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In the face of the growing biodiversity crisis, we must move to document and evaluate the biota of our natural areas. As taxonomists, it is part of our job to name, place into groups, and keep track of the species that we study. Often we use the distribution of the taxa to help with our work and to provide a broader context for the results. In doing this job, taxonomists produce checklists, floras and faunas, and monographs. In fact, collecting specimens and producing these documents are essential elements in our quest to understand the natural world and how it evolved. Checklists are the ‘‘first pass’’ in our attempts to understand the diversity of an area. They give us the first approximation of the known diversity of any group or groups of organisms and they often provide the first profile of the biodiversity in relatively poorly known parts of the globe. For many groups, they may represent the most complete information available and since basic taxonomic data provide the essential information for studies in systematic and evolutionary biology, we continually seek to improve and update it. Checklists have many uses: they are aids in the identification and correct naming of species, they serve as essential resources for biodiversity estimates and biogeographic studies, and they are starting points for more detailed studies of an area’s biota. When reviewed by many specialists, they often represent the most advanced state of knowledge available in the field. But they do more than that, beyond these basics they increase our knowledge of this fascinating region and act as a starting point for additional biodiversity research because they give insight into the species richness, endemicity, and floral and faunal affinities for the region and provide the baseline information for analyzing species turnover rates and migration or invasion events and many other biological phenomena (e.g., Funk & Richardson 2002, Funk et al. 2002, 2005; Ferrier et al. 2004, Kelloff & Funk 2004). Checklists also increase national and regional pride by demonstrating the diversity of the area and provide important public outreach and fundamental information to be used by governments and conservation organizations in addressing the biodiversity crisis. This Checklist of the Fishes of the Guiana Shield, when combined with the recently published Checklist of the Terrestrial Vertebrates of the Guiana Shield (Hollowell & Reynolds 2005), and Checklist of the Plants of the Guiana Shield (Funk et al. 2007), provides a sound basis for future research and conservation efforts. This Checklist of the Fishes of the Guiana Shield is an excellent example of effective interaction, involving ichthyologists from around the world who contributed in diverse ways to its completion. It began as an INTRODUCTION V. A. FUNK and CAROL L. KELLOFF extraction from Reis et al. (2003) but quickly grew into a larger and more involved project. As with any endeavor of this type, insights that specialists have gained through their experience are irreplaceable in correcting errors and updating classifications. In order to make future editions of this checklist as current and accurate as possible, specialists are encouraged to contact the Smithsonian’s Biological Diversity of the Guiana Shield Program with additions or corrections. The Guiana Shield The Guiana Shield region is a biologically rich area that includes much of northeastern South America (Fig. 1). It is strictly defined by the underlying geological formation known as the Guiana Shield, and in the context of this volume the term Guiana Shield also refers to the corresponding geographic region. That region includes the Venezuelan states of Bolívar and Amazonas, and a portion of Delta Amaçuro; all of Guyana, Suriname, and French Guiana; and parts of northern Brazil. Several geological outliers of the Guiana Shield occur west of the Orinoco River in Colombia. In Spanish and Portuguese speaking countries, the region is often referred to as the ‘‘Guayana’’; thus the terms Colombian Guayana, Brazilian Guayana, and Venezuelan Guayana are often used. The total area of the Guiana Shield is approximately 1,520,000 km 2 . Table 1 lists the square kilometers of political divisions that occur within the region. See Berry et al. (1995) for a review of definitions of and terminology related to the Guiana Shield region. Geology The Guiana Shield (Fig. 1) is a distinct geologic region that underlies Guyana, Suriname, French Guiana, parts of Venezuela, and Brazil, and a small area in Colombia. It is roughly bounded by the Atlantic Ocean to the north and east, the Orinoco River to the north and west, the Río Negro (a major tributary of the Amazon River) to the southwest, and the Amazon River to the south (Gibbs & Barron 1993). The Guiana Shield is a distinct ancient geological formation that includes the mountain systems that form the watershed boundary between the Amazon and Orinoco rivers. On the Shield’s western side, the Orinoco River and Río Negro are connected by the Río Casiquiare, making most of the region somewhat like an island; however, there are some areas of nearby Colombia that have remnants of the Shield formation. The southern boundary of the Guiana Shield is
2 BULLETIN OF THE BIOLOGICAL SOCIETY OF WASHINGTON Figure 1. The Guiana Shield; adapted from Gibbs & Barron (1993), with the region of western outliers indicated. difficult to define precisely, as a broad band of outwash materials resulting from erosion occurs between mountains on the southern boundary of the Shield and the Amazon and Negro rivers stretching into parts of northern Brazil. Also, much of the Venezuelan state of Delta Amacuro occurs over thick sediments deposited primarily by the Orinoco River and is really not strictly part of the Shield; however, some mountains of the Guiana Shield occur in this state’s southern section, and a large proportion of the sediments of the delta are derived from outwash from the highlands of the Shield. For more detailed discussions of the Table 1.—Divisions of the Guiana Shield in approximately west to east arrangement, with abbreviations used and estimated areas. Division Abbr. Area (km 2 ) *Colombian Guayana CG 120,325 Amazonas, Venezuela VA 175,750 Bolívar, Venenzuela BO 238,000 *Delta Amacuro, Venezuela DA 40,200 *Amazonas, Brazil BA 125,550 *Roraima, Brazil RO 173,750 *Pará, Brazil PA 243,280 *Amapá, Brazil AP 98,750 Guyana GU 214,970 Suriname SU 163,270 French Guiana FG 91,000 Total (km 2 ) 1,896,845 *5 not all parts of these politically defined areas are included in the Guiana Shield region. geology of the area, readers should refer to Gibbs & Barron (1993) and Huber (1995a). The base of the Guiana Shield is composed of crystalline rocks of Proterozoic origin; these are mainly granites and gneisses formed between 3.6 and 0.8 billion years ago (Mendoza 1977, Schubert & Huber 1990). Large areas of the Shield were overlain with sediments from 1.6 to 1 billion years ago and cemented during thermal events (Huber 1995a). These quartzite and sandstone rocks comprise the Roraima formation and today remnants are scattered across the central portion of the Shield extending west from the Potaro Plateau of the Pakaraima Mountains in central Guyana through parts of Venezuela and Colombia (Arbeláez & Callejas 1999) and south into northern Brazil (Leechman 1913, Gibbs & Barron 1993). Within this area, erosion has resulted in numerous verticalwalled, frequently flat-topped mountains called ‘‘tepuis,’’ among them are Chimantí-tepui (2550 m), Cerro Duida (2358 m), and Auyán-tepui (2450 m). Pico de Neblina (3014 m) is the Shield’s western-most tepui and highest point, located on the southern-most segment of the border between Venezuela and Brazil. Mount Roraima (2810 m) is located at the juncture of Guyana, Venezuela, and Brazil and includes the highest point within Guyana. The eastern-most peaks in Guyana reach approximately 2000 m elevation, including Mt. Ayanganna (2041 m). Several of these mesa-like formations are virtually inaccessible by foot
Page 1 and 2: BULLETIN of the Biological Society
Page 3 and 4: CHECKLIST OF THE FRESHWATER FISHES
Page 5 and 6: CONTENTS CONTRIBUTORS. . . ........
Page 7 and 8: Paulo H. F. Lucinda, Laboratório d
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Page 17 and 18: History A vast complex of wetlands,
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PHOTOGRAPHIC ATLAS OF FISHES OF THE
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NUMBER 17 55 Figure 4. Author photo
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NUMBER 17 57 white and vice versa).
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NUMBER 17 59 (Serrasalminae), dans
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