瓯江中,下游海南沼虾苗种资源开发利用探讨

1987年在瓯江中,下游江段发现了大量的海南沼虾苗种资源,经调查,仅青田县境内江段捕捞上市的就可供近百公顷池塘进行精养。开发利用海南沼虾苗种资源的方法和措施是:利用过冬幼虾和当年早苗进行一年两茬养殖,建立越冬基地利用后期溯江幼虾进行养殖,改进幼虾捕捞技术,加强渔政管理。     

海南沼虾后期苗种的冬季暂养技术

海南沼虾(Macrobrachium hainanense)又称瓯江大虾,是海淡水洄游性虾类。在瓯江中下游,虾苗的溯江洄游汛期是7月下旬至10月初。9月初以前的虾苗可以当年养成商品虾,而9月初以后的后期虾苗则当年养不到商品规格。我们于1991～1994年研究了后期苗种的冬季暂养技术,现介绍如下。1 暂养池的准备 暂养池应选在交通方便、有电力供应、水源充足、无污染、排灌方便的地方,最好具有     

影响罗氏沼虾幼虾成活率的因素及对策

近年来罗氏沼虾养殖在南通市港闸区得到大力推广，但单产水平悬殊较大，高的每亩150公斤左右，低的只有30公斤。虾的成活率主要取决于放养后30～40天的幼虾培育阶段。因此，提高罗氏沼虾幼虾成活率成为养殖关键。笔者根据调查与实践，对影响罗氏沼虾幼虾成活率的因素与对策浅析如下：一、水温罗氏沼虾的适宜水温范围为18～32C，死亡临界温度下限是14C，本地区从4月底至5月下旬平均水温都有可能达到18’C以上，但要看当年的气象变化。1994年4月30日我们放养的虾苗成活正常，1995年5月上旬虽然平均水温已在18C左右，但在5月11日放养虾苗时，…     

瓯江海南沼虾的生物学及人工养殖初探

描述了瓯江海南沼虾的一般生物学特性,并对其人工育苗,天然苗种及成虾养殖等进行了初步探讨.     

淡水幼虾湿法运输的初步试验

本文报道了淡水幼虾的湿法运输试验。试验表明:气温低于20℃时,利用蟹苗箱进行海南沼虾和日本沼虾的中、短途运输、效果较好。气温低于10℃时,可进行湿法中、长途运输。     

罗氏沼虾和海南沼虾网箱饲养可行性初探

网箱养鱼已为世人所熟知,网箱养日本沼虾和罗氏沼虾亦已有报道。网箱中混养罗氏沼虾(Macrobrachium rosenbegii)和海南沼虾(M.hainanense)情况若何?多层网箱混养情况又如何?皆为作者所关心。为此我们于1989年进行了这两种淡水虾网箱饲养可行性的初步探索。     

池塘养殖罗氏沼虾的技术要点

我场从1981年起引进罗氏沼虾,进行池塘养殖,经过几年来的摸索.基本掌握了罗氏沼虾的池塘养殖技术。每亩平均单产在60～80公斤,最高可达130公斤。罗氏沼虾的利润已占池塘总产值的50%左右,经济效益比较高。自1983年起罗氏沼虾人工繁殖获得成功后,每年生产虾苗100～150万尾.1990年计划生产1000万尾左右,已初步形成系列化养殖罗氏沼虾的生产基地。     

虾（罗氏沼虾）鱼混养初试和效益

虾（罗氏沼虾）鱼混养初试和效益１９９３年４月１０日，水库渔业研究所在广西扶绥汪庄水库坝下池塘进行虾鱼混养试验。结果亩产罗氏沼虾６８．４２公斤，商品鱼１０４．２１公斤，饲料系数２．５０，取得了较好的经济效益。现将试验过程中所采取的措施和经济效益总结如下...     

海南沼虾繁殖特性的初步观察

海南沼虾(Macrobrachium hainanense)是海淡水洄游虾类,在我国,分布于浙南瓯江中下游及两广、海南地区。肉眼区分雌雄虾最主要依据是雄虾第二腹足内肢内侧具有一细长棒状雄性附肢,而雌虾则无此附肢。雌虾在水温20℃左右,进行生殖蜕皮,然后,雌雄虾交配,雌虾抱卵。雌虾抱卵量2 000～10 000粒,随个体大小而异。卵椭圆形,长径0.55毫米,短径0.45毫米。在水温31℃的水族箱中,从雌虾抱卵到仔虾出膜约需11天。     

罗氏沼虾养殖技术要点

罗氏沼虾原产于热带淡水或咸淡水域。1 96 2年人工繁殖取得成功 ,1 976年我国从日本引进试养 ,并很快推广到全国各地。近年养殖面积不断增加 ,养殖技术也不断提高。现将罗氏沼虾的养殖技术要点进行归纳 ,希望对养殖户有所帮助。1　生态习性罗氏沼虾的幼体生活在半咸水域 ,经 1 1次蜕壳变态为幼虾 ,幼虾经淡化后 ,一生都可在淡水中生活。罗氏沼虾对水温及溶氧量敏感 ,最适生长水温为 2 2～ 30℃ ,高于 35℃或低于 1 8℃时活动减弱 ,1 4℃以下开始死亡。溶氧量低于 3ｍｇ/Ｌ时 ,易浮头 ,反应迟钝。罗氏沼虾是底栖虾类 ,白天潜伏水底 ,晚上活动…     

The potential of mixed culture of genetically improved farmed tilapia (Oreochromis niloticus) and freshwater giant prawn (Macrobrachium rosenbergii) in periphyton-based systems

The production performance of genetically improved farmed tilapia (GIFT, Oreochromis niloticus) and freshwater prawn (Macrobrachium rosenbergii) in periphyton‐based systems were studied in farmers' ponds at Mymensingh, Bangladesh. Fifteen ponds (200–300 m² area and 1.0–1.5 m in depth) were used to compare five stocking ratios in triplicate: 100% GIFT, 75% GIFT plus 25% prawn, 50% GIFT plus 50% prawn, 25% GIFT plus 75% prawn and 100% prawn. Ponds were stocked at a total density of 20 000 GIFT and/or prawn ha^?1. Bamboo poles (mean diameter 6.2 cm and 5.5 pole m^?2) were posted in pond bottoms vertically as periphyton substrate. Periphyton biomass in terms of dry matter (DM), ash‐free DM and chlorophyll a were significantly higher in ponds stocked with prawn alone than in ponds with different combinations of GIFT and prawn. Survival of GIFT was significantly lower in ponds stocked with 100% GIFT (monoculture) whereas, that of prawn was significantly higher in its monoculture ponds indicating detrimental effects of GIFT on prawn's survival. Individual weight gains for both species were significantly higher in polyculture than in monoculture. The highest total fish and prawn yield (1623 kg GIFT and 30 kg prawn ha^?1) over 125–140 days culture period was recorded in ponds with 75% GIFT and 25% prawn followed by 100% GIFT alone (1549 kg ha^?1), 50% GIFT plus 50% prawn (1114 kg GIFT and 68 kg prawn ha^?1), 25% GIFT plus 75% prawn (574 kg GIFT and 129 kg prawn ha^?1) and 100% prawn alone (157 kg ha^?1). This combination also gave the highest economic return. Therefore, a stocking ratio of 75% GIFT plus 25% prawn at a total density of 20 000 ha^?1 appeared to be the best stocking ratio in terms of fish production as well as economics for a periphyton‐based polyculture system.     

瓯江口海域夏秋季蟹类数量分布与环境的关系

本文利用2007年6月和9月瓯江口海域渔业资源调查资料,分析瓯江口蟹类资源密度的分布,及蟹类优势种、水团、水深和水文因子对蟹类数量分布的影响。结果表明,6月和9月蟹类重量密度分别为112.99 kg/km2和73.48kg/km2,尾数密度为16.84×103ind/ km2和3.80×103ind/ km2,资源总量为50845.5 kg和33066.0 kg。蟹类密度分布,在6月调查海域东部高于西部,南部高于北部,高密度区出现在瓯江口洞头群岛外侧,尤其是受台湾暖流影响明显的海域;在9月仅是南部明显高于北部,其他海域分布比较均匀。瓯江径流从瓯江北口下泄,在口外形成冲淡水水团,使瓯江口北侧蟹类密度较低。瓯江口温、盐度环境因子与蟹类重量密度负相关关系显著,与尾数密度不显著。水深与蟹类密度呈错综复杂的关系,并非线性相关关系。日本蟳（Charybdis japonica）是瓯江口蟹类最重要的优势种,三疣梭子蟹（Portunus trituberculatus）是最重要的经济品种。     

Evaluation of freshwater prawn‐small fish culture concurrently with rice in Bangladesh

An integrated aquaculture of freshwater prawn (Macrobrachium rosenbergii) and self‐recruiting small fish mola (Amblypharyngodon mola) was conducted in farmers' rice fields at Mymensingh, Bangladesh. There were four treatments with three replications. Four stocking densities, 10 000, 15 000, 20 000 and 25 000 ha^?1, of freshwater prawn were applied. The stocking density of mola was the same (20 000 ha^?1) in all treatments. During land preparation, triple super phosphate (TSP) and murate of potash (MP) were applied at the rate of 150 and 75 kg ha^?1 respectively. Urea was applied at the rate of 200 kg ha^?1 in equally distributed three installments after 16, 45 and 65 days of rice plantation. Prawns were fed with commercial pelleted feed at 3–8% body weight. All water quality parameters were found to be within the suitable range for freshwater prawn culture. There was a homogenous abundance of plankton communities in all treatments. The results of a 4‐month culture period showed that the average production of prawn ranged from 222 to 388 kg ha^?1, mola 51 to 68 kg ha^?1 and rice 2 880 to 3 710 kg ha^?1. Significantly higher production of both prawn and mola was recorded in the plots where the freshwater prawn stocking density was 15 000 ha^?1. This treatment resulted in a net profit of USD 1100 ha^?1.     

左旋咪唑对罗氏沼虾免疫功能及抗病力的影响

以0(对照)、50、100和150 mg/kg饲料的剂量将左旋咪唑(LMS)添加于基础饲料中制成颗粒饲料投喂罗氏沼虾(Macrobrachium rosenbergii)14 d,采样测定了罗氏沼虾血细胞吞噬活性、血清酚氧化酶(PO)、溶菌酶(LSZ)及超氧化物岐化酶(SOD)活性,并以6×105cells/mL浓度的致病性嗜水气单胞菌(Aerom onas hydrophila)对罗氏沼虾进行肌肉注射(20μL/尾),记录接种7 d后罗氏沼虾的累积死亡率。结果表明,3个LMS处理组的罗氏沼虾血细胞吞噬百分比和吞噬指数、血清PO、LSZ及SOD活性均显著地高于对照组(P<0.05);LMS处理组的罗氏沼虾对嗜水气单胞菌的抵抗力明显增强。因此,饲喂适量的LMS能促进罗氏沼虾的免疫力和抗病力;在本试验条件下,100 mg/kg饲料的剂量为最适添加剂量。     

脊尾白虾全人工繁育技术初步研究

脊尾白虾是我国沿海地区池塘养殖重要品种,但目前尚未实现全人工繁育,严重制约了产业进一步发展。选取野生脊尾白虾作为亲虾,经过越冬培育、促熟交尾、幼体孵化培育、仔虾选育等手段,进行了脊尾白虾全人工繁育技术研究。试验结果显示,在盐度31.3、水温18.1~26.2℃、pH 8.1条件下,室内越冬脊尾白虾亲虾可成功培养至性腺成熟,并交尾抱卵,平均抱卵率达70%,平均孵化率为61.02%。幼体最佳培育密度20尾/L,仔虾适宜养殖密度0.13~0.53尾/L,培育至2cm时存活率可达80%,继续培育3个月后发育至性成熟。一年可繁殖2~3代。在此基础上建立了脊尾白虾近交家系,现已培育至第6代,各家系繁殖力、生长速度和存活率均未出现近交衰退现象。本研究初步解决了脊尾白虾室内全人工繁育技术,并为试验动物培育奠定了良好的技术基础。     

缢蛏与对虾无公害生态养殖技术研究

改造66．7hm^2对虾养殖池塘,放养规格6000粒／kg的缢蛏苗种6250kg,日本对虾苗种1200万尾（2茬）,当年共收获缢蛏（规格6．67cm）270100kg,对吓124400kg,实现产值537．39万元,利税369．67万元。     

乌鳢当年苗养成商品鱼高产试验

为缩短乌鳢养殖周期,笔者于1997-1998年,在沅江市鱼类良种繁育场选择2口面积均为333m^2的池塘,进行了使用乌鳢当年孵化的鱼苗,当年养成商品鱼的高产试验,现综述如下：     

Potential of mixed culture of freshwater prawn (Macrobrachium rosenbergii) and self-recruiting small species mola (Amblypharyngodon mola) in rotational rice–fish/prawn culture systems in Bangladesh

The effects of different stocking densities of freshwater prawn (Macrobrachium rosenbergii) on its growth and production in relation to the presence of small self‐recruiting species mola (Amblypharyngodon mola) were investigated in modified rice fields after rice harvest at Mymensingh, Bangladesh. Keeping the stocking density of mola fixed at 20 000 ha^?1 in each treatment, four densities of freshwater prawn (treatments) were maintained: 10 000, 15 000, 20 000 and 25 000 ha^?1 respectively. The rice plots were limed (CaCO₃) and fertilized with urea, triple super phosphate and cowdung regularly. The prawns were fed daily with commercial pellets. Water quality parameters such as temperature, dissolved oxygen, transparency, pH, total alkalinity, inorganic nitrogen (nitrate, nitrite and total ammonia), chlorophyll a and orthophosphate were determined fortnightly. Numerical analysis of plankton communities was performed monthly. All water quality parameters were found to be within the suitable range for freshwater prawn culture, except high temperature, in the peak summer months. There was a homogenous abundance of plankton communities in all treatments throughout the experimental period. Mola started to breed in the second month of the original stocking with partial harvesting after the second month and continued until the final harvest. The total production of mola ranged between 124 and 152 kg ha^?1 during the 4‐month culture period. The average prawn survival ranged from 49% to 57% without any significant difference among treatments. Freshwater prawn production ranged from 294 to 596 kg ha^?1 with significantly higher production in the treatment where 20 000 ha^?1 freshwater prawn were stocked. This treatment also resulted in a higher net profit margin (74%), indicating that stocking at a combination of 20 000 ha^?1 freshwater prawn and 20 000 ha^?1 mola could be the optimum proposition for prawn–mola culture in modified rain‐fed rice fields after rice cultivation.     

A Comparison of Two Feeding Technologies in Freshwater Prawns,Macrobrachium rosenbergii,Raised at High Biomass Densities in Temperate Ponds

ABSTRACT

Recent developments in prawn production technologies (i.e., added substrate, increased stocking densities, size grading, and increased feed rates) have increased production rates from 900-1,000 kg/ha to over 2,500 kg/ha. While prawn can receive substantial nutritional benefit from natural foods at the lower biomass densities, at higher production rates prawn are likely to be more dependent on prepared diets. To ensure that maximum production is being achieved by these new production technologies, production rates must not be nutritionally constrained. This study was conducted to compare the current recommended technology of phase feeding of different quality feedstuffs to prawns of different sizes with the feeding of a high-quality penaeid diet throughout the production season. Two treatments were evaluated: Treatment 1 was phase feeding (current technology-control) where prawns were fed unpelleted distillers' grains with solubles (DDGS) for the first four weeks, then a 28%-protein prawn diet for weeks 5-12, and finally a 40%-protein penaeid diet for weeks 13-16. In Treatment 2, prawn were fed the 40%-protein penaeid diet throughout the entire production period. Feeding rates in both treatments were based upon a feeding table. Three 0.04 ha ponds were used for each treatment. All ponds were stocked at 59,280 juveniles/ha and were provided with artificial substrate in the form of a polyethylene “safety fence” oriented vertically to increase available surface area by 50%. After 106 culture days, no significant differences (P >0.05) were observed between treatments in terms of yield, average individual weight, food conversion ratio (FCR), or survival, which averaged 2,575 kg/ha, 46 g, 2.3, and 94%, respectively, overall. Due to the higher cost of the penaeid diet (US$0.84/kg), feeding costs for the penaeid diet treatment (Treatment 2) were 38% higher than those for Treatment 1. No benefit to using higher protein diets during the first 12 weeks of prawn pond production was observed.     

东方对虾（Penaeus orientalis）在长江口外海区的索饵特性研究

东方对虾（Ｐｅｎａｅｕｓｕｓｏｒｉｅｎｔａｌｉｓ）是分布在我国黄渤海及东海北部的重要经济虾类。长江口海区（１６９渔场）受淡水迳流的影响，浮游生物及底栖动物的生物量较高，构成了对虾良好的索饵、肥育、越冬场所。本研究通过周年样品采集（共２１６尾），逐尾进行个体测量和胃含物观察分析，查明了东方对虾在该海区的食物组成和摄食强度季节变化。其食物组成有８大类：硅藻类、原生动物、海绵动物、环节动物、软体动物、甲壳动物、棘皮动物及鱼类。摄食强度以春夏季和秋季为高，但冬季也摄食。在不同的水域（沿岸、近海）和环境（大潮、小潮）下有不同的食物组成，表明东方对虾的食性相当广泛。