Experimental studies on intensive polyculture of Chinese shrimp with bay scallop

用放在海水池塘中的８个陆基围隔（５０ｍ×５０ｍ×１８ｍ），研究中国对虾（Ｐｅｎａｅｕｓｃｈｉｎｅｎｓｉｓ）与不同密度海湾扇贝（Ａｒｇｏｐｅｃｔｅｎｉｒａｄｉａｎｓ）投饵混养的放养方式、生产力和极限放养量。对虾体长（２８５±０１６）ｃｍ，扇贝壳长（１１０±０１２）ｃｍ，放养密度分别为６０尾／ｍ２和０，１５，４５，７５粒／ｍ２，用投饵和施肥（鸡粪和化肥）饲养。结果表明，扇贝密度为０和１５粒／ｍ２时，对虾的成活率无显著差异。混养（扇贝１５粒／ｍ２）时对虾的出塘体长、体重和产量分别比单养高２５％，３８％和６５％；当扇贝密度高于１５粒／ｍ２时，对虾的平均体长、体重和产量随扇贝密度的增加而显著减少（Ｐ＜００５）。扇贝密度为１５和７５粒／ｍ２时，其产量由４７０ｋｇ／ｈｍ２增至１２３６ｋｇ／ｈｍ２；当扇贝密度高时，去壳后湿重占体重的百分数从（４２８４±３４４）％降至（３７８８±４２６）％。扇贝的极限放养量为６００～８００ｋｇ／ｈｍ２，适宜放养密度为１０～１５粒／ｍ２。     

鲈-中国对虾-罗非鱼混养的实验研究

1996年 5～ 10月在 1.7hm2 池塘中设 6个 5.0m× 5.0m× 2 .0m陆基围隔 ,研究了鲈 (Lateolabraxjaponicus)、中国对虾 (Penaeuschinensis)和台湾红罗非鱼 (Oreochromismossambicus×O .niloticus)投饵混养的养殖模式。鲈和罗非鱼放养在围隔内的浮式网箱中 ,对虾散放在围隔中 ;鲈在围隔中设 3个放养密度 ,分别为 0 .76、1.52和 2 .2 8尾 /m2 ;对虾 ( 2 .2 8尾 /m2 )和罗非鱼 ( 0 .2 4尾 /m2 )均为单一密度 ,每个处理 2个重复。给鲈投喂冻杂鱼 ,对虾不投喂。实验结果表明 ,鲈出塘体重 ( 2 14.2～ 34 8.3g)和成活率 ( 2 6.3%～ 10 0 .0 % )随放养密度的增加而减少 ,净产量为 174 3.3～ 2 4 68.7kg/hm2 ,生产力为 3.2 6g/d·m2 ,负荷力 2 50 0～2 80 0kg/hm2 。鲈的密度为 1.52尾 /m2 时 ,对虾的出塘体长 ( 10 .2 5cm )、产量 ( 58.35kg/hm2 )和成活率( 17.55% )最高 ,生产力为 0 .4 3g/d·m2 。鲈的适宜放养密度为 38尾 /m2 ,与对虾和罗非鱼的适宜数量比为 1∶( 3～ 4 )∶0 .2 4。还讨论了 3种生物调节水质的生态作用。     

低盐水体南美白对虾与鲢鳙鱼混养的试验

在6口低盐淡水(盐度2～10)池塘中放养体长0 8～1 0cm的南美白对虾(Penaeusvan namei)(30万尾/hm2),其中三口塘再放养鲢(Hypophthalmichthysmolitrix)、鳙(Aristichthysno bilis)夏花(体长2 0～3 0cm)(1500尾/hm2,鲢:鳙=1:1)。鱼、虾分别精养90d和60d。混养池塘中对虾的成活率(24 6%)为单养池(9 1%)的2 7倍,产量(800 0±86 7)kg/hm2为单养池的3 2倍;鱼产量为(93 9±7 9)kg/hm2,鳙的出塘规格大于鲢,产量高于鲢。混养池塘水中氨氮、亚硝态氮和溶解氧含量低;透明度和活性磷含量高;pH值波动幅度小。     

混养锦鲤对微咸水凡纳滨对虾池水质及产量的影响

在6口面积均为0.4 hm2的微咸水池中养殖凡纳滨对虾,密度为7.5×105尾/hm2,其中4口混养锦鲤,密度分别为1500、3000、60001、2 000尾/hm2,研究混养锦鲤对凡纳滨对虾池水质及产量影响。结果表明:混养池水质比较稳定,透明度、NH4+-N和NO2--N波动幅度较小且数值较低,混养池对虾平均产量为3345 kg/hm2,比单养池平均产量2268 kg/hm2高47.5%,其中混养锦鲤3000尾/hm2的池虾产量最高,达到3765 kg/hm2。     

对虾养殖池塘混养牡蛎对底质有机负荷的作用

以18个海水池塘陆基围隔进行对虾池塘不同密度混养牡蛎试验,利用N、S、P综合相对污染指数对不同密度混养牡蛎对虾池塘底质养殖负荷进行评估,结果表明,混养牡蛎虾池底质中N、S、P营养指标随养殖进程呈上升趋势,到实验结束时,不同密度梯度牡蛎混养围隔底质污染程度不同,根据N、S、P综合相对污染指数评估养殖负荷,各围隔呈低谷状排列:Ⅱ组(98.14)>Ⅲ组(60.64)>Ⅳ组(33.05)>Ⅴ组(29.68)<Ⅵ组(126.85);不同密度处理中,位于谷底的Ⅴ组为最佳放养密度点,对于养殖密度为4.5×106尾/hm2的对虾池塘,混养牡蛎最佳生物量为1003.2g/m3,转换为生产规模,则混养牡蛎最佳生物量为1.01×104kg/hm2。     

淡水池塘南美白对虾与鲻鱼生态混养技术研究

2017、2018年连续2年利用7口0.4 hm2(6亩)对虾养殖池在淡水条件下进行了鲻鱼与南美白对虾混养试验.试验结果:鲻鱼放养规格48～80 g/尾,放养密度为75～225尾/hm2,收获鲻鱼规格为420～520 g/尾.2017年,南美白对虾单养池(对照池)产量为6090 kg/hm2,6口鱼虾混养池产量分别比对...     

凡纳滨对虾微咸水土池混养瓯江彩鲤试验

利用6 口微咸水土池中进行凡纳滨对虾与瓯江彩鲤的混养试验,各池对虾的放养密度均为5万尾/667 m2,瓯江彩鲤夏花的放养密度分别为0、0、100、200、400、800 尾/667 m2.试验结果表明:混养瓯江彩鲤的池塘,对虾产量及养殖经济效益明显好于单养池,而瓯江彩鲤夏花鱼种的混养密度以200 尾/667 m2为最好.     

不同密度的卵形鲳鲹与凡纳滨对虾混养效果研究

在水温27.6～33.6℃下,在0.2 hm2池塘中放置21个24 m2(4 m×6 m×水深1.5 m)围隔,放养体质量3.4 g的凡纳滨对虾Litopenaeus vannamei 1 728尾(即7.2 x 105尾/hm2),分别混养体质量65 g的卵形鲳鲹Trachinotus ovatus 0尾(C 组)、...     

贝类对对虾养殖池塘沉积物中小型底栖动物的影响

通过分析凡纳滨对虾单养及其与泥蚶混养实验的沉积物的理化特性、小型底栖动物种类组成及其生物量的变化,研究贝类对对虾池中小型底栖动物的影响。实验中对虾放养密度均为17×10~4个/hm~2,泥蚶密度分别为0粒/m~2(S)、60粒/m~2(SC1)、120粒个/m~2(SC2)和180粒/m~2(SC3)。结果显示,随养殖时间增加:(1)沉积物中有机物含量呈上升趋势,pH与氧化还原电位逐渐下降;随贝类放养密度增加,底质环境恶化程度趋缓;(2)小型底栖动物的丰度和生物量呈下降趋势,随着贝类放养密度增加,小型底栖动物的群落结构变化逐渐减少;(3)回归分析表明,介形类与线虫比值与对虾产量呈较好的相关性,一定密度贝类混养有利于底泥中介形类与线虫比值的提高,初步结果为养殖过程中该比值平均要达到6,单次值不低于3.5。研究表明,对虾与泥蚶混养有利于底质的改善和小型底栖动物的生长,较高密度的泥蚶(80~140个/m~2)有明显净化底质的作用。     

对虾养殖池塘混养罗非鱼对底质有机负荷的作用

采用18个36 m2的围隔进行对虾单养和对虾–罗非鱼混养实验,利用N、S、P综合相对污染指数对单养和混养围隔底质有机负荷进行研究。实验分为6组,每组3个围隔。各围隔放养体长为(0.45±0.01)cm的凡纳滨对虾3 000尾,放养体重为(201±25)g的罗非鱼分别为0(Ⅵ组)、4(Ⅰ组)、8(Ⅱ组)、12(Ⅲ组)、18(Ⅳ组)和24尾(Ⅴ组),放养对虾1个月后再放养罗非鱼。实验期间各围隔均不进行水交换,实验周期为70 d。结果表明,各围隔底质中N、P、S呈现显著上升趋势,但对虾-罗非鱼混养围隔底质中N、P、S的积累量均小于对虾单养围隔。其中,Ⅲ组的N、P、S增长率最小。各组围隔相对污染指数排列如下:Ⅵ(10.78)Ⅴ(8.30)Ⅰ(7.68)Ⅳ(7.40)Ⅱ(6.09)Ⅲ(4.12),其中Ⅲ组的相对污染指数显著小于Ⅵ组(P0.05)。Ⅲ组为本实验的效果最佳组,即混养最佳配比为凡纳滨对虾8.3×105尾/hm2、罗非鱼3 320尾/hm2,罗非鱼均重为(201±25)g/尾。本研究可为对虾–罗非鱼混养中选定合适的养殖容量提供参考。     

对虾池不同综合养殖系统效率和效益的比较研究

利用５０个５．０×５．０×１．８ｍ陆基围隔研究了中国对虾与台湾红罗非鱼、海湾扇贝和缢蛏投饵或施肥混养及鲈鱼与中国对虾和台湾红罗非鱼混养最佳结构的生态效率、生产效果和经济效益。结果表明,几种综合养殖系统最佳结构下各种养殖对象对Ｎ的绝对利用率由高至低依次为：鲈鱼－对虾－罗非鱼（３０．９１％）＞对虾－海湾扇贝（２１．０９％）＞对虾－罗非鱼施肥混养（２０．１２％）＞对虾－罗非鱼投饵混养（１７．８１％）＞对虾－缢蛏（１６．９３％）＞单养对虾（１１．５２％）;对Ｐ的绝对利用率由高至低依次为：对虾－缢蛏（１６．０８％）＞鲈鱼－对虾－罗非鱼（１２．８３％）＞对虾－罗非鱼投饵混养（１２．６３％）＞单养对虾（１０．８８％）＞对虾－海湾扇贝（６．０１％）＞对虾－罗非鱼施肥混养（４．０４％）;其产出投入比由高至低依次为：对虾－罗非鱼投饵混养（１．９９）＞对虾－罗非鱼施肥混养（１．９８）＞对虾－海湾扇贝（１．５３）＞单养对虾（１．３８）＞鲈鱼－对虾－罗非鱼（１．３０）＞对虾－缢蛏（１．２３）。     

凡纳滨对虾-鲻网围分隔混养模式下经济与生态效益评价

为探索新型对虾生态养殖模式,于池塘中构建围网开展了凡纳滨对虾（Litopenaeus vannamei）-鲻（Mugil cephalus）混养试验。鲻密度依次为0尾（M0,对照组）、250尾（M250）、500尾（M500）和800尾（M800）。结果显示,鲻放养组的饵料系数均比对照组低,但组间差异不显著（P〉0.05）。M250组对虾产值（30.30×10^4元·hm-2）及总产值（31.02×10^4元·hm^-2）为各组最高,M800组对虾产值（20.96×10^4元·hm^-2）及总产值（23.30×10^4元·hm^-2）最低。试验结束后,放养较多鲻的处理组（M500和M800）的总有机碳（TOC）有约20 mg·L^-1幅度的下降,而M0和M250则变动极小,但组间差异不显著（P〉0.05）。养殖末期鲻放养组的亚硝态氮（NO2-N）质量浓度均高于对照组M0,且M250组NO2-N及氨氮（NH4-N）质量分数居于各组最高（P〉0.05）。试验表明,在池塘围网混养少量鲻（M250）时对虾产量最高,而混养较多鲻（M500和M800）时饲料成本较为节约且水质指标较好。采取养殖前期多放鱼,后期适当分鱼以降低密度的措施,可能更有利于虾塘经济与生态效益的提高。     

Semi-Intensive Commercial Grow-Out of Penaeus vannamei Fed Diets Containing Differing Levels of Crude Protein During Wet and Dry Seasons in Honduras

Shrimp were grown under ideal management conditions during two distinct seasons of the year at stocking densities used most often in Honduras with the objective of evaluating the usefulness of high protein diets. A randomized design in 2 × 2 factorial arrangement was used to test a diet composed of either 20 or 40% crude protein in earthen ponds that were stocked with juvenile Penaeus vannamei at 5 to 11/m². The study was repeated during wet and dry seasons. Dietary protein level had no significant effect ( P > O .05) on survival, yield, or average weight of shrimp at either density during either season. Higher stocking rates yielded significantly greater shrimp production during both seasons. Mean shrimp weight in high density ponds was significantly lower than mean shrimp weight in low density ponds during the wet season, but there was no significant weight difference because of stocking density during the dry season. Mean survival was significantly lower at the higher stocking rate during the dry season. Net income was negative during the dry season, particularly at the high stocking density. Mean production was 240% greater in the wet season than in the dry season. Diets offered P. vannamei stocked at 5 to 11/m² should contain no more than 20% protein, regardless of season. Higher dietary protein levels increase costs and waste nitrogen without resulting in greater shrimp yields. The high stocking density might increase profitability in the wet season, but long term sustainable production may be more feasible at lower stocking rates because of reduced nutrient wastes.     

Effects of zooplankton refuge on the growth of tilapia (<Emphasis Type="Italic">Oreochromis niloticus</Emphasis>) and plankton dynamics in pond

Effects of zooplankton refuge on the growth of tilapia (Oreochromis niloticus) and plankton dynamics in pond were assessed by using 12 land-based experimental enclosures (7 m× 4 m) in a saline–alkaline pond. There were 4 treatments resulting from a combination of 2 stocking densities of tilapia (5 and 10 kg per enclosure) and 2 enclosure types (refuge and nonrefuge). Each treatment had three replicates. In the enclosures with refuge, all fish were excluded from a water column ¼ of the enclosure’s size with a polyethylene net (1.5 cm mesh size). Our field experiment showed that the individual gain in weight of tilapia increased 6.4 times with refuge treatment at the stocking density of 5 kg per enclosure than that in nonrefuge treatment. But at the stocking density of 10 kg per enclosure, the individual fish weight in all enclosures decreased due to the excessive density of fish stocking. Our results also showed that the refuge significantly increased the rotifer biomass and phytoplankton diversity and decreased the phytoplankton biomass (P < 0.05), but the copepod biomass was not affected by the refuge.     

Production and yield of Penaeus semisulcatus (de Haan) cultured at different densities

Two trials were conducted with two sizes, grow‐out (80.0 mg b.w.) and fattening (5.0 g b.w.), of Penaeus semisulcatus to compare the production and yield of shrimp cultured at different stocking densities within an indoor running‐seawater system. In the first experiment, postlarvae were cultured at 50, 100, 150 and 200 m^?3 for 68 days, while in the second experiment, juveniles were cultured at 24, 50, 74 and 100 m^?3 for 126 days. The results of the two experiments showed significant decrease in weight of shrimp as the stocking density increased. During the grow‐out stage, no statistical differences were observed on survival rates among the shrimp stocked at different densities. Thus, as the primary factor to consider at this stage is the number of shrimp produced, it is recommended to use a density of 200 shrimp m^?3. During the fattening stage, the survival rate at the highest density was statistically lower than the other three densities. The mean yield was 437.02, 869.16, 1217.62 and 1446.78 g m^?3 for shrimp stocked at 24, 50, 74 and 100 m^?3 respectively. Although the average harvest size of juveniles at the lowest stocking density was statistically higher than those stocked at the highest stocking density, both sizes (18.12 and 16.67 g) will be classified as one size group in the market, i.e. medium. As the yield significantly increases as the stocking density is increased, it is therefore recommended that the stocking density for the fattening stage be 100 shrimp m^?3.     

养殖密度对克氏原螯虾生长及消化酶、免疫酶活性的影响

水温(25±1)℃时,将体质量(3.11±0.10)g的克氏原螯虾幼虾饲养在120 cm×60 cm×20 cm的水族箱中,密度分别为14尾/m2(低密度组)、28尾/m2(中密度组)和42尾/m2(高密度组),研究室内养殖不同密度对生长、摄食、消化酶活性及非特异性免疫的影响.8周的养殖结果显示,克氏原螯虾的存活率随养...     

密度对网箱养殖硬头鳟生长及经济效益的影响

本文主要研究密度对网箱养殖硬头鳟Oncorhynchus mykiss存活和生长的影响。在水温8.2~19.1℃下,将体质量1.02 kg的硬头鳟鱼种养殖在5m×10m×6m网箱中,网箱放置在松花江上游的松山水库中,密度分别为5尾/m~2(Ⅰ组)、8尾/m~2(Ⅱ组)、11尾/m~2(Ⅲ组)和14尾/m~2(Ⅳ组),投喂粗蛋白含量为42%、粗脂肪22%的颗粒饲料,常规养殖。145d的养殖表明:网箱养殖的放养密度对硬头鳟的生长有一定影响。第Ⅳ组鱼的存活率显著低于其他3组(P0.05);放养密度为5~11尾/m~2时硬头鳟的生长与密度呈正相关,大于此密度范围则呈负相关。第Ⅲ组鱼的终末体质量、日增重、增重率、利润和利润率显著高于其余3组(P0.05);4个密度组硬头鳟的产量随放养密度增加而递增。本试验表明:网箱养殖硬头鳟的放养密度为11尾/m~2较适宜。