Download or read book Endocrine Regulation of Early Sexual Maturation in Male Atlantic Salmon Parr written by Gersende Maugars and published by . This book was released on 2007 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Endocrine Aspects of Sexual Maturity in Male Atlantic Salmon Parr written by Paul Anthony Charles Stuart-Kregor and published by . This book was released on 1981 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Regulation of Leptin by Sexual Maturation and Energy Status in Male Atlantic Salmon Salmo Salar L Parr written by and published by . This book was released on 2014 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Endocrine Aspects of Sexual Maturity in Male Atlantic Salmon Parr Salmo Salar L Juv written by P. A. C. Stuart-Kregor and published by . This book was released on 1981 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Histological Analysis of Endocrine Disruptive Effects in Small Laboratory Fish written by Daniel Dietrich and published by John Wiley & Sons. This book was released on 2009-07-31 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Timely title assembling the combined knowledge of some of the leading authorities in the field of small fish reproduction - an important topic for risk assessment and registration of chemical, agricultural, and pharmaceutical compounds Provides guidance on the microscopic structure of living tissue and evaluation of the reproductive glands of small laboratory fish Includes state-of-the-art science along with sufficient anatomical and physiological background for understanding and interpreting test results Helps standardize the interpretation of results from aquatic bioassays and field observations, which will also clarify inconsistencies in the current scientific literature Note: CD-ROM/DVD and other supplementary materials are not included as part of eBook file.
Download or read book Salmon Farming written by Odd-ivar Lekang and published by 5m Books Ltd. This book was released on 2022-07-31 with total page 527 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aquaculture production is expanding worldwide in both volume and scope, with a number of new species being introduced to aquaculture every year. Salmon Farming provides an overview of aquaculture production systems focusing on Atlantic salmon farming, which will enable users to: produce broodstock, juveniles and adult fish develop a production plan for juvenile and ongrowing farms evaluate and optimize the key working operations on juvenile and ongrowing farms identify the factors that are important for economic and sustainable production identify the factors that affect the rate of production, how these factors can be changed, and what effects such changes have adopt the best procedures for season-independent smolt production understand water quality requirements and evaluate the suitability based on water analysis prepare documents for production control and propose amendments prepare working plans for smolt production and ongrowing production farms establish maintenance routines/plans for smolt production and ongrowing production estimate the investment and running cost for the main components of smolt and ongrowing farms remain up to date with the laws and regulations that need to be considered in aquaculture production planning internationally stay abreast of new trends in the industry. Salmon Farming gives an overview of aquaculture production systems focusing on Atlantic salmon farming. However, much of the subject coverage and overall structure of the book are directly transferable to other species, with much of the core of the book being species-independent and applicable internationally. 5m Books
Download or read book Sexual Maturation in Atlantic Salmon Salmo Salar L Aspects of Environmental and Hormonal Control written by Geir Lasse Taranger and published by . This book was released on 1993 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Smoltification and Early Sexual Maturation in the Baltic Salmon Salmo Salar L written by Magnus Rydevik and published by . This book was released on 1989 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Incidence and Genetic Implications of Sexual Maturity in Male Atlantic Salmon Parr written by Richard L. Saunders and published by . This book was released on 1978 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Anadromy Versus Residency written by Monika Schmitz and published by . This book was released on 1993 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Management Strategies to Control Sexual Maturation in Sea reared Atlantic Salmon Salmo Salar L written by Eric Leclercq and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Pre-harvest sexual maturation in farmed Atlantic salmon, Salmo salar, remains a key biological bottleneck compromising biomass and financial output, production predictability, environmental respect, stock welfare and the overall sustainability of the on-growing industry. The management practices currently in place are not optimized and events of high maturation rate are still sporadically observed. From an ecological perspective, the escape of reproductively competent, domesticated Atlantic salmon constitutes a threat to the integrity of wild stocks. The forecasted expansion of the Scottish salmon industry compels the need for a comprehensive and more reliable control of sexual maturation. The general aim of this research project was to optimize the current management strategy (windows of light-manipulation and quality grading) and test alternative practices (lighting-technologies, selective harvest and triploidization) in the control of pre-harvest sexual maturation within the Atlantic salmon on-growing industry. In that end, a number of trials were performed using stock reared in sea-cages on a full commercial-scale or in tanks on an experimental scale. The results of this project are organized around three experimental chapters dealing consecutively with body-size dimorphism, grading and harvest quality; light manipulations and triploidy. In each chapter, two original manuscripts either published or in review are included. In addition to these experimental results, a literature review chapter composed of two review papers on the photoperiodic synchronization and developmental regulation of maturation in salmonids and on morphological skin colour changes in teleosts (published) are presented. In the first experimental chapters, we aimed at investigating the possibility of detecting and selectively harvesting a high proportion of sexually recruited fish before flesh quality deterioration. Results clearly showed that body-size dimorphisms between maturity cohorts at the end of the anabolic window of reproduction (June/July) are strong and standard predictors of maturation among related populations with the same freshwater history. Dimorphism can therefore be modelled to easily and accurately estimate maturation rate in a number of discrete rearing-units. If required, a high proportion of sexually recruited fish can be selectively harvested as superior quality product while leaving the immature fish for further on-growing. This provides an alternative to visual grilse grading that is not feasible in large-scale aquaculture systems, prevents downgrading and increases production predictability as compared to emergency harvests. Furthermore, our results showed immature males grow faster than immature females which should be further investigated to fully determine gender specific performances and nutritional requirements. Weight-grading performed earlier in the cycle affects the sex-ratio within individual pens and in turn apparent performance. This work also revealed that Atlantic salmon can exhibit significant variations in skin colouration resembling the onset of nuptial display but that are not related to sexual recruitment and do not correlate with reduced flesh quality. This originates from a lack of purine (silver) pigments which was also identified, to a larger extent, as characteristic of the nuptial display. This suggests a degree of desmoltification in these histologically immature fish. The instrumental colouration of the altered phenotype was shown to be improved towards a more silver-like appearance by direct ice-contact. This knowledge could facilitate post-harvest quality grading towards the most appropriate market channel and increase product acceptance and attractiveness. The second experimental chapter investigated the possibility of improving photoperiodic manipulation used to suppress early maturation, currently applied for 6-months during the second winter at sea using wide-spectrum, high-intensity lighting systems. Our results showed that the window of continuous artificial-light (LL) exposure can be reduced to 4-months following its onset in early January without compromising its efficiency in suppressing pre-harvest maturation. In addition, alternative lighting technologies were also highly potent at suppressing sexual maturation. The mean-irradiance (intensity) generated within a commercial sea-cage was inversely proportional to the suppression of nocturnal plasma melatonin (light perception hormone) and negatively correlates with the maturation rate within the commercial sea-pen. Threshold levels of light-intensity required to achieve optimal (total) suppression of sexual maturation are suggested. Alternative, narrow band-width lighting-technologies (cold cathode and light-emitting diodes) present an array of technical, practical, economic and welfare benefits comparing to the system currently in use. Clear improvements of the photoperiod-manipulation strategy were demonstrated and these would reduce economic and environmental costs but also potential impacts on animal welfare. The third experimental chapter showed the strong potential of sterile-triploid Atlantic salmon stocks both in freshwater and seawater. Triploid out-of-season smolts were produced for the first time using a classical accelerated "square-wave" photoperiod. Triploidization affected the smoltification pattern but had no detrimental effects on freshwater and early seawater performances under both a S0+ and S1 regime. This illustrates the need to adapt the timing of seawater transfer for successfully producing triploid Atlantic salmon post-smolts. Following one year of seawater rearing, the prevalence of external deformities was higher in triploids but remained within acceptable levels. Importantly, the incidence of vertebral deformities and ocular cataract was higher in triploids possibly due to their specific requirements. It is suggested that tailoring the diet to the nutritional requirements of triploids holds strong potential for remediation. This must be addressed if the use of sterile-triploid stock is to become a commercial reality. The present research project provides means to optimize the maturation management strategy within the Atlantic salmon on-growing industry through light-manipulation, maturation detection and selective harvest, and quality grading. Proposed improvements have the potential to increase biomass and financial output, production predictability, environmental respect and animal welfare and will allow standardization of the overall control of pre-harvest sexual maturation. Their implementation provides a comprehensive strategy likely to favour a sustainable expansion of the Atlantic salmon industry. From a longer term perspective, the rearing of sterile-triploid stocks is promising and should be actively investigated to isolate domesticated strains from their wild conspecifics. This would also eliminate the need for on-growers to deploy a maturation management strategy that that might still affect stock welfare and remains, despite the strong improvements demonstrated, not 100% reliable, costly, technical and protracted.
Download or read book Sexual Maturation and Smoltification in Baltic Salmon Salmo Salar written by Ingemar Berglund and published by . This book was released on 1991 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evolutionary Biology of the Atlantic Salmon written by Tomislav Vladić and published by CRC Press. This book was released on 2015-08-10 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atlantic salmon (Salmo salar, L) is an anadromous species contributing to major fishery catches and comprising a significant part of the aquaculturally produced fish for human consumption. The aim of this book is to incite the interest in the field of knowledge gathered from a broad scope of disciplines that have investigated this fish species. Und
Download or read book Parr smolt Transformation in Nonanadromous Atlantic Salmon Salmo Salar and Effects of Sexual Maturation on the Parr smolt Transformation in Male Anadromous Atlantic Salmon written by Timothy Peter Birt and published by . This book was released on 1985 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spawning Migration of the European Eel written by Guido van den Thillart and published by Springer Science & Business Media. This book was released on 2008-12-18 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: Freshwater eels are almost infinitely improbable creatures. They spawn and die in the middle of the ocean, often associated with undersea mountains. Their tra- parent, leaf-like larvae move with ocean currents for months or years until they approach the mouths of freshwater rivers. Then they undergo a dramatic transf- mation in morphology, physiology and behavior. They move from their planktonic oceanic environment, migrate upstream and live for several years as apex fre- water predators. Then, almost impossibly, as they become sexually mature, they reverse their migration downstream to the ocean and back to spawning grounds to complete their life cycle. The dramatic changes in their life cycles are incredible. The efforts to unravel the details of their life history have been truly daunting. Much of the past research was the work of dedicated individuals who devoted their lifetime research to these fishes. Freshwater eels merit a separate chapter in almost any textbook dealing with ichthyology, marine biology or animal migration. We know a great deal about some aspects of the biology of freshwater eels. However, our understanding of their bi- ogy still resembles a work of art as much as a work of science. To some it appears like the sweeping brush strokes of a Japanese Zen landscape, to others it resembles the work of a French impressionist, and to still others it appears as magic realism.
Download or read book Age Growth and Mortality of Juvenile Atlantic Salmon in Streams written by Patrick W. Bley and published by . This book was released on 1987 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ecology of Atlantic Salmon and Brown Trout written by Bror Jonsson and published by Springer Science & Business Media. This book was released on 2011-05-03 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt: Destruction of habitat is the major cause for loss of biodiversity including variation in life history and habitat ecology. Each species and population adapts to its environment, adaptations visible in morphology, ecology, behaviour, physiology and genetics. Here, the authors present the population ecology of Atlantic salmon and brown trout and how it is influenced by the environment in terms of growth, migration, spawning and recruitment. Salmonids appeared as freshwater fish some 50 million years ago. Atlantic salmon and brown trout evolved in the Atlantic basin, Atlantic salmon in North America and Europe, brown trout in Europe, Northern Africa and Western Asia. The species live in small streams as well as large rivers, lakes, estuaries, coastal seas and oceans, with brown trout better adapted to small streams and less well adapted to feeding in the ocean than Atlantic salmon. Smolt and adult sizes and longevity are constrained by habitat conditions of populations spawning in small streams. Feeding, wintering and spawning opportunities influence migratory versus resident lifestyles, while the growth rate influences egg size and number, age at maturity, reproductive success and longevity. Further, early experiences influence later performance. For instance, juvenile behaviour influences adult homing, competition for spawning habitat, partner finding and predator avoidance. The abundance of wild Atlantic salmon populations has declined in recent years; climate change and escaped farmed salmon are major threats. The climate influences through changes in temperature and flow, while escaped farmed salmon do so through ecological competition, interbreeding and the spreading of contagious diseases. The authors pinpoint essential problems and offer suggestions as to how they can be reduced. In this context, population enhancement, habitat restoration and management are also discussed. The text closes with a presentation of what the authors view as major scientific challenges in ecological research on these species.
