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1.
浅析南美白对虾白斑综合征发病原因及防控对策   总被引:1,自引:0,他引:1  
南美白对虾(Penaeus vannamei),学名凡纳滨对虾,其头小身大,出肉率高,口味鲜美,作为海虾淡养的优良品种在全市得到了大力推广和迅猛发展。在杭州地区白2000年的1000多亩发展到2007年的10万余亩,2007年全市南美白对虾总产量达到3.5万吨,总产值达6.3亿元。由于南美白对虾产量高、效益好、国内外市场空间大、广大虾农养殖积极性很高,其发展势头很猛,己成为我市水产养殖的主要优势产业之一。  相似文献   

2.
<正>杭州地区南美白对虾养殖面积自2000年的1000多亩发展到2013年的10.3万亩,2013年全市南美白对虾总产量达到3.4万吨,和中华鳖养殖并列成为杭州市水产养殖的主导品种。与此同时,随着养殖规模的日益扩大,各类病害也纷至沓来。多种病原体(病毒、细菌、原生生物等)能够使南美白对虾产生疾病,其中病毒性疾病是导致南美白对虾死亡的主要病害。白斑病毒(WSSV)、传染性皮下及造血组织坏死病毒(IHHNV)和桃拉综合征病毒(TSV)是南美白对虾的三种主要的病毒病原,给南美白对虾养  相似文献   

3.
福建省漳州市是全国重点的南美白对虾生产基地之一,全市南美白对虾养殖面积达7万多亩,尤其是近几年来推广的南美白对虾对淡养殖更是以其生产成本低、养殖周期短、发病率低、高产高效等而迅速发展。目前,养殖面积已达3万多亩,年亩产量高达500千克,最高单季亩产达800千克。养殖区域主要集中在龙海、漳浦、南靖等县(市),南美白对虾对淡养殖已成为漳州市水产养殖业的支柱产业和新的经济增长点。然而,发展中也存在一些不容忽视的问题,其中病害问题最为突出。病害已成为南美白对虾养殖业发展的主要制约因素,病害防治是当前十分…  相似文献   

4.
正南美白对虾是杭州市水产养殖的主推品种,全市年养殖面积保持在10万亩左右,年养殖总产量近4万吨,杭州是浙江省内主要的南美白对虾淡水养殖区域,也是市农业的主导产业之一。然而,由于虾苗质量不稳定、恶劣气候和环境污染影响等因素,近年来养殖风险加大,养殖病害上升、成功率下降。为降低  相似文献   

5.
博兴县南美白对虾养殖从2001年试养成功后,2002~2003年面积迅速发展到1.5万亩,平均亩产达到260kg,总产量达到3900t,创产值9360万元。南美白对虾已成为我县水产养殖的重要产业。但经调查了解,全县南美白对虾产量高低悬殊较大。2003年全县养殖南美白对虾1.5万亩,平均亩产260kg,其中亩产400kg以上的面积有2500亩,  相似文献   

6.
<正>南美白对虾是余姚市的主导养殖品种,全市南美白对虾养殖面积1万多亩。近年来,由于南美白对虾养殖病害多发,养殖效益不景气,养殖企业开始寻求新的养殖模式,以增加养殖效益、减少养殖损失,南美白对虾套养罗氏沼虾土池大棚养殖模式应运而生。以余姚市海深特种水产养殖场2018年9#土池大棚塘为例,该池塘土壤属于海涂盐碱地,面积6亩,3月28日放养南美白对虾苗80万尾进行标粗,1个月后将48万尾翻到隔壁外塘放养,剩余的在土池大棚塘中留养,土池大棚中再放养规格2~3厘米的罗氏沼虾苗12万尾。南美白对虾在10月15日捕完,产量3118.5千克(不包括翻出部分),销售收入122050元;罗氏沼虾在10月30日清塘捕完,产量1000千克,销售收入  相似文献   

7.
南美白对虾养殖存在的问题与对策   总被引:2,自引:0,他引:2  
2001年,东营市南美白对虾养殖面积6.5万亩,其中海水养殖5.9万亩,盐碱地地下水养殖0.6万亩,总产对虾1800t,总产值7200万元,利税4000万元,涌现出了一大批养殖面积大,产量高,效益好的典型。本文从另一侧面找出南美白对虾养殖存在的问题,并提出对策,以促进南美白对虾养殖健康稳定发展。  相似文献   

8.
<正>南美白对虾自2000年引进天津市以来,养殖面积从6.7hm~2发展到现在的2万hm~2,逐步形成了从引种、繁苗到养殖完整的产业链。尽管受南美白对虾种质及病害等不利因素影响,目前天津全市南美白对虾苗种年需求量仍高达180亿尾。天津市形成了以汉沽、大港工厂化育苗为龙头的南美白对虾繁育聚集地,全市南美白对虾繁育企业有30家左右,不仅供应天津本市,而且也供应天津周边省市的南美白对虾养殖生产。  相似文献   

9.
<正>2001年唐山市引入南美白对虾进行小规模池塘养殖试验,2003年开始在全市范围内进行全面推广,目前已成为唐山市对虾养殖主要品种之一,养殖面积达10万余亩,年产量1.5万吨以上。养殖模式由单一的池塘养殖发展为池塘养殖、盐田晾水池养殖、小棚养殖、工厂化养殖等多种模式。随着南美白对虾养殖的迅猛发展,苗种产业也快速发展起来。经调研,唐山现拥有南美白对虾苗种场近百家,育苗水体约18万米3,年产虾苗200多亿尾,除满足唐山的苗种需求外,还销往天津及河北省周边地市。由于唐山地处温带,南美白对虾繁育的成本较高,因此唐山的南美白对虾苗种场主要从海南、广东、福建等地引进P5仔虾进行标粗,苗种品质无法把控。  相似文献   

10.
在天津市农委和天津移动通信集团支持下,天祥水产协会于2006年5月1日在全市第一个开启了"农信通"水产手机短信互动平台。一年多来,发送科技信息2万多条,使协会会员从中受益。天祥水产协会拥有会员1100户,养殖面积5万亩。"昌翠牌"武昌鱼、南美白对虾及武昌鱼配合饲料3个产品被天津市人民政府认定为天津农业名牌产品,其中南美白对虾养殖  相似文献   

11.
Anguilla luzonensis and A. huangi were each described in 2009 using eels obtained from northern Luzon Island. We examined the taxonomic status of these two groups of eels using morphological and molecular genetic characters. There were no significant differences in two vertebrae counts between eels of A. luzonensis and A. huangi. Mitochondrial 16S ribosomal RNA and cytochrome b genes sequences were obtained and compared among 28 specimens of A. luzonensis, the holotypes of A. luzonensis and A. huangi, and one specimen of the other 15 anguillid species. The specimens of A. luzonensis exhibited almost identical sequences, including the holotype, with only a few site differences, and the genetic difference between the holotypes of A. luzonensis and A. huangi was within the range of differences of specimens of A. luzonensis. The other anguillid species were genetically very different from A. luzonensis and A. huangi, although A. interioris is a closely related species. It is clear that A. luzonensis and A. huangi are the same species, and according to the principle of priority in zoological nomenclature, A. luzonensis Watanabe, Aoyama, and Tsukamoto, 2009 is the valid species name, and A. huangi Teng, Lin, and Tzeng, 2009 is a junior synonym of A. luzonensis.  相似文献   

12.
The purpose of this study was to evaluate the acute toxicity of lead for different life stages of shrimp, Litopenaeus vannamei, and to determine the effect of its sublethal concentrations on osmoregulatory capacity (OC) as well as the possible histological alteration in the gills of juvenile shrimp. The 24‐, 48‐, and 96‐h LC50 values for lead to L. vannamei increased progressively with increasing life stage, from nauplii < zoeae < mysis < postlarvae < juvenile. After 15‐d exposure to 3.25, 6.50, and 9.75 mg Pb/L, the OC values of exposed shrimp were reduced by 39, 73, and 157%, respectively compared to control animals. Compared to controls, the lead concentrations in gill tissues increased significantly by 127,500, 137,500, and 141,000% in shrimps exposed to 3.25, 6.50, and 9.75 mg Pb/L, respectively. After lead exposure, hemocytic congestion in efferent vessels and multiple hyperplasia were observed in gill filaments, resulting in narrowed hemolymphatic lacuna. The histopathological effects increased with increasing Pb concentration.  相似文献   

13.
Mulloway (Argyrosomus japonicus) occur in estuarine and coastal waters surrounding Australia, Africa, India, Pakistan, China, Korea and Japan, where they are important in fisheries. This study identified that mulloway in south-eastern Australia had similar growth rates, but matured at smaller lengths and younger ages, to those in South Africa and Western Australia. Growth of both sexes was similar to about 5 years, after which females grew faster and attained a greater maximum length than males. Female mulloway matured at 4–5 years of age with a L50 of 68 cm, whereas males matured at 2–3 years of age with a L50 of 51 cm. The commercial fishery in New South Wales was characterised by declining catches and a reduction in the proportion of mulloway of mature lengths in landings. During 2002–2005 commercial landings were dominated (83%) by fish within 15 cm of the current minimum legal total length of 45 cm and aged 2 and 3 years (>80%), even though mulloway can attain lengths of 200 cm and live >30 years. Estimates of the rates of instantaneous total mortality ranged between 0.34 and 0.45, whilst the rate of instantaneous natural mortality (M) was estimated to be approximately 0.12. Yield-per-recruit analyses indicated that mulloway in New South Wales are being growth overfished and substantial increases in yield could be achieved by increasing the length at first harvest. Values of the spawning potential ratio were below 0.2 under a range of mortality estimates, suggesting that mulloway are at risk of recruitment overfishing. These results suggest that the spawning stock of mulloway in south-eastern Australia has been depleted and that remedial management action is required to protect this iconic species.  相似文献   

14.
Mosquitofish, Gambusia sp., have been spread throughout the world to biologically control mosquitoes. However, the fish has gained a reputation as an invasive species and has been implicated in displacing native aquatic species. Gambusia affinis are native to the southeastern United States and commonly occur in commercial channel catfish, Ictalurus punctatus, production ponds. We investigated effects of mosquitofish presence on zooplankton populations, water quality, disease occurrence, and fish production in experimental ponds. There were no differences between ponds with or without mosquitofish in numbers of calanoid copepods, cyclopoid copepods, total copepods, Bosmina sp., Ceriodaphnia sp., Moina sp., Daphnia sp., or total cladocerans. There were also no differences in copepod and cladoceran sizes. Copepod nauplii were more numerous during the summer months in ponds with mosquitofish. There were no differences in water quality variables (soluble reactive phosphorus, nitrate, nitrite, ammonia, total nitrogen, total phosphorus, pH) or phytoplankton density between ponds stocked with and without mosquitofish. Catfish production and disease occurrence were also similar between ponds with and without mosquitofish. Although mosquitofish may cause problems when stocked outside their native range, there does not appear to be any adverse effects of mosquitofish presence in catfish production ponds.  相似文献   

15.
The effects of exposing the eggs of Pacific threadfin and amberjack eggs (AEs) to different concentrations of hydrogen peroxide for 5 min on hatch rate and survival were assessed in a series of experiments using a petri dish model rearing system. Despite significant inter‐batch variation in hatch rate, it was shown that eggs of both species could be safely exposed to up to 11 340 mg L−1 H2O2 for 5 min. Exposure to 34 230 mg L−1 H2O2 for 5 min was shown to be lethal to AEs at a late stage of development. In two further experiments, it was demonstrated that Pacific threadfin eggs were resistant to all tested concentrations of a range of polyvinylpyrrolidone iodine (PVP‐I) concentrations and contact times (up to 1000 mg L−1 PVP‐I for 10 min). The level of bacteria adhering to the eggs of both species was highly variable. Where eggs were heavily colonized (>104 cfu egg−1), hydrogen peroxide concentrations of at least 11 340 mg L−1, or PVP‐I concentrations higher than 500 mg L−1 for 10 min, were required for effective sterilization. In less colonized batches, rinsing in sterile seawater or exposure to lower (550 mg L−1) concentrations of H2O2 was sufficient to result in high apparent levels of surface sterility (<1 cfu egg−1).  相似文献   

16.
对驼背鲈(Chromileptes altivelis)的胚胎发育及仔、稚、幼鱼的形态特征进行了详细的观察与研究,描述了从受精卵到仔、稚、幼鱼各发育期的时间和形态特征变化。结果表明,在水温25-26℃、盐度30的海水中,受精卵历时27 h 25 min完成整个胚胎发育过程,经历从卵裂、囊胚、原肠、神经胚到肌节形成、各器官的逐渐形成、变化、完善等一系列的胚胎发育和变化过程;根据其卵黄囊消长情况、鳞片的覆盖状态、体色发生的不同变化以及第二背鳍和腹鳍的消长,将胚后发育分为仔、稚、幼鱼3个阶段。在水温22-26℃、盐度29-31、DO≥5 mg/L的条件下,2-3 d仔鱼卵黄囊消失,开口摄食;生长发育至31 d,仔鱼已变态进入稚鱼期;培育至57 d,稚鱼完成变态,成为幼鱼。第二背鳍棘和腹鳍棘的生长与收缩等石斑鱼类早期发育的共性生长特征及其体表特性体色变化特征为驼背鲈胚后发育过程中最明显的特征。  相似文献   

17.
As an intertidal species, Apostichopus japonicus is subject to diel and seasonal temperature fluctuations. Color variation is a distinct characteristic of A. japonicus, and a new color morph, purple A. japonicus, was recently found on the coast of Rushan, Weihai City. This study was conducted to compare the performance of green, white, and purple color morphs of A. japonicus at different water temperatures to help improving aquaculture technology and management. In this study, green, white, and purple color morphs of juvenile A. japonicus (1.5 ± 0.1 g) were cultured at 10, 14, 18, 22, and 26 C for 60 d, according to the suitable temperature range for sea cucumber growth. Temperature was shown to have a significant effect on growth, energy budget, and physiology of sea cucumbers (P < 0.05). Specific growth rates, feed conversion efficiencies, and the proportion of energy allocated to growth of all three color morphs were optimal at 18 C. Activities of the enzymes related with oxidative stress, immune response, and digestion were determined. Superoxide dismutase (SOD) and trypsin activities generally reached a maximum in all three color morphs at 18 C. The purple color morph of A. japonicus was higher in growth rate, food conversion efficiency, and proportion of energy allocated to growth than green and white color morphs at 18 and 22 C, consistent with its higher trypsin and SOD activity, indicating the mutual effect of growth and physiology. At 18, 22, and 26 C, the green color morph had the highest level of lysozyme activity and purple color morph had the lowest, indicating possible infection by external pathogens of green color morph, which might be caused by high temperature. These results suggested that the optimum temperature for culture of the three color morphs was approximately 18 C, the purple had a better adaption to high temperature, and the green and white color morphs may be more susceptible to thermal stress than the purple color morph.  相似文献   

18.
《水生生物资源》1999,12(4):239-246
The effect of different parameters on short-term storage capacity of turbot ova was assessed over a 45-h period after ova collection for fertilization rates and over a 9-h period after ova collection for hatching rates. Increasing the volume of ova sampling from 0.5 to 2.5 mL, as well as adding an antibiotic–antimicotic solution or oxygen did not significantly change the storage capacity of ova. Regarding the hatching rates, a higher storage ability was recorded at 8 and 13 °C, compared to 3 °C. The mean composition of the ovarian fluid was determined (n = 57 spawns). Use of a diluent mimicking the ovarian fluid significantly decreased the storage ability as assessed by the fertilization rates but did not modify the hatching rates. Diluting ova in an artificial ovarian fluid deprived of calcium significantly decreased the fertilization and hatching rates during the storage period. Furthermore, addition or not of soybean trypsin inhibitor (Sigma T 9003) to the artificial ovarian fluid deprived of calcium did not significantly change the results. Storage capacity of control batches of ova was low: at 13 °C, without any diluent and when ova were fertilized 3 h after stripping, the hatching rate was lowered to 62.4 ± 29.4 % (mean ± SD) of the initial value.  相似文献   

19.
20.
The effects of diets containing different levels of essential oils from savory Satureja khuzestanica Jamzad and myrtle Myrtus communis L and an immunity complement were investigated on growth, survival, nutritional indices, serum biochemistry, and hematology of farmed rainbow trout, Oncorhynchus mykiss, fry (n = 4500; 5 ± 2 g). The essential oils were dosed as 300 and 500 mg/kg diet. After 60 d, the fish fed 300 mg/kg of the essential oils showed the highest counts of white blood cells (P < 0.05). The same treatment revealed the greatest levels of hematocrit, total protein, and albumin, but glucose and cholesterol values significantly decreased compared with the control (P < 0.05). Feeding fish with 300 mg/kg of the essential oils led to highest records of specific growth rate and survival rate but the lowest feed conversion ratio (FCR), and those fed with immunity complement attained the lowest values of growth parameters. The fry fed with immunity complement and 300 mg/kg of myrtle essential oil achieved the highest and lowest FCR values, respectively. The results indicate that dietary supplementation of 300 mg/kg of the above essential oils exert positive impacts on the growth performance, feeding efficiency, and hematological factors in O. mykiss.  相似文献   

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