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1.
Although aquatic species cryopreservation protocols have been studied around the world over the past 60 yr., germplasm repository development efforts and commercialization have begun only recently. The goal of this project was to develop a self‐contained mobile laboratory for on‐site high‐throughput cryopreservation of aquatic species. The objectives of this study were to: (1) identify how a mobile laboratory would function in different operational scenarios, (2) customize an enclosed cargo trailer to function as a mobile laboratory, (3) evaluate the laboratory layout and ability of cryopreservation equipment to operate from generator power, and (4) document the investment costs for private and public groups to integrate a mobile laboratory into an existing cryopreservation facility at three levels of automation and estimate the total cost per trip based on hypothetical assumptions for two scenarios (aquaculture production and repository development). There were three operational designs identified for the mobile laboratory: (1) self‐contained work inside the unit using generator power, (2) work inside the unit using external facility power, and (3) using the equipment inside of a host facility. The investment costs for a base‐level mobile laboratory ranged between US$5670 and US$5787 for private groups and between US$5208 and US$5315 for public groups. With the addition of a range of automated processing equipment, total investment costs ranged from US$13,616 to US$103,529 for private groups and US$12,494 to US$94,891 for public groups. The total cost per trip to cryopreserve sperm of 59 blue catfish, Ictalurus furcatus, males to produce 6300 0.5‐mL French straws was estimated to range from US$6089 to US$14,633 for private and between US$5703 and US$16,938 for public groups depending on the level of automation. Total cost per trip to cryopreserve sperm of 500 males of five different species in the genus Xiphophorus to produce 641 0.25‐mL French straws was estimated to range from US$6653 to US$7640 for private and US$7582 to US$8088 for public groups depending on level of automation. Overall, a commercial‐scale mobile laboratory was developed that can assist current germplasm activities and support future repository and industry development, and the layout information provided can help others to design and build comparable units.  相似文献   

2.
Emerging commercial‐level technology for aquatic sperm cryopreservation has not been modelled by computer simulation. Commercially available software (ARENA, Rockwell Automation, Inc. Milwaukee, WI) was applied to simulate high‐throughput sperm cryopreservation of blue catfish (Ictalurus furcatus) based on existing processing capabilities. The goal was to develop a simulation model suitable for production planning and decision making. The objectives were to: (1) predict the maximum output for 8‐h workday; (2) analyse the bottlenecks within the process, and (3) estimate operational costs when run for daily maximum output. High‐throughput cryopreservation was divided into six major steps modelled with time, resources, and logic structures. The modelled production line processed 18 fish and produced 1164 ± 33 (mean ± SD) 0.5‐mL straws containing one billion cryopreserved sperm. Two such production lines could support all hybrid catfish production in the United States and 15 such lines could support the entire channel catfish industry if it were to adopt artificial spawning techniques. Evaluations were made to improve efficiency, such as increasing scale, optimizing resources, and eliminating underutilized equipment. This model can serve as a template for other aquatic species and assist decision making in industrial application of aquatic germplasm in aquaculture, stock enhancement, conservation and biomedical model fish.  相似文献   

3.
Infrastructure development and overfishing in the Amazon make it imperative to define adequate scales for the ecosystem‐based management of commercial fisheries and the wetlands on which they depend. We mapped fisheries and fish ecology data from Brazil, Peru, Bolivia and Colombia to an explicit GIS framework of river basins and mainstems. Migratory species account for more than 80% of the known maximum catches of commercial fisheries across the Amazon. Of these migratory species, we nominated six long‐distance migratory fish taxa as flagship species to define the two main commercial fishery regions. The migrations of at least one goliath catfish species define a large‐scale longitudinal link joining the Andes, Amazon Lowlands and Amazon River estuary. Migratory Characiforms demonstrate interbasin wetland connectivity between nutrient‐rich and nutrient‐poor rivers over at least 2 million km2, or about one‐third of the Amazon Basin. We show that flooded forest area is the most important wetland variable explaining regional variations in migratory characiforme biomass as indicated by maximum annual fishery catches. The sustainable management of Amazon fisheries will require transnational cooperation and a paradigm shift from local community management alone to a more integrated approach that considers both rural and urban consumers and challenges, and the realistic life histories of migratory species.  相似文献   

4.
Cryopreservation of aquatic invertebrate semen: a review   总被引:8,自引:0,他引:8  
Research on cold storage and cryopreservation of aquatic invertebrate spermatozoa is reviewed in this paper. A few studies are available on the cryopreservation of aquatic invertebrate semen. These have been limited to echinoderms (sea urchin, sand dollar and starfish), molluscs (oyster and abalone), polychaetes and crustacea (shrimp and crab). In fact, only about 30 species have been investigated to date, and research has been primarily concentrated on the spermatozoa of the oyster. Although aquaculture of decapod crustaceans has become very important, information on sperm biology is limited, and sperm preservation techniques are sparse. The sperm of decapod (shrimp and crab) crustaceans are aflagellate and non‐motile, and eggs are not readily available. One of the main reasons for the problems in the cryopreservation of crustacean sperm is considered to be the lack of reliable viability evaluation. Conclusions and new avenues of future research are proposed.  相似文献   

5.
The commercial‐scale production of fish by use of artificial (induced) spawning would require reliable, large‐volume sources of sperm. Cryopreservation can be used to preserve and store sperm within commercial and research germplasm repositories, but is limited in its application to aquaculture. Straw volume and cooling chamber size restrict the quantity of sperm that can be frozen, and straws must be filled by hand. In contrast, the dairy industry has refined methods for freezing of bull sperm, including automation of straw filling and the use of large cooling chambers. These methods could be used for commercial‐scale cryopreservation of fish sperm, although application would require testing. To supply sperm in large volumes, bags originally developed for swine semen could be cooled using dairy protocols and used as a container for fish sperm. The current study documented the use of commercial‐scale dairy cryopreservation techniques for the production of hybrids of channel catfish Ictalurus punctatus (female) by blue catfish Ictalurus furcarus. Four cryoprotectants (methanol, dimethyl sulfoxide, dimethyl acetamide, and glycerol) were initially evaluated for use with blue catfish sperm. During May 2000 and March to April 2001, suspensions of blue catfish sperm were cryopreserved with 10% methanol in 0.5‐mL French straws and in commercial swine semen bags (Cochette* bags, IMV International. Minneapolis, Minnesota, USA). Cryopreservation took place at a dairy breeding cooperative, using technology employed for bull semen. Sperm motility before freezing was 26 ± 18% during Year 1 (2000) and 62 ± 30% during 2001. Sperm were thawed at 40 C and used to fertilize the eggs of channel catfish (yielding hybrids). Motility after thawing for sperm frozen in 0.5‐mL straws was 11 ± 10% during 2000 and 50 ± 24% during 2001. Motility after thawing was 41 ± 17% for sperm frozen in swine semen bags in 5‐mL aliquots and 43 ± 10% for sperm frozen in 10‐mL aliquots. Neurulation of eggs fertilized with thawed sperm from straws was 83 ± 13% during 2000 and 54 ± 27% during 2001. Neurulation was 57 ± 24% using sperm frozen in swine semen bags in 5‐mL aliquots and 55 ± 10% using sperm frozen in 10‐mL aliquots. There was no correlation between sperm motility before freezing (in 0.5‐mL straws) and after thawing during 2000 (r= 0.52) or during 2001 (r= 0.49). In addition, there was no correlation between initial motility and neurulation of channel catfish eggs fertilized using thawed sperm during 2000 (r= 0.14) or during 2001 (r= 0.29). Sperm of blue catfish can thus be cryopreserved at a commercial scale using dairy protocols and can be made available for the production of hybrid catfish when viable eggs are available.  相似文献   

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This study provides an overview of successful genetic improvement programmes for important farmed aquaculture species in Asia, with a focus on lessons and experiences gained as well as challenges remaining. In both fish and prawns (Macrobrachium rosenbergii), conventional selective breeding approaches have resulted in significant improvement in productivity, with genetic gains ranging from 8 to 12% per generation. Selection for high growth has also brought about beneficial changes in fillet weight of fish and edible meat in prawns without detrimental effects on flesh quality attributes and fitness‐related traits. Genetically improved animals show remarkable vigour and high adaptation to a range of culture environments/conditions in Asian countries. Despite these successes, however, the conduct and practical implementation of such breeding programmes still present several challenges. These include the expansion of breeding objectives, management of inbreeding in closed‐selection populations, controlling the effects of genotype by environment interactions, simultaneous production of large number of full‐ and half‐sib families for species with asynchronous spawning behaviour, maintaining pedigree records, dissemination of the improved strains for widespread production, as well as a reluctance by many to carry out systematically designed genetic improvement for aquatic animal species. There are also challenges with regard to the application of genomic information in genetic enhancement programmes and the development of genetically improved strains in response to climate and environmental changes. In this study, each of these challenges is discussed and solutions are proposed to increase efficiency of future genetic improvement programmes for economically important aquaculture species.  相似文献   

8.
Cryopreservation of sperm in marine fish   总被引:10,自引:0,他引:10  
Since the first work of Blaxter in 1953, fish sperm cryopreservation has been attempted on about 30 marine species. The present paper reviews the techniques used and the results published in these species. Particular attention is paid to the handling procedure of sperm before freezing, the problems of semen ageing and semen contamination with urine. The quality of frozen–thawed semen was evaluated using previously standardized biotests, such as a two‐step motility activation technique adapted for the different species and fertilization assays using a discriminating insemination technique. Most extenders used in marine fish are saline or sugar solutions. From the investigated cryoprotectants, dimethyl sulphoxide (DMSO) generally leads to the best results. Cooling rates range from 8 °C to 99 °C min?1; the thawing rate is generally high. Compared with freshwater species, a high percentage of spermatozoa survives cryopreservation. Therefore, and because of the simplicity of the techniques, the cryopreservation of marine fish sperm is suited for application in aquaculture.  相似文献   

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  • 1. Multivariate analysis of vegetation and water beetles recorded in the abandoned drains and flooded workings of a cut‐over lowland Irish raised bog, Montiaghs Moss, shows that water depth and trophic status are key predictors of plant species composition and that vegetation community structure significantly explains water beetle composition.
  • 2. The spatial distribution of secondary and tertiary drains and peat pits influences species composition indirectly, through trophic status, by connecting habitats with primary agricultural drains passing through the bog.
  • 3. Habitat isolation and the cessation of drain management promote change in the submerged aquatic vegetation, emergent‐swamp and poor‐fen habitats recorded by facilitating vegetation development and surface acidification.
  • 4. The ecological consequences are likely to be a reduction in the area of open‐water habitats, the development of poor‐fen vegetation and the subsequent loss of high conservation value species of plants and beetles.
  • 5. Management for biodiversity conservation should initially address water quality, for example, through the European Union (EU) Water Framework Directive, followed by restoration to promote structural and spatial heterogeneity of drain and peat‐pit habitats.
  • 6. At a landscape scale, implementing ditch and peat‐pit management across abandoned cut‐over lowland raised bog habitats in the farmed Northern Ireland countryside, through EU Common Agricultural Policy agri‐environment schemes, would give regional gains.
Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

11.
1. Tropical aquatic ecosystems are species rich, with high numbers of endemics. Increasing pressure from human activities, including demands for food and energy, growing human population, and economic aspirations, highlights the need for a more concerted effort towards aquatic conservation. 2. Understanding of tropical aquatic ecosystems has developed largely from a northern temperate perspective that might not be always appropriate. Applying classic models of how water bodies function can hinder effective conservation strategies. This is coupled with very incomplete knowledge of species distributions and their ecology. 3. Better understanding of tropical aquatic ecology to guide conservation needs a research agenda that connects more strongly with the social‐ecological realities of tropical ecosystems. 4. Although approaches to conservation may be contested, a fundamental challenge to protection of aquatic habitats is a lack of capacity at the individual and institutional level. Without this, the development of improved techniques and approaches for tropical aquatic conservation will fail to reverse current trends of degradation. Research outputs on tropical aquatic ecosystems remain dominated by institutions based outside the tropics. 5. Building awareness and practice to conserve the aquatic ecosystems of the tropics can be supported through extending the dialogue across sectors and by connecting tiers of governance. An ecosystem services framework that identifies the benefits that humans derive from ecosystems provides a powerful tool, often linked with estimates of economic value. However, this can neglect important regulating services or distract from more fundamental existence value. 6. The preservation of tropical aquatic diversity will only be achieved if recognized as important at all levels, from local to global. Targeted external support can build awareness and capacity, but conserving aquatic ecosystems requires local commitment. Developing community monitoring that provides straightforward information on ecosystem health presents opportunities to connect citizens with the ecosystems that, ultimately, they depend on. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

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The aim of this study was to optimize the cryopreservation protocols for the sperm of red seabream, Pagrus major. The 2‐mL cryovials and programmable freezer were employed for cryopreservation. Six extenders, six cryoprotectants in various concentrations ranging from 6 to 20% (v/v), four cooling rates, and three thawing temperatures were evaluated by postthaw sperm motility and fertility. The ratio of sperm to egg for postthaw sperm fertilization trials was experimentally standardized and was optimal at 500:1. The best motility of postthaw sperm (79.4 ± 4.7% to 88.6 ± 8.0%), fertilization rates (89.6 ± 2.9 to 95.6 ± 1.9%), and hatching rates (85.3 ± 5.1% to 91.4 ± 4.3%) were achieved when Cortland extender, dimethyl sulfoxide (15, 18, and 20%) or ethylene glycol (9, 12%) as cryoprotectants, 20 C/min as the cooling rate, and 40 C as the thawing temperature were employed. Moreover, the results on embryonic development were not significantly different between cryopreserved sperm and fresh sperm during incubation process. In conclusion, these methods of cryopreservation of red seabream sperm are suitable for routine aquaculture application and preservation of genetic resources.  相似文献   

14.
Argopecten nucleus is a small scallop from the Caribbean Sea and a relatively new species for aquaculture. One of the key challenges to develop the farming operations for this species from the current pilot scale to commercial level is to improve its harvest size. In this study, we tested three different methods for triploidy induction. Additionally, the effect of these protocols on survival, developmental rate and size of larvae and post‐larvae were assessed. Three different mechanisms to stimulate the inhibition of the release of the second polar body were tested; (1) cold shock (18°C); (2) 6‐dimethylaminopurine (6‐DMAP); (3) cytochalasin B (CB) and (4) dimethylsulphoxide (DMSO). The treatment with 6‐DMAP yielded the highest percentage of triploid larvae (39%). The survival and development rate, however, were higher in non‐treated larvae (control) than in the treatment groups. Interestingly, larvae from CB and the DMSO control groups exhibited lower growth rates in length than those from control and the other two treatments. No influence of the triploidy induction treatments was observed on post‐larvae survival, but the size of post‐larvae was larger for the cold shock treatment and DMSO control group. Our results indicate that the use of 6‐DMAP has the greatest potential to produce triploid larvae of A. nucleus without affecting negatively growth and survival of post‐larvae.  相似文献   

15.
水产动物育种分析与管理系统的开发和应用   总被引:2,自引:0,他引:2  
针对国内水产动物多性状选择育种研究处于起步阶段的现状,以BLUP遗传评定为核心的水产动物多性状复合育种技术体系为依托,结合国内水产动物育种项目研究,开发了一套适合大多数水产动物育种分析与项目管理的软件系统。该系统是在WindowsXP环境下利用MicrosoftSQLServer2000数据库和基于ObjectPascal语言的DelphiIDE工具开发完成的。主要包括6个功能模块:系统管理、基本信息、种质管理、性能管理、育种分析和销售管理等,覆盖整个育种项目周期,并对流程实行标准化,能够自动化完成种质和性能测定数据的管理、遗传参数估计、育种值计算和配种方案制定等主要工作。软件已经在中国对虾、大菱鲆和罗氏沼虾等育种项目中得到应用,其推广和应用能够有效提升行业的整体育种技术水平,推动我国水产动物育种工作的发展。  相似文献   

16.
The Brazilian freshwater fish diversity is the richest in the world. Only 0.7% of all Brazilian species have had any aspect of their sperm biology addressed up to this date. The majority of the fish species described in this review migrate during the spawning season (a phenomenon known as piracema). Urbanization, pollution, hydroelectric dams and deforestation are some of the causes of stock depletion or even local extinction of some of these species. The knowledge concerning sperm quality and minimum sperm:egg ratio is important to maximize the use of males without reducing hatching rates. Furthermore, sperm cryopreservation and gene banking can guarantee the conservation of genetic diversity and development of adequate breeding programs of native fish species. In this review, we present and evaluate the existing information on Brazilian fish species that have been subject to sperm quality and cryopreservation studies. The following parameters were evaluated: volume of extractable sperm, sperm motility, sperm concentration, freezing media, freezing methods, and post-thaw sperm quality. Although the existing protocols yield relatively high post-thaw motility and fertilization rates, the use of cryopreserved sperm in routine hatchery production is still limited in Brazil.  相似文献   

17.
鱼类配子和胚胎冷冻保存研究进展及前景展望   总被引:25,自引:5,他引:25  
陈松林 《水产学报》2002,26(2):161-168
种质资源是水产养殖生产、优良品种培育及水产养殖业可持续发展的重要物质基础。我国是一个水生生物种质资源较为丰富的国家 ,丰富多样的水生生物种质资源和遗传多样性对于我国水产养殖业的快速发展起到了非常重要的作用。然而 ,由于渔业资源的过度捕捞、无序利用及人工放流等 ,造成了某些鱼类资源的衰退和濒临灭绝 ,如不及时采取保护措施 ,若干年后 ,在自然界中将难以找到上述鱼类原种、良种的遗传资源 ;由于忽视鱼类种质保护及品种选育的工作 ,养殖鱼类近亲交配越来越严重 ,造成种质退化 ,遗传多样性减少 ,生长速度减缓 ,品质下降 ,对病害…  相似文献   

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Fishers’ economic status is hard to assess because fisheries socio‐economic data, including earnings, are often not centrally available, standardized or accessible in a form that allows scaled‐up or comparative analyses. The lack of fishing income data impedes sound management and allows biased perceptions about fishers’ status to persist. We compile data from intergovernmental and regional data sets, as well as case‐studies, on income earned from marine wild‐capture fisheries. We explore the level and distribution of fishers’ income across fisheries sectors and geographical regions, and highlight challenges in data collection and reporting. We find that fishers generally are not the poorest of the poor based on average fishing income from 89 countries, but income levels vary widely. Fishing income in the large‐scale sector is higher than the small‐scale sector by about 2.2 times, and in high‐income versus low‐income countries by almost 9 times. Boat owners and captains earned more than double that of crew and owner‐operators, while income from fisheries is greater than that from agricultural work in 63% of countries in this study. Nonetheless, incomes are below national poverty lines in 34% of the countries with data. More detailed fishing income statistics is needed for quantitative scientific research and for supporting socio‐economic policies. Key gaps to address include the lack of a centralized database for fisheries income statistics and the coarse resolution at which economic statistics are reported internationally. A first step to close the gap is to integrate socio‐economic monitoring and reporting in fisheries management.  相似文献   

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