Internal fertilization is universal in chondrichthyan fishes and, as such, requires a suite of biological activities, including behavioral, morphological and physiological mechanisms, to ensure successful copulation and fertilization. This volume correlates available data and ideas concerning the development, reproductive morphology, function, and

Chondrichthyes are a group of cartilaginous fish, where we have sharks, rays, and chimeras as members. This group plays an important role in aquatic ecology, as they act as predators throughout the food chain (e.g., sharks). However, many populations of Chondrichthyes are threatened by several factors (increased direct fishing, high mortality rate as accompanying fauna, marine pollution, habitat destruction, etc.). These declines are evident in many parts of the world and have come to the attention of scientists, conservation organizations, the media, and the general public. Fisheries legislation regulating international fisheries markets has been amended to provide greater protection for this group along with other species of fish. However, little is known about these species, which reinforces the importance of studies in order to have a better understanding of the elasmobranch stocks, as well as to identify the influences of the anthropic action of fishing. In response to knowledge on the low sustainability of cartilaginous fish fisheries on a global scale, FAO has developed an international plan of action for the management and conservation of these fish, with the aim of developing and implementing national plans of action to ensure management and conservation of these stocks, having as main recommendation the collection of information about the Chondrichthyes, especially the sharks. Even so, this group is little known in terms of biodiversity, ecology, behavior, and a host of other characteristics relevant to this taxon, which is very worrying. Chondrichthyes - Multidisciplinary Approach attempts to portray to the readers up-to-date information on Chondrichthyes to promote an overview of the current taxon, serving as an indispensable source of access to more accurate and detailed information on shark rays and chimeras.

Dr. D. S. Henderson, Chairman of the 1. L. B. Smith Institute of Ichthyology and Vice Chancellor of Rhodes University This book is a unique, international collaborative effort ranging all of the colour plates for the book. For the past of 76 scientists, representing 15 countries. Several skilled eight years, she has been assisted in the research, writing artists and photographers have also contributed to the and editing of the book by Dr. P. C. Heemstra. numerous and beautiful illustrations. Research done in It is essential for the proper management of the marine South Africa was supported by the Council for Scientific fish resources of southern Africa that we know what species and Industrial Research. Work on the book at the J.L.B. we are dealing with. This book will greatly facilitate the Smith Institute was also funded by the Department of identification of our fishes. It will thus be of vital import National Education and The Trustees of the Sea Fishes of ance to the understanding and wise use of our tremendously Southern Africa Book Fund. Expenses of visits by ichthy diverse and valuable fish fauna. ologists from overseas were defrayed by a grant from the We are proud of the affiliation of the J.L.B. Smith Insti John S. Schlesinger Foundation. tute with Rhodes University and happy to see the successful Although this book is an impressive contribution to the completion of this long-awaited work.

Skates have become a concern in recent years due to the preponderance of these elasmobranchs that are caught as bycatch or as a directed fishery. This has raised concern because skates have life history characteristics that may make them vulnerable to over-exploitation. It was due to this concern that prompted Drs. David Ebert and James Sulikowski to organize an international symposium on the “Biology of Skates”. The aims and goals of the symposium were to bring together an international group of researchers to meet, discuss, perhaps develop collaborations, and present their most recent findings. The symposium was held over two days, on 13-14 July, 2006, in conjunction with the 22nd annual meeting of the American Elasmobranch Society in New Orleans, LA. A total of 31 authors from four countries contributed 16 papers that appear in this volume. The papers are broadly arranged into four separate categories: systematics and biogeography, diet and feeding ecology, reproductive biology, and age and growth. This is the first dedicated book on the biology of skates. We hope that readers will find this volume of interest and that it helps encourage and stimulate future research into these fascinating fishes.

Chondrichthyes are a group of cartilaginous fish, where we have sharks, rays, and chimeras as members. This group plays an important role in aquatic ecology, as they act as predators throughout the food chain (e.g., sharks). However, many populations of Chondrichthyes are threatened by several factors (increased direct fishing, high mortality rate as accompanying fauna, marine pollution, habitat destruction, etc.). These declines are evident in many parts of the world and have come to the attention of scientists, conservation organizations, the media, and the general public. Fisheries legislation regulating international fisheries markets has been amended to provide greater protection for this group along with other species of fish. However, little is known about these species, which reinforces the importance of studies in order to have a better understanding of the elasmobranch stocks, as well as to identify the influences of the anthropic action of fishing. In response to knowledge on the low sustainability of cartilaginous fish fisheries on a global scale, FAO has developed an international plan of action for the management and conservation of these fish, with the aim of developing and implementing national plans of action to ensure management and conservation of these stocks, having as main recommendation the collection of information about the Chondrichthyes, especially the sharks. Even so, this group is little known in terms of biodiversity, ecology, behavior, and a host of other characteristics relevant to this taxon, which is very worrying. Chondrichthyes - Multidisciplinary Approach attempts to portray to the readers up-to-date information on Chondrichthyes to promote an overview of the current taxon, serving as an indispensable source of access to more accurate and detailed information on shark rays and chimeras.