不同来源罗氏沼虾幼体的育苗对比试验

2010年2月,对采自江苏吴江、广西三塘和广西南宁国家级良种场共3种不同来源的罗氏沼虾(Macrobra-chium rosenbergii)进行从幼体阶段至变态苗阶段的培育试验;干量容积法推算产苗量,计算育苗成活率。试验结果表明,3种不同来源幼体的育苗成活率分别为73.6%、65.2%和90.4%,成活率差异明显;其中,国家级广西南宁罗氏沼虾良种场的育苗成活率最高。在育苗生产中,必须注重罗氏沼虾亲本的种质复壮与培育,才能保证幼虾的质量,有利于提高其养殖成活率。     

人工海水对罗氏沼虾幼体生长发育及能量收支影响初探

通过自制人工海水培育罗氏沼虾(Macrobrachium rosenbergii)幼体,与天然海水对比分析人工海水特性及养殖过程中的水质状况,探究人工海水对罗氏沼虾幼体生长发育及能量收支的影响。试验在广西南宁国家级罗氏沼虾良种场进行,罗氏沼虾幼体和饵料丰年虫无节幼体均由该良种场提供,罗氏沼虾幼体规格(湿重)为(1.476±0.050)g,共80万尾;在幼体开始培育前配制人工海水1 000 kg,配比为海盐:MgSO_4∶CaCl_2∶KCl∶H_3B_3O_3∶KBr∶ETDA∶生石灰=2000∶600∶72∶36∶24∶4∶1∶2;设置天然海水为对照组,试验组及对照组分别设置4个重复。结果显示,人工海水中,Mg~(2+)∶K~+∶Ca~(2+)=3∶1∶1,与北部湾天然海水接近,且水质无毒性作用;与天然海水相比,人工海水培育的罗氏沼虾幼体成活率为95.00%,蜕皮率为16.82%,并提高了幼体的特定生长率和食物转化率,降低了摄食率;幼体在天然海水中生长和脱壳所用能量[(18.83±1.35)%和(0.99±0.16)%]分别显著低于人工海水[(19.64±0.51)%和(1.47±0.06)%](P0.05);而在呼吸、排泄和排粪上的能量比例无显著性差异。研究表明,自制的人工海水对罗氏沼虾幼体的生长发育、蜕皮具有促进作用。     

“鱼虾可乐”对罗氏沼虾育苗水质和效果的影响

为加快水质培育速度,促进藻类快速繁殖,利用藻类降解有害物质,增强水体的自净能力,为幼体提供良好的生态环境,以提高罗氏沼虾育苗成活率[1],我们进行了"鱼虾可乐"对水质和育苗效果的影响试验,对照组不投放"鱼虾可乐"。在相同的技术管理条件下进行罗氏沼虾育苗试验,试验过程中注意观察育苗水体浮游生物的变化情况,定期检测水体中的有害物质的浓度,育苗结束时计算育苗成活率,通过水质培育效果和育苗效果来评估"鱼虾可乐"在罗氏沼虾育苗中的效果。结果显示:试验组水体中氨氮含量降低19.76%,亚硝酸氮含量降低21.43%,溶解氧提高11.93%,有效改善了育苗水质,为幼体生长和活动提供比较稳定的生态环境,使育苗成活率提高了11.29%。表明:"鱼虾可乐"能缩短育苗水质培育时间,有效改善育苗水体环境,是一种营养型水质改良剂。     

罗氏沼虾蚤状幼体培育技术

<正>罗氏沼虾又名马来西亚大虾、金钱虾等,原产于东南亚地区,因其生长快、个体大、食性广、易养殖等优点,而深受养殖户欢迎。罗氏沼虾受精卵刚孵出的幼体即是罗氏沼虾蚤状幼体,经过11次蜕皮,变态成仔虾,此过程称为罗氏沼虾蚤状幼体培育。若培育池中已有80%幼体发育成为仔虾,便可淡化3天~5天再进行池塘养殖。沼状幼体能否变成仔虾,是罗氏沼虾育苗关键,本文为大家介绍罗氏沼虾蚤状幼体培育技术。     

罗氏沼虾生态育苗技术

<正>为了提高出苗率,很多人应用了大量的抗生素类药物,这虽然能提高虾苗的出苗率,但对虾苗自身产生很大的危害,为探索罗氏沼虾全生态育苗技术,笔者于2014年3-8月多次在广西南宁国家级罗氏沼虾良种场进行幼体培育实验,并取得了理想的结果。一、育苗场地与设施育苗池规格为1.5米×4.0米×0.8米,为了方便控制温度,育苗池内装有加热管道,充气方式为底层微孔充气,由鼓风机经管道输送到育苗车间,同时备有海水、淡水蓄水池等设施。     

广西罗氏沼虾的引种和选育初显效果

广西水产研究所于2007—2008年实施区水产畜牧兽医局下达的《罗氏沼虾的引种》和《罗氏沼虾的良种选育》项目,近日已通过有关部门的阶段验收,该项目由国家级广西南宁罗氏沼虾良种场实施。两年来,项目组共引进孟加拉、越南和缅甸等3个天然野生罗氏沼虾原种,分别采取了选择育种和杂交育种两种方法进行良种选育工作,现已取得初步结果：     

提高罗氏沼虾育苗成活率的试验

提高罗氏沼虾育苗成活率的试验陆锦天，潘家模，洪新明（上海市水产研究所，２００４３３）近年来，罗氏沼虾的人工育苗技术虽已有所提高，但尚未完善。存在的主要问题是单位水体出苗量低；幼体成活率不高，以致生产成本居高不下；产量也很不稳定。为了提高罗氏沼虾的育苗...     

罗氏沼虾工厂化育苗试验

利用对虾育苗场的设计进行罗氏沼虾工厂化育苗试验，于１３６ｍ＾３水体中投放状幼体１４３８万尾，育出商品仔虾９６４万尾，幼体培育成活率为６７％，平均每尾亲虾出苗４７２５尾，单位水体平均出苗量为７．０９万尾，最高为１０．２万尾／ｍ＾３。从４月上旬到５月下旬，罗氏沼虾雌性亲虾可抑卵三次以上，前后抱卵批次所孵出的幼体质量没有明显差异。试验还证明，幼体培育池内氨氮浓度高达１０５６．４μｇ／ｌ对成活率没有多大曩     

低盐度条件下罗氏沼虾人工育苗试验

在水温30的条件下,用8个盐度梯度(4、7、10、13、16、19、22、25)的育苗用水进行罗氏沼虾人工育苗对比试验,结果表明:在7￣13的盐度范围内,罗氏沼虾幼体生长发育正常,变态时间均值为181d,而过高或过低盐度明显延长变态时间,且存活率很低;用淡水孵化罗氏沼虾幼体,每天增加盐度2￣10,幼体的生长发育和变态与育苗盐度始终保持在10的对照组相比没有显著差异;罗氏沼虾在盐度为10的水体中孵化并发育到第期后,每天降低盐度2直到变态,幼体变态时间平均缩短2￣3d,且变态同步性较高。研究表明,罗氏沼虾幼体对盐度变化有较强的适应能力,因此在低盐度条件下进行罗氏沼虾生产性育苗是可行的,本研究可明显节约罗氏沼虾育苗过程中的海水用量,降低育苗成本,为内陆地区大面积推广罗氏沼虾养殖提供了一定的技术依据。     

卤虫的营养强化及其对罗氏沼虾幼体培育的影响

用小球藻强化培育卤虫，研究不同时间后卤虫体内脂肪酸的变化，并用此卤虫投喂罗氏沼虾幼体，研究其对罗氏沼虾幼体发育及成活的影响。实验结果表明，卤虫在强化12h后EPA及HUEA含量最高，强化时间延长至24h，EPA和HUFA含量反而下降。卤虫经营养强化可明显地促进罗氏沼虾幼体的生长发育并提高育苗成活率，而且在24h内随着强化时间的延长，效果越明显。     

晚期罗氏沼虾苗短周期养殖试验

本文报导了7月底育成的0.7～0.9厘米罗氏沼虾苗,每平方米放养25尾左右,与鱼混养,经104天的饲养,达到了每公顷产罗氏沼虾1528公斤和鱼种2661公斤。平均每公顷经济效益达31315.5元,投入产出比为1:1.82。罗氏沼虾的成活率为67.9％。平均规格为9.1克/尾,雄虾最大个体重达24克,雌虾达15.8克。85％的虾体长在7～9.7厘米。文章还讨论了进一步提高规格和产量的可能性。     

异型雄性罗氏沼虾遗传多样性的微卫星分析

利用微卫星DNA标记研究3种近亲交配形态型雄性罗氏沼虾遗传多样性,所用虾样均采自国家级(南宁)罗氏沼虾良种场,共150尾成年近亲交配的雄虾,其中蓝色长臂型、橙色长臂型、小个体型各50尾。研究结果表明,3组样品的生长发育差异显著,蓝色长臂型、橙色长臂型、小个体型各组中微卫星位点的总等位基因分别为24、28和22,3组样品所有位点的平均观察杂合度为0.474～0.556。其平均群体内近交系数为-0.0189,说明杂合子过剩,对比分析和群体间分化系数表明,3组雄虾遗传差异明显,最大遗传间距位于蓝色长臂型和小个体型,最小的遗传间距位于蓝色长臂型和橙色长臂型。研究结果将为罗氏沼虾优质父本选育和调控雄性遗传发育提供基础性遗传信息。     

The effects of dietary lipid sources and lecithin on the production of giant freshwater prawn <Emphasis Type="Italic">Macrobrachium rosenbergii</Emphasis> larvae in the Mekong Delta region of Vietnam

The giant freshwater prawn, Macrobrachium rosenbergii, is cultured widely in the Mekong Delta region of Vietnam but it is often difficult or expensive for hatchery operators to purchase commercial diets used as a feeding supplement to Artemia nauplii. Therefore, in the present study, the effects of lipid sources and lecithin on the growth and survival rate of M. rosenbergii larvae were examined in order to develop suitable hand-prepared larval diets for seed production of M. rosenbergii in this area. Six egg custard diets consisting of various ratios of lipid (originating from soybean oil and squid oil) and lecithin were used for rearing Macrobrachium rosenbergii larvae. Treatments in which larvae were fed diets containing squid oil exhibited the highest body length and survival rates (7.14–7.43 mm and 51.1–68.1%, respectively), and differed significantly from other treatments (P<0.05). Use of dietary soybean oil yielded the lowest body length and survival rates (6.29–6.75 mm and 22.0–48.7%), respectively). The supplementation of dietary lecithin did not increase final body weight but did improve larval survival rates. The n-3 HUFA content of prawns fed dietary squid oil was higher than those of animals provided with other diets. These results indicated that the most appropriate diet for rearing M. rosenbergii larvae is the diet containing 3% squid oil and 1.5% lecithin.     

Biochemical Changes in Freshwater Prawn Macrobrachium rosenbergii During Larval Development

Abstract.— Quantitative changes in the protein, lipid and carbohydrate were studied in the early larval stages of developing freshwater prawn Macrobrachium rosenbergii reared under fed and starved conditions to understand the relative importance of these nutrients in energy metabolism of the growing larvae. Larvae obtained from several females were stocked into three 250-L tanks at a density of 30 larvae/L. The feeding regime consisted of newly hatched Artemia nauplii. Protein was always the major organic constituent followed by lipids and then carbohydrates of both fed and starved larvae. Protein levels of both fed and starved larvae increased during development, suggesting an important role in morphogenesis. The decline of lipid during the larval growth that was more rapid for starved larvae, suggests a probable utilization of lipid as the major metabolic source of energy. Carbohydrates formed less than 5 and 2.4% of the larval dry weight of fed and starved larvae, respectively, suggesting their limited role in larval metabolism.     

罗氏沼虾大规模家系构建与培育技术研究

为建立罗氏沼虾育种项目,2006年利用罗氏沼虾3个群体,通过巢式交配设计,实现了大规模构建罗氏沼虾父系半同胞家系。实验中,每箱放置亲虾1雄5雌,按交配设计共布置100个交尾网箱;通过对培育条件及幼体数量的标准化,使每个家系在幼体培育的各个阶段的条件尽量保持一致,减少由于条件不一致造成的家系间的环境偏差。结果显示,500尾雌虾抱卵虾为271尾,亲虾抱卵率平均为54.2%,且每个网箱出现两尾以上抱卵虾的网箱数为92个,占全部网箱数的92%;通过标准化培育,最终建立了123个家系,其中含有父系半同胞家系37个。本试验结果为建立罗氏沼虾全同胞和半同胞家系提供了依据。     

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：     

厚壳贻贝早期幼虫低温保存的影响研究

探讨低温(4 ℃)条件下的厚壳贻贝早期幼虫保存可能性,同时调查了不同培育密度对低温保存的影响。在正常条件下,继续培育低温保存后的幼虫,并调查其存活率和生长的变化。 结果表明,在低温保存后,早期幼虫存活率较高,超过95%;厚壳贻贝早期幼虫的壳长和壳高出现显著性的增长。不同培育组间,培育密度对厚壳贻贝早期幼虫的存活和生长影响不同,表明密度是幼虫低温保存的一个重要因素。在正常培育条件下,低温保存后的幼虫,3周后其存活率明显低于对照组,但仍超过50%,且其生长速度明显高于对照组。因此,低温培育是保存厚壳贻贝早期幼虫的有效方法,可用于今后贝类幼虫生物学实验和人工育苗技术的改善研究。     

罗氏沼虾池塘养殖高产试验

本文报导0.7厘米罗氏沼虾苗经3～21天的网箱暂养,体长达到1.0～2.5厘米,每公顷池塘放养11.35万尾左右,与鱼混养,经120天的饲养,达到了每公顷产罗氏沼虾1532.3公斤和鲢鱼1152.0公斤,平均每公顷经济效益达43059.0元,投入产出比为1:1.79,罗氏沼虾的饲料系数2.12,平均成活率75.3％,平均规格18.4克。     

Larval Development of the Giant River Prawn Macrobrachium rosenbergii at Different Ammonia Concentrations and pH Values

The effect of ammonia and pH levels on giant river prawn Macrobrachium rosenbergii larvae were evaluated to provide science-based information on safe levels of ammonia and pH for larviculture. Survival rate, developmental stage, and larval weight gain were determined for larvae kept in water with total ammonia (NH ₄-N)concentrations of 0, 1, 2, 4, and 8 mg\L and pH 7, 8, and 9. The trials were conducted in two phases: phase 1, larvae from stages I through VIII and phase 2, larvae from stage VIII until metamorphose. Oxygen consumption was determined for larvae in stages I and VIII at total ammonia concentrations of 0, 4, and 8 mg/L and pH 8. Survival rate up to stage VIII varied from 86 to 98% and did not differ for total ammonia concentrations in pH 7 and 8 and for 0 mg/L NH₄ N in pH 9. Survival rate was significantly lower (0–20%) for total ammonia concentrations from 1 to 8 mg/L (0.43–3.41 mg/L of unionized ammonia) in pH 9. Larval stage indexes (7.9–8.0 range) and weight gain (1.572–2.931 mg range) of larvae at the end of phase 1 of the experiment did not differ for the different ammonia concentration solutions, but were significantly lower in pH 9. In phase 2, no parameter differed among treatments for pH 7 and 8; however there was total mortality at pH 9 until 96h. Respiration rates diminished when larvae were exposed to total ammonia concentrations of 4 and 8 mg/L (0.28 and 0.55 mg/L of unionized ammonia), but development remained unaltered. Therefore, M. rosenbergii larvae tolerate high levels of total ammonia, while toxicity depends primarily on unionized ammonia concentrations. In addition, alkaline pH (9) acted directly on the larvae, curbing development and causing severe mortality. Larval tolerance to high ammonia and pH levels decreases for the last zoeal stages.