Inheritance and reliability of random amplified polymorphic DNA-markers in two consecutive generations of common carp (Cyprinus carpio L.)

Random amplified polymorphic DNA (RAPD) markers have been used in a variety of genetic studies in fisheries and aquaculture. Most population studies are performed without preliminary data demonstrating the Mendelian inheritance and reproducibility of RAPD markers. In this study, the inheritance and reproducibility of RAPD markers was examined in two consecutive generations of common carp, Cyprinus carpio L. Variability and segregation of RAPD markers were investigated in one F₁ progeny and three F₂ progenies. Seventy-four RAPD markers were generated by five primers using DNA extracted from the initial ornamental (koi) common carp female and wild-type colour common carp male. Fifty-five of these RAPD markers were transmitted to the F₁ progeny and the inheritance patterns were analysed. Twenty RAPD markers were fully reproducible and demonstrated dominant simple Mendelian inheritance patterns in two consecutive generations. Twenty-four RAPD markers were not reproducible in all progenies. Thirteen markers displayed inheritance ratios in the progenies that did not fit simple Mendelian inheritance patterns. Non-reproducibility of RAPD markers and distorted ratios may be caused by the absence of amplification, poor amplification or by the appearance of artefact bands. Random amplified polymorphic DNA markers with poor reproducibility and non-Mendelian inheritance can lead to misinterpretations of data in population studies, resulting in errors in the estimation of genetic diversity within and between individual populations. Therefore, it is recommended to first identify the set of reproducible RAPD markers that demonstrate Mendelian inheritance before application of the RAPD technique in population studies.     

Perception of Asian carp as a possible food source among Missouri anglers

Silver and bighead carps were imported from China to the United States in the 1970s as a biological control mechanism for improving water quality. After escaping captivity, both species spread into the Mississippi River Basin and now threaten to enter the Great Lakes. Human consumption is one solution, but many Americans believe that carp is unsavory. A random sample of 2,000 licensed anglers in Missouri was asked to complete a mail-back questionnaire about Asian carp, yielding a 27% response rate (n = 465). Results indicated that knowledge and perception about carp were poor, and food neophobia (fear of new foods) scores were above average. Less than 15% of respondents had eaten carp, but nearly 53% were willing to try. Marketing should focus on the benefits of consumption while downplaying any possible concerns. Although education programs are worthwhile, taste might be more influential to change public attitudes toward Asian carp.     

低磷低鱼粉饲料中添加植酸酶和蛋白酶对草鱼生长性能和消化生理的影响

本试验旨在研究低磷低鱼粉饲料中添加植酸酶和蛋白酶对草鱼生长性能、消化酶活性、营养物质表观消化率和免疫力的影响。试验选取平均体重为9.66 g的健康草鱼630尾,随机分为7个组,每组3个重复,每个重复30尾鱼。7组草鱼饲喂如下试验饲料:正常磷(磷酸二氢钙添加量2.0%)正常鱼粉(鱼粉添加量3.0%)饲料(对照)、低磷(磷酸二氢钙添加量1.3%)正常鱼粉饲料、低磷正常鱼粉并添加0.03%植酸酶饲料、正常磷低鱼粉(鱼粉添加量1.5%)饲料、正常磷低鱼粉并添加0.05%蛋白酶饲料、低磷和低鱼粉饲料、低磷低鱼粉并添加0.03%植酸酶和0.05%蛋白酶饲料。饲养试验持续56 d。结果显示:与饲喂正常磷正常鱼粉饲料草鱼相比,饲喂低磷低鱼粉饲料草鱼的增重率、特定生长率、营养物质(干物质、蛋白质、钙和磷)表观消化率、肠道消化酶(胰蛋白酶、糜蛋白酶和淀粉酶)活性、血清溶菌酶活性均显著降低(P<0.05),饲料系数和血清丙二醛含量显著升高(P<0.05)。在低磷正常鱼粉饲料、正常磷低鱼粉饲料、低磷低鱼粉饲料中分别添加植酸酶、蛋白酶、植酸酶与蛋白酶后,草鱼的上述指标均得到显著改善(P<0.05)。以上结果表明,在低磷低鱼粉饲料中添加植酸酶和蛋白酶能够提高草鱼的营养物质表观消化率、肠道消化酶活性和免疫力,从而改善其生长性能。     

利用紫苏子提取物作为异育银鲫饲料添加剂的生产试验

通过在异育银鲫饲料中添加300mg/kg紫苏子提取物,经随机抽取两处10口池塘,计算同期池塘应用及未应用紫苏子提取物添加饲料池塘投入产出情况:应用紫苏子提取物作为添加剂的池塘,异育银鲫增重率比未使用紫苏子提取物的池塘高9%～15%;饲料系数下降11.4%～11.8%,异育银鲫重量增长了50～99kg/亩,产值增长680～853元/亩。     

草鱼巨噬细胞的集结及相关的组织变化

给草鱼腹腔注射细微炭粒（墨汁）后不同时间取样,比较观察了草鱼胸腺、肝、脾、头肾和肾组织中巨噬细胞集结（ｍ ａｃｒｏｐｈａｇｅ ａｇｇｒｅｇａｔｉｏｎ , Ｍ Ａ）状况及相应组织的变化。结果表明,在头肾和脾组织中, Ｍ Ａ 的数量和体积均较肝和肾中的多而大,胸腺中所产生的 Ｍ Ａ 数量较肝和肾中的少,体积也小;注射墨汁后 １～３ 周内,在胸腺、头肾、肝和脾组织中, Ｍ Ａ 的数量和体积均有不同程度的增加,但在注射墨汁后第 ４ 周的肾组织中, Ｍ Ａ 的体积缩小而且密度降低,同时肾组织结构有逐渐恢复的趋势,可能是由于 Ｍ Ａ 分解后通过肾小球和肾小管排泄到膀胱或体外的缘故。对草鱼 Ｍ Ａ 的组织分布、排除等分析认为, Ｍ Ａ 可作为草鱼非特异细胞防御作用的解剖学和细胞学的一种生物标记。     

Essential oil of Aloysia citriodora Paláu and citral: sedative and anesthetic efficacy and safety in Rhamdia quelen and Ctenopharyngodon idella

ObjectiveTo verify the efficacy of citral in inducing sedation and anesthesia in silver catfish (Rhamdia quelen) and grass carp (Ctenopharyngodon idella) and to assess the safety of essential oil (EO) of Aloysia citriodora and citral in inducing and maintaining anesthesia in silver catfish.Study designClinical study, randomized, parallel, multi-arm with control group in target species.AnimalsA total of 96 juvenile and 72 adult silver catfish and 80 juvenile grass carp were used.MethodsSilver catfish and grass carp were exposed to different concentrations of citral, 15–675 and 15–600 μL L^–1, respectively, during the maximum period of 30 minutes to verify sedation and anesthesia induction and recovery times. In addition, for anesthetic induction, silver catfish were exposed to the EO of A. citriodora and citral at 225 μL L^–1 for 3.5 minutes. Then, fish were transferred to an anesthesia maintenance solution at 50 μL L^–1 for 10 minutes to assess hematologic and biochemical variables at 60 minutes, 2 and 6 days after treatment.ResultsCitral only induced sedation from 15, 25 and 40 μLL^–1 in both species. Anesthesia without mortality was induced in silver catfish at 50–600 μL L^–1 and grass carp at 75–450 μL L^–1. At 675 and 600 μL L^–1, mortality was recorded in silver catfish and grass carp, respectively. The EO of A. citriodora and citral were safe in inducing and maintaining anesthesia in silver catfish, with mean corpuscular hemoglobin concentration being the only variable that varied in relation to time and treatments.Conclusions and clinical relevanceCitral was effective in inducing sedation and anesthesia in both species. In addition, A. citriodora EO and citral were safe in inducing and maintaining anesthesia in silver catfish. Both agents are promising substances for the development of new drugs for fish.     

饲料中不同脂肪酸对草鱼组织脂质含量和脂肪酸构成的影响

实验选用初始作重约1．4g的草鱼，在60天的饲养期中分别投喂1种不含脂肪的饲料和8种含3％不同脂质的饲料，观察了饲料中添加油酸（18：1n-9）、亚油酸（18：2n－6）、亚麻酸（18：3n－3）和n－3系列高度不饱和脂肪酸（n－3HUFA；20：5n－3＋22：6n－3）对草鱼肝胰脏、肌肉、头部和去肝胰脏内脏脂质含量和脂肪酸构成的影响。实验结果表明，与摄食单纯含油酸饲料的草鱼相比，含1％18：2n－6和1％18：3n－3或1％18：2n－6和0．5％n－3HUFA饲料组草鱼的肝胰脏脂质含量显著降低，但内脏脂质含量升高。向饲料中添加18：2n－6、18：3n－3和n－3HUFA能明显影响草鱼肝胰脏、肌肉和头部脂质多不饱和脂肪酸的相对含量；组织中n－6系列和n－3系列高度不饱和脂肪酸含量分别与饲料中添加18：2n－6和18：3n－3有相关关系，表明草鱼具有生物转化18：2n－6和18：3n－3为高度不饱和脂肪酸的能力。     

氯霉素在草鱼和复合四倍体异育银鲫体内的比较药代动力学

研究并比较了给草鱼和复合四倍体异育银鲫（简称高倍体鲫鱼）单次腹腔注射氯霉素１００ｍｇ／ｋｇ后的药代动力学特征。采用ＨＰＬＣ测定血液中氯霉素的浓度。试验期间水温为（２０±２）℃。结果表明,氯霉素在这２种鱼体内的处置过程相似,均可用带一级吸收的二室开放模型进行描述;药物从腹腔吸收迅速,给药后分别在０．９２ｈ和０．６３ｈ血中浓度达到高峰,无吸收时滞;在草鱼和高倍体鲫鱼体内药物的ｔ１２β相近,分别为１１．９ｈ和１１．１ｈ,但体清除率（ＣｌＢ）相差较大;氯霉素在高倍体鲫鱼体内比在草鱼体内有更强的亲组织性,总表观分布容积（Ｖｄ）分别为２．０７和１．２０Ｌ／ｋｇ。     

鲤吉陶单极虫体被结构的扫描电镜观察

应用扫描电镜,对鲤鱼肠道内的吉陶单极虫体被进行了形态学观察。吉陶单极虫的孢子呈瓜子形,后端钝圆,向前一端逐渐尖细。从孢子的后端向前端方向常常包裹着一个无色透明的薄膜。孢子可分为背面和腹面,背面光滑无皱褶,并可见一长卵圆形的极囊,极囊一般较大,约为孢子长度的一半。孢子的腹面褶皱不平,形成形态各异、大小和数量不等的迷宫状沟回,沟回主要分布在孢子的中后端。偶见放出极丝的孢子,极丝较长,常为孢子长度的1倍以上。     

氧化鱼油对鲤鱼生产性能和肌肉组织结构的影响

将新鲜鱼油(过氧化物值 ,POV ,1.28meqO2/kg)和POV分别为59.28、118.79、159.85、189.37、331.82和367.86meqO2/kg 的6个氧化程度不同的鱼油按3 %加入半纯化饲料中 ,投喂60g左右二龄鲤鱼鱼种9周。结果表明 :氧化鱼油损害鲤鱼生产性能 ,即降低鲤鱼增重率(P<0.05)、增加饲料系数(P<0.05) ;氧化鱼油导致肝体比(HSI)、肾体比(KSI)和脾体比(SSI)增加 ,以POV为59.28meqO2/kg 的低氧化程度鱼油增加幅度最高 ,超过此氧化程度 ,增加态势相对减弱 ,这预示低量氧化产物刺激肝胰脏、肾脏和脾脏增生 ,高量氧化产物破坏性增强 ,抑制增生作用 ;氧化鱼油破坏肌肉组织 ,使肌纤维间隙急剧扩大、肌原纤维降解、肌原纤维模式紊乱。