共查询到20条相似文献,搜索用时 10 毫秒
1.
Mayara de Moura Pereira Mariana Machado Evangelista Enric Gisbert Elizabeth Romagosa 《Aquaculture Research》2019,50(8):2181-2190
The aim of this study was to assess the activity of gastric, pancreatic and intestinal digestive enzymes during the embryonic and larval development of Nile tilapia (Oreochromis niloticus) GIFT strain Aqua America® 1 obtained from a broodstock fed two levels of crude protein (CP). A total of 72 females and 24 males, 10 hapas, two CP levels (32% and 38%) and six phases of embryonic (cleavage, blastula, gastrula) and larval (hatching, 7 and 10 days post hatch, dph) stages were used. The eggs were collected in cleavage, blastula and gastrula stages, 300 mg was collected, and kept in cryogenic tubes in liquid nitrogen. For the samples at larval stage, the remaining eggs were separated according to crude protein level and kept in hatcheries and samples were collected on 7 and 10 dph the same way as before. A total of 48 samples were collected: at each protein level (32% and 38% CP), four samples were collected in each phase of embryonic and larval development. Statistical differences were not observed during embryonic development for acid proteases, trypsin, amylase and lipase activity at both levels of crude protein (32 and 38% CP). Differences for acid proteases were noticed on 7 dph; trypsin and amylase on 7 dph and 10 dph. Significant differences on blastula and 7 dph for protease; as for aminopeptidase, there was significant difference on 7 dph. The data indicated early appearance of digestive enzymes in Nile tilapia broodfish receiving 32% CP taking into account the rapid growth and development of this species. 相似文献
2.
Historical aspects, current status and prospects of pejerrey aquaculture in South America 总被引:1,自引:0,他引:1
Gustavo M Somoza Leandro A Miranda Gustavo E Berasain Darío Colautti Mauricio Remes Lenicov & Carlos A Strüssmann 《Aquaculture Research》2008,39(7):784-793
The pejerrey Odontesthes bonariensis (Valenciennes, 1835) is an inland water fish from the Pampas region comprising part of Argentina, Uruguay and the South of Brazil. Pejerrey is a very popular fish in this region and has a long history of domestic and international introductions, which attests to the high quality and market value of its flesh, as well as its attractiveness as a game fish. The desirable characteristics of pejerrey also make it a good candidate for aquaculture, and the first trials on pejerrey cultivation (atheriniculture) were started more than a century ago in Argentina. In spite of the considerable interest in its development, little progress has been made and atheriniculture is still restricted to propagation and stocking for sport fishing purposes. In this review, we summarize the history of atheriniculture and the biological, technological, scientific, cultural and infrastructural constraints to pejerrey aquaculture development thus far. We also suggest possible scenarios of pejerrey aquaculture development compatible with the socio–economic conditions of South American countries. Our projections also take into consideration recent scientific findings on the biology of pejerrey and technological advances in seafood processing, storage and transportation, as well as the latest trends of seafood consumption and international markets. The best production strategy remains to be determined by trial and error but it is likely that, initially, production should focus on a differentiated, high‐quality fish for the premium or international markets rather than attempting to compete with the cheap fish from natural sources. An international cooperation project with Japan has successfully demonstrated the feasibility of breeding pejerrey in captivity and mass producing seeds efficiently in Argentina, and has provided the foundation for the development of intensive and extensive farming of this species. 相似文献
3.
本文分析了养殖水体氮转化过程中可能产生N_2O的环节,总结了关于水产养殖活动中N_2O排放量的相关研究进展。结果表明,养殖过程中的N_2O排放系数总体上低于废水处理过程中的N_2O排放系数;不同的养殖模式氮的利用效率及未被利用的氮的去向有较大差别,其中循环水养殖模式的氮处理过程最接近于废水处理厂中的处理途径,但循环水养殖产量占全球水产养殖产量的比例较低,且现有水产养殖总产量中约有一半的渔获物不需要投饵,因此,基于废水处理厂的N_2O排放系数和总养殖产量的N_2O排放量的估算会明显高于实际排放量。目前尚缺乏关于水产养殖N_2O产生的基础性研究,本研究未进行相关估算。应尽快开展水产养殖活动中产生N_2O的系统性研究,为客观评估养殖活动N_2O的排放提供理论支撑。 相似文献
4.
Organic aquaculture has lagged behind the agriculture sector in terms of the quantities and diversity of certified organic products because of the absence of detailed accepted standards and criteria until recently. The main challenges for organic aquaculture are to improve the coordination between production and market and to achieve an appropriate framework to drive further development. Priorities for research include organic feeds and fish nutrition, consumers’ needs, food safety, environmental concerns and trade issues. In organically cultured fish, differences in feeds and nutrition compared to conventional systems are likely to result in differences in the quality of the flesh, and this is a significant factor in consumer choice. The review covers aspects of current use of eco‐certification, formulated feeds, feed composition, aquafeed technology, sustainable alternatives to common feed ingredients, nutritional physiology and general nutritional principles and product quality in the context of the organic aquaculture. There is a future for the development of organic aquaculture but its success depends on new knowledge and technical development to meet consumers’ growing interest. The industry has to utilize the research results and update and modify the criteria and standards and thus provide high‐quality products. 相似文献
5.
2010—2013年,对神农架林区玉泉河、长坊河的齐口裂腹鱼(Schizothorax prenanti)的生物学进行了调查,并对其人工繁殖技术进行了多次尝试。对166尾野生齐口裂腹鱼样本的生物学研究表明:神农架齐口裂腹鱼在自然环境中生长缓慢;雌雄性比为1.79∶1;卵径在2.05~3.13 mm之间,平均值为(2.68±0.448)mm;Ⅳ期卵巢成熟系数4.90%~19.44%,平均(11.12±5.07)%;绝对繁殖力在1 316~11 070粒之间,平均(4 259±2886)粒,相对繁殖力为(12.83±5.67)粒/g。流水池塘培育齐口裂腹鱼,运用雌鱼尾柄粗糙程度判断雌鱼成熟度,选择成熟度好的雌雄亲鱼,用LHRH-A2和鲤脑垂体人工催产,有效催产剂量为LHRH-A2(30~40)μg/kg+鲤鱼脑垂体(2.5~3.0)mg/kg;单用LHRH-A2为60μg/kg。适时人工授精,受精卵在孵化箱内孵化。2010~2013年,共计催产18批次,结果为:催产率89.12%,受精率90.11%,孵化率88.32%。 相似文献
6.
Lydia M. Vasilyeva Ashraf. I. Gh. Elhetawy Natalia V. Sudakova Svetlana S. Astafyeva 《Aquaculture Research》2019,50(4):979-993
Since natural sturgeon populations have drastically declined, aquaculture of these valuable fish is important to meet the ever‐increasing demand for meat and caviar, thereby reducing the pressure on natural sturgeon resources. There are two directions in sturgeon aquaculture: controlled propagation for release and commercial farming. The controlled propagation supports the conservation of natural fish populations, while the commercial cultivation of sturgeons supplies the needs of the consumer market with the delicacy production of caviar (mainly). This review deals with the current status of the controlled propagation and stocking in the Volga‐Caspian basin and the commercial farming of sturgeons in Russia. The article also investigates the management of farmed broodstocks of sturgeons, which are used for obtaining seedlings and caviar. It is for sure that the active and continuous development of the two directions of sturgeon aquaculture will allow preserving these unique ancient fish on our planet until natural populations can be re‐established by self‐sustaining populations. 相似文献
7.
2001年3月由美国缅因州引进美国金鳟(Oncorhynchus mykiss Walbaum)发眼卵10万粒。孵化水温为2~8℃,流水中进行,孵出仔鱼在3~17℃水温条件下进行人工养殖,培育出3龄鱼,对其生长发育、摄食、形态、生物学以及养殖环境等因素进行了初步的观察和研究。 相似文献
8.
9.
10.
以温州市洞头区人工养殖羊栖菜和野生羊栖菜为研究样本,详细描述了羊栖菜成熟孢子体有性生殖,假根与侧生枝无性生殖的繁殖生物学特征和生活史流程。详细记录了羊栖菜卵、精子和受精卵的减数分裂和有丝分裂过程,假根、茎(主茎和侧生茎)、叶(气囊)和生殖托(雌托和雄托)等4类器官生长、发育和分化过程,胚、幼孢子体和成熟孢子体形态结构特征。在此基础上对现有羊栖菜繁殖生物学特征及生活史流程进行了补充和修正,增加了羊栖菜侧生枝无性生殖和羊栖菜幼孢子体期有性生殖的相关内容,并重新绘制了羊栖菜生活史流程图。该研究结果将为开展羊栖菜养殖生态学研究,深层次解析羊栖菜生殖节律、种群繁衍与环境关系奠定基础。 相似文献
11.
12.
13.
14.
团头鲂是我国主要的淡水养殖鱼类之一,其具有食性广、养殖成本低、生长快、成活率高、易捕捞、易繁殖等特点,且具有味美、头小、含肉率高、体形好、规格适中等优点,深受消费者欢迎,在增加优质水产动物蛋白供应、提高全民营养健康水平、保障我国食物安全等方面做出了重要贡献。本文综述了团头鲂全产业链技术研究进展,包括新品种培育及育种技术、饲料营养需求调控及投喂技术、养殖应激与病害的生态防控技术、新型养殖模式、营养品质及加工技术等,提出了具有生产性能优、抗病抗逆性强和适于加工的团头鲂种质资源的挖掘,集约化健康养殖模式建立及精准营养供给、生态防控和高品质加工调理技术的研发等产业发展需求和研究方向,以期为团头鲂全产业链的绿色高质量可持续发展提供参考。 相似文献
15.
Carlos G. Wurmann Raul M. Madrid Andre M. Brugger 《Aquaculture Economics & Management (Blackwell Science)》2013,17(3-4):117-141
Abstract Shrimp farming in Latin America and the Caribbean (hereinafter, LA&C) is a complex, diverse and dynamic activity, occurring in 22 out of 36 countries, producing 231,000 tons, valued at US$ 1.2 billion in 20021. Farmed shrimp represents 52% of all shrimp volumes produced regionally, and almost 18% of all shrimp and prawn (S&P, hereinafter) cultivated worldwide. Whiteleg shrimp (Litopenaeus vannamei) constitutes 91% of all shrimp farmed in LA&C and five nations, led by Brazil ‐formerly by Ecuador‐, comprise 82% of farmed production. Over 90% of LA&C shrimp production is exported (230,000 tons of end products from both aquaculture and wild origin valued at US$ 1.36 billion), generating a trade surplus of US$ 1.28 billion (2002). Farmed shrimp could easily surpass 513,000 tons by 2030, more than doubling current regional figures (2.9% annual growth rate, compounded). However, competition with Asian countries, anti‐dumping accusations and other factors might limit the expansion process, which is increasingly determined by strategically important matters rather than by physical production constraints. Here, a ‘production‐driven’ process of past decades is being replaced by a ‘demand‐led’ situation, where market and marketing issues will increasingly influence the outcome of shrimp farming. Growing market competition will continue to press prices down and industry will be forced into a permanent process to improve competitiveness. Here, development strategies include actions by governments and producer associations, promotional and marketing campaigns and the application of good management practices across the production and distribution chains. 相似文献
16.
综述了开展贝类设施养殖的重要性。介绍了国内外贝类设施养殖产业的发展现状及趋势;列举了我国在贝类设施养殖方面与国外先进技术的差距,包括养殖设施、设备相对落后,机械化、自动化程度不高,水处理技术设备落后,基本为流水式开放系统等;提出了贝类设施养殖产业今后发展的重点任务应主要集中于贝类养殖设施装备与技术的建立和完善,养殖工厂设施设备及生产工艺的标准化设计,贝类养殖适宜生态环境条件的工程调控与优化等,在基础研究方面应重视工程设计的技术原理、贝类生长发育对环境因子胁迫的响应及适应机制、贝类-环境-设施系统综合调控机理研究等。 相似文献
17.
To target development efforts, the technological options for investments in Clarias gariepinus hatchery systems were compared for cost, average weight, number of fingerlings harvested, survival and profitability in periurban Yaoundé, Cameroon. Costs were proportional to the level of intensity of production, with labour accounting for about 70% of the total. Profitability was similar among systems, with highly variable survival being a key constraint. Overall, system profitability was most strongly influenced by the number of fingerlings harvested per m2, regardless of individual average weight. Focusing extension effort on farmers with the capacity to intensify is thus more likely to produce sectoral growth in the short term. 相似文献
18.
中国主要海洋底层鱼类生物学研究的回顾与展望 总被引:2,自引:1,他引:2
回顾了中国海洋主要底层经济鱼类资源生物学的研究历史和科研成果,并重点叙述了带鱼、小黄鱼、大黄鱼和绿鳍马面鲀等重要经济鱼类资源生物学研究概况.概述的内容包括地理种群及其产卵群体的鉴别和划分、生活史型的演变、种群和群体结构、种群数量变动、年龄组成和生长特性、摄食习性、性成熟周期、性腺成熟指数(GSI)、产卵群体生殖力、产卵场、索饵场、越冬场及洄游路线、资源量和渔获量、各种作业渔船的调整及其捕捞力量的限制措施等,并展望了中国海洋底层经济鱼类资源生物学研究的前景. 相似文献
19.
Roberto Mendoza Olga Santillán Agnés Revol Carlos Aguilera Julio Cruz 《Aquaculture Research》2012,43(5):649-661
Alligator gar (Atractosteus spatula) is a non‐teleost bony fish distributed in North America. Gar populations have drastically declined as a consequence of habitat deterioration and the lack of regulation for their capture. Control of reproduction is critical for recovering their natural populations. The impossibility to distinguish genders and the determination of sexual maturity have hindered their successful reproduction. This research was aimed at developing an enzyme‐linked immunosorbent assay (ELISA) for the quantitative estimation of vitellogenin (VTG), a female‐specific protein. Plasmatic VTG from 17β‐estradiol (E2)‐induced juveniles and ovary vitellin from adult females were purified and characterized. Polyclonal antibodies against both proteins were produced to develop an ELISA. The immunoassay was validated by quality tests such as sensitivity, parallelism, recovery, reproducibility and specificity. Vitellogenin was determined in different tissues (plasma, mucus, liver and gills) of alligator gar. Vitellogenin and E2 concentrations in female breeders were found to be higher in November, before the spring spawning season. This approach represents a quick, reliable and non‐invasive practical alternative to distinguish genders and evaluate gonad maturation. 相似文献