共查询到20条相似文献，搜索用时 23 毫秒
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Roberto Mendoza Alfaro Carlos Aguilera González & Allyse M Ferrara 《Aquaculture Research》2008,39(7):748-763
Many lepisosteid populations in North America have declined and many are now threatened as a consequence of habitat loss and alteration and commercial and sport overfishing. Over the last two decades, morphological, histological and molecular studies allowed distinguishing between different phases of development and the nutritional condition of larvae. Ontogeny of the digestive enzymes of gar larvae indicated the possibility to feed them artificial feeds since early developmental stages. An in vitro digestibility system to test different feed ingredients has been used. Important characteristics of artificial diets were identified through different feeding experiments. Endocrinological studies showed the feasibility of altering larval development and the digestive capacity of larvae. Cloning of gar growth hormone opened new avenues to enhance growth in the gars. Plasmatic vitellogenin was isolated and purified, to develop a competitive enzyme‐linked immunosorbent assay, which allowed the straightforward separation of males from females to establish appropriate proportions for reproduction and also was used to evaluate hormonal protocols to induce gonad recrudescence and spawning. This review analyzes the biology, ecology and physiology of different gar species as a basis for their domestication, mass production of larvae for repopulation experiments and for the culture of commercial‐size gar. 相似文献
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Abstract. Cyprinid herpesvirus 1 (CHV) or Herpesvirus cyprini was virulent for carp, Cyprinus carpio L., fry following 1 h immersion in water at 20 °C. Cumulative mortality for carp fry was 86–97% in 2-week-old common carp, 20% in 4-week-old fancy carp, and 0% in both 8-week-old common and fancy carp. The virus did not produce mortality in fry of crucian carp, grass carp or other cyprinids. It was also oncogenic in carp, inducing papillomas to the extent of 55% among both common and fancy carp fry. The neoplasms appeared 5–6 months after carp had been exposed to the virus by immersion and recurred at an incidence of 83% in carp 7·5 months post-desquamation of the tumour. The CHV was reisolated from all moribund fish and from all survivors. It also induced papillomas at an incidence of 13% in adult mirror carp and at 10% in adult fancy carp 5 months after intraperitoneal inoculation of 105 TCID50 ml-1 fish. The virus was rcisolated only from the ncoplastic tissue and not from internal organs. The neoplasms were normally located on fin, skin or mandible, at the intraperitoneal inoculation site. Specific fluorescence for CHV antigen was frequently detected in the gills, liver, kidneys and intestine of 2-week-old fry from 3 to 21 days following challenge with CHV. It was found in greater concentrations in experimentally induced papillomata on 2-week-old carp fry survivors examined 24 weeks after challenge than in naturally occurring neoplasms. 相似文献
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Cichlid biogeography: comment and review 总被引：4，自引：0，他引：4
Prosanta Chakrabarty 《Fish and Fisheries》2004,5(2):97-119
Phylogenetic analyses dealing with disjunct distributions (distributions that require marine dispersal or vicariant events) are reviewed for the Cichlidae. The most corroborated relationship between clades across a Gondwanan disjunction is the sister relationship between Indian and Malagasy cichlids. The minimum age of the Cichlidae as implied by the fossil record is at odds with the timing of the Cretaceous break of the Indian–Madagascar landmass. All well sampled phylogenies for this group fit a pattern reflecting Gondwanan break‐up. Grounds for strictly dispersalist hypotheses are not well founded for any cichlid disjunct distribution, leaving vicariance alternatives as the only explanation. 相似文献
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Aphanomyces astaci: isolation and culture 总被引：1，自引：0，他引：1
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Shrimp and fish pond soils: processes and management 总被引：7，自引：0，他引：7
The pond bottom soil and the accumulated sediments are integral parts of ponds. Concentrations of nutrients, organic matter and microorganism density in the pond bottom are several orders of magnitude greater than in the water. The accumulation of organic sediments may limit pond intensification. The intensive organic matter degradation at the pond bottom and high sediment oxygen demand exceeds the oxygen renewal rate. This leads to the development of anoxic conditions in the sediments and at the sediment–water interface. A series of anaerobic processes, affected by the redox potential of the system, are taking place. A large number of potentially toxic materials are generated. Among those are organic acids, reduced organic sulfur compounds, reduced manganese and sulfides.
Shrimp, as animals that normally live on or near the bottom, are exposed to conditions on the pond bottom. Exposure to toxic materials endanger the well being of the cultured shrimp. Reduced feeding, slower growth, mortality and possibly higher sensitivity to disease are reported.
The rational use of aerators to minimize the area of sludge accumulation, construction of ponds to trap sludge, stirring sediments, chemical poising of the redox system and environmentally accepted treatment and reuse of drained sediments are means to control the conditions at the pond bottom. 相似文献
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主要论述了海洋与渔业应急预案编制的指导思想与理论基础,并就海洋与渔业应急预案编制的程序体系,以及四类不同的海洋与渔业突发公共事件应急预案的编制内容等问题进行了较为全面地归纳与系统地阐述。 相似文献
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Depensation: evidence, models and implications 总被引：5，自引：0，他引：5
We review the evidence supporting depensation, describe models of two depensatory mechanisms and how they can be included in population dynamics models and discuss the implications of depensation. The evidence for depensation can be grouped into four mechanisms: reduced probability of fertilisation, impaired group dynamics, conditioning of the environment and predator saturation. Examples of these mechanisms come from a broad range of species including fishes, arthropods, birds, mammals and plants. Despite the large number of studies supporting depensatory mechanisms, there is very little evidence of depensation that is strong enough to be important in a population's dynamics. However, because factors such as demographic and environmental variability make depensatory population dynamics difficult to detect, this lack of evidence should not be interpreted as evidence that depensatory dynamics are rare and unimportant. The majority of depensatory models are based on reduced probability of fertilisation and predator saturation. We review the models of these mechanisms and different ways they can be incorporated in population dynamics models. Finally, we discuss how depensation may affect optimal harvesting, pest control and population viability analysis. 相似文献
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J. R. Tomasso 《Aquaculture International》2012,20(6):1107-1116
During the past four decades, researchers have gained a good understanding of the effects of environmental nitrite on cultured aquatic animals and how to manage elevated environmental nitrite concentrations by the addition of chloride to the environment. Our understanding of the mechanisms of nitrite toxicity has largely paralleled the development of an understanding of chloride influx mechanisms in aquatic organisms. We need to expand our phylogenetic understanding of chloride influx mechanisms in order to predict nitrite resistance in taxa that are being considered for aquaculture. A better understanding of the role of salinity in modulating nitrite toxicity in euryhaline species is also needed. 相似文献
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海洋生物资源增殖放流回顾与展望 总被引：14，自引：6，他引：8
海洋生物资源增殖放流是一项实现海洋渔业可持续发展的重要管理措施。本文简要回顾了海洋生物资源增殖放流的发展历史,分析了过去一百多年来各国增殖放流实践中的经验和教训,同时介绍了当前倡导的负责任海洋生物资源增殖放流理念,以期为中国今后的增殖放流工作提供参考与借鉴。 相似文献
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Fisheries Science - Cytokines are low molecular weight glycoproteins involved in the regulation of the immune system, and more than 100 cytokines have hitherto been identified in humans. Cytokines... 相似文献
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B. Chevassus 《Aquaculture (Amsterdam, Netherlands)》1979,17(2):113-128
This report presents a critical review of interspecific hybridization in salmonids and discusses the potentiality of hybrids for water management and fish farming. 相似文献
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Dale Squires 《Fish and Fisheries》2010,11(4):366-387
Buybacks of fishing vessels, licences, access and other rights, and gear, sometimes called decommissioning schemes, have traditionally been a key policy tool to address overcapacity, overexploitation of fish stocks, and distributional issues in fisheries. Two more issues can be added, sustainable use of ecosystems and conservation of biodiversity (i.e. ecological public goods and services) and providing a transition to a more rationalized fishery. This study discusses reasons for buybacks; examines consequences; considers asymmetric information, design of buyback auctions and other design issues; buybacks as a transition to a rationalized industry with strong property rights and governance, financing and transnational fisheries; draws out key lessons from the international experience; and provides an overall evaluation. 相似文献
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