三疣梭子蟹与不同虾类混养技术研究

分别利用中国明对虾、凡纳滨对虾、日本囊对虾和脊尾白虾等虾类与三疣梭子蟹进行混养。结果表明:日本囊对虾与三疣梭子蟹混养组三疣梭子蟹养殖单产最高,平均产量1678.5 kg/hm2,其次为凡纳滨对虾与三疣梭子蟹混养组,平均产量1659 kg/hm2。对虾养殖单产以凡纳滨对虾与三疣梭子蟹混养组最高,平均产量990 kg/hm2,其次为中国明对虾与三疣梭子蟹混养组,平均产量952.5 kg/hm2。但考虑到日本囊对虾市场售价为其他混养虾类的两倍,因而日本囊对虾与三疣梭子蟹混养组养殖效益最高。     

锯缘青蟹大眼幼体与凡纳滨对虾混养试验

利用3口池塘共1.14 hm2进行锯缘青蟹大眼幼体与凡纳滨对虾的混养试验,投放锯缘青蟹大眼幼体8500只,凡纳滨对虾苗2.03×105尾,经96~129 d的养殖,收获锯缘青蟹729.1 kg,凡纳滨对虾2804.3 kg;锯缘青蟹平均312 g/只,凡纳滨对虾57.5尾/kg;锯缘青蟹大眼幼体成活率27.5%,凡纳滨对虾成活率79.4%。试验结果表明,锯缘青蟹大眼幼体可以直接投入池塘中与凡纳滨对虾混养,将为今后大规模发展锯缘青蟹养殖摸索出一条有效途径。     

凡纳滨对虾与点带石斑鱼混养的试验研究

在2.5m×4.0m×2.0m的水泥池中,按3.0×106尾/hm2的密度放养体长2~3cm、4~5cm和8~9cm的凡纳滨对虾。每种规格的对虾3口池塘,其中两口池塘在对虾养殖10d后,分别放入5尾体长为12.3~13.6cm和17.6~18.8cm的点带石斑鱼,另一池单独饲养凡纳滨对虾作为对照组。60d的养殖结果显示,单养池中2~3cm、4~5cm的凡纳滨对虾的质量增加显著低于混养(P0.05),但存活率显著高于混养(P0.05);混养时对虾规格越大增长越快,存活率越低,其中凡纳滨对虾2~3cm,点带石斑鱼17.6~18.8cm及凡纳滨对虾4~5cm,点带石班鱼17.6~18.8cm混养组合的质量增加最大(分别为7.88g与7.67g)。单养和混养时,8~9cm的凡纳滨对虾存活率差异不显著(P0.05)。方差分析显示,对虾规格与养殖模式间的交互作用对对虾质量增加和存活率影响极显著(P0.01);混养时对虾规格对鱼的质量增加影响不显著(P0.05),17.6~18.8cm的点带石斑鱼平均质量增加显著大于12.3~13.6cm(P0.05),对虾规格越大,混养鱼的捕食量越小,凡纳滨对虾8~9cm,点带石班鱼17.6~18.8cm的混养组合对虾存活率高,鱼虾的交互作用对鱼的质量增加和捕食量均有极显著影响(P0.01)。凡纳滨对虾混养的利润显著大于单养(P0.05),其中凡纳滨对虾4~5cm、点带石斑鱼17.6~18.8cm,凡纳滨对虾4~5cm、点带石斑鱼12.3~13.6cm,凡纳滨对虾2~3cm、点带石斑鱼17.6~18.8cm混养组合的利润显著高于其他混养组合(P0.05),凡纳滨对虾8~9cm的养殖利益显著低于其他规格对虾。建议凡纳滨对虾体长达到4~5cm开始混养点带石斑鱼。     

混养奥尼罗非鱼对凡纳滨对虾固着类纤毛虫的影响

于2015年8—12月对混养奥尼罗非鱼的凡纳滨对虾池塘进行对虾体表固着类纤毛虫的研究。在显微镜10×10倍视野下纤毛虫个体数量处于1级(≥30个)情况下,试验池1~#、2~#和3~#池分别放养奥尼罗非鱼苗体长10.0 cm密度4 500尾/hm~2、体长2.1 cm密度15 000尾/hm~2、体长6.0 cm密度9 000尾/hm~2均可以使凡纳滨对虾体表的固着类纤毛虫个体数量降低到4级(≤3个),通过控制饲料的投喂量和投喂频率,每15天测定试验池对虾体表虫体个数,均处于4级(≤3个)水平,1~#、2~#和3~#池净利润分别为75 489、46 625、55 682元/hm~2。试验结果表明:混养一定数量的奥尼罗非鱼对凡纳滨对虾固着类纤毛虫疾病具有防治作用,为该类寄生虫导致的疾病防治提供参考。     

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.     

上海市奉贤地区淡水池塘凡纳滨对虾和鱼类混养模式探讨

为在上海市奉贤全区范围内推广鱼虾混养模式,对该区四团镇有代表性的14个对虾养殖户在凡纳滨对虾和鱼类养殖过程中混养鱼类品种、数量、放养时间和水质管理等关键技术进行了研究和探讨。结果表明:(1)虾池内混养不同品种鱼类的养殖模式,对虾单产由高到低依次为C(对虾、青鱼、草鱼、鲢、鳙混养)B(对虾、斑点叉尾鮰混养)E(对虾、斑点叉尾鮰、鲢混养)A(对虾、鲢混养)D(对虾、青鱼、鲢混养),平均亩产(15亩=1 hm~2,下同)389.6 kg,与同年四团镇6 331亩单养虾塘平均亩产310.38 kg相比增加了79.22 kg。(2)3种规格斑点叉尾鮰(≤500、500~1 000、1 000 g/尾)与对虾混养,对虾单产为400~525 kg/亩,单位面积效益在12 000~15 000元/亩;≤500 g/尾的小规格斑点叉尾鮰组在养殖期间的净增体质量分别为其它两组的2.1倍和1.7倍,表明小规格斑点叉尾鮰在虾池中的生长速度较快。建议凡纳滨对虾池内混养的斑点叉尾鮰规格以500 g/尾左右为宜。     

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...     

方格星虫与凡纳滨对虾池塘混养试验

为研究如何充分利用凡纳滨对虾养殖池的水体、底质空间和饵料资源,降低养殖成本,提高养殖经济效益,进行了凡纳滨对虾与方格星虫的混养试验。试验池塘1口,面积2800 m2,放养体长0.8～1.0 cm的凡纳滨对虾苗22万尾,放养体长2～3 cm、平均体质量0.402 g的方格星虫苗种6万条。经过117～123d养殖,收获凡纳滨对虾2 453 kg,规格66尾/kg,成活率73.6%,产值58 872元;收获方格星虫268 kg,规格159条/kg,成活率71.0%,产值17688元。试验总产值76560元,利润36218元。     

鲻鱼密度和规格对鱼虾混养效果的影响

在室内进行鲻鱼与凡纳滨对虾的混养试验,放养虾苗密度均为100尾/m2,设计了混养大、小规格鱼苗的处理组,混养密度分别为0、0.13、0.26、0.52、1.04、2.07尾/m2和0.13、0.26、0.52尾/m2。试验结果表明,对虾产量、规格和成活率未出现显著差异(P0.05)。混养组对虾产量、规格总体上表现出随混养鲻鱼的密度和规格的提高而呈下降的趋势;混养鲻鱼密度最高两组(2.07、0.52尾/m2)的对虾规格、产量均小于其他混养组;混养组对虾存活率高于对照组,混养鲻鱼密度最高两组对虾成活率最高,且其鱼虾总产量显著高于其他组,其他混养组间未出现显著差异(P0.05)。混养组的饲料系数较对照组均略有降低,混养鲻鱼密度最大组合(2.07尾/m2)的饲料系数最低,饲料转化效率有随混养鲻鱼的密度提高而略有上升的趋势,但不同处理间未出现显著差异(P0.05)。整个试验期间不同处理间水温、盐度、溶氧、pH及生化耗氧量没有出现显著差异;氨氮含量前低后高,亚硝酸氮含量、硝酸氮含量在中后期明显升高,但未表现出与混养鲻鱼密度的明显关系。无机磷含量则在整个养殖期间较稳定,不同处理间未出现显著差异(P0.05)。因此,混养合适密度和规格的鲻鱼不会对凡纳滨对虾产量产生负影响,可以提高对虾成活率,有利于提高饲料转化效率,对水质有一定的稳定作用。     

生物絮团技术在凡纳滨对虾工厂化养殖中的应用试验

为研究设定密度条件下凡纳滨对虾(Litopenaeus vannamei)养殖过程中养殖池水质指标变化趋势和养殖效果,采用生物絮团技术在室外循环水养殖设施进行凡纳滨对虾的养殖试验。投苗规格为0. 158 g/尾,养殖密度为600尾/m~3,使用14口面积为15 m~2的水泥池进行试验,养殖周期120 d。结果显示:在养殖试验期间,试验池养殖水体氨氮平均质量浓度为(0. 81±0. 99) mg/L,亚硝酸盐氮的平均质量浓度为(2. 00±3.96) mg/L,p H 7. 48±0. 36,弧菌的平均质量浓度为(120±77) cfu/m L;经过120 d的养殖,对虾的平均全长达到(14. 022±0. 269) cm,平均体质量达到(15. 748±1. 803) g。研究表明,在室外循环水养殖水泥池利用生物絮团技术进行凡纳滨对虾养殖,具有养殖存活率高、换水率低、养殖产量高等优点,应用前景广阔。     

不同养殖模式及光照对凡纳滨对虾生长和水质的影响

利用室内水泥池4种不同养殖模式(虾单养或混养不同鱼类)和2种光照(自然光和弱光)对凡纳滨对虾生长、产量和水质的影响开展了研究。试验共设6个试验组,2个对照组,每个组别共设3个重复:自然光虾单养组、弱光组对虾单养、自然光虾鳅混养、弱光虾鳅混养、自然光虾鲢混养、弱光组虾鲢混养、自然光虾鳅鲢混养、弱光虾鳅鲢混养,养殖70d。测定试验前后试验池虾规格、总质量、存活率及饵料系数和鱼的规格、总质量。每隔15~20d测定水质指标。试验结果表明,单养组的虾自然光条件下规格显著大于其他组(P0.05),而弱光单养组的虾规格显著小于其他组(P0.05),其他组别差异不显著(P0.05)。饵料系数方面,单养组显著大于混养组(P0.05),存活率混养组显著高于单养组(P0.05),自然光组饵料系数和存活率显著高于弱光组(P0.05)。水质方面,养殖期间各组的硝态氮、亚硝态氮、氨氮呈稳步上升趋势,但亚硝态氮质量浓度,虾单养组和虾鳅混养组均显著高于虾鲢混养组和虾鳅鲢混养组(P0.05),自然光组显著低于弱光组(P0.05),氨氮,虾单养组显著高于其他组(P0.05),自然光组低于弱光组(P0.05)。试验结果显示,适当的光照是凡纳滨对虾生长的重要因素,泥鳅能大幅提高池塘经济效益节约成本,而鲢鳙鱼可有效地改善水质,当泥鳅以及鲢鳙鱼共同混养在虾池时,保证对虾池水质良好的同时,可提高对虾养殖的产量。     

The effect of fish density and species combination on growth and utilization of natural food in ponds

Abstract. Interactions between bottom-feeding fish (common carp, Cyprinus carpio L., and hybrid tilapia) and a filter feeder (silver carp, Hypophthalmichthys molitrix (Valenciennes)) in polyculture were studied in fertilized ponds with no supplementary feeding. The silver carp were stocked at two densities: 1300 and 2600/ha. Growth rate and yield of each of the species were also compared with those in polyculture of bottom feeders alone, and in a monoculture of silver carp alone, at the same densities. The consumption of natural feed as melabolizable energy (ME) was calculated by the energy balance (requirement for maintenance and growth divided by the utilization efficiency).
Increasing the density of silver carp reduced proportionally their own growth rate, due to the limited amount of food. Above a density of about 1000/ha, silver carp inhibit the growth rate of common carp and tilapia. This inhibition was small at 1300 silver carp/ha, but considerable at 2600/ha. However, the presence of bottom feeders increased the growth rate of silver carp at both densities. Calculated natural food consumption showed that growth interactions between species were brought about through the availability of food. The synergistic effect of the bottom-feeding fish on the silver carp is assumed to be due to the upwelling of bottom nutrients to the upper layers of water by the burrowing of the fish in the mud. Combined yield of all species in the polyculture was highest at the density of 1300 silver carp/ha (2116 kg/ha in 156 days). At 2600 silver carp/ha the inhibition of growth rate of silver carp itself, reduced total yield as compared with the lower density.     

Evaluation of the production potential of Macrobrachium rosenbergii (de Man) in monoculture and in polyculture with Nile tilapia and common carp in Saudi Arabia

The feasibility of polyculture of Macrobrachium rosenbergii (de Man) with two fish species, Nile tilapia, Oreochromis niloticus (L.), and common carp, Cyprinus carpio L., was examined and compared with monoculture of M. rosenbergii in 100-m² ponds. Overall percentage of females (56.8%) was higher than that of males (43.2%). The proportions of females, males and their morphotypes did not differ significantly between monoculture and polyculture. After 196 days of culture, the mean harvest weight of prawns in monoculture (30.2 g) was significantly greater than that in polyculture (21.3 g). Yield in monoculture (1152 kg ha^-1) was significantly greater than (1.62 times) that of polyculture (711 kg ha^-1). Total yield from polyculture including yield of tilapia (2544 kg ha^-1) and common carp (2999 kg ha^-1) was almost five times as great as that of prawn monoculture. Survival and food conversion rate of M. rosenbergii did not differ significantly between monoculture and polyculture.     

Effects of Stocking Size and Density of Tilapia on Macrobrachium rosenbergii in Polyculture

Studies were conducted to determine the effect of stocking size and density of prawns in polyculture.
In one experiment, postlarval prawns (av. wt. 0.02 g) were stocked in six 0.02 ha earthen ponds at 35,00O/ha. Two ponds were stocked with tilapia fry (av. wt. 0.14 g) and two were stocked with tilapia fingerlings (av. wt. 30.1 g), each at 10,000/ha. Two control ponds had no tilapia. Tilipia stocking size had no effect on prawn growth. Mean weight of prawns after 70 days of culture ranged from a low of 4.5 g when cultured with tilapia fingerlings to a high of 6.6 when cultured in monoculture. Prawn survival was adversely affected by tilapia fry. Average prawn survival in tilapia fry ponds was 65% compared to 75% and 91%, respectively, in tilapia fingerling and monoculture ponds.
In a second experiment, postlarval prawns were stocked in nine 0.02 ha earthen ponds at 40,000/ ha. Six ponds were stocked with 30 g tilapia fingerlings, three at 5,000/ha and three at 15,000/ha. Three control ponds received prawns only. After 100 days of culture, prawn weight ranged from an average of 15.9 g in monoculture ponds to 11.5 g in polyculture ponds. Survival was highest (93.8%) in low density polyculture ponds. Survival was lowest (85.6%) in prawn monoculture ponds. Tilapia reproduction had a negative impact on shrimp production.     

Comparison of Tilapia Monoculture and Carp Polyculture in Fertilized Earthen Ponds

A comparison of a monoculture of Nile tilapia Oreochromis niloticus and a polyculture of carps (silver carp Hypophthalmichthys molitrix; rohu Labeo rohita; and mrigal Cirrhinus mriga la; ratio 4:3:3) was carried out in 200-m² earthen ponds fertilized with cattle manure and supplemented with inorganic fertilizer at 3-kg nitrogen and 1.5-kg phosphorus/ha per day. A control treatment of a tilapia monoculture without fertilizer inputs was included to assess the effect of pond basal fertility. Net yields of 23.5 kg/pond per 112 d (3.8 t/ha per 1 yr) in the tilapia monoculture and 19.2 kg/pond per 112 d (3.1 t/ha per yr) in the carp polyculture were not significantly different; net yields from unfertilized tilapia monoculture ponds were negative. In the carp polyculture, silver carp was the dominant species at harvest contributing 73% of the total net fish production compared to 9% and 19% by rohu and mrigal, respectively. Water quality data suggested that tilapia yields could have been further improved by increasing fertilization rate but that critical dissolved oxygen concentration constrained this option for carp polyculture.     

Polyculture of Freshwater Angelfish Pterophyllum scalare and Pacific white shrimp Litopenaeus vannamei in low‐salinity water

In this study, we evaluated the production potential of the polyculture of Freshwater Angelfish (Pterophyllum scalare, Cichlidae) and Pacific white shrimp (Litopenaeus vannamei). Two experimental trials were set up. The first trial entailed the use of a randomized design to investigate three treatments options: angelfish monoculture, shrimp monoculture, and fish and shrimp polyculture in 12 experimental 15 m² ponds. In the second trial, we investigated two treatments (polyculture of caged fish and uncaged fish) in 10 experimental units. In trial 1, polyculture negatively affected fish growth and survival. However, fish did not affect shrimp growth and the greatest profit was achieved in polyculture. In trial 2, caging fish improve the growth of both fish and shrimp. An economic analysis showed the greatest profit and benefit cost ratio for caged fish compared with uncaged fish. We conclude that growing P. scalare and L. vannamei together is a better strategy than shrimp monoculture in low‐salinity water. The use of caged fish in such a polyculture operation would enhance productivity and profitability.     

中华绒螯蟹(Eriocheir sinensis)种苗土池培育技术研究Ⅰ-Ⅰ期溞状幼体的适宜密度

在６口海水土池（计１．９ｈｍ２）中分别按下列密度（万／ｍ３）布苗：３,４,５,３,４和０．２７,比较研究了中华绒螯蟹（Ｅｒｉ－ｏｃｈｅｉｒｓｉｎｅｎｓｉｓ）Ⅰ期氵蚤状幼体（Ｚ１）的密度对幼体变态率和成活率的影响。结果表明,Ｚ１的密度为４万／ｍ３时,大眼幼体的变态率（大眼幼体密度占Ｚ５密度的％;２１．６％）和成活率（大眼幼体的密度占Ｚ１密度的％;２．４％）及产量（４２ｋｇ／ｈｍ２）最高。     

Comparison of food selection and growth performance of koi carp, Cyprinus carpio L., and goldfish, Carassius auratus (L.) in mono- and polyculture rearing in tropical ponds

To compare the effect of polyculture against conventional monoculture on ornamental carp production, investigations on food selection and growth performance of koi carp (K), Cyprinus carpio L. and goldfish (G), Carassius auratus (L.) were conducted in a 11‐week rearing experiment in two monoculture (100% K and 100% G) and five polyculture (90% K–10% G, 70% K–30% G, 50% K–50% G, 30% K–70% G and 10% K–90% G) conditions in tropical ponds. There were three replicates for each treatment. Environmental conditions and food availability were similar in all the treatments. Ivlev's electivity index showed that both fish species avoided phytoplankton and preferred cladocerans to other zooplankton groups (copepods and rotifers) in monotypic conditions. However, in the polyculture treatments, the positive electivity of goldfish towards cladocerans reduced significantly (P<0.05), while the percentage of copepods, rotifers and phytoplankton in the gut content increased. No significant differences in weight gain, specific growth rate and deformities were recorded at harvest for koi carp between the different treatments (P>0.05). Even the survival rate of koi carp recorded above 90% in all the treatments. However, the goldfish recorded significantly better weight gain, specific growth rate and survival in monoculture (100% G), compared with the polyculture treatments (P<0.05). Goldfish deformities were lowest (P<0.05) in the monoculture treatment (2.42%). The number of marketable fish above a set size limit of 4 g total weight was significantly higher in the two monoculture treatments, compared with the five polyculture treatments (P<0.05). Keeping in view of the dietary similarities of koi carp and goldfish, and the aggressive nature of koi carp in polyculture, it is suggested to refrain from polyculture of goldfish and koi carp until further documentations relating to optimum stocking density and management of polyculture of ornamental carps are available.     

Polyculture of western white shrimp,Litopenaeus vannamei Boone, 1931 with Grey mullet,Mugil cephalus Linnaeus, 1758 controls external parasites of western white shrimp

The main aim of this study was to examine the effects of a polyculture system on the control of the external parasites of western white shrimp, Litopenaeus vannamei. To this end, the western white shrimp postlarvae (PLs) were stocked in nine earthen ponds (600 m²) at a density of 20 PLs m^?2 and reared for 4 months. After 40 days of shrimp stocking, Mullets, Mugil cephalus, were stocked at various densities including: control (0 fish/100 m² pond), treatment 1 (T₁: 2 fish/100 m² pond) and treatment 2 (T₂: 4 fish/100 m² pond). Over the course of the experiment, the external parasites of shrimps were investigated by the preparation of a wet mount from the gill tissue. Based on the obtained results, totally two genera of protozoan parasites, i.e. Zoothamnium sp. and Epistylis sp., were identified over the course of the experiment. In all experimental groups, the incidence and abundance of Zoothamnium sp. was significantly higher than Epistylis sp. (P < 0.05). Also, mean incidence per cent and mean abundance of Zoothamnium sp. and Epistylis sp. were significantly lower in the polyculture treatments (T₁ and T₂) compared to the monoculture group (control) (P < 0.05). Throughout this experiment, the total organic matter (TOM %) content of the bottom sediments and biological oxygen demand (BOD₅ mg L^?1) of water samples in the polyculture ponds were significantly lower than the monoculture group (P < 0.05). In contrast, the polyculture ponds had a higher concentration of water dissolved oxygen (O₂ mg L^?1) compared to the monoculture (P < 0.05). In conclusion, our results show that mullet as a secondary farmed species can reduce indirectly the parasitic pollution of western white shrimp probably through reducing the total organic matters in water and sediments and improving the water quality parameters.