罗氏沼虾早苗的中间培育及成虾高产养殖

介绍了在塑料棚控温土地内对罗氏沼虾早繁苗进行放养前中间培育及池塘成虾高产养殖的具体过程和方法，探讨了罗氏沼虾早苗中间培育和成虾养殖的一些技术问题。     

罗氏沼虾养殖技术之三:罗氏沼虾一年两茬养殖技术要点

利用塑料大棚培育早繁虾苗,5月至8月中旬养殖第一茬罗氏沼虾,8月中旬至10月中旬养殖第二茬罗氏沼虾;或6月至9月养殖罗氏沼虾,10月至翌年5月养殖青虾。这样,一年养殖两茬虾,可以充分利用养殖水面和其中的饵料生物资源,大幅度提高养虾经济效益。一、选好塘口要求池塘面积8亩～10亩,水源充足,水质良好,水深2m以上,坡比1∶2.5。池塘中央开一道4m～6m宽的集虾沟,以便于捕捞。根据养殖规模,可采用高灌低排工艺,以建好进、排水系统。二、种苗培育养殖两茬罗氏沼虾,3月下旬至4月上旬购进早繁虾苗,利用塑料大棚强化培育,力争6月中下旬虾苗规格达到体…     

两季虾养殖技术

两季虾的养殖系指利用塑料大棚温室培育早繁虾苗，5月至8月中旬饲养前茬罗氏沼虾，8月中旬至10月份再养后茬罗氏沼虾；或6月至9月底前茬饲养罗氏治虾，10月至翌年5月再养一季青虾。青虾、罗氏沼虾都是当前市场上的抢手货，需求量大，价格看好。推行两季虾的养殖，一可充分利用养殖水体和饲料资源，增加有效产出；二可大幅度提高池塘养虾的经济效益，一般每亩可增加利润1000元以上，大有可为。推行两季虾的养殖，要掌握以下技术要点。王选好过口，拍好配套建设选作两季虾养殖的池塘，面积以10～20亩为宜，长方形，东西向，底上以粘壤上为好，…     

报刊要闻

<正> 两季虾养殖技术 两季虾的养殖系指利用塑料大棚温室培育早繁虾苗,5月至8月中旬饲养前茬罗氏沼虾,8月中旬至10月份再养后茬罗氏沼虾;或6月至9月底前茬饲养罗氏沼虾,10月至翌年5月再养一季青虾。其养殖技术要点为:(1)选好池塘,搞     

一年养殖两季虾技术

１、池塘选择与建造 池塘应选择在紧靠水源、水质清新、没有污染、进排水方便的地方。虾池面积以１０～１５亩为宜，要求水深１．８－２米。对新开挖的养殖池要在池底中央开一道４～６米宽的集虾沟，以便捕捞。 ２、种苗培育 饲养两季虾，要提前建好塑料大棚。３月下旬至４月上旬购进早繁罗氏沼虾苗进行强化培育，力争５月中下旬虾苗规格达到３厘米；６月上旬购买青虾苗，选好培育池，设置小网箱若干，放养抱卵青虾，至９月底青虾虾苗规格可达３厘米左右。 ３、合理放养 前季养殖罗氏沼虾，每亩放虾苗２万～２．５万尾，后季青虾每亩放养１…     

塑料大棚强化培育罗氏沼虾早繁苗的优点

从1992年起，我县开始进行罗氏沼虾养殖，在养殖初期，对于虾苗投放，先采取直接投放、暂养池暂养后投放，以及目前大家采用的将早繁虾苗经过塑料大棚强化培育后再投放三种方法，我们简称为直放苗、暂养苗和大棚苗。暂养池一般使用养虾池，暂养达到一定规格时放入大面积水中进行饲养，这样便于彻底除害、集中投饵等早期管理，既可确保仔虾有安全的生活环境，又可保证仔虾有适口的饵料来源。在早春时节，水温低于15℃，不＼能将虾苗投入池中饲养。塑料大棚利用棚内小面积人工增温的办法，将早繁虾苗进行强化培育，使其达到一定的规格，再进行…     

浅析罗氏沼虾"转池"现象产生的原因、危害及防控措施

罗氏沼虾的“转池”就是指虾在水表层或中下层出现的缓游、漫游等异常活动现象，一般来说“转池”具有集群性，罗氏沼虾从虾苗培育阶段到成虾养殖的整个过程中经常会出现虾苗、幼虾的“转池”现象，尤其是从3月中下旬至5月中旬的（锅炉加温）塑料大棚苗的培育阶段（为达到提前放苗、提早上市的目的，高邮市的罗氏沼虾养殖大多采用塑料大棚培育虾苗，其中60％左右的大棚为锅炉加温塑料大棚），由于放苗密度较大（一般每平方米放苗3000～5000尾），培育时间长，     

塑料大棚养殖二茬罗氏沼虾技术

在长江中下游地区,池塘养殖罗氏沼虾一般的放苗时间在5月上中旬,这是因为前期水温低且容易受冷空气的影响,在4月初室外水温还不到15℃,虾苗不能直接下池培育。利用简易塑料大棚进行罗氏沼虾苗种的前期强化培育,对提高罗氏沼虾的单位产量及商品虾提前上市,增加经济效益可以起到明显的作用。一、塑料大棚暂养育苗池的建设应用简易塑料大棚暂养苗种,经过25天~30天时间的培育,使罗氏沼虾苗种出池时的规格达到体长3cm以上,从而对低水温影响的适应能力增强,提高了养成成活率。同时,苗种提前25天左右放入大池中养殖,也为二茬养殖打下了坚实的基础。…     

罗氏沼虾养殖技术之一塑料大棚养殖二茬罗氏沼虾技术

在长江中下游地区,池塘养殖罗氏沼虾一般的放苗时间在5月上中旬,这是因为前期水温低且容易受冷空气的影响,在4月初室外水温还不到15℃,虾苗不能直接下池培育.利用简易塑料大棚进行罗氏沼虾苗种的前期强化培育,对提高罗氏沼虾的单位产量及商品虾提前上市,增加经济效益可以起到明显的作用.     

罗氏沼虾高产养殖试验

1996年5-10月利用3口共11亩池塘进行罗氏沼虾单养高产试验，养殖前期侧重利用温室中间培育大规格虾苗，清塘肥水，及采取措施提高虾苗下塘成活率；养殖中期侧重强化饲料投喂，预防浮头，及调控好水质；养殖后期侧重采用综合的生态方法促进虾蜕皮生长，保证出塘虾质量，及商品虾捕捞均衡上市，经过4个月左右的养殖，平均亩产虾144.4kg，最高亩产226.5kg，平均亩净利润3458.6元。     

人工控制培育缢蛏幼苗研究

本文探索采用缢蛏幼体实验生态研究的成果，控制缢蛏幼体各发育阶段较佳生态条件，进行人工控制培育幼苗研究，取得了较好的效果．单位出苗量为5．46万粒／M^2。至21．06万粒／M^2。，每公顷产量达8000千克至20000千克．这比自然海区正常年景蛏苗产量提高10-20多倍，从而显示出工厂化人工育苗的可行性和发展前景．文中也提及在人工控制培育幼苗中亟待解决的若干问题。这些为缢蛏人工控制培育幼苗进一步深入研究提供有益的参考．     

Estimation of flow in a rearing tank of marine fish larvae by simplified numerical computation—a case of two-dimensional flow

Marine fish larvae are fragile against physical stress. However, few studies have been conducted to evaluate the flow field in a rearing tank, which is assumed to provide a high degree of physical stress to marine fish larvae. The flow field in a rearing tank (volume of 1 m³) is generated by aerators, which are commonly used to provide oxygen.

This paper is a report on the estimation of stationary flow in the rearing tank of marine fish larvae. The larvae are seven band grouper larvae of Epinephelus septemfasciatus, which have a very low survival rate immediately after the hatching of eggs. The experiments of rearing of seven band grouper larvae were carried out using rearing tanks with four aeration rates (1000, 200, 50 ml/min, and no aeration). The effects of aeration on the survival and floating death of seven band grouper larvae were examined. The experiments confirmed that the mass mortality of seven band grouper larvae depends on the flow rate in the rearing tank. Aeration at 200 ml/min resulted in the highest survival and growth rates of grouper larvae.

Larvae-rearing experiments provided evidence that the flow rates of the rearing tanks are very important design aspects of rearing tanks. The estimation of flow in a rearing tank for an aerating rate of 200 ml/min was carried out by numerical calculation. The computation was simplified by a two-dimensional flow based on experimental results. The calculated flow in the rearing tank was compared with the experimental one. The calculation of the stationary flow in the rearing tank showed good qualitative and quantitative agreement with the experimental results. The numerical estimation of the flow in a rearing tank of marine fish larvae was confirmed to be effective and satisfactory for the design of a tank that would provide optimum performance.     

Larval Age at Stocking,Growth, and Survival During Fingerling Production of the Endangered Sun Catfish,Horabagrus brachysoma

An experiment was conducted to ascertain the initial rearing period required for Horabagrus brachysoma larvae before releasing them into the nursery tank for fingerling production. Hatchlings were reared for 7, 14, or 21 days in larval rearing tanks before stocking to nursery tanks. The 7-day-old larvae were significantly smaller at the end of the 2-week nursery rearing, but over the course of nursing, the 7-day-old larvae caught up to the 14- and 21-day larvae. The specific growth rate (SGR) of 7-day larvae was highest among the three treatments. However, mortality of 7-day larvae was the highest among the groups. Hence, it appears important to rear the larvae at least 2 weeks before stocking for fingerling production so as to increase survival rate.     

鲈鲤苗种培育及苗种生长特性的研究

为研究鲈鲤(Percocypris pingi)苗种的生长特性,开发鲈鲤育苗技术,采用水泥池流水单养模式,在自然水温条件下,开展了10日龄至110日龄鲈鲤苗种培育试验。经过100 d的培育,鲈鲤鱼苗体质量从(46.45±4.03)mg增加到(2600.09±105.18)mg,平均体长从(16.22±0.46)mm增长到(50.78±2.97)mm,平均成活率为82.00%;体质量变异系数在4.05%~24.80%,体长变异系数在2.49%~7.32%,体质量变异系数大于体长变异系数;体质量变异系数整体呈现先升高后降低的变化趋势,体长变异系数整体变化较为平缓,在整个培育阶段,鲈鲤种群生长离散呈现从加剧到减弱的变化规律;体质量特定生长率在(0.91±0.49)%/d~(7.75±2.18)%/d,体长特定生长率在(0.47±0.29)%/d~(1.94±1.46)%/d,体质量特定生长率大于体长特定生长率;在水温16.8~23.0℃条件下,鲈鲤生长状况良好,特定生长率相对较高,当水温高于23.0℃之后,特定生长率呈降低趋势,表明16.8~23.0℃是鲈鲤鱼苗适宜的生长水温范围;肥满度变化范围在(1.09±0.10)~(2.85±0.18)g/cm^3,肥满度变化呈现先升高后降低的变化趋势;体长(x)和体质量(y)的拟合方程为y=0.0015x^3.7566(R^2=0.9806),b值为3.7566;全长(y)和体长(x)的拟合方程为y=1.223x-0.5055(R^2=0.9908)。试验结果表明,鲈鲤苗种在水泥池流水单养模式及自然水温条件下生长状况良好,16.8~23.0℃是鲈鲤苗种的适宜生长水温。     

Effects of temperature, salinity and pH on larval growth, survival and development of the sea cucumber Holothuria spinifera Theel

For large-scale seed production of sea cucumbers through a hatchery system, it is imperative to know the effects of environmental parameters on larval rearing. Auricularia larvae (48 h post-fertilization) were obtained from induced spawning of Holothuria spinifera and used in experiments to ascertain the effects of temperature, salinity and pH on the growth and survivorship of the larvae. The larvae were reared for 12 days at temperatures of 20, 25, 28 and 32 °C; salinities of 15, 20, 25, 30, 35 and 40 ppt; and pH of 6.5, 7.0, 7.5, 7.8, 8.0, 8.5 and 9.0. The highest survivorship and growth rate and fastest development of auricularia indicated that water temperature of 28–32 °C, salinity of 35 ppt and pH of 7.8 were the most suitable conditions for rearing larvae of H. spinifera.     

太平洋牡蛎控温育苗高产技术

介绍了太平洋牡蛎亲贝的选择和促熟，获卵与孵化，幼虫发育和培育技术，以及附苗和单体牡蛎苗种生产方法。     

Variations in Bacterial Community of Rearing Water and Gut of Common Dentex,Dentex dentex (Linnaeus 1758), Larvae Using Three Microalgae Management Approaches

Microorganisms present in the rearing water colonize the gut of first feeding larvae and represent the first barrier against opportunistic pathogens. The aim of the experiments presented herein was to standardize a protocol for the management of rearing water and microalgae suitable for the larval rearing of common dentex. In Experiment 1, bacteria–algae interactions were tested using a monospecific microalgal community, Tetraselmis chuii, suitable for nutritional experiments and with known antibacterial activity. In Experiment 2, the evolution of the bacterial community and larval performance (growth and survival) were monitored daily, in three conditions: (1) mature water: T. chuii was added 5 d before the rearing of common dentex larvae, (2) green water: T. chuii was added 1 d before, and (3) clear water: no T. chuii addition. The results show the influence of the presence of T. chuii on the evolution of the bacterial communities, both in terms of bacterial density and morphology, and indicate green water is the most suitable water treatment for management of larval rearing for common dentex.     

硬壳蛤的生物学及养殖

硬壳蛤广泛分布于北美洲东海岸，是美国大西洋沿岸各州的重要经济双壳数。该种对温度和盐度适应性较广，适应多种底质生活。2000年，由美国引入大连，本文结合引入后对其人工育苗和养殖的初步研究，综述了硬壳蛤的生长、繁殖、幼体发育和生态习性等养殖生物学特性和硬壳蛤浮游幼体培养、中间育成及养殖技术等，为硬壳蛤在我国开展增养殖提供参考。     

Reduction of skeletal anomalies in meagre (Argyrosomus regius,Asso, 1801) through early introduction of inert diet

The consolidation of meagre (Argyrosomus regius) in aquaculture requires an understanding and optimization of larval rearing and nutritional conditions. The aim of this study was to analyse the effects of an early introduction of inert diets during larval rearing, on growth performance, digestive enzymes activity and development of skeletal anomalies. This study evaluated the effects of three different timings for the introduction of inert diet during larval rearing: a control group (CTRL) where inert diet was initiated at 14 days after hatching (DAH) and two treatment groups that had an earlier introduction of inert diet at 8 DAH (T1) and 11 DAH (T2). Meagre larvae exhibited similar pancreatic and intestinal enzymatic activities among the different dietary treatments. No differences in the overall prevalence of anomalies were observed between treatments at 25 or 50 DAH, however, a significant reduction was observed in all groups with the transition from larval to juvenile stage. The precocious introduction of inert diet shifted the distribution of vertebral anomalies to a more anterior vertebral column region. Altogether, this study shows that earlier introduction of inert diets in meagre hatcheries can be beneficial for meagre production in aquaculture.     

Larval rearing of African carp,Labeo parvus Boulenger, 1902 (Pisces: Cyprinidae), using live food and artificial diet under controlled conditions

This study aimed at (1) evaluating the efficacy of live food organisms (Artemia and natural zooplankton) and an artificial diet in the larval rearing of African carp Labeo parvus and (2) determining appropriate rearing conditions. After yolk sac resorption, the larvae were separated into five different feeding trials with two replicates. At the end of the larval rearing period (28 days post‐hatching), the highest (94.6%) and the lowest (53.7%) cumulative survival rates were found when larvae were fed with natural zooplankton for 7 days followed by Nippai food for 21 days, and when larvae were fed from the beginning of exogenous feeding with Nippai food only respectively. The significant highest body weight (351.6 mg), total length (34.4 mm) and specific growth rates (15.5%day^?1) were recorded when the larvae were fed with Artemia nauplii for 14 days followed by Nippai food for 14 days. The lowest growth performance (body weight and specific growth rates) were obtained when larvae were fed exclusively Nippai food. These results indicate that L. parvus can be successfully cultured in indoor nursery systems from hatching to the early juvenile stage.