Freshwater Algae of North America (eBook)

Ecology and Classification

J. Patrick Kociolek, Robert G. Sheath, John D. Wehr (Herausgeber)

eBook Download: PDF | EPUB

2015 | 2. Auflage
1066 Seiten
Elsevier Science (Verlag)
978-0-12-385877-1 (ISBN)

Infos

Freshwater Algae of North America: Ecology and Classification, Second Edition is an authoritative and practical treatise on the classification, biodiversity, and ecology of all known genera of freshwater algae from North America. The book provides essential taxonomic and ecological information about one of the most diverse and ubiquitous groups of organisms on earth. This single volume brings together experts on all the groups of algae that occur in fresh waters (also soils, snow, and extreme inland environments). In the decade since the first edition, there has been an explosion of new information on the classification, ecology, and biogeography of many groups of algae, with the use of molecular techniques and renewed interest in biological diversity. Accordingly, this new edition covers updated classification information of most algal groups and the reassignment of many genera and species, as well as new research on harmful algal blooms. - Extensive and complete - Describes every genus of freshwater algae known from North America, with an analytical dichotomous key, descriptions of diagnostic features, and at least one image of every genus. - Full-color images throughout provide superb visual examples of freshwater algae - Updated Environmental Issues and Classifications, including new information on harmful algal blooms (HAB) - Fully revised introductory chapters, including new topics on biodiversity, and taste and odor problems - Updated to reflect the rapid advances in algal classification and taxonomy due to the widespread use of DNA technologies

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Chapter 1

Introduction to the Freshwater Algae

Robert G. Sheath1; John D. Wehr2    1 Department of Biological Sciences, California State University San Marcos, San Marcos, California, USA
2 Louis Calder Center—Biological Station, Fordham University, Armonk, New York, USA

Abstract

This chapter briefly introduces the diverse morphologies of freshwater algae, explaining seven basic types, which range from unicells to colonies (which may or may not be flagellated), pseudofilaments to true filaments (with or without branching), pseudoparenchymatous forms to true tissues, and coenocytic structures. Photographs of each type of morphology are provided. The chapter then provides a key to the taxonomic chapters in the book with an accompanying table of distinguishing features. The groups of freshwater algae are briefly described based on the taxonomic organization of the book.

Keywords

algae

classification

diversity

freshwater

identification

morphology

Chapter Contents

I. Introduction   1

II. Classification   5

A. Key to the Taxonomic Chapters in This Book   5

III. Groups of Freshwater Algae   7

A. Cyanobacteria   7

B. Red Algae   7

C. Green Algae   8

D. Euglenoids   8

E. Eustigmatophyte, Raphidiophyte, and Xanthophyte Algae   8

F. Chrysophycean Algae   8

G. Haptophyte Algae   9

H. Synurophyte Algae   9

I. Diatoms   9

J. Dinoflagellates   9

K. Cryptomonads   10

L. Brown Algae   10

Literature Cited   10

I Introduction

Freshwater algae are globally ubiquitous and highly diverse, with tens or perhaps hundreds of thousands of species, in a myriad of forms and sizes (Andersen, 1992; Norton et al.; 2004; Mann and Vanormelingen, 2013; Guiry and Guiry, 2014). The algae represent between eight and 12 major evolutionary lineages (Graham et al., 2008; Cock et al., 2010), and all have representatives in inland waters. Current classifications consider most algae to be protists with chloroplasts, but there are also photosynthetic prokaryotes (the cyanobacteria) and a subset of the land plants, the Charales, which have been considered to be algae in previous texts (Patterson, 2014). With new molecular tools being applied to understanding algal taxonomy, systematics, and evolution, our understanding of this diversity is rapidly changing and expanding. Efforts to characterize this biological diversity (such as the Tree of Life Project: Maddison et al., 2007) have contributed to a better understanding of many groups of freshwater algae (e.g., Lane and Archibald, 2008; Entwisle et al., 2009; Hall et al., 2010; Ashworth et al., 2013; Stancheva et al., 2013a; Fučíková et al., 2014).

For simplicity, algae are treated in this book in the same sense as they are in recent phycology texts (e.g., Graham et al., 2008; Lee, 2008); that is, they are considered to be a loose (polyphyletic) group of organisms that have all or most of the following characteristics: aquatic, photosynthetic (possessing chlorophyll a), simple vegetative structures without a vascular system, and reproductive bodies that lack a sterile layer of protecting cells. There are important exceptions, however, particularly with regard to their habitat (Chapter 2), colorless relatives (lacking photosynthetic pigments; Chapters 10, 12, and 18), and species that switch between photosynthesis and predation on bacteria (mixotrophy; Chapters 10, 12, and 17). Both prokaryotic (those with cells lacking membrane-bound organelles) and eukaryotic taxa (cells with organelles) are considered in this book. Within the algae, there is an enormous range of vegetative morphologies, including the following:

1. Unicells: Species that occur as solitary cells that may be non-motile or motile, the latter of which move by using one or more flagella or gliding along surfaces via mucilage or other means. A wide variety of forms exist among unicells, including those contained within a gelatinous sheath (Fig. 1A); cells with intricate shapes, walls, and markings (Figs. 1B and C); cells having flexible cell shapes (Fig. 1D); and cells with two flagella of equal length (Fig. 1E) or flagella with unequal length (Fig. 1F). Cells can be drawn out into hornlike projections (Fig. 1G) or are contained in a hardened case or lorica (Fig. 1H).

Figure 1 Unicellular and colonial forms of freshwater algae. A. Chroococcus giganteus (coccoid cyanobacterium), a unicell to small grouping of cells (regarded as colonial) contained within concentrically layered gelatinous sheaths. B. Micrasterias americana (conjugating green alga, desmid), a unicell with a deep incision (isthmus) that divides two semicells (clear central area is the nucleus), each of which has several deep incisions that may be subdivided into a series of lobes and lobules. C. Didymosphenia geminata (pennate diatom), a large unicell whose walls are constructed from silica, with a central raphe slit, and marked by a series of intricate pores arranged in lines (striae). D. Euglena sp. (photosynthetic euglenoid), a uniflagellate unicell with multiple green chloroplasts, red eyespot, and exterior covering composed of a series of proteinaceous strips (pellicle) that can readily change shape. E. Dunaliella sp. (flagellated green alga) a unicell with two equal flagella. F. Ochromonas sp. (chrysophycean alga), a golden unicellular alga with two apically inserted flagella, one long (tinsel) and one short (smooth). G. Ceratium hirundinella (dinoflagellate), a unicell with a theca composed of cellulose plates with cellular extensions or horns and a transverse flagellum and trailing longitudinal flagellum. H. Lagynion sp. (chrysophycean alga) a golden rhizopodial unicell within a rigid lorica. I. Woronichinia naegeliana (coccoid cyanobacterium), a colony with spherical or ovoid cells arranged at the periphery of a gelatinous matrix. J. Tetraspora lubrica (nonmotile colonial green alga), a sac-like colony of irregularly arranged special cells within a gelatinous matrix. K. Dictyosphaerium granulatum (non-motile colonial green alga), a colony with spherical cells attached together by gelatinous strands. L. Oocystis lacustris (non-motile colonial green alga), a colony with groups of four to eight cells produced inside the walls of parent cells. Scale bars = 25 μm, except E, F, H = 10 μm; B, C, G = 50 μm. (Photos A, D, K, L courtesy of Chris Carter, with permission, photo F courtesy of Peter A. Siver, Chrysophytes LLC, with permission).

2. Colonies: An aggregation of cells that are held together either in a loose (Fig. 1I and J) or tight well-organized pattern (Figs. 1K-L, 2A-C). Depending on the algal taxon, colonies may contain a variable number of cells, or they may be constant throughout their development (coenobium). Colonies may be composed of flagellated or non-flagellated cells. The basis for cellular connection varies among colonies, including a surrounding gelatinous matrix (Fig. 1I and J), gelatinous stalks (Fig. 1K), or a common parental wall (Fig. 1L). Cells may be arranged in a highly organized pattern (Fig. 2A), directly attached at their cellular edges (Fig. 2B), or at the middle portion of each cell (Fig. 2C). Alternatively, cells may be connected to others by their loricas (Fig. 2E).

Figure 2 Colonial, pseudofilamentous, and filamentous forms of freshwater algae. A. Merismopedia sp. (coccoid cyanobacterium), a colony of numerous cells arranged in rectangular rows within a flattened colony. B. Tabellaria flocculosa (pennate diatom), a colony with rectangular cells seen in side (girdle) view, attached at their edges by mucilage pads in a zigzag fashion. C. Fragilaria crotonensis (pennate diatom), a ribbon-like colony of linear cells attached only at the central region by interlocking spines. D. Dinobryon divergens (chrysophycean alga), a colony of golden flagellates contained within individual funnel-shaped loricas. E....

Produkt-Details

• Erscheint lt. Verlag: 5.6.2015
• Sprache: englisch
• Themenwelt: Naturwissenschaften ► Biologie ► Botanik
• Themenwelt: Naturwissenschaften ► Biologie ► Limnologie / Meeresbiologie
• Themenwelt: Naturwissenschaften ► Biologie ► Ökologie / Naturschutz
• Themenwelt: Technik
• ISBN-10: 0-12-385877-1 / 0123858771
• ISBN-13: 978-0-12-385877-1 / 9780123858771