维生素与矿物质对大菱鲆幼鱼色素恢复作用的研究

利用交叉组合设计了16组大菱鲆(Turbot)幼鱼饲料,在各组饲料中,复合维生素、矿物质的含量分别为0～3％,共进行了60d的喂养实验。结果表明,白化大菱鲆幼鱼可以通过调整配合饲料配方,使体色恢复为正常体色。经过60d的试验,添加1％的复合维生素和3％的复合矿物质的效果最好。维生素与矿物质的比例及组合对大菱鲆白化苗种色素的恢复有着直接的关系。试验组中平均色素覆盖率最高为90％,完全恢复正常体色的比例可达23％。本研究所配制的复合维生素和复合矿物质对大菱鲆体色的恢复起了重要作用。     

生物饵料对养殖大菱鲆仔鱼的影响

为研究生物饵料对大菱鲆仔鱼生长和体色的影响,分别给仔鱼投喂经过强化和未强化过的生物饵料,并检测其生长指标和体色状况。试验结果,试验组和对照组鱼体体长的相对增长率分别为0.40 mm·d-1和0.37 mm·d-1,体质量相对增长率分别为0.033 8 g·d-1和0.030 9 g·d-1,畸形率分别为0.96 %和2.85 %,组间差异不大(P>0.05);试验组鱼的存活率明显高于对照组(P<0.05),分别为17.00 %和12.07 %;试验组鱼的白化率极显著低于对照组(P<0.01),分别为2.25 %和79.5 %。结果表明,投喂经过裂壶藻、Vc及海水鱼多维强化的生物饵料,可以显著降低大菱鲆仔稚鱼的白化率,说明生物饵料的营养是大菱鲆仔稚鱼正常体色形成最重要的影响因素之一。     

大菱鲆25日龄3个经济性状的遗传参数评估

为估计我国引进大菱鲆群体的遗传学参数,2006年从多个大菱鲆养殖场采集源于不同国家和地区、不同进口批次的大菱鲆亲鱼,利用人工授精技术构建了66个全同胞家系,包括26个父系半同胞家系组。选用混合模型方程,通过约束最大似然法进行了方差、协方差、遗传力和遗传相关等估计。结果表明,大菱鲆25d仔鱼体长、存活率和白化率的遗传力分别为0.20、0.07和0.22;3个性状间呈负遗传相关关系,检验不显著。研究结果表明,大菱鲆体长和白化率是中度遗传力,选择育种潜力较大;3个性状任何性状的选择对其他两个性状的影响很小,利用一个性状对另一个性状的间接选择是不可行的。     

天然饵料对牙鲆鱼苗白化率和底板黑斑率的影响

正牙鲆隶属硬骨鱼纲、鲽形目、鲆科,是一种名贵鲆鲽鱼类。该鱼肉质细嫩、口感好、价值高,生长快、易活运,已成为我国海水养殖的主要品种之一,在养殖生产中牙鲆鱼幼鱼白化已经成为多发病和易发病,研究结果显示,正常体色牙鲆与白化牙鲆不仅体色不同,生长性能和优势性状方面也存在较大差异。幼苗的底板黑斑病是人工培育的苗种在腹面出现单个或多个黑斑,同时也有的伴有背部白化和个体形态异常,一般认     

半滑舌鳎白化现象的初步研究

通过建立半滑舌鳎家系对其白化现象进行了初步研究。实验共建立半滑舌鳎家系17个,首先对这17个家系白化率进行了抽样统计和方差分析,并对部分家系的白化个体的眼睛异常率进行了统计;其次,选取其中白化率较高的4个家系,对白化个体和正常个体的生长情况进行了对比;最后,对白化率较高的4个家系白化个体和正常个体的抗鳗弧菌病能力进行了比较。结果发现,不同家系个体白化率有较大的差别,3号家系白化率最高,高达94.50%,15号、33号和37号家系白化率为0.00%;父本为养殖群体的家系的平均白化率最高,为19.68%,父本为野生群体的家系的平均白化率最低,为3.21%,父本为选育群体的平均白化率为7.50%,但3者之间差异不显著(P0.05);3个家系的白化个体眼睛异常率较高,5号家系为48.48%、10号家系为45.83%和12号家系为88.89%。选取4个家系对其白化个体和正常个体的生长情况进行比较发现,同一家系中3~4月龄白化个体在全长、体宽和体质量方面均显著或极显著小于正常个体,但生长至12~13月龄时,这种差异基本不显著,1号和17号家系白化个体的全长、体宽和体质量甚至超过了同家系的正常个体;1号和17号家系白化个体的日增重分别超过了同家系的正常个体。对选取的4个家系的白化个体和正常个体进行鳗弧菌感染实验发现,白化个体的死亡率均低于同家系正常个体,1号和17号家系的白化个体的抗病性相对同家系正常个体较突出,死亡率分别比正常个体低24.92%和20.25%。研究表明,半滑舌鳎野生群体的后代白化率较低,白化现象会伴随一定比例的眼睛异常,白化个体初期生长较慢,后期生长加快,甚至会超过正常个体,并且同一家系中白化个体的抗病性要优于正常个体。     

半滑舌鳎快速生长及高雌性家系的筛选

为查明半滑舌鳎不同家系雌、雄鱼遗传和生理性别比例及其与生长速率的关系,并试图筛选出生理雌鱼比例高且生长快的家系,实验首先建立了22个半滑舌鳎家系,并进行同池养殖以比较生长性能,再选取5个正常雄鱼家系和5个伪雄鱼家系进行遗传性别和生理性别测定.结果发现,不同家系鱼苗不仅生长速度差异显著,而且雌雄比例差异也很显著.筛选出生长快速的家系2个(家系16号和61号),其相对增重率分别为0.81和0.56 g/d;筛选出生长较快的家系4个(家系21、28、57和63号),其相对增重率为0.48 ～0.53 g/d;筛选出生长速度一般的家系12个,生长慢速家系4个.所检测的5个正常雄鱼(ZZ类型)家系的遗传雌鱼比例平均为51.87％,生理雌鱼比例平均为42.94％,遗传雌鱼转化为生理雄鱼的比例平均为14.08％.相反,检测的5个伪雄鱼(ZW类型)家系的遗传雌鱼比例平均为49.34％,生理雌鱼比例平均为4.45％,遗传雌鱼转化为生理雄鱼的比例平均为91.41％.实验发现半滑舌鳎不同家系在雌、雄生理性别比例上存在明显差异;伪雄鱼后代中的遗传雌鱼更容易转化为伪雄鱼,增加养殖群体中生理雄鱼的数量.研究表明,通过家系选育可以筛选出雌性比例高、生长速度快的半滑舌鳎家系.     

大菱鲆生长和耐高温性状的遗传参数估计

对来自40个家系的753尾大菱鲆个体进行耐高温实验,测定其生长和耐高温性状.基于是否考虑全同胞家系效应,建立了两种动物模型,用于估算大菱鲆生长和耐高温性状的遗传参数.利用WOMBAT程序采用平均信息约束极大似然法估计各模型中性状的方差组分,用似然比检验法进行不同模型的差异检验.方差组分分析结果显示,估计体质量遗传参数时,采用模型Ⅰ效果较好,相应遗传力为(0.22±0.09);估计肥满度时,两模型间差异不显著,其遗传力范围为(0.21±0.18)～(0.39±0.11);估计耐热性时,采用模型Ⅰ比较理想,遗传力为(0.026±0.034).表型和遗传相关分析结果表明,体质量与肥满度、耐热性的表型相关系数分别为0.13和0.04,肥满度与耐热性的表型相关系数为0.13;体质量与肥满度、耐热性遗传相关系数分别为0.01和-1.00,肥满度与耐热性的遗传相关系数为0.05.研究结果表明,没有考虑全同胞家系效应的模型Ⅰ是估计大菱鲆生长和耐高温性状遗传参数的较好模型.     

盐度对漠斑牙鲆幼鱼存活、生长及摄食的影响

盐度对漠斑牙鲆幼鱼的存活的影响较小,将漠斑牙鲆幼鱼从盐度为32的海水直接放入盐度为24、16、8、0的水中观察48 h存活情况,仅盐度0组成活率为75%,其他盐度组均为100%.在盐度为32、24、16、8、0各试验组中,经1个月饲养,生长速度和饵料系数均无显著差异.盐度越低越有利于漠斑牙鲆白化个体康复正常体色.     

高植物蛋白饲料中不同水平低分子水解鱼蛋白对大菱鲆(Scophthalmus maximus L.)幼鱼生长及肝脏IGF-I受体表达的影响

本研究利用低分子水解鱼蛋白设计了4组等氮等能的高植物蛋白饲料,研究不同水平低分子水解鱼蛋白对大菱鲆(Scophthalmus maximus L.)幼鱼[(4.16±0.01)g]生长性能、鱼体组成及肝脏中类胰岛素生长因子Ⅰ受体(Insulin-like growth factor receptor,IGF-IR)表达的影响.水解鱼蛋白分别替代总蛋白的5％(UF-5)、10％(UF-10)、20％(UF-20)的鱼粉,无添加FPH组为对照组(UF-0),用这4种饲料饲喂大菱鲆幼鱼84 d,结果显示,UF-0、UF-5和UF-10组的增重率、特定生长率无显著差异(P＞0.05),但显著高于UF-20组(P＜0.05);UF-0、UF-5组的饲料效率、蛋白质效率和蛋白质沉积率无显著差异(P＞0.05),而显著高于UF-10、UF-20组(P＜0.05);UF-0、UF-5和UF-10三组鱼体粗蛋白、粗脂肪含量无显著差异(P＞0.05),但显著高于UF-20组(P＜0.05);UF-5组必需氨基酸含量及必需氨基酸与非必需氨基酸比值显著高于其他3组(P＜0.05),其他3组间无显著差异(P＞0.05);肝脏中IGF-IR mRNA的表达随着水解鱼蛋白替代水平的增加而升高,且UF-20组与其他3组差异显著(P＜0.05).结果表明,适当添加低水平水解鱼蛋白(UF-5)可促进大菱鲆幼鱼的生长、提高饲料效率及促进肌肉必需氨基酸的积累;高水平添加低分子水解鱼蛋白(UF-20)会抑制其生长及饲料利用等;低分子水解鱼蛋白可提高大菱鲆肝脏中IGF-IR基因的表达量.     

红鳍东方鲀(Takifugu rubripes)生长性状的遗传参数估计

通过人工受精的方法获得红鳍东方鲀8个半同胞家系(16个全同胞家系),共测量了790尾红鳍东方鲀8个半同胞家系(16个全同胞家系)135日龄和200日龄的体质量和体长。将135日龄生长性状作为协变量构建3个动物模型,模型(1)包含加性遗传效应、母本遗传效应和全同胞效应;模型(2)包含加性遗传效应和母本遗传效应;模型(3)包含加性遗传效应和全同胞效应。利用DMU软件,采用平均信息约束极大似然法估计各模型中性状的方差组分,用似然比检验法进行不同模型的差异检验。选择最优模型估计红鳍东方鲀200日龄生长性状的遗传参数。结果表明,母本遗传效应对200日龄红鳍东方鲀生长性状无显著影响,确定模型(3)为最优模型。200日龄红鳍东方鲀,体质量和体长的遗传力分别为0.16和0.14,全同胞效应比率分别为0.12和0.13。研究表明,红鳍东方鲀生长性状具备一定的选择潜力,应用家系选育方法能够获得较好的遗传进展。     

Accuracy of pairwise methods in the reconstruction of family relationships, using molecular information from turbot (Scophthalmus maximus)

Many estimators and algorithms have been developed to infer the genealogical relationships from molecular marker data when there is no pedigree information. Most pairwise methods provide estimates in a continuous range that needs to be converted into genealogical relationships (namely full-sibs, half-sibs and unrelated) if there is a previous knowledge of the population structure. Transformations are usually based on arbitrary thresholds, but the possibility of correcting the coancestry estimates via explicit pedigree reconstruction methods has been suggested. Using molecular data for ten highly polymorphic microsatellite loci on a population of turbot (Scophthalmus maximus) with a known genealogy, the behaviour of four pairwise marker-based coancestry estimators and the molecular coancestry has been evaluated. The population consisted on 138 families with 4 full-sib individuals each and one family with 8 full-sib individuals (up to 15 half-sib families were also present due to the sharing of parents between some of the full-sibs families). Our results suggested that transforming the pairwise estimators and the molecular coancestry to family relationships through the establishment of thresholds performs slightly better than the explicit pedigree reconstruction method, when accuracy is measured in a pairwise basis. However, if joint relationships between more than two individuals were tested at a time, the threshold methods led to a high percentage of incongruous triads of full-sib individuals, with Mendelian incompatibilities appearing in congruous full-sib families (more than 70% and 60% in our study, respectively). The explicit pedigree reconstruction approach, due to its nature, is free from such problems. Therefore, the pedigree reconstruction approach seems to be a valuable tool to provide a congruent and compatible pedigree when the pairwise marker-based coancestry matrices or the molecular coancestry need to be transformed.     

菲律宾蛤仔家系的建立及早期生长发育

采用不平衡巢式设计建立33个菲律宾蛤仔家系(11个父系半同胞家系和33个全同胞家系),并对各家系蛤仔的卵径、受精率、孵化率及生长、存活和变态的相关指标进行了分析。结果表明:各家系蛤仔的卵径、受精率无显著差异(P>0.05,n=90),但孵化率有明显差异(P<0.05,n=90)。在不同时期各家系蛤仔的生长情况不同。幼虫期间,9日龄C2生长最快比生长最慢的F2平均壳长大28.24%,且差异显著(P<0.05,n=90)。D3绝对生长最大比平均值高37.24%。稚贝期间,40日龄I1生长最快比生长最慢的B3平均壳长大78.29%,且差异显著(P<0.05,n=90)。I1绝对生长也最大比平均值高87.61%,其中400～500μm个体占30%,500μm以上个体占53.33%,家系内个体趋于大型化,而B1、B3家系内个体生长性状出现衰退现象,趋于小型化,300μm以下个体分别占整个家系的83.33%、90%。在相同时期各家系蛤仔的存活率不同。幼虫期间,9日龄I2存活率最高比平均存活率高94.14%,E3存活率最低比平均存活率低72.65%。稚贝期间,40日龄时各家系稚贝的存活率较高,都在85%以上。变态期间,同胞...     

Weaning of Wild Young-of-the-Year Winter Flounder Pleuronectes americanus (Walbaum) on a Dry Diet: Effects on Growth, Survival, and Feed Efficiency Ratios

Winter flounder Pleuronectes americanus is being developed for aquaculture in Atlantic Canada. Weaning, the switch from a live diet to formulated feed, is a critical stage in the culture of any fish species. In this study, we used wild young-of-the-year stock to determine whether juvenile winter flounder can be weaned from live, cultured Artemia onto dry feed. The dry feed used was originally formulated for turbot Scophthalmus maximus and cod Gadus morhua by BP Nutrition, Stavanger, Norway. The performance of live feed and dry pellets was compared in terms of survival, growth and feed efficiency over three months. We were able to wean wild juvenile winter flounder onto dry feed after one week. Increased specific growth rates and feed efficiency ratios in weaned juveniles indicated that prepared diet was a better food source than Anemia . Survival was not influenced by food type.     

养殖大菱鲆主要疾病及防治技术

在流行病学调查的基础上,对目前我国大菱鲆养殖中常见疾病进行了较全面的介绍,包括病毒性、细菌性和寄生虫性疾病。系统地描述了这些疾病的流行特征、发病症状、危害程度、感染率及致病原等。同时为各种疾病提供了具体的防治技术和措施,对大菱鲆养殖生产与疾病防治具有理论指导意义和重要的参考价值。本文系国内首次对养殖大菱鲆疾病进行的全面性报道。     

Biochemical and histochemical activities of tyrosinase in the skins of normal and albino turbot scophthalmus maximus

Albinism occurr frequently in hatchery-reared turbot, particularly in China. To elucidatethe mechanism of albinism, we comparedthe biochemical and histochemical activity of tyrosinase inthe skins of normal and albino turbot using substrate L-3,4-dihydroxyphenylalanine (L-dopa). It was foundthat: (1) tyrosinase activity existed in allthe skin extracts tested, including pigmented and non-pigmented skins from ocular or blind side of normal and albino turbot, andthe tyrosinase activity ofthe ocular skin extracts was significantly higherthanthat ofthe blind skin extracts from a single individual for both normal and albino turbot. Unexpectedly,the tyrosinase activity inthe extracts from albino skin ofthe ocular side of albino turbot (termed AOA skin) was about 56% higherthanthat from pigmented skin ofthe ocular side of normal turbot (termed PON skin); (2) histochemical staining showedthat tyrosinase activity was present only inthe PON skin but not inthe AOA skin, andthe white skin ofthe blind side of albino (termed WBA skin) and normal turbot (termed WBN skin). A large amount of positive black granules was formed inthe epidermal cells of PON skin but no black granules were formed inthe skins of AOA, WBA and WBN; (3) temperature and salinity have similar effects onthe tyrosinase activity of ocular pigmented and of albino skin extracts, andthe optimal temperature was 5560°C and optimal salinity 26; however, different pH values had different effects onthese tyrosinase activities, andthe optimal pH value of ocular pigmented skin extracts was 7.0 and ocular albino skin extracts 8.0; allthethree activators tested (SDS, trypsin and zymosan) can increasethe activity of tyrosinase in both ocular pigmented and albino skin extracts of turbot. Butthe level of activation onthe ocular albino skin extracts of albino turbot was significantly higherthanthat on ocular pigmented skin extracts of normal turbot.Onthe basis ofthese observations, it is suggestedthat a large amount of wild type tyrosinase is expressed in albino skin butthe tyrosinase activity is blocked by some unknown inhibitory factors andthe blocked activity of tyrosinase can be readily recovered bythe homogenization of skin tissues in vitro.the unknown inhibitory factors need further studying.     

Application of amplified fragment length polymorphism markers to assess molecular polymorphisms in gynogenetic haploid embryos of turbot (Scophthalmus maximus)

Among the variety of cultured marine species, the turbot Scophthalmus maximus is a fish of growing importance in European aquaculture. In this paper, an advanced application of AFLPs to estimate the genetic diversity of haploid gynogenetic families with the aim of obtaining a preliminary genetic map is presented. Ten EcoRI/TaqI primer combinations were tested in four families comprising diploid mothers and their haploid progenies. The amplified fragment length polymorphism (AFLP) analysis revealed an average of 6.8 polymorphic bands per primer combination and a total number of 88 polymorphisms out of 579 fragments. Among various primer pairs, seven combinations were selected in relation to the quality of profiles and number of polymorphic fragments, to be used in the determination of genetic linkage relationship between AFLP markers within the largest haploid family. Co‐migration of non‐homologous fragments was also investigated in one primer combination adding a fourth selective nucleotide to the three used in the classic TaqI AFLP protocol. Surprisingly, a rate of 38.7% of non‐homologous fragments co‐migrating with monomorphic bands was identified, due to the combined effect of homoplasy and the protocol used. Additional polymorphic markers discovered by this protocol were included in the linkage map. The turbot AFLP linkage map comprises 52 AFLP markers distributed in 12 linkage groups. On the basis of this map, turbot expected total genome length sums up to 1225.6 cM. The results confirm the usefulness of AFLPs in revealing genome segregation in haploid turbot progeny.     

弧菌对养殖大菱鲆的危害及其防治方法研究新进展

弧菌是细菌性疾病的常见病原,不但会感染大菱鲆(Scophthalmus maximus),还会对人类健康造成重大危害.大菱鲆是我国重要的海水养殖鱼类,具有较高的经济价值,然而疾病问题严重阻碍了其养殖业的发展.近年来,有关大菱鲆弧菌病检测及防治方面的研究有了新的突破.文章介绍了几种常见弧菌病原对养殖大菱鲆的危害,对新的检...     

颗粒饲料携带细菌与大菱鲆疾病发生的相关性

白便症是工厂化养殖大菱鲆Scophthalmus maximus的一种常见和多发病,常造成大规模的死亡.2006年针对大菱鲆所用饲料携带细菌与其疾病发生的关系展开调查.调查发现,山东蓬莱(A)、莱州(B)和威海(C)3家大菱鲆养殖场均不同程度的感染了白便症,损失惨重.为查明病因,从切断病原入手,详细调查了这3家养殖场的病鱼、水源和养殖所用的颗粒饲料,通过细菌分离和形态学比较,发现颗粒饲料携带细菌KL-1与大菱鲆白便症的病原菌BB-1具有一致性,经常规生理生化测试、API-ID32E鉴定和16S rRNA序列分析,发现KL-1与BB-1是同一种细菌,为假交替单胞菌属的一种(Pseudoalteromonas sp.),人工感染试验也证明这2株细菌都是大菱鲆白便症的致病原,感染症状与自然发病特征基本一致,表明颗粒饲料携带细菌是大菱鲆白便症的直接病原.并对菌株KL-1和BB-1进行了药敏试验测试,为该疾病的控制提供参考.