条斑紫菜低潮位海区包维网栽培技术

为探索新的条斑紫菜栽培技术,利用聚乙烯尼龙包维网在面积为8 hm2的低潮位海区进行了栽培试验。试验结果证明,包维网比普通多股线网帘质量轻,滤水快,干露时间短,从而节约了菜苗时间,提高了紫菜苗成活率。包维网的保苗性能非常好,能提高紫菜的生长速度,使得收菜时间缩短了5～7 d,可多收1～2次菜,增产20%左右。经过近一年的试验,8 hm2的低潮位海区,压水鲜紫菜总产量达到98991kg,平均产量12 374 kg/hm2;总产值554350元,总利润227850元。     

条斑紫菜主要病害及其防治

紫菜栽培是我国传统的海水养殖项目,近年来条斑紫菜栽培以江苏为主要产地,北至山东,南到浙江迅猛地发展起来,但是每年发生于各地的病害已成为条斑紫菜优质、高产、稳产的最大障碍。1993-1994年度江苏南部沿海海区、1994-1995年度浙江沿海海区的条斑紫菜均爆发了严重的传染性病害,造成了大欠收。根据有关资料,自然     

连云港地区坛紫菜育苗技术总结

正坛紫菜是浙江、福建沿海的主要栽培种;条斑紫菜是长江以北地区的主要栽培种,坛紫菜适应较高的温度,生长快,产量高,近年已在连云港等北方地区栽培获得成功,仅连云港地区坛紫菜2015、2016和2017年度的栽培面积分别达到90万m2、540万m2和576万m2。为适应坛紫菜在北方地区迅速推广的需要,作者从2014年开始在北方地区进行坛紫菜育苗试验,经过几年的试验研究,坛紫     

坛紫菜翻转式养殖技术初探

福建省吉庆和海洋发展有限公司在霞浦东壁海区开展了坛紫菜翻转式养殖新技术试验,养殖面积共6 hm2。结果表明坛紫菜翻转式养殖是一种结构简单、操作方便、节能环保、生产成本低、经济效益高、应用范围广、产品质量高的养殖方式。坛紫菜翻转式养殖产量为1 100 kg/200 m2,产值为10 550元/200 m2,扣除生产成本1 150元/200 m2,利润为9400元/200 m2。本文详细介绍了该翻转式养殖新技术,总结了本试验的经验和不足,希望能够为紫菜养殖模式的创新以及日后翻转式养殖技术的大规模推广应用提供参考。     

紫菜养殖技术之一大面积栽培条斑紫菜高产高效配套技术

条斑紫菜属于红藻门、原红藻纲、红毛菜目、红毛菜科,作为经济价值与营养价值较高的海藻,它具有食品、药用、保健等多种功能。条斑紫菜的生物学特性决定了适宜栽培海区的局限性与栽培技术的特殊性,而江苏省海安县条斑紫菜栽培海区面积近3万亩,全县11家紫菜企业年产一次性条斑干紫菜近10万箱,条味紫菜6万箱,条斑紫菜的育苗、栽培、加工是该县水产业的支柱产业。本项目通过研究条斑紫菜半浮动筏式栽培中的海区选择、栽培设施、苗网培育、病害防治、成菜栽培管理和成菜采收等技术关键, 1700公顷栽培海区3年平均单产9950kg／公顷,单产高于同类海区20％以上。一、栽培海区的选择栽培海区应选择离岸较远的近海辐射沙洲,     

日本三重县礁膜的养殖和利用

礁膜(Monostroma nitidum Wittrock)是石莼目礁膜科的一种绿藻。喜生长在内湾温暖的浅海水域。日本的三重、爱知、爱嫒、德岛、高知、静冈县沿海均有养殖。年产干品1，500吨。伊势湾一带渔民把紫菜称为黑紫菜，礁膜称作绿紫菜，后者在日本紫菜养殖业中占有一定地位。日本礁膜的自然种群有河口型和内湾型之分。河口型分布在低盐海区，叶片基部放射状，12月至4月是生长繁盛期，     

福建宁德霞浦县试养条斑紫菜获得成功

<正>福建宁德霞浦县2013年从上海海洋大学引进条斑紫菜新品种进行人工育苗试验取得成功,11月26日在三沙镇石头鼻海区开展试验养殖,2014年2月17日收获鲜菜22 kg,条斑紫菜在霞浦首次试验养殖获得成功。条斑紫菜原产于江苏连云港、南通等北方海区,是北方地区的主要养殖品种。2012年霞浦县首次从上海海洋大学引进条斑紫菜进行人工育苗试     

鱼——螺——藕互惠种养试验

<正>2011-2013年,我们连续在被称为莲产业之乡的五夫镇,开展了鱼-螺-藕互惠种养试验,取得了良好的效果。现把试验情况介绍如下:一、材料与方法1.试验环境位于武夷山市五夫镇田尾村,试验区含一座容量为25万米3、可养面积60亩的小(二)型水库及下方20块共80亩低丘缓坡式莲田,莲田引用水库底排水,两排串联式灌溉。2.水库养殖2011-2013年先后以建鲤和草鱼为水库主养鱼,2011年因水库大坝维修加固,投放夏花苗外,其余年度均为冬片苗种外加大规格草鱼     

南海野生坛紫菜选育研究

以南海粤东海域的野生坛紫菜为选育材料,采用选择育种的方法并进行海区栽培验证,培育出产量高、耐高温和质量优的优良品系。第1茬采收时紫菜藻体平均长度比对照组（传统栽培坛紫菜品种）增加了73．9％,产量和单位产量分别提高了25％和19．0％。3～5cm叶状体在29℃水温条件下培养6天后才出现烂斑,海区栽培没有出现因高温造成的烂苗现象。第1茬坛紫菜16种氨基酸总量比对照组高36．5％。本研究成果不仅为粤东及周边地区的坛紫菜栽培生产提供一个具有实用性的优良品系,而且也为今后坛紫菜良种选育提供了更广泛的研究材料。     

一起条斑紫菜拟油壶菌病的诊断

赤腐病(red rot disease)和拟油壶菌病(Oplidiopsis disease)是海上栽培紫菜(Pyropia)的主要病害,常引起紫菜大面积病烂。2019年1月江苏省盐城市大丰区某条斑紫菜(Pyropia yezoensis)栽培海区有134 hm2发生了紫菜病烂,本研究对该起病烂进行了病害调查和病原鉴定。结果显示,患病紫菜的病症与拟油壶菌病一致,主要表现为发病初期,在叶片边缘、基部和中部出现粉红色的病斑,随着病程发展,病斑逐渐褪色并扩大;发病后期,整个叶片颜色变浅,叶片组织溃烂脱落;在显微镜下可观察到紫菜细胞内寄生1~4个圆球状菌体,菌体内有多个油滴状物质。以病烂紫菜叶片或其匀浆液为感染源,分别在10℃和20℃条件下进行人工感染实验,二者均能使正常紫菜出现拟油壶菌病的病症。对现场采集及人工侵染后的病烂紫菜疑似病原进行cox1基因测序和系统发育学分析。研究表明,所测cox1基因均与紫菜拟油壶菌(Oplidiopsis porphyrae、O. pyropiae、O. porphyrae var. koreana)聚为一支,相似度为100%。综上所述,该起条斑紫菜的病烂由紫菜拟油壶菌(Oplidiopsis sp.)引起。     

可口革囊星虫分级养殖技术初探

为探索可口革囊星虫高效养殖模式,提高养殖效益,于2015—2016年在浙江省温岭市七一塘开展了可口革囊星虫分级养殖试验。试验苗种为潮间带采集的自然苗。试验池塘面积共4.67 hm²,其中1.47 hm²用于可口革囊星虫苗种的标粗及养成,3.20 hm²用于分养经过中间培育的苗种。于2015年7月中旬按每公顷1425 kg(约892.5万条)的密度放养规格为6260条/kg的苗种,经6个月的中间培育后,起捕规格773条/kg的中苗10400 kg,分养至总面积为3.20 hm²的4口池塘,用于标粗的2口池塘(1.47 hm²)内留存一部分苗种,经整理后继续养成。2017年1月中旬至2月下旬起捕上市,共收获可口革囊星虫61970 kg,产值322.54万元,净利润185.54万元。经折算,平均产量达13270 kg/hm²,平均产值为69.07万元/hm²,平均利润为39.73万元/hm²。     

沿海滩涂低盐水体条件下大型池塘斑点叉尾鱼回高效养殖技术

为进一步优化沿海滩涂低盐水体条件下大型池塘斑点叉尾鱼回养殖技术模式,在江苏盐城东台、大丰、射阳、连云港等地分别设置4个试验点,每个试验点选取2口池塘开展了养殖试验.采取低密度(9000～15000尾/hm2)放养大规格(0.25～0.30 kg)斑点叉尾鱼回鱼种的方式,加强饲养管理,投喂优质膨化颗粒饲料,并做好养殖病害...     

坛紫菜北方海区养殖试验

为进一步拓展坛紫菜“南菜北养”的范围，2018年和2019年在山东烟台海区进行了坛紫菜“闽丰2号”的养殖试验。2018年9月中旬将购自江苏、幼苗肉眼可见的网帘投放下海，至12月上旬采收五水(第一次采收的紫菜叫头水或一水紫菜，后面的依次叫二水、三水、四水、五水),总产量为2 359.5 kg/hm²(干质量);2019年8月下旬，采用坛紫菜成熟贝壳丝状体在当地进行采苗、下海，9月下旬进行一水紫菜的收获，至11月中上旬共采收五水，总产量为1 574.3 kg/hm²(干质量)。随着收获期的延长，藻体的长度、宽度均呈增加趋势，但2个年度产量分别以三水和四水为最高。海区营养盐测定结果表明：海水中的无机氮浓度随着养殖时间的延长呈降低趋势，10月份的无机氮浓度明显低于8月份的，晒网同时喷洒施肥后藻体颜色快速好转，且产量有所提高，表明试验海区营养盐条件是影响坛紫菜养殖的重要因素之一。为避免病害发生，在养殖过程中应及时施肥以促进藻体生长，提高坛紫菜的产量和质量。     

Longline cultivation of some Laminariaceae in British Columbia, Canada

Abstract. Seedlings of Laminaria groenlandica Rosenvinge. L. saccharina (L.) Lamour. and Cymathere triplicata (Post. & Rupr.) J. Ag. were produced directly from mixed gametophytes and indirectly from cloned gametophytes. When cultivated in the sea, these seedlings produced up to 8 wet kg.m⁻¹ of cultivation rope for L . saccharina , 20 wet kg.m⁻¹ for L. groenlandica and 2·7 wet kg.m⁻¹ for C. triplicata . These values are similar to those reported from other parts of the world. Plant sizes for cultivated L. groenlandica and C. triplicata were greater than observed in wild stands Production by L. groenlandica was positively correlated with nutrient concentrations and negatively correlated with temperature. The time required to achieve harvestable size may he reduced from 16 to 9 months by employing seedlings produced indirectly from cloned gametophytes.     

Comparison of nutrients release among some maricultured animals

Integrated mariculture is a feasible method to maintain sustainable and high productivity of aquaculture. The choice of cultured animals and biofilters in the integrated system has to be made on the basis of their nutrient release rates and the clearance rate of each component of the system. We are examining the nutrient release rates among fish (mangrove snapper, Lutjanus russeli, and sea perch, Abudefduf septemfasciatus), abalone (Haliotis diversicolor), scallops (Chlamys noblis), and green mussels (Perna viridis) in the laboratory. Fish feed is the major sources of inorganic nutrient input in fish farms. The orthophosphate and ammonia release rates of minced trash fish (1593 μg P g⁻¹ day⁻¹ and 150 μg N g⁻¹ day⁻¹) were respectively 6–12 times and 4–88 times higher than those of cultivated fish. Mangrove snapper had the overall highest nutrient release rate, followed by sea perch, abalone, scallops, and mussels for nitrite and nitrate; and followed by abalone, sea perch, mussels, and scallops for orthophosphate and ammonium. Among mollusks, abalone had the highest orthophosphate (162 μg P g⁻¹ day⁻¹), nitrate (1.4 μg N g⁻¹ day⁻¹), nitrite (1.6 μg N g⁻¹ day⁻¹) and ammonium (25.0 μg N g⁻¹ day⁻¹) release rates per gram wet weight per day. Abalone released large amounts of orthophosphate, nitrite and nitrate in the experiment. Scallops and green mussels had low nutrient release rates.     

虾夷马粪海胆的海区渡夏、室内中间培育及工厂化养成↑（*）

１９９３年７月～１９９７年５月,在夏季采用网袋、网箱开展虾夷马粪海胆Ｆ２代稚海胆的海区渡夏,壳径日平均生长量比室内提高３３．６％～６１．６％;采用网箱平面培育方法进行Ｆ２代稚海胆室内中间育成和Ｆ３代稚海胆室内中间育成中试,壳径的日平均生长量随时间呈下降趋势,为０．５３×１０－２～１．４６×１０－２ｃｍ／ｄ,体重日平均生长量呈上升趋势,介于２．３２×１０－２～１０．７２×１０－２ｇ／ｄ之间,培养中密度过大会降低海胆的成活率并导致疾病发生;采用立体水槽开展陆地工厂化养成,经１３个月,海胆壳径由１．１６ｃｍ增至５．９８ｃｍ,体重由０．４７ｇ增至６１．０ｇ,性腺指数达１８．０％。     

Performance evaluation of rice–fish integration system in rainfed medium land ecosystem

This study was carried out for three successive years during 1999–2001 to evaluate growth and yield performance of fish, prawn and paddy under rice–fish integration system in rainfed medium land ecosystem. Irrespective of stocking density, faster growth rate was recorded for Catla catla followed by Cyprinus carpio, Cirrhinus mrigala, Labeo rohita and Macrobrachium rosenbergii. C. carpio and C. mrigala performed better growth rate against that of L. rohita probably due to the fact that being bottom dwellers, C. carpio and C. mrigala are more tolerant to fluctuation of oxygen concentration. Productivity of fish and prawn was, however, higher (p<0.05) in refuges with 10-cm weir height plots, irrespective of stocking density, while overall yield performance was good at stocking density of 25,000 ha⁻¹. It was observed that, even with supplemental feeding, with increase in stocking density, biomass yield increased up to an optimum and then decreased. An average minimum and maximum yield of 906.6–1282.3 kg ha⁻¹ of fish and prawn has been achieved, which was much higher than the earlier recorded productivity in a season under rice–fish integration system. Highest grain yield was recorded at 15-cm weir height plot (3629 kg ha⁻¹), probably contributed by higher number of panicles per square meter (235.5) and number of filled grains per panicle (121.7). Percentage increase in rice yield under rice–fish integration system was 7.9–8.6% against control, where paddy was cultivated without integration of fish and prawn probably due to better aeration of water, greater tillering effect and additional supply of fertilizer in form of leftover feed and fish excreta. Irrespective of stocking density, the overall rice equivalent yield (REY) of the system was high (4.22–4.55 tons ha⁻¹) at 12.5-cm weir height plots-cum-refuge, without using any pesticide, herbicide, etc.     

Effects of dietary protein level on muscle cellularity and flesh quality in Atlantic salmon with particular reference to gaping

Growth performance, muscle cellularity and flesh quality were investigated in Atlantic salmon (Salmo salar L.) fed either of two diet ranges [high protein (HP), or low protein (LP)], which differed in digestible protein/digestible energy ratios but were of equivalent digestible energy content (21.4 MJ kg⁻¹ wet weight). Smolts from an early maturing (Lochy) and a late maturing (Mowi) strain were PIT-tagged and reared together in duplicate 5×5×5-m sea cages for each diet. The Lochy and Mowi fish were harvested in May and August, respectively, after 417 and 515 days in seawater. The average body weight of fish in each cage at harvest was in the range 3.8–5.4 kg, with no significant difference between diets. The total cross-sectional area of white muscle and the number and diameter of muscle fibres was determined at the level of the first dorsal fin ray. The distribution of muscle fibre diameters was investigated using nonparametric smoothing and bootstrapping techniques. Diet had no effect on fibre size distribution or fibre number in the Mowi strain, and small but significant effects for the Lochy strain. At harvest, in Lochy salmon of average fork length 69 cm there were around 15% more fibres in fish fed the HP than LP ratio diets. However, the 50th percentile of fibre diameter was 20% greater in fish fed the LP than HP diets, such that the total muscle cross-sectional area was similar. The lipid content (14.1–15.3% wet mass), astaxanthin pigment concentration (7.0–8.5 mg kg⁻¹ wet mass) and colour (RocheSalmoFan™ and Minolta Chromatometer readings) of the flesh were similar for both strains and diets. There was no significant difference in the average muscle fibre density between strains and diet, which varied between 60 and 140 fibres mm⁻² muscle cross-sectional area. Gaping during processing of the fillet was in part related to muscle cellularity. Little or no gaping was observed in any fish with a fibre density in excess of 95 fibres mm⁻² muscle. It was concluded that individual variation in fibre density is important in the development of gaping, but that muscle cellularity and flesh quality are relatively insensitive to the protein to energy ratio in the diet over the range studied.     

Using a macroalgae Ulva pertusa biofilter in a recirculating system for production of juvenile sea cucumber Apostichopus japonicus

A simple indoor recirculating system for production of juvenile sea cucumber (Apostichopus japonicus) was operated on a commercial scale for 90 days during winter. The system consists of three 70 m³ sea cucumber rearing tanks and one biofilter tank where macroalgae (Ulva pertusa) was used as a biofilter in order to reduce water requirements. Effluent from the sea cucumber tanks drained into the macroalgae biofilter tank and were then returned to the sea cucumber tanks by a discontinuous-flow recirculation system. Survival and growth rates in the sea cucumber culture tanks were similar to those in the control tank (with one water exchange per day). The survival rate averaged about 87%. The average body weight increased from 3.5 ± 0.3 g to 8.1 ± 0.8 g and total sea cucumber biomass production over the experimental period was 745 g m⁻² after initial stocking densities of 375 g m⁻². The growth rate of U. pertusa was 3.3% day⁻¹. U. pertusa was efficient in removing toxic ammonia and in maintaining the water quality within acceptable levels for sea cucumber culture; there were only small daily variations of temperature, pH and DO. The U. pertusa tank removed 68% of the TAN (total ammonia-nitrogen) and 26% of the orthophosphate from the sea cucumber culture effluent; the macroalgae biofilter removed ammonia at an average rate of 0.459 g N m⁻² day⁻¹. It would be efficient to use the U. pertusa biofilter in a recirculating system for production of A. japonicus juveniles in winter.     

A laboratory scale recycling water unit for tilapia breeding

The technical features of a laboratory scale water recycling unit for experimental small scale tilapia breeding are described. Two units (1 and 2) were operated during a 6 month period, carrying a similar fish load (7·5 kg) and feeding rate (2% fish body weight/day). Unit 1 received natural illumination, while unit 2 was artificially illuminated (14/10 - light/dark cycle). Both units were equipped with a biological filter bed (substrate surface area, 3500 cm²). In unit 1, total ammonium and nitrite concentrations ranged from 0·05 to 0·5 mg liter⁻¹, while nitrate varied between 10–40 mg liter⁻¹. In unit 2 corresponding values were 0·15-3 mg liter⁻¹, 0·05–0·8 mg liter⁻¹ and 10–40 mg liter⁻¹. Temperatures ranged between 20–29°C and pH values between 7·5–6·9 in both units. Dissolved oxygen concentrations decreased gradually from 5·6 to 3·4 mg liter⁻¹ in unit 1 and from 5·6 to 2·6 mg liter⁻¹ in unit 2. Twenty-six spawnings occurred in unit 1 in March and April, while only eight spawnings occurred in unit 2, possibly because of the absence of sunlight. The significance of these results are discussed.