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1.
河蟹工厂化育苗中人工半咸水的净化与循环利用研究   总被引：1，自引：0，他引：1  
采用室内、室外大循环的水交换形式，将生物净化和物理、化学处理相结合对河蟹育废水进行净化与循环利用，可提高育苗用水利用率2—3倍。节约配水原料50％以上，同时把生物净化与单胞藻，轮虫的培养结合在一起，既达到了净化育苗废水的目的，又为蟹苗提供了大量的生物饵料．蟹苗成活率较对照池提高2．5％．  相似文献   

2.
河蟹生态育苗的特点即在整个育苗过程不加温，从布苗到大眼幼体不使用抗生素等药物。生态育苗培育的蟹苗体质健壮，生命力强，成活率高，从大眼幼体培育至扣蟹的成活率可达２０％左右。１设施与材料１．１育苗池面积２０～４０m２，水深１m，每单元育苗面积５６０m２。育苗池上方用双层塑料薄膜覆盖，中间内隔３０cm，可起到保温作用。１．２人工配制海水布苗前半个月开始配制人工海水，配制海水用的淡水直接从池塘中打入配水池，不用沉淀和过滤。１．３循环过滤系统由蓄水池、育苗池、排水沟、过滤池组成封闭循环系统。１．４幼体培育的饵…  相似文献   

3.
河蟹育苗试验中,通过在过滤池中接种生物膜,向育苗池及过滤池中施用水质改良菌等方法对育苗水进行生物净化,降低水体中的ＮＯ２－－Ｎ,ＮＨ３－Ｎ等,循环利用配制海水育苗;通过调节水质控制发病率,不施用任何抗生素。结果表明：整个试验过程中育苗用水量减少,各期蚤状幼体发病率降低,Ｚ１￣Ｍ阶段的变态率分别为７８．２％、８７．５％、７３．２％、６２．５％,４２．３％,育苗成活率平均为１２．９％,并减少了药害苗。  相似文献   

4.
河蟹配制海水育苗技术探讨   总被引：1，自引：0，他引：1  
河蟹育苗试验中,通过在过滤池中接种生物膜、向育苗池及过滤法中施用水质改良菌等方法对育苗进行生物净化、有效降低水体中的ＮＯ２－Ｎ、ＮＨ３－Ｎ,并通过调节水质控制发病率,不施用任何抗生素。整个试验过程中育苗用水量减少,各期蚤状幼体发病率降低,Ｚ１－Ｍ阶段的变态率分别为７８．２％、８７．５％、７３．２％、６２．６％、４２．３％。育苗成活率平均为１２．９％。  相似文献   

5.
１试验条件与方法１．１池塘条件养殖池在岚山办事处虎山乡东湖盐场８号池，东西走向，长方形，面积１０亩，水深１．５ｍ，底质为泥沙质。池四周用塑料薄膜围起一道高 ６０ ｃｍ的围栏，防止青蟹外逃。１．２苗种来源蟹苗购于日照水产研究所全人工培育的二期幼蟹，平均壳宽 １．５ ｃｍ。蟹苗箱内铺一层清洗干净的海草，蟹苗经计数后放入蟹苗箱运输。１．３蟹苗放养养殖池提前清淤。晒池一周后，带网纳水 ２０ ｃｍ，亩施生石灰 ２５０ ｋｇ，边施边搅动池底，然后纳水至 ５０ｃｍ肥水。于 １９９８年 ５月 ２６日放养蟹苗 ４ ０００只。１…  相似文献   

6.
庞璞敏 《水产科学》1999,18(2):21-23
用１０００ｍ＾３水体的室内育苗池和６口海水土池糖培育中华绒螯蟹苗,比较两种河蟹人工繁殖技术的生态效益和经济效益。经３５天培育表明,土池培育１ｋｇ大眼幼体可获利２０６３元,比室内育苗获利高４．２倍,产出投入比（２．０７）比室内育苗（１．３３）高４５．７７％。若采用土池育河蟹苗,每年至少可以少排放各种化学药物４２０ｔ。  相似文献   

7.
河蟹常规人工育苗一般在4月底~5月初结束。近年来由于天然蟹苗资源匾乏，越来越多的养殖户购买人工蟹苗进行养殖。培育扣蟹一般购买5－6月人繁的后期蟹苗，因此要求育苗单位保存好抱卵种蟹以生产后期蟹苗。本文就抱卵种蟹的保存技术进行了探索，总结如下。1保存方法1．l抱卵蟹胚胎发育至眼点，个别有心跳，加冷冻海水降温，并维持水温5℃－8℃，20天后拖卵蟹仍可以孵幼育苗。1．2推迟种蟹交配时间，一般在春节后交配，抱卵蟹直接放入低温池中，当水温高于10℃时采用加冰的方法降温，控制水温在8℃－10℃，这样可延迟到5－6月育苗，推迟育苗l…  相似文献   

8.
泥蚶人工繁殖育苗在江苏沿海地区起步较晚，为了综合利用河蟹育苗场，以提高育苗场的经济效益，笔者于２００１年２月～２００１年５月进行了泥蚶早繁育苗技术的试验研究，通过对３５kg（约８４００只）亲蚶的提早升温、促热、催产育苗，最后产苗约５亿粒。现将试验情况报告如下：一、材料与方法１．苗池改造。本试验在江苏省如东县河蟹育苗场进行，选择该场水泥蟹苗孵化池８口（规格为５m×４m×１．５m作为泥蚶育苗池（兼作催产池），用水泥浆将池壁、池底抹平，并在原出水管道上安装可控排水速度的阀门，以便倒池、采苗之需。改造后的育…  相似文献   

9.
一、工厂化育苗主要设施１．育苗室：可利用鱼、虾、贝类育苗室空闲季节进行育苗，也可与其同步进行育苗。若新建成的育苗室，要考虑多功能综合利用。８０％以上的原色玻璃钢波形瓦覆盖顶，室内房顶设置遮光布，门窗挂棉帘，以便调光、保温和通风。２．一级培育池（蚤状幼体～大眼幼体培育阶段）：指室内育苗池，有效水体１０～６０米３之间，水深１．２～１．６米，池底、池壁要求光滑。要安装供热、供水、供气管道系统。池内升温的蒸汽管道宜选用不锈钢管，有关这些管道安装要求坚固安全，便于日常管理操作、维修。３．二级培育池（大眼幼…  相似文献   

10.
在市场经济推动下，河蟹养殖已成为大长市水产养殖的重头戏。我市从95年开始，在省内率先进行早繁蟹苗塑料大棚培育幼蟹试验成功后，在全市迅速推广，97年我市育苗户达105户，大棚面积2．5万平方米，购蟹苗210公斤，育苗平均成活率20％，最高成活率达40％以上。通过塑料大棚的增温作用强化培育早繁蟹苗。经一个多月育成V期以上幼蟹后，放养池塘、湖泊、水库内、当年养成商品蟹上市，缩短了养殖周期，降低了养殖成本，提高了经济效益。笔者根据三年的实践经验和有关资料，就我市塑料大棚培育幼蟹过程中的技术关键探讨如下：一、培育池建造。…  相似文献   

11.
The present study identifies and quantifies appropriate sites for brackish water aquaculture development in southwestern Bangladesh using remote sensing, GPS and geographical information systems (GIS). A colour composite Landsat TM image from 1996 covering the southwestern part of Bangladesh was used to identify the extent of brackish water and to classify land use. The remotely sensed data were complemented by secondary data digitised from a range of sources, including hard copy maps, to create a spatial database that included environmental and infrastructural data. A series of GIS models were developed in order to identify and prioritise the most suitable areas for brackish water shrimp and crab farming. Using qualitative and quantitative output from the models, the benefits of shrimp and crab farming and alternative land uses in the Khulna region were compared, based on gross production, economic output and employment potential. Comparisons were made of brackish water shrimp and crab culture with moderately saline-tolerant tilapia and prawn culture, freshwater carp culture and traditional rice production systems. Shrimp was identified as the most capital intensive and risky production system. Earnings per hectare were a little higher for shrimp culture than for crab culture. The present study demonstrates the usefulness of GIS as an aquaculture planning tool in a region where natural resources are already under considerable pressure.  相似文献   

12.
Abstract— Differences in culture duration, metamorphosis rate and the productivity in hatchery culture of M. rosenbergii using a closed system with natural and artificial brackish water were evaluated. Reuse of brackish water in more than one hatchery cycle was also evaluated. Natural and artificial brackish water constituted the two tested treatments, which were distributed in four independent recirculating systems (tank and respective biofilter). Four batches of cultures were conducted and the 2nd and 4th reused the water from the 1st and 3rd. respectively. Mean duration of the hatchery period was 28 d in natural brackish water and 31 d in artificial brackish water. The metamorphosis rate and the average productivity for the natural brackish water treatment were 74% and 60 postlarvael l, respectively, and values obtained with artificial brackish water were 55% and 44 postlarvae/L. The successful hatchery culture of M. rosenbergii in this specific artificial brackish water suggests its potential use in enterprises located far from the coast. Brackish water can be used in two consecutive cultures without a negative effect on productivity.  相似文献   

13.
The current study combined P and N removal using organic flocculant chemicals and woodchip bioreactors in both freshwater and brackish water (7 ppm) recirculating aquaculture systems (RAS). The use of carbon (C) containing flocculant chemicals in the process was hypothesized to further stimulate C-demanding N removal (denitrification) in bioreactors. The trial of combined P and N removal consisted of four treatments: freshwater and brackish water RAS with and without the addition of supernatant from flocculation process to the woodchip reactor. Duplicate woodchip reactors were used per treatment and the trial was run for six weeks. 56% and 49% of P was removed from fresh and brackish sludge water, respectively. The nitrate-N (NO3-N) removal rate was improved in the treatment when supernatant from flocculation process was used together with RAS discharge water when compared against the control. In brackish water RAS, the improvement was more pronounced (from 6.6–16.5 g NO3-N m−3 d-1) than in freshwater RAS (from 5.1–6.5 NO3-N m−3 d-1). In the freshwater bioreactors using supernatant, N was largely discharged as a nitrite-N (NO2-N). High NO2-N concentrations in freshwater reactors allude to incomplete denitrification reactions taking place. The results suggest that the organic flocculants did provide an additional C source for denitrification, which improved the N-removal process. However, in freshwater RAS this might have been partly due to untargeted processes such as DNRA (dissimilatory nitrate reduction to ammonium), and/or insufficient denitrification reactions taking place (excessive NO2-N production).  相似文献   

14.
河蟹人工育苗池水循环净化处理技术研究   总被引：1，自引：0，他引：1  
采取在养殖池内投放和接触氧化水循环处理装置内接种挂膜光合细菌、硝化细菌和放线菌等环境有益微生物 ,并与微藻、光合细菌等活饵料应用技术相结合的池水净化循环处理技术 ,通过基础试验和生产性试验进行了研究考察 ,结果表明本方法可使育苗池水循环利用 ,降低生产成本 ,减少对周边水环境的污染。试验苗池溶解氧 (DO)高于 7 5mg/L ,氨氮低于 0 5mg/L ,水质明显优于对照苗池 ,符合河蟹育苗要求。试验苗池蟹苗总成活率 19 4 % ,产量 175 8g/m3 ,蟹苗成活率、产量和质量均明显优于对照苗池  相似文献   

15.
This case study looks at changing livelihood strategies of the coastal population in Soc Trang Province in the Mekong Delta, Vietnam, and their impacts on natural resources. It provides an opportunity not only to document the impact of shrimp farming on coastal livelihood but also to better understand the link between brackish water aquaculture development and natural resource use. The approach includes a socio‐economic survey in six villages of the province focusing on risk strategies and livelihood diversification. Shrimp farming was found to be less risky and more profitable for households and private companies with a higher investment capacity than for poorer households. Households facing a high risk in shrimp farming diversified their aquaculture production, with other high‐value species like mud crab and elongated goby as a coping mechanism. The use of natural resources' collection is shifting from home consumption towards market‐oriented sales of juvenile mud crabs, clams or fish (elongated goby) to supply seed for brackish water aquaculture developments.  相似文献   

16.
拟穴青蟹两种养殖模式的比较   总被引：1，自引：0，他引：1  
以拟穴青蟹为主养品种,比较半封闭式养殖模式与传统开放式中水体理化生因子、放养品种的存活率和产量,以探索汕头牛田洋的适宜青蟹养殖模式。经过10个月的养殖试验,半封闭式养殖模式水体理化指标、污染物指标、菌体指标等总体优于开放式养殖模式。半封闭式养殖模式青蟹存活率高出开放式养殖模式66.22%,其他养殖品种的存活率和产量也均高于开放式养殖模式。研究结果表明,与传统的开放式养殖模式相比,半封闭养殖模式能有效降低水体污染指标,提高养殖产量,较为适合在汕头牛田洋青蟹养殖区进行推广。  相似文献   

17.
采用基于Illumina Hi Seq测序平台的高通量测序技术,对拟穴青蟹(Scylla paramamosain)肠道及其养殖池塘水体、底泥中细菌种类及丰度进行了研究。测序结果显示,3个样品共获得有效序列234575条,可聚类于2812个分类操作单元(OTUs),归属于拟穴青蟹肠道、养殖水体、池塘底泥样品的操作分类单元(OTU)个数分别为453、706和2547,其中有184个OTU均能在3个样品中检测到,在青蟹肠道和养殖水体、青蟹肠道和池塘底泥中分别检测到197和309个共有OTU。物种注释结果显示,拟穴青蟹肠道中优势细菌种类为变形菌门(Proteobacteria)(39.96%)、柔膜菌门(Tenericutes)(23.09%)和厚壁菌门(Firmicutes)(16.58%);养殖水体中优势细菌种类为变形菌门(63.02%)、放线菌门(Actinobacteria)(24.96%)和拟杆菌门(Bacteroidetes)(8.41%);池塘底泥中优势细菌种类为变形菌门(75.23%)、拟杆菌门(5.72%)和放线菌门(3.83%)。此外,对各样品中丰度最高的前10位OTU分析显示,不同样品中占优势地位的10种细菌在数据库(SILVA)缺乏相关已知序列,并且各样品中的优势细菌种类完全不同。实验结果表明拟穴青蟹肠道与其池塘养殖环境中菌群结构存在着密切的相关性,但肠道菌群同时具有一定的独立性,其优势细菌种类与养殖环境中优势细菌种类无关。本研究旨在为拟穴青蟹健康养殖和微生态调控提供实验依据。  相似文献   

18.
Nitrate reducing potency of 88 bacterial isolates segregated from marine and brackish water nitrifying bacterial consortia (NBC), generated for activation of nitrifying bioreactors, was confirmed by determining the nitrate reducing capability under aerobic conditions as maintained in nitrifying bioreactors. All the isolates had the potential to be used as bio‐augmentors for activating nitrate dissimilation in recirculating aquaculture system. The existence of nitrate reducers with nitrifiers in NBC and in the reactor configuration negates the requirement of integrating anoxic denitrifying system for effective removal of NO3?‐N. Phylogenetic analyses of representative isolates from each cluster of the dendrograms generated based on phenotypic characterization and amplified ribosomal DNA restriction analysis revealed profound diversity of nitrate reducing bacterial flora in the NBC. They were composed of Streptomyces enissocaesilis, Marinobacter sp., Pseudomonas sp., Microbacterium oxydans, Pelagibacterium halotolerans and Alcanivorax dieselolei from marine NBC and Streptomyces tendae, Nesterenkonia sp., Bacillus cereus, Microbacterium oxydans and Brevibacterium sp. from brackish water NBC. The diversity indices of the consortia were calculated using Mega 5.0, primer 7 and VITCOMIC softwares. Marine NBC exhibited higher Shannon wiener diversity and mean population diversity than brackish water NBC. The study delineated higher species richness and diversity in marine NBC than in its brackish water counterpart, a possible reflection of the higher biodiversity of marine systems, and hence, the former is more promising to be used as start‐up cultures for the activation of nitrifying bioreactors after appropriate acclimatization to the desired salinity.  相似文献   

19.
湖区河蟹群体通常由三个年龄组组成。造成河蟹资源量年变化有三方面原因。影响其资源盛衰主要有十大因素。秋冬季河蟹捕获量中Ⅱ秋龄占多数达61.68％。蟹苗放流后的回捕指数400～800,回捕率2～4％。放流效果由湖区饵料基础、放流密度、栖息环境、水位变动、潮泊性状和人为伤害等条件决定。  相似文献   

20.
An epizootic outbreak of the parasitic barnacle, Polyascus gregarius, was reported for the first time in cultured commercial mitten crab, Eriocheir sinensis. Observations were made in a freshwater culture pond in Shenjia Dang, Zhejiang province, China, from June to October 2007. The surface morphology and appearance of the interna, externa, or scar of P. gregarius were recorded in 1464 crabs, including 871 males and 593 females. Overall prevalence of infection was 37.8 and 31.7% in male and female crabs, respectively. The monthly variation of infection was mainly dependent on the mortality of the host, with the highest prevalence (58.0% of males and 51.3% of females infected) in June, and the lowest (13.4% of males and 6.3% of females) in October. A host with multiple externae or scars was encountered frequently, with the maximum of 28 externae or 19 scars on a single crab. Being restricted in the culture pond, the hosts could not escape and return to the brackish water of the estuary; therefore, the externae were never exposed to male cyprids and remained unfertilized. As a result, all the externae degenerated and dropped off finally after 2–3 mo. This parasite caused castration, anecdysis, and increased mortality in the host, and therefore, had both direct and indirect effects on the commercial culture of E. sinensis. Infected males were castrated and displayed morphological modifications of secondary sexual characters. The size of infected crabs was significantly smaller than that of uninfected crabs because the molting was reduced by infection. After all the externae dropped off, the scarred host crabs finally died. A high mortality (possibly >50%) due to parasitism was observed in this study.  相似文献   

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