E-Book, Englisch, 314 Seiten
Pandian Environmental Sex Differentiation in Fish
1. Auflage 2014
ISBN: 978-1-4822-5438-9
Verlag: Taylor & Francis
Format: PDF
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)
E-Book, Englisch, 314 Seiten
ISBN: 978-1-4822-5438-9
Verlag: Taylor & Francis
Format: PDF
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)
Fish constitute an important natural renewable resource and any reduction in their ability to propagate as a result of human interference may have significant socioeconomic consequences. The negative effect of human activity on sex differentiation and reproductive output in fish is so diverse that it has been difficult to encompass it in a single book. This book serves as the first attempt to do so.
Unlike in mammals, the expression of a host of sex differentiation genes in fish is mostly controlled by environmental factors. Not surprisingly, environmental sex differentiation is ubiquitous in fish. Overexploitation by capture fisheries does not disrupt sex differentiation but crowding in aqua-farms does, by reducing accessibility to food supply.
Some of the man-made chemicals routinely used worldwide mimic endogenous hormones. For example endosulfan, which is widely used in developing countries, disrupts endogenous hormones and feminizes fish. For the first time, this book views endocrine disruption from the point of labile early life and non-labile adult stages. It shows that sex can irreversibly be reversed, when exposed to endocrine disrupting chemicals (EDCs) during early labile stages but reversibly impairs reproductive output on exposure to EDCs during non-labile adult stage. A consequence of climate change, elevated temperature, and declining oxygen and pH levels is that it masculinises genetic female fish.
Fish display a remarkable ability to postpone the labile period. Besides postponement, some primary and tertiary gonochores have two distinct labile periods amenable to temperature and hormonal manipulations. Hermaphrodites have retained the period until the end of the adult stage and are capable of sex change/reversal more than once in both male and female directions.
Autoren/Hrsg.
Fachgebiete
Weitere Infos & Material
Introduction
Genetic basis
Genes meet environment
Social structure
Mating system
Parental care
Hermaphroditism
Model fishes
References
Overexploitation by fisheries
Fisheries scenario
Sexual maturity
Fecundity
Spawning stress
Collapse of fishery
Sex change
Sperm economy
Social induction
Reproductive life span
References
Aquaculture and crowding
Human interventions
Crowding and consequences
References
Endocrine disruption
Labile and non-labile stages
History and prevalence
Routes of entry
Mechanism of disruption
Selected labile stages
Morphology and anatomy
Ovotestis and testis-ova
Vitellogenesis
Gametogenesis
Courting and mating
Spawning and spermiation
Fertilization and fecundity
Hatching and survival
New from old
Reference
Hypoxia and anoxia
Hypoxic habitats and fisheries
Hypoxia and differentiation
Hypoxia and impairments
Anoxia
References
pH and precipitation
pH and sex ratio
Precipitation
References
Temperature and sex ratio
Identification of GSD and TSD
Patterns 2 and 3
Parental genetic role
Insensitive fishes
Germ cells and aromatase
Model fishes
Prevalence and patterns
References
Climate change and differentiation
Model systems
Impairment and distribution
Global food security
References
Conservation
Cryopreservation
Vitrification
Androgenesis
Cloning
Reprogramming
Tissue culture
Xenogenesis
References
Labile period and new hypothesis
Author index
Species index
Subject index
