our knowledge of extant species. She has given a solid foundation for future work. Grateful thanks are also due to C. R. Tomas for editorial assistance as well as to R. Heimdal and E. Holm, who assisted with the preparation of the line drawings and other technical aspects of this chapter.
In addition to the acknowledgments given in the Forewords, the following agencies and institutions have substantially contributed to this work. Without their financial and logistical support, this work could not have been completed. The editor and authors are indebted to the support of the following: The Norwegian Research Council for Science and the Humanities The Norwegian Fisheries Research Council Stazione Zoologica "Anton Dohrn" di Napoli UNESCO
Department of Biology, University of Oslo
University of Bergen, Department of Fisheries and Marine Biology Florida Department of Environmental Protection, Florida Marine Research Institute
For supporting the International Phytoplankton Course from which this literature was developed, contributions were also made by:
Was this article helpful?