Sexuality in Fishes


Book Description

The unprecedented level of diversity recorded among the clones of self-fertilizing gynogenetic unisexuals and self-fertilizing simultaneous hermaphrodites challenges current ideas on the predominant role of recombination in promoting evolution of biological diversity. Though limited to a few species, the existence of self-fertilizing and cycli




Reproduction and Sexuality in Marine Fishes


Book Description

Marine fishes represent astonishing diversity with respect to practically every aspect of their biology. Reproductive modes and sexual patterns are especially fascinating and provide deep insight into general evolutionary problems. In this volume, chapters focus on reproduction and sexuality among groups of fishes defined by habitat, taxon, and the reproductive processes that are critical for reproductive success. The book illustrates how knowledge of reproductive biology among marine fishes can help identify vulnerable and potentially vulnerable species in the face of changing environmental conditions and increasing human-based pressures.




Sex Determination in Fish


Book Description

This book is the first to report that research in allogenics/xenogenics has conclusively shown that fishes have retained bisexual potency even after sexual maturity and spermiation. The XY genotype found in the unexpected female phenotypes sired by supermales (Y1Y2) and androgenic males (Y2Y2) points out the need to employ sex specific molecular ma




Genetic Sex Differentiation in Fish


Book Description

A comprehensive study of sex differentiation gonochoric and hermaphroditic fishes, this book examines sex chromosomes and sex determining genes, emphasizing the need to search for more than one sex-determining gene residing on different chromosomes. It traces the origin of hermaphrodites from secondary gonochores and explains the conservation of ho




Sex Control in Aquaculture


Book Description

Awarded Bookauthority's "Best Aquaculture Books of all Time" A comprehensive resource that covers all the aspects of sex control in aquaculture written by internationally-acclaimed scientists Comprehensive in scope, Sex Control in Aquaculture first explains the concepts and rationale for sex control in aquaculture, which serves different purposes. The most important are: to produce monosex stocks to rear only the fastest-growing sex in some species, to prevent precocious or uncontrolled reproduction in other species and to aid in broodstock management. The application of sex ratio manipulation for population control and invasive species management is also included. Next, this book provides detailed and updated information on the underlying genetic, epigenetic, endocrine and environmental mechanisms responsible for the establishment of the sexes, and explains chromosome set manipulation techniques, hybridization and the latest gene knockout approaches. Furthermore, the book offers detailed protocols and key summarizing information on how sex control is practiced worldwide in 35 major aquaculture species or groups, including fish and crustaceans, and puts the focus on its application in the aquaculture industry. With contributions from an international panel of leading scientists, Sex Control in Aquaculture will appeal to a large audience: aquaculture/fisheries professionals and students, scientists or biologists working with basic aspects of fish/shrimp biology, growth and reproductive endocrinology, genetics, molecular biology, evolutionary biology, and R&D managers and administrators. This text explores sex control technologies and monosex production of commercially-farmed fish and crustacean species that are highly in demand for aquaculture, to improve feed utilization efficiency, reduce energy consumption for reproduction and eliminate a series of problems caused by mixed sex rearing. Thus, this book: Contains contributions from an international panel of leading scientists and professionals in the field Provides comprehensive coverage of both established and new technologies to control sex ratios that are becoming more necessary to increase productivity in aquaculture Includes detailed coverage of the most effective sex control techniques used in the world's most important commercially-farmed species Sex Control in Aquaculture is the comprehensive resource for understanding the biological rationale, scientific principles and real-world practices in this exciting and expanding field.




Endocrine Sex Differentiation in Fish


Book Description

Of all vertebrates, fish exhibit unparalleled diversity of sexual plasticity and flexibility, ranging from gonochorism to unisexualism, and exceptional patterns of functional hermaphroditism. Fish farming and monosex aquaculture have led to reproductive dysfunction with males producing less milt, and females failing to ovulate and spawn. This book brings together relevant information on the role of the endocrine system on sexual differentiation in fish, and bridges the gap between molecular endocrinologists and fishery scientists.




Fishes: A Guide to Their Diversity


Book Description

"This is a coursebook and reference guide for ichthyology courses that will also serve as a tool for ichthyologists, fisheries scientists, marine biologists, and vertebrate zoologists. It will cover the basic anatomy and diversity of all 62 orders of fishes, focusing on the distinguishing characteristics of approximately 180 of the most commonly encountered fish families. Each family will be diagnosed with easily observed characteristics and clear photos--many in color and from living specimens. This guide will be distinctive through the use of photographs of preserved specimens primarily from the Scripps Institution of Oceanography Marine Vertebrate Collection, supplemented by radiographs and additional illustrations of key characters. The goal is to give ichthyology students, fisheries scientists, marine biologists, vertebrate zoologists, and others with an interest or stake in the diversity of fishes a broad overview of the morphological diversity of fishes, arranged in a modern classification system. For students, it's a natural complement to primary ichthyology textbooks, which don't cover the breadth of morphological characteristics necessary to identify fish"--Provided by publisher.




Intersexuality in the Animal Kingdom


Book Description

When Richard Goldschmidt' coined the term "intersexuality" in 1915, he intended it to apply to normally dioecious species which exhibit some kind of mixture between male and female characters. However, as knowledge of the bewildering variability present in the sexual orga nization of members of the animal kingdom has increased, the original meaning of the word has changed. Today many authors define inter sexuality as "the presence of both male and female characteristics, or of intermediate sexual characteristics, in a single individual".2 This more extensive and widely accepted concept justifies the title of our book •. Among all the anatomical and physiological features of living organisms the reproductive system has a unique importance for the perpetuation of the species. Conversely, reproductive processes are of little or no account for the viability of the individual. Therefore, within the framework of general biology reproduction has all too often been looked at solely from the point of view of genetics. Lively discussions about genotypic versus phenotypic sex determination long dominated the sci entific literature on sexuality in animals; this one-sided emphasis has tended to obscure many important facets of an organism's ability to reproduce. Recent developments in current biological research have brought the classic problem of sex differentiation into focus again, and the rapid progress being made in comparative endocrinology has added a new di mension to the study of reproductive biology.




Fish Reproductive Biology


Book Description

Fish recruitment is a key process for maintaining sustainable fish populations. In the marine environment, fish recruitment is carried out in many different ways, all of which have different life history strategies. The objective of this book is to argue for greater linkages between basic and applied research on fisheries recruitment, and assessment and management of exploited fish stocks. Following an introductory chapter, this second edition of Fish Reproductive Biology is organized into 3 main sections: Biology, Population Dynamics and Recruitment Information Critical to Successful Assessment and Management Incorporation of Reproductive Biology and Recruitment Considerations into Management Advice and Strategies The authors collectively bring a wide range of diverse experience in areas of reproductive biology, fisheries oceanography, stock assessment, and management. Fully updated throughout, the book will be of great interest to a wide audience. It is useful as a textbook in graduate and undergraduate courses in fisheries biology, fisheries science, and fisheries resource management and will provide vital information for fish biologists, fisheries scientists and managers.




Fish Reproduction


Book Description

With the decline in world fish stocks, our knowledge of fish reproduction has become fundamental. Reproduction is an essential commitment to future generation. It is also a continuous development process throughout ontogeny, requiring energetic, ecological, physiological, anatomical, biochemical and endrocrinological adaptations. The first chapters highlight important issues affecting fish normal ways of reproductive development; details would focus on species living in opposite environments, such as tropical and polar fishes; far related, as teleosts and cartilaginous fishes; and finally, fish having different reproductive strategies. Thereafter, since many fishes live in detrimental environments, mainly induced by the continuous input of xenobiotic substances into waterways, the authors found it highly pertinent to include this topic. Herein, the authors fix their attention on the factors and mechanisms that may well affect reproductionrelated hormonal systems as also on known consequences for fish living i