Tropical Marine Mollusks

An Illustrated Biogeographical Guide

Edward J. Petuch, David P. Berschauer

• Publisher: CRC Press
• Year: 2020
• Print ISBN: 9780367636388
• eBook ISBN: 9781000285420
• Edition: 1
• Topic: Biological Sciences
• Subtopic: Ecology
• Index: Biological Sciences

Marine biogeography, the study of the spatial distribution of organisms in the world's oceans, is one of the most fascinating branches of oceanography. This book continues the pioneering research into the distributions of molluscan faunas, first studied by biologists over 160 years ago. It illustrates 1778 species of gastropods in full color, many of which are extremely rare and poorly known endemic species that are illustrated for the first time outside of their original descriptions.

The spatial arrangements of malacofaunas shown in this book can be considered proxies for worldwide oceanic conditions and used as tools for determining patterns of global climate change. The book's documentation of evolutionary "hot spots" and geographically restricted endemic faunas can also be used as a base line for future studies on patterns of environmental deterioration and extinction in the marine biosphere.

Documenting the evolution of the amazingly rich worldwide gastropod fauna, this book will appeal to physical and chemical oceanographers, systematic and evolutionary biologists, historical geologists, paleontologists, climatologists, geomorphologists, and physical geographers. The authors incorporate aspects of all of these disciplines into a new classification system for the nomenclature of biogeographical spatial units found in tropical, subtropical, and warm temperate seas.

CHAPTER 1.Biogeographical Patterns in the Marine Biosphere

For over 160 years, oceanographers, marine biologists, malacologists, and marine ecologists have recognized that the shallow water marine molluscan faunas of the world are distributed in distinct, geographically definable areas. Intensive shell collecting by eighteenth and nineteenth-century naturalists in the English, Spanish, French, Portuguese, and Dutch tropical colonies resulted in the discovery of an overwhelming number of spectacular new species and genera. These new taxa, brought home to Europe by sailors in the late 1600s and early 1700s, were highly prized by wealthy shell collectors and a large, highly-competitive market for rare and desirable species quickly developed. These new taxa supplied the first evidence for the existence of larger and richer molluscan faunas beyond the European and Mediterranean worlds. As more data on new molluscan faunas poured into Europe in the early 1800s and, later in the United States in the mid-1800s and early 1900s, the geographical patterns of these faunas became even better defined. Building on this new pool of information, the European and American malacologists, in recognizing latitudinal distributions, were unknowingly planting the seeds for the development of a completely new branch of marine science: marine biogeography, the study of the spatial distribution of marine organisms and the ecological parameters that determine their distributions.

A formal framework for the study of worldwide biogeography was first proposed in two contemporaneous books, both published in 1856. The first of these, The Physical Atlas of Natural Phenomena by Alexander Johnston, divided the world into 25 provinces within a series of nine horizontal, latitudinally-arranged zones that he referred to as “Homoizoic Belts”. This geographical classification scheme is generally considered to be the first comprehensive book ever written on worldwide marine biogeography. Johnston's work was based upon earlier discoveries by the “Father of Modern Marine Biology”, Edward Forbes, Jr., who recognized a series of “provinces” in the European seas, including the “Arctic, Boreal, Celtic, Lusitanian, Mediterranean, and Black Sea.” Forbes also commented on the broad distributional patterns of corals in respect to latitudinal gradations in water temperature, foreshadowing subsequent studies on the physiological and ecological parameters that delineate tropical and subtropical marine faunas. In his Manual of Conchology, which was published at the same time as Johnston's work, Samuel P. Woodward, a student of Edward Forbes, was the first worker to formally define a province, describing it as “an area in which 50% of the species are endemic”. Using this “50% Rule”, Woodward went on to describe and define 25 worldwide marine molluscan faunal provinces and the original book was considered so important that it underwent several editions (including 1856 and 1880 editions). Some of these provinces, such as the Carolinian, Caribbean, South African, Indo-Pacific, Eritrean, Japonic, Californian, and Panamic, are used here in this book, underscoring the brilliance of S.P. Woodward's original pioneer work.

Although only qualitative in nature, Woodward's scheme of 25 separate worldwide molluscan provinces became the standard for marine biogeography throughout the late nineteenth century and the first half of the twentieth century. This view of a 25 province world was overturned in 1953, when Sven Ekman published his highly informative survey of worldwide marine faunas, the classic book Zoogeography of the Seas. Although covering all types of marine organisms, not only the Mollusca, Ekman abandoned Woodward's province concept, preferring instead sets of regions and subregions. The area that we here consider to represent four separate faunal provinces (the Carolinian, Caribbean, Brazilian, and Paulinian), Ekman fused together into a single subregion (the “Subtropical American Subregion”) of his large “Atlanto-East Pacific Region” (covering these four provinces along with the Californian and Panamic Provinces of the Eastern Pacific). Following this concept of a single giant tropical area in the western Atlantic, Germaine Warmke and R.T. Abbott (in Caribbean Seashells, 1961: 319) recognized an expanded Caribbean Province which extended from Cape Hatteras and Bermuda southward through Florida, the Gulf of Mexico, the Caribbean Sea, to Cabo Frio, Brazil. Both Ekman's and Warmke and Abbott's biogeographical schemes are now considered to be overgeneralized and, intrinsically, do not offer the level of resolution needed for the recognition of localized species radiations and island endemism.

The concept of broad, generalized faunal regions was challenged in the 1970s, primarily in the works of James Valentine. Expanding upon Woodward's original marine molluscan province concept, Valentine, in his Evolutionary Paleoecology of the Marine Biosphere (1973:337), was the first to offer a quantitative definition of a faunal province. Augmenting Woodward's 50% Rule, Valentine also applied cluster analysis, multivariant analysis, Jaccard's Coefficient, and other statistical methods to determine the boundaries of provinces and subprovinces around the world. Although retaining three of Woodward's provincial names, the Carolinian, Caribbean, and Patagonian, Valentine also added a fourth province, the Gulf Province (considered here to be a composite of four separate subprovinces within the Gulf component of the Carolinian Province). His analytical studies, although now outdated, were the first to pin down provincial boundaries by using mathematical techniques and Valentine was also the first biogeographer to use plate tectonics and physiological restrictions (limiting factors) to explain provincial distributions.

Several years after Valentine's monumental work, the theoretical ecologist, Geerat Vermeij, took a reductionist viewpoint and defined only two broad provinces for the entire tropical western Atlantic (in his Biogeography and Adaptation, 1978). These consisted of a “Tropical Western Atlantic Province” (from Palm Beach, Florida and Bermuda, the southern Gulf of Mexico, the Caribbean Basin, and south to Brazil) and a “Warm-Temperate Northwest Atlantic Province” (Cape Hatteras, North Carolina south to Palm Beach). These broad faunal regions were based primarily on latitudinal patterns of predation on m...

Table of contents

• Cover
• Half Title
• Title
• Copyright
• Dedication
• Contents
• Introduction
• Acknowledgments
• Foreword
• CHAPTER 1. Biogeographical Patterns in the Marine Biosphere
• CHAPTER 2. Western Atlantic Region
• CHAPTER 3. Eastern Atlantic Region
• CHAPTER 4. Eastern Pacific Region
• CHAPTER 5. Indo-Pacific Super-Region and Central Pacific Region
• CHAPTER 6. Western Pacific Tropical Region
• CHAPTER 7. Indian Tropical Region
• CHAPTER 8. Australian Super-Region and North Tropical Australian Region
• CHAPTER 9. South Australian Paratropical Region
• CHAPTER 10. Southern Africa Region
• APPENDIX. Quantitative Methods for Defining Provinces and Subprovinces
• Bibliography
• Systematic Index
• Biogeographical Index
• About the Authors