How to decelerate loss of global biodiversity is one of the greatest challenges of our generation. Reproductive technologies have enormous potential to assist the recovery of species by enhancing reproductive output, facilitating genetic management, and supporting reintroduction of threatened species. Of particular value are cryopreservation technologies coupled with the establishment of global gene banks to conserve, in perpetuity, the remaining extant genetic diversity of threatened amphibians. Reproductive Technologies and Biobanking for the Conservation of Amphibians brings together leading experts in the field to provide a comprehensive overview of current best practices, summarise technological advancements, and present a framework for facilitating the integration of reproductive technologies and biobanking into conservation breeding programs for threatened amphibians. It is an invaluable reference for the next generation of conservation practitioners: captive breeding facilities, researchers, and policy-makers involved with biodiversity conservation.
The increasing dependence on amphibian captive breeding programs to support at-risk populations has led to growth in the application of assisted reproductive technologies (ART) to aid with the management of decreasing population density and genetic diversity. Already the integration of ART within these programs has led to monumental successes and shows great promise as a means to augment amphibian breeding efforts when natural breeding has low success. The focus of this project was to continue the optimization of ART to aid in making these technologies more widely applicable. Specific objectives include developing a framework that can be used to standardize follicular grading of oocytes through ultrasound assessments, demonstrating how advantageous routine sonography assessments are in providing insight into the female reproductive cycle in captive amphibians, and determining the differences in offspring growth and development between Ambystoma tigrinum larvae produced through in-vitro fertilization with either freshly collected or frozen-thawed sperm.
This second edition emphasizes the environmental impact on reproduction, with updated chapters throughout as well as complete new chapters on species such as sharks and rays. This is a wide-ranging book that will be of relevance to anyone involved in species conservation, and provides critical perspectives on the real utility of current and emerging reproductive sciences. Understanding reproductive biology is centrally important to the way many of the world’s conservation problems should be tackled. Currently the extinction problem is huge, with up to 30% of the world’s fauna being expected to disappear in the next 50 years. Nevertheless, it has been estimated that the global population of animals in zoos encompasses 12,000 – 15,000 species, and we anticipate that every effort will be made to preserve these species for as long as possible, minimizing inbreeding effects and providing the best welfare standards available. Even if the reproductive biology community cannot solve the global biodiversity crisis for all wild species, we should do our best to maintain important captive populations. Reproductive biology in this context is much more than the development of techniques for helping with too little or too much breeding. While some of the relevant techniques are useful for individual species that society might target for a variety of reasons, whether nationalistic, cultural or practical, technical developments have to be backed up by thorough biological understanding of the background behind the problems.
[Truncated abstract] Assisted Reproductive Technologies (ART) encompass a range of techniques that manipulate reproductive endocrinology, gametes, and embryos, for the purpose of enhancing reproductive success. The emerging field of amphibian ART has gained momentum in recent years due to the alarming rate at which amphibians are declining worldwide. Current estimates report 30.3% (1,917) of amphibian species are threatened with extinction, a greater proportion than any other vertebrate class. In response to the amphibian extinction crisis, numerous institutions have initiated captive breeding programmes (CBPs). CBPs play a key role in maintaining populations of endangered species, but in most cases reproductive rates are too low to support long-term reintroduction programmes. A powerful new approach to ex situ conservation has emerged, where sophisticated ART techniques are coupled with traditional captive breeding methods in order to improve the propagation and genetic management of threatened vertebrate species. To date, few studies have attempted to apply ART to Australian anurans, and the success of such studies has been limited. This thesis aimed to advance our understanding of how to a) successfully control aspects of the amphibian endocrine system to promote gamete-release, and b) optimise artificial fertilisation (AF) protocols to maximise fertilisation success. Chapter 2 provides a direct comparison of the effectiveness of two exogenous hormones, human chorionic gonadotropin (hCG) and luteinizing hormone-releasing hormone (LHRHa) as inducers of spermiation in eight, previously unstudied Australian anurans. Importantly, this study was the first to investigate patterns in spermiation responses across species, and found that all species belonging to the family Myobatrachidae responded better to LHRHa, while species from the family Limnodynastidae released a greater number of spermatozoa in response to hCG. These results suggest that there may be a phylogenetic basis to the effectiveness of hCG and LHRHa at stimulating spermiation among species. Chapters 3 and 4 focus on the refinement of gamete-release induction protocols for the terrestrial toadlet, Pseudophryne guentheri. Chapter 3, establishes an LHRHa dose-response relationship, and quantifies the effects of arginine vasotocin (AVT) administration on spermiation. LHRHa proved highly effective at inducing spermiation, however the administration of AVT alone or in combination with LHRHa resulted in the inhibition of sperm-release. Chapter 4 is an investigation of the effect of low-dose priming injections of LHRHa on spermiation and ovulation. In male P. guentheri, a single injection of LHRHa without priming was most effective at stimulating spermiation. In contrast, female P. guentheri failed to ovulate without priming, and one or two priming injections were needed to induce the release of an entire clutch of oocytes. Interestingly, oocytes obtained from females in the two priming treatment could not be fertilised, while those obtained from females in the one priming treatment exhibited consistently high fertilisation success. In Chapter 5, ART protocols were applied for the first time to a critically endangered Australia anuran, the Southern Corroboree Frog, Pseudophryne corroboree...
Amphibians are among the most threatened groups of animals on earth. In part due to their highly permeable skin, amphibians are highly sensitive to environmental changes and pollution and provide an early-warning system of deteriorating environmental conditions. The more we learn about the impact of environmental changes on amphibians, the better we as humans will be able to arrest their demise, and our own. Status of Conservation and Decline of Amphibians brings together the current knowledge on the status of the unique frogs of Australia, New Zealand, and the Pacific. Although geographically proximate, each region presents unique challenges and opportunities in amphibian research and conservation. This book contributes to an understanding of the current conservation status of the amphibians of each region, aims to stimulate research into halting amphibian declines, and provides a better foundation for making conservation decisions. It is an invaluable reference for environmental and governmental agencies, researchers, policy-makers involved with biodiversity conservation, and the interested public.
This book deals with reproduction of Amphibians belonging to three extant orders: Caecilians, Salamanders, Frogs and Toads. Separate chapters have been written for males and females; the chapters describe gonad structure and development, gametogenesis, urogenital connections, and reproductive tracts. The authors have provided a synthesis of the lit
Australian waters contain the highest diversity of cephalopods (squid, cuttlefish and octopus) found anywhere in the world. They are highly significant ecologically, both as top-level predators and as prey for numerous vertebrates, including fishes, seals, cetaceans and seabirds. Cephalopods of Australia and Sub-Antarctic Territories is a comprehensive guide covering 226 species, which represent over a quarter of the world’s cephalopod fauna. With an emphasis on identification, this book includes keys, species descriptions, full-colour illustrations and distribution maps, as well as a summary of the biology and behaviour of cephalopods and fisheries information. This is an invaluable tool for researchers and fisheries experts as well as amateur naturalists, fishers and divers.
Throughout much of the world, frog populations are declining, with the survival of many species under threat. In Australia, several species have become extinct in the past 35 years. This second edition of Field Guide to the Frogs of Australia provides fully updated accounts of all the known frogs of Australia. There are 248 species within the five native frog families: Hylidae, Limnodynastidae, Microhylidae, Myobatrachidae and Ranidae. Also included are the introduced Cane Toad and nine ‘stowaway’ species that have arrived in Australia. Each species account includes details of size, status, distribution, habitat, behaviour and advertisement call. Species are beautifully illustrated with full-colour paintings and distribution maps are also included. Closely related frogs are shown in identical poses so that comparisons can be made readily. The introductory section of the book covers frog biology and habitats and includes notes on families and genera.
The Hymenoptera is one of the largest orders of terrestrial anthropods and compromises the sawflies, wasps, ants, bees and parasitic wasps. This book examines the current state of all major areas of research for this important group of insects, including systematics, biological control, behaviour and use in education.
Comparative endocrinology is one of the most rapidly developing subdis ciplines within the field of endocrinology, and it is having a significant impact on research at the molecular, cellular, organisma1 and environmental levels. Much of the current ferment in endocrinology is in reproductive endocrinology. The purpose of this volume on hormones and reproduction in fishes, amphibians and reptiles is to summarize our present understandings and to identify important research problems to be addressed in the area of comparative reproductive endocrinology. It was inspired by the gathering at Copper Mountain, Colorado, of eminent endocrine scientists from around the world on the occasion of the Tenth International Symposium on Comparative Endocrinology in July, 1985. While preparing for that meeting, we decided that a special volume on reproductive endocrinology was needed to summarize what is known and to stimulate research in particular directions. Why do we emphasize fishes, amphibians and reptiles? First, knowledge about the reproductive endocrinology of these ectothermic vertebrates can provide a clearer picture of the evolution of reproductive hormones and their effects on target organs. This comparative approach can lead to new theories about the evolution of reproductive control mechanisms. Second, studies concerning the reproductive endocrinology of "lower" vertebrates can result in development of "model systems" for application to studies of birds and mammals. Indeed, information about the patterns of reproductive control in ectothermic vertebrates can tell us which are evolutionarily stable and which are labile.
