河蟹真菌病——离壶菌病

我国天然蟹苗逐年减少,且不稳定,已不能适应河蟹养殖发展的需要。目前国内增养殖主要依靠天然海水人工育苗,也有一部分在内地靠人工配制海水育苗, 1999年河蟹苗种生产已达到 180吨以上。在河蟹养殖生产上还存在很多问题,其中河蟹养殖病害问题日趋突出,成蟹养殖的颤抖病造成经济损失 20亿～ 30亿元。在蟹苗生产过程中,河蟹真菌病还没有引起人们高度的重视,其实它对苗种生产造成巨大的经济损失,远远超过河蟹颤抖病。 　　1994～ 1995年在江苏省启东市吕泗港刚开始河蟹人工繁殖时发现在幼体上寄生一种真菌,虽采用孔雀石绿、福尔马…     

大规格种蟹池塘养殖技术研究(上)

中华绒螯蟹又称河蟹、毛蟹、大闸蟹,隶属于十足目、方蟹科、绒螯蟹属,广泛分布于长江中下游两岸江河湖泊。20世纪70年代,随着工业发展带来的污染和长江天然河蟹的大肆捕捞,天然蟹苗日益枯竭,其质量已无法满足河蟹养殖发展的需要;80年代以后我国海水河蟹育苗技术成功并得到推广,河蟹的增养殖规模逐渐扩大,产量持续增加,但养殖出的河蟹依然存在个体规格小、抗病性差等种质资源退化的现象。     

河蟹养殖及蟹文化——河蟹的生物学

河蟹是我国水产养殖的主导品种之一。近几年来，我国的河蟹养殖业发展迅速，河蟹养殖也已形成规模化，但同时也带来了种质、资源、环境及病害等诸多问题。由于持续过度捕捞，河蟹的天然资源每况愈下；不同水系间河蟹的盲目引种和苗种的无序流动，造成种质混杂与种质严重退化，种质问题已成为制约我国河蟹产业持续发展的瓶颈。由于多年的快速发展，长江流域的绝大多数湖泊等大水面已开展了河蟹养殖，养殖的集约化程度不断提高，造成养殖环境不断恶化，病害频繁发生。为了我国河蟹产业的可持续发展，有必要针对当前河蟹产业发展中存在的关键问题进行一次整理和规范。 新年伊始，本刊特约上海水产大学王武、成永旭、李应森三位教授推出有关河蟹的专题讲座，对河蟹的生物学、河蟹的人工繁殖和育苗技术、仔蟹培育技术、1龄蟹种培育技术、商品蟹养殖技术、蟹文化等进行了较为全面、系统的阐述，以飨读者。[编者按]     

工厂化人工海水繁殖河蟹成功

河蟹——中华绒螯蟹，是我国水产珍品之一，营养丰富，肉味鲜美，为国内外市场所欢迎。但河蟹自然繁殖受自然环境的影响很大，为了实行人工繁殖，我国水产战线的科研人员和工人曾付出了许多辛勤的劳动。安徽省滁县河蟹人工海水育苗试验小组，几年来坚持试验，采取工厂化方式，成功地进行了河蟹人工海水育苗，这将为河蟹养殖生产的发展，     

河蟹“抖脚”症的病理分析及防治方法初探

我国河蟹人工育苗与养殖技术在近年来日臻成熟与完善,形成了天然海水、半人工海水和全人工海水育苗技术模式,相应也有了围网养殖、池塘养殖、稻田养殖等多种养殖模式,使河蟹人工养殖产量逐年上升。但是自95年在上海崇明首次发现了具有“胸肢颤抖”症状而死亡的病蟹后,至98年在江、渐、皖、沪,以及辽宁盘锦等河蟹养殖主产区,相继发生严重疾病,各地依病蟹的主要临床症状,称为“抖脚病”、“抖肢病”、“腹水病”和“仔蟹上岸”等。从幼蟹（5－10g／只）到成蟹（200－2509／只）皆有发生,发病时间自春季到秋季皆有,随着放养密度越高…     

河蟹育苗生产技术初探

近年来，河北省河蟹育苗生产发展很快，沿海百余座水产育苗室中有近一半开展了河蟹育苗生产、年产蟹苗1万余公斤。目前生产中出现的主要问题：一是备状1期至蚤状Ⅱ期和蚤状Ⅴ期至大眼幼体变态难；二是时常发生大眼幼体大批死亡。为此，我们对这几个问题进行了初步探讨。1亲蟹的选择目前我省河蟹育苗所需亲蟹，大体上有三个来源：一是上年秋收购的人工养殖的二龄成蟹，移入半成水中促其交尾、抱卵，然后越冬，第二年春天再起捕移入室内产卵；二是春天收购淡水池塘中养殖的二龄蟹；三是春季收购的海捕抱卵蟹。海捕蟹虽然个体较大，抱卵较多、…     

河蟹“长荡湖1号”土池生态繁育效果评估

<正>河蟹土池育苗与以前的工厂化育苗相比，节省成本且整个过程很少用药，对环境的污染较小。国内长江流域的河蟹养殖规模、产量最大，长江水系河蟹大都未经遗传选育，优势性能遗传不稳定，还曾一度出现辽蟹南下、瓯蟹北上的局面，造成河蟹苗种来源复杂、养殖效果不稳定的现象，亟须通过选择育种进行遗传改良，选育出符合生产发展需要、抗逆性强的河蟹新品种。河蟹“长荡湖1号”是自2017年起选育的适合长荡湖地区生长的河蟹新品系，现对2022年河蟹“长荡湖1号”A/B系繁育结果总结如下。     

河蟹工厂化育苗的水体调控

<正> 近年来,由于工业、生活、养殖等废水的污染,造成海水富营养化、赤潮频繁发生,使致病因子增多,给河蟹工厂化育苗造成了极大危害。因此,在河蟹育苗生产中对育苗用水进行系统的改良调控,为幼体的发育提供一个适宜的生态环境是至关重要的     

河蟹大眼幼体的选购及运输

河蟹大眼幼体即蟹苗，其质量的好坏和运输成活率的高低是河蟹养殖成败的关键。为此，笔者根据多年从事河蟹育苗、蟹苗选购和苗种培育的经验，介绍一些选购蟹苗的技巧和运输的方法，以供读者购苗时参考。1河蟹大眼幼体的选购蟹苗的质量受系蟹的品质、水质、投饲方法、药品的应用及淡化过程等因素的影响，所以，不同的育苗厂生产的蟹苗质量不同，而且同一个育苗厂的不同批蟹苗质量也有很大差别。蟹苗的质量我们可以从以下几点来鉴别。1．l了解亲蟹的情况亲蟹的品系对河蟹养殖影响较大。雌雄蟹最好来自不同的地区，避免近亲繁殖a抱卵蟹要求在12…     

抱卵河蟹拟阿脑虫病的诊治

<正> 近十年来,河蟹的人工养殖已遍及全国的大部分省市,取得了可观的经济效益和社会效益。但随着水产养殖集约化程度的不断提高及环境的污染,河蟹养殖的病害种类越来越多,病情越来越严重。近几年本人在育苗生产过程中遇到的抱卵蟹拟阿脑虫病就非常严重,此病主要感染亲蟹,传播快、死亡率高,造成的损失大,甚至延误一年的育苗生产。现将此病及防治技术介绍如下。     

开口微囊饵料在河蟹育苗生产上的应用

为寻找卤虫卵的合适代用饵料,降低河蟹育苗成本,在１９９７年春季各期河蟹育苗中,进行投喂“高成”牌开口微囊配合饵料试验。结果;试验池幼体胃肠饱满度好,蜕壳时间短,变态整齐,成活率与对照组判别不五,而成本仅为对照池的４５％,经济效益显著,且不会对以后幼体发育造成不良影响。     

地下卤水在河蟹育苗中的应用研究

地下卤水与自然海水所含主要离子种类一致，但含量差别较大。地下卤水经调配后，作为河蟹人工育苗用水，每茬最高出苗量达６．５万只／ｍ＾３，平均出苗量２．５万只／ｍ＾３。专家鉴定认为：本技术具有不受外源污染、病原少、易操作、成本低、效益好等优点，属国内首创。     

鲍育苗设施的设计原则与技术参数研究

研究了鲍工厂化育苗设施设备的场址选择，平面立体配置，沉淀贮水池容量，亲鲍培育室、鲍育臻育苗池的技术参数以及育苗用水的处理工艺。     

Long‐term trends and drivers of larval phenology and abundance of dominant brachyuran crabs in the Gulf of St. Lawrence (Canada)

Climate change has led to major shifts in the timing of biological events, with many studies demonstrating earlier phenology in response to warming. However, few of these studies have investigated the effects of climate change on the phenology of larvae in marine species. Phenological shifts can result in mismatches between consumers and prey and hence affect growth and survival of individuals, and ultimately population demography. We investigated the temporal changes in phenology and abundance of the larvae of dominant brachyuran crabs in the southern Gulf of St. Lawrence (eastern Canada) based on plankton collections spanning 1982–2012. The Gulf of St. Lawrence has warmed since the early 1990s, and our analyses revealed that larvae of snow crab (Chionoecetes opilio) and toad crabs (Hyas spp.) exhibited a significant trend towards earlier phenology over the 30‐year study period. This shift in phenology appeared to be a consequence of the effect of climate warming on both the timing of hatching and larval development rate. Larval abundance responded differently by crab taxon to climate warming, likely due to differences in thermal tolerance. The warming trend was unfavourable to snow crab, which is the most cold‐adapted and stenothermic of the taxa examined in this study. The abundance of snow crab larvae was lower when sea ice retreat occurred earlier than day 110 of the year and sea surface temperature was higher than 8.5°C. On the other hand, larval abundance of rock crab (Cancer irroratus), which prefers higher temperatures, was positively related to surface temperature.     

３种微生态制剂对养殖水体水质影响的比较研究

对3种微生态制剂改善河蟹养殖池水质的效果进行分析比较。实验组各池中分别加入超浓缩光合细菌(PSB)、"西菲利"活菌生物净水剂、活菌净水剂以及3种微生态制剂组成的混合制剂。观察氨态氮、亚硝态氮、硫化氢、溶解氧、化学耗氧量、pH及异养菌总数等水质指标。结果表明:3种微生态制剂均能改善水质,抑制异养菌的过度增长,但对水质指标的改善各有侧重,混合制剂优于单一制剂。     

The impact of Chinese mitten crab culture on water quality, sediment and the pelagic and macrobenthic community in the reclamation area of Guchenghu Lake

The effects of crab aquaculture on the water and sediment quality and the pelagic and macrobenthic community of the adjacent reclamation area of Guchenghu Lake, Jiangsu Province were evaluated over two consecutive crop cycles from April 2010 to November 2011. The results indicated that most of the nutrient concentrations in both the water column and the sediment varied temporally and showed significant spatial differences. The peak values of most of the physico-chemical parameters measured were obtained during the summer or autumn, whereas the opposite result was observed for suspended solids. A higher zooplankton density and lower phytoplankton biomass were observed in ponds than in other sampling sites, whereas Cyanophyta (80 %), with Planktothrix rubescens as the dominant taxon, was predominant in the canal closest to the ponds. The benthic community was dominated by Bellamya aeruginosa in the ponds. Limnodrilus hoffmeisteri was the predominant species in the canal. Comparative analysis of the impact of crab culture showed that it produced a relatively low level of disturbance but introduced large quantities of nutrients and organic matter into the canal around the farming ponds. The introduction of these substances increased the risk that Guchenghu Lake would be affected by pollution.     

中华绒螯蟹养殖与固城湖水体氮、磷相关性研究

近年来固城湖水环境质量日益恶化的现象呈现明显,为寻求固城湖水环境质量污染原因,本文将利用物料平衡原理,建立氮磷总量的数学模型,计算固城湖中华绒螯蟹养殖每年所产生的氮磷量,经与实测结果验证,该模型是合理可行的。采用Spearman秩相关系数法计算得到,固城湖中华绒螯蟹养殖所产生的氮、磷量与固城湖大湖区、港口和河口的氮、磷量具有明显的相关性。说明固城湖中华绒螯蟹养殖可导致固城湖水体的氮磷总量呈现快速增长。为更好地保护固城湖水生态环境,应严格控制中华绒螯蟹养殖的规模,杜绝中华绒螯蟹养殖产生的有机污水直接排放入固城湖。     

庙岛海峡以东浅海养殖结构调整的研究

研究了烟台市庙岛海峡以东浅海筏式养殖的历史，现状以及大面积贝类养殖对生态环境的影响，提出了调整养殖海区、分层养殖、养捕海区兼顾，调整养殖品种，发展海底增养殖，推广先进养殖方法的措施。专家通讯鉴定认为，本研究成果属国内领先水平。     

A comparison of development opportunities for crab and shrimp aquaculture in southwestern Bangladesh, using GIS modelling

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.     

Concurrent rice‐shrimp‐crab farming systems in the Mekong Delta: Are conditions (sub) optimal for crop production and survival?

The Mekong Delta is the most important rice‐ and shrimp‐producing region for food and economic security in Vietnam. Rice‐shrimp farming is practised where salinity fluctuates substantially between wet and dry seasons. Research points to several potential risk factors for rotational systems, but how these link directly to both rice and shrimp production remains poorly quantified for systems that stock and harvest animals year‐round. We examined water and soil quality of 18 rice‐shrimp‐crab ponds, in which shrimp and crab are grown in both wet and dry seasons, in the Cà Mau Province of Vietnam. Multiple lines of evidence indicated that environmental conditions experienced by both rice and shrimp were suboptimal and contributed to low yields and survival. Year‐round cropping of shrimp and crab was associated with sustained suboptimal salinity, intensified by drought, for the wet‐season cultivation of rice. Although rice seedlings were sown in all 18 ponds, only three had a harvestable crop. Low shrimp production and survival was associated with sustained suboptimal water temperatures (too high), salinity (too high in the dry season and too low in the wet season) and dissolved oxygen concentrations (too low). Food availability and quality may also have affected shrimp production. Improving productivity of rice‐shrimp‐crab ponds in the study region may require (1) separation of rice and shrimp crops and improving efficiency of soil washing practices such that salinity conditions are more suitable for each when grown, and (2) management intervention to increase oxygenation of water, and the availability and quality of food for shrimp.