从多宝鱼事件探讨HACCP在水产养殖中的应用

分析了多宝鱼事件发生的原因,阐述了我国水产养殖中水产品质量安全控制面临的问题,并探讨了HACCP(危害分析与关键点控制)体系在水产养殖中的应用。     

12种中草药对大菱鲆幼鱼的诱食效果研究

[目的]研究12种中草药对大菱鲆幼鱼的诱食效果,为斑马鱼人工配合饲料的研制提供参考。[方法]以200尾平均体长为3cm,体重为1 g,60日龄的大菱鲆幼鱼为试验对象,选用丁香、肉桂、八角、山萘、薄荷、黄连、黄柏、黄岑、栀子、苦参、乌梅、诃子肉等12种中草药,以2‰添加量分别加入到基础饵料中,进行单方筛选试验,并根据单方试验结果选取诱食效果较好的中草药进行梯度试验和两两组合试验,分析不同中草药对大菱鲆幼鱼的诱食效果。[结果]苦参、栀子、黄岑和山萘的诱食效果较好;4种中草药梯度试验结果表明,2‰栀子、5‰苦参、5‰黄岑和2‰山萘对大菱鲆幼鱼诱食效果最好;在复方试验中,2‰栀子与苦参混合物对大菱鲆幼鱼的诱食效果最好。[结论]对大菱鲆幼鱼的诱食效果与中草药种类和浓度相关。     

米曲霉AS 3.951发酵豆粕对大菱鲆摄食生长的影响

以初始平均体重(2.07±0.02)g的大菱鲆(Scophthalmus maximus L.)为实验对象,进行为期70天的摄食生长实验,研究不同添加水平的发酵和未发酵豆粕对大菱鲆摄食生长的影响.用米曲霉(Aspergillusoryzae)AS 3.951对豆粕进行固态发酵.经检测.与未发酵豆粕相比较,发酵豆粕中胰蛋白酶抑制因子、植酸、大豆皂甙、水苏糖和棉籽糖的含量分别下降了46.5%、26.6%、11.7%、30.1%和19.7%.实验共制作6种等氮等能的饲料,其中以全鱼粉饲料为对照饲料;未发酵豆粕蛋白分别替代25%、40%和55%的鱼粉蛋白;发酵豆粕蛋白分别替代40%和55%的鱼粉蛋白.结果表明,饲料中添加一定量的豆粕对大菱鲆的成活率没有显著的影响(P>0.05).饲料中未发酵豆粕蛋白替代鱼粉蛋白的水平为25%时,对大菱鲆的摄食率、特定生长率、饲料效率和蛋白质效率均没有显著的影响,但替代水平为40%和55%时,以上指标显著降低(P<0.01).饲料中发酵豆粕替代水平为40%时,未降低大菱鲆的摄食率、特定生长率、饲料效率和蛋白质效率,替代水平为55%时,显著降低大菱鲆的摄食率和特定生长率(P<0.01).     

Improving the efficiency of wild Pecten maximus spat collection: potential effects of spat bag design and of species temporarily settling in spat bags

The single and combined effects of external bag size and external bag mesh size upon the collection and retention of wild King Scallop spat (Pecten maximus L.), other scallop species (Aequipecten opercularis) and other animal groups were investigated in a collection area off the west coast of Scotland. Collection was assessed after 5 weeks and at harvest (after 20 weeks). After 5 weeks, 90% of collected animals consisted of scallops (P. maximus and A. opercularis), Mytilus edulis (Mollusca: Bivalvia) and Lacuna vincta (Mollusca: Gastropoda). One-way analysis of variance on count data obtained after 5 weeks showed that the larger bag and mesh size treatments had collected significantly greater numbers of scallop spat when numbers collected were compared to the quantity of material used for each treatment (P<0.05). This was partly attributed to significantly greater numbers of L. vincta crawling juveniles temporarily recruiting in the smaller bag and mesh treatments (P<0.05). Similar trends of spat abundance in treatment bags were observed at harvest, although all treatments had scallop spat retention efficiencies of less than 12%. The importance of the structural design of spat bags for spat collection and the effects of incidentally collected non-predatory species upon the collection of scallop spat are discussed.     

大菱鲆不同部位营养与质构品质分析评价

以大菱鲆(Scophthatmus maximus)为研究对象，系统比较分析了其背部、腹部、胸腔部、尾部、裙边和鱼皮的基本营养成分、胶原蛋白含量、氨基酸与脂肪酸组成及质构特性，并进行了营养价值评价，获得了大菱鲆各部位营养与质构品质的基础数据。研究结果显示，不同部位的粗蛋白含量存在差异，鱼皮中含量最高为29.04%，而裙边含量最低为12.99%，与其他部位肌肉差异均极显著(P<0.01)。背部、腹部、胸腔部和尾部的粗蛋白含量分别为18.76%、18.96%、17.91%和18.39%；裙边粗脂肪含量最高达17.47%，脂肪酸种类最多为27种，并且含量达318.09 mg/g，多不饱和脂肪酸的含量为其他部位的3.90~6.76倍，其中亚油酸含量最高(107.26 mg/g)，其次为DHA(64.39 mg/g)和EPA(26.61 mg/g)；鱼皮中胶原蛋白含量达224.69 mg/g，显著高于其余部位(P<0.01)，可作为制备胶原蛋白的原料。各部位中均检测出18种氨基酸，背部、腹部、胸腔部、尾部和裙边中第一限制性氨基酸均为Met+Cys，而在鱼皮中第一限制性氨基酸为Trp；另外，大菱鲆除鱼皮之外，其余各部位氨基酸组成均符合FAO/WHO参考模式标准；通过质构特性分析，发现胸腔部肌肉的硬度、咀嚼性和弹性显著高于其余部位(P<0.05)，口感更佳。     

Biological and environmental factors associated with the detection of elephant endotheliotropic herpesvirus in Asian elephants (Elephas maximus) in Thailand

Elephant endotheliotropic herpesvirus (EEHV) infection is one of the most common diseases in young elephants, causing severe fatal hemorrhagic disease. Subclinical infection was previously described; however, information about the factors associated with virus shedding and reactivation were scarce. To identify the biological and environmental factors related with EEHV detection, blood and oral swab samples were collected from nine captive Asian elephants in Thailand for one year and tested for EEHV presence using real-time PCR. Data including hematological values, management, environmental temperature, and serum cortisol levels were also recorded and analyzed. Results showed that the viral detection frequency ranged from 0–25%. The highest detection frequency was found in the two youngest elephants, aged less than 15 years. Three types of viruses, EEHV1, EEHV4, and EEHV5, were found in this study, which also detected mixed infection in five elephants. Additionally, the study found that sample type, changes in hematological values, management and health issues, and serum cortisol levels were not associated with herpesvirus detection in the elephants. However, EEHV detection percentage was significantly increased in the summer (mid-Feb to mid-May), possibly due to body fitness reduction from food source limitation and low nutrient content. To obtain a broad aspect of EEHV management, long-term EEHV monitoring is highly recommended in every captive elephant herd.     

大菱鲆脾肾结节病病原菌的分离和鉴定

2017年夏季，江苏省连云港市某养殖场大菱鲆出现大规模死亡，发病鱼体表无明显症状，解剖可见脾脏、肾脏出现白色散在结节，从发病鱼的内脏中分离得到1株优势菌SM-Myco001。人工感染实验结果显示，SM-Myco001可以引起大菱鲆内脏结节症状并造成鱼类死亡，且在高养殖水温(22℃)条件下发病更为剧烈。生理生化鉴定和16S rRNA基因分析结果显示，SM-Myco001属于海分枝杆菌(Mycobacterium marinum)。本研究首次报道了我国养殖大菱鲆感染海分枝杆菌的病例，可为大菱鲆养殖过程中的疾病防控提供参考。     

应用高通量测序技术分析大菱鲆幼鱼肠道及其养殖环境的微生物群落结构

采用基于Illumina测序平台的高通量测序技术,对大菱鲆(Scophthalmus maximus)幼鱼肠道及其养殖水体、生物饵料中细菌种类及丰度进行研究。测序结果显示,养殖水体、生物饵料和大菱鲆幼鱼肠道等19个样品共获得有效序列547621条,可聚类于3771个可分类操作单元(OTUs),归属于养殖水体、生物饵料、健康幼鱼和发病幼鱼的操作分类单元(OTU)个数分别为3038、1090、87和777,其中,健康幼鱼与生物饵料、健康幼鱼与养殖水体特有的OTU个数分别为57和0,发病幼鱼与生物饵料、发病幼鱼与养殖水体特有的OTU个数分别为481和31。表明幼鱼肠道微生物多样性与生物饵料密切相关。根据细菌注释结果,拟杆菌门(Bacteroidetes)、厚壁菌门(Firmicutes)和变形菌门(Proteobacteria)在大菱鲆幼鱼肠道中占优势地位,其中,健康幼鱼肠道微生物共聚类为8个门,发病幼鱼的肠道微生物可聚类为19个门。与健康幼鱼相比,发病幼鱼肠道门水平上的3种主要优势菌群落结构出现失衡。此外,对各样品中丰度最高的100位OTU分析显示,幼鱼肠道优势菌种类与生物饵料中的优势菌种类密切相关,而每个发病幼鱼肠道优势菌种类具有一定的独立性。本研究旨在为大菱鲆健康养殖和微生态调控提供实验依据。     

Statistical properties and performance of pairwise relatedness estimators using turbot (Scophthalmus maximus L.) family data

The statistical properties and performance of four estimators of pairwise relatedness were evaluated in several scenarios using the microsatellite genotype data from a set of large known full‐sibships of turbot. All estimators showed a significant negative bias for the four kinships commonly used in these studies (unrelated: UR, half‐sibs, full‐sibs and parent–offspring), when allele frequencies of the reference population were estimated from the individuals analysed. When these frequencies were obtained from the base population from which all families proceeded, the bias was mostly corrected. The Wang (W) and Li (L) estimators were the least sensitive to this factor, while the Lynch and Ritland (L&R estimator) was the highest one. The error (mean around 0.130) was very similar in all scenarios for W, L and Queller and Goodnight (QG) estimators, while L&R was the highest error‐prone estimator. Parent–offspring kinship resulted in the lowest error, when using W, L and QG estimators, while UR resulted in the lowest error with the L&R estimator. Globally, W was the best‐performing estimator, although L&R could perform better in specific sampling scenarios. In summary, pairwise estimators represent useful tools for kinship classification in aquaculture broodstock management by applying appropriate thresholds depending on the goals of the analysis.     

三甲氧苄氨嘧啶对养殖大菱鲆盾纤毛虫病治疗效果的研究

从感染纤毛虫的养殖大菱鲆上分离获得盾纤毛虫进行体外培养,通过药物抑制实验发现,三甲氧苄氨嘧啶(TMP)对盾纤毛虫的最小有效抑制浓度为25×10~(-6);TMP对大菱鲆的毒性实验表明,24小时半致死量为每千克鱼体内含药物量为0.35357 g,48小时半致死量为每千克鱼体内含药物量为0.33912 g,安全量为每千克鱼体内含药物量为0.09361 g;TMP对大菱鲆盾纤毛虫病的治疗实验结果显示,与对照组相比,注射药物或投喂药饵后,感染纤毛虫的大菱鲆成活率提高了50%～107.1%。