Controlling the growth of a cyanobacterial contaminant, Synechoccus sp., in a culture of Tetraselmis chui (PLY429) by varying pH: Implications for outdoor aquaculture production

In aquaculture, large volumes of phytoplankton are often grown outdoors to reduce costs. However, growing microalgae in an environment not as well-controlled as in the laboratory can lead to unwanted phytoplankton, including cyanobacteria, contaminating a culture. A cyanobacterial contaminant was isolated from an outdoor culture of Tetraselmis chui (PLY429) at the Milford Laboratory. This study investigated the growth of PLY429 and the cyanobacterium in pure cultures and a mixed culture in a pH range of 6.5-9.5. The division of PLY429 was greater at a pH range of 7.0-8.0; whereas, for the cyanobacterium, higher growth was obtained at pH 8.0-9.0. Results from combined cultures of PLY429 and the cyanobacterium grown at various pHs indicated that maintaining pH near 7.1 yields higher growth of PLY429 than those of the cyanobacterium. These findings suggest that controlling pH may reduce the population of a cyanobacterial contaminant in an aquaculture feed culture.     

The mariculture potential of the Indonesian reef-dwelling sponge Callyspongia (Euplacella) biru: Growth, survival and bioactive compounds

In the present study, the Indonesian reef-dwelling sponge Callyspongia (Euplacella) biru de Voogd [de Voogd, N.J., 2004. Callyspongia (Euplacella) biru spec. nov. (Porifera: Demospongiae: Haplosclerida) from Indonesia. Zool. Meded. 78, 477-483.] (Demospongiae, Callyspongiidae) was cultured for a period of 6 months at three sites in the Spermonde Archipelago, Indonesia. A total of 250 sponge cuttings of two size classes (30 and 40 mm in length) were threaded on either polyethylene or very fine nylon rope and attached to horizontal mooring systems. All sponge cuttings were photographed at regular time intervals. Survival rates were high (82%-100%) among all treatments used. Growth rates differed significantly among treatments, but did not differ significantly per location, farming method, explant size and explant position obtained from the parent sponge. The concentration of the bioactive compound amphitoxin in the cultured explants was not significantly lower than in the natural population, but the concentration did vary significantly between explants used in the different treatments, and also between the different fragments of the natural population. The high growth potential and high survival rate suggest that this sponge species is a promising candidate for further mariculture development.     

大黄鱼碱性磷酸酶基因的克隆及表达特征分析

碱性磷酸酶(alkaline phosphatase,ALP)是一种广泛分布的单脂磷酸水解酶,是动物生物代谢过程中重要的调控酶。实验首次克隆了大黄鱼ALP基因cDNA全序列,命名为LcALP,其全长为2 345 bp,开放阅读框为1 629 bp,编码543个氨基酸。实时荧光定量PCR检测发现,LcALP在大黄鱼雌雄各组织中均有表达,其中在眼和头肾的表达量最高,雌性鳃和脑中LcALP表达量显著高于雄性,而在性腺和脾脏中的表达量则显著低于雄性;胚胎发育过程中,多细胞期、囊胚期和原肠期LcALP基因表达水平相对较低,在卵黄栓形成期明显提高,至孵出期达到峰值,而初孵仔鱼期则显著下调;大黄鱼肌肉细胞系经LPS处理后6 h LcALP表达量降低,12 h显著下调,而poly I:C处理后表达水平持续上升,24 h显著上调至峰值。研究表明,LcALP在大黄鱼胚胎发育调控以及机体免疫防御中发挥重要作用。     

欧洲鳗鲡MyD88基因的克隆及其免疫功能分析

髓样分化因子(myeloid differentiation factor 88,My D88)是TLR(toll-like receptor)信号通路的关键接头蛋白,在先天性免疫中发挥重要作用。实验首次克隆了欧洲鳗鲡My D88基因c DNA全长序列,命名为Aa My D88,其全长为1 539 bp,开放阅读框为846 bp,编码282个氨基酸。该蛋白三维丝带空间结构图与人类的My D88十分相似,具有My D88家族典型的死亡结构域和TIR(toll-like/IL-1 receptor)结构域,其中TIR结构域中含有3个序列高度保守的box1、box2和box3。同源性分析显示,欧洲鳗鲡My D88氨基酸序列与斑点叉尾相似性最高,为76.3%,与其他鱼类相似性为67.5%~73.2%,与哺乳动物相似性较低,为61.6%~62.6%。欧洲鳗鲡My D88在系统进化树中与其他鱼类My D88聚为一支,哺乳类以及两栖类My D88分别聚为一支。实时荧光定量PCR检测发现,Aa My D88基因在欧洲鳗鲡各组织器官中均有表达,其中在肝脏中的表达量最高,心脏、肠、脾脏以及肾脏中也有较高的表达,而肌肉和鳃中的表达水平较低;欧洲鳗鲡经山羊Ig G肌肉注射后,肾脏Aa My D88基因在第7天表达量有显著性提高,14 d后恢复至正常水平,而脾脏Aa My D88基因表达水平从第7~21天持续显著上调,于第7天达到峰值,其表达量为肾脏的1.7倍;欧洲鳗鲡鳍细胞系经poly I:C处理后,Aa My D88基因表达水平在3 h显著降低,6~48 h均有显著升高,于12 h达到峰值。LPS处理后的欧洲鳗鲡鳍细胞系Aa My D88基因表达水平在3 h显著降低,6和12 h显著升高,于12 h达到峰值,24 h后恢复至正常水平。poly I:C处理组My D88基因表达水平在12~48 h均显著高于LPS处理组。研究表明,My D88在欧洲鳗鲡抵御外源微生物的免疫应答反应中发挥重要作用。     

急性操作胁迫对刀鲚应激反应相关神经内分泌因子的影响

为深入了解刀鲚应激反应中相关神经内分泌因子作用的分子机理,采用手工捕捉的方式对刀鲚进行了急性操作胁迫。通过放射免疫法和化学发光法测定刀鲚应激反应后头肾和血浆皮质醇含量的变化,结果显示,刀鲚胁迫刺激后血浆皮质醇含量极显著性升高,血浆皮质醇浓度平均升高56.48%,头肾皮质醇含量显著性升高,头肾皮质醇浓度平均升高49.68%,表明急性操作胁迫确实引起刀鲚的应激反应。通过同源克隆的方法获得刀鲚促肾上腺皮质激素释放激素(CRH)、硬骨鱼紧张肽(UI)、阿黑皮素原(POMC)基因的部分序列,并应用实时荧光定量PCR(RT-qPCR)方法检测上述神经内分泌因子mRNA的表达变化,结果显示,CRH基因的表达水平极显著性下降,POMC基因的表达水平显著性下降,UI基因的表达水平有下降趋势但不显著。上述结果显示,皮质醇、CRH、UI和POMC等神经内分泌因子通过鱼类下丘脑—脑垂体—肾间腺轴参与刀鲚应激反应的调节,为进一步了解刀鲚胁迫应答的作用机理,实现对其有效调控打下基础。     

饲料中浒苔添加量以及处理方法对幼刺参生长、消化率、消化酶和非特异性免疫酶的影响

采用单因素实验设计,先配制6种浒苔含量(0、5％、10％、15％、20％和25％)饲料饲养初始体质量(1.44±0.01)g幼刺参49 d,然后根据浒苔含量实验结果配制20％含量、3种方法处理的浒苔[干燥粉碎(DC)、纤维素酶酶解后干燥粉碎(DCC)和蛋白酶酶解后干燥粉碎(DCP)]饲料饲养初始体质量(4.58 ±0.23)g幼刺参60 d,以研究饲料中浒苔添加量以及处理方式对幼刺参生长、消化率、消化酶和非特异性免疫酶的影响.实验每组饲料设3个重复,每个重复饲喂35头刺参.结果显示:(1)浒苔对提高刺参特定生长率(SGR)、肠道淀粉酶(AMS)活性和超氧化物歧化酶(SOD)和降低饲料系数(FCR)有显著作用(P＜0.05),其中20％浒苔含量最好,浒苔能显著降低饲料干物质表观消化率(ADCd)和粗蛋白质表观消化率(ADCp)(P＜0.05),对刺参摄食率(FI)、成活率(SR)、肠道胃蛋白酶(PP)活性和酸性磷酸酶(ACP)无显著性影响(P＞0.05).(2)3种方法处理的浒苔中,DCC和DCP浒苔对提高刺参SGR、ADCd、ADCp、肠道AMS、PP、SOD和ACP活性和降低FCR有显著作用(P＜0.05),其中DCC浒苔最好,3种方法处理的浒苔对刺参FI和SR亦无显著性影响(P＞0.05).在本实验条件下,幼刺参饲料中浒苔适宜含量为20％;纤维素酶酶解后干燥粉碎浒苔是一个理想的浒苔处理方法.     

Identification and characterization of a green-type mutant of Porphyra tenera Kjellman var. tamatsuensis Miura (Bangiales, Rhodophyta)

We identified two green-colored conchocelis strains of cultivated Porphyra, ‘Oba-green’ and HGT-6 (F₁ strain of ‘Oba-green’), based on PCR-RFLP and sequence analyses of the nuclear ITS region and the plastid RuBisCO spacer region. These molecular analyses confirmed that the two strains were green-type mutants of the endangered species Porphyra tenera, although their blade color was not green. Under the same culture conditions, blade length increase was significantly higher in HGT-6 than in a wild strain HGT-1 of P. tenera, and the blade shape of HGT-6 was extremely elongate compared with that of HGT-1. From the growth characteristics and ITS-1 sequence data, HGT-6 was confirmed to be a green-type mutant of P. tenera var. tamatsuensis, a vigorously growing cultivar. Although photosynthetic pigment contents were lower in HGT-6 than in HGT-1, total content of four major free amino acids was higher and the blade thickness was almost the same in HGT-6 and HGT-1. These results suggest that the green-type mutant HGT-6 has potential as breeding material for further development of Porphyra breeding.     

Pathological and PCR detection of mycobacteriosis in pond-cultured Chinese soft shell turtles, Trionyx sinensis

Mycobacteriosis due to infection of Mycobacterium marinum is a common disease in pond-cultured Chinese soft shell turtles, especially in those surviving beyond their first year. The infected turtles independently showed either heterophilic or histiocytic granulomas in various organs such as the spleen, liver, lungs, intestine, kidneys, stomach and pancreas. The heterophilic granuloma contained many acid-fast unbranching bacilli intracellularly in macrophages and extracellularly in the necrotic center. The histiocytic granuloma had only a few bacteria, mainly in the cytoplasm of Langhan's giant cells. The organisms were rarely observed in the advanced lesions of both types. Based on PCR assays for partial hsp65 gene of Mycobacterium spp., all of our strains were identified as M. marinum which can be divided into two groups. The strains of the first group induced heterophilic granulomas and had very high nucleotide sequence identities (99.8%-100%) to the reference strains of M. marinum (AF456471) and M. pseudoshottsii (AY550226). Those strains of the second group caused histiocytic granulomas and also showed very high identities (99.8%-100%) to the reference strains of M. marinum ATCC 927 (AF456470) and M. shottsii (AY550225). However, when we compared the partial sequence of the hsp65 gene from group one and two strains the identities between the two groups range from 98.8% to 99.3%, therefore we can not assert that these two belong to the same species.     

紫外辐射对条斑紫菜不同部位藻体光化学效率和光合色素含量的影响

实验室条件下研究了紫外辐射(UVR)对条斑紫菜藻体不同部位最大光化学效率(Fv/Fm)和光合色素含量的影响,以探讨条斑紫菜不同部位对紫外辐射反应的差异性。在全光谱 PAB(PAR+UV-A+UV-B,280~700 nm)和滤除紫外辐射UVR(UV-A+UV-B)的有效光辐射(PAR,395~700 nm)两种处理下进行测定。实验结果表明,PAB处理后的各部位藻体最大光化学效率下降程度均高于PAR处理后,且弱光期恢复程度低、速度慢。藻体不同部位间最大光化学效率下降程度也存在差异,藻体梢部对PAB的耐受性高,恢复也较快;基部耐受性最差,恢复也较慢。藻红蛋白(phycoerythrin,PE)和藻蓝蛋白(phycocyanin,PC)对不同辐射处理较敏感,PAB辐射处理后,各藻体部位的PE、PC含量均显著上升(P<0.05),其中藻体梢部PAB处理后的PE、PC含量的均极显著升高(P<0.01)。然而不同部位藻体在PAB和PAR照射下,叶绿素a(Chl.a)和类胡萝卜素(Car)并无显著变化(P>0.05)。藻体的紫外吸收物质(MAAs)的含量从基部到梢部逐步升高,不同辐射处理前后,各藻体部位的紫外吸收物质也未显著增加(P>0.05)。总之,条斑紫菜不同部位藻体光合生理特性存在较大差异。推测条斑紫菜应对紫外辐射的策略有遮蔽作用,积累紫外吸收物质和动态光抑制作用。     

The effect of stocking density of Chinese mitten crab Eriocheir sinensis on rice and crab seed yields in rice-crab culture systems

Normally Chinese mitten crab Eriocheir sinensis were cultured for 2 years, 1 year is cultured from crab larvae to seeds or button sized crab in ponds, tanks or rice fields, the another year is cultured from seeds to market size in ponds, reservoirs or other waters. The present study was conducted to determine the effect of stocking density (0, 3.75, 15, 30 and 60 inds. per m², respectively) of Chinese mitten crab larvae on rice and crab seed yields in rice-crab culture systems using land-based enclosures (4 m × 7 m, with three replicates for each stocking density) at the Panjin Guanghe Fisheries Co. Ltd, in the Liaohe Delta, China. Zoobenthos biomass, production of crab and rice paddy, and economical profit among the treatments were determined. The experiment showed that zoobenthos biomass in rice-crab culture systems was relatively variant and not significantly correlated to these stocking density. The biomass of aquatic plant declined significantly with increasing stocking density. Specific growth rates (SGR) and survival rates of the crab were significantly higher at the lower stocking density (P < 0.05); in addition, the ratio of precocious crab and total crab significantly increased with the stocking density increasing (P < 0.05); There were not significant effect of presence of crab on yields of rice straw and rice paddy (P > 0.05). Net crab yield and net profit were the highest at the 15 treatment (P < 0.05), however, the net profits among 3.75, 15 and 30 treatments did not show significant difference (P > 0.05) economically. Based on the observations above, a stocking density of 3.75 to 30 inds. per m² was considered reasonable in rice-crab culture system.     

中华绒螯蟹蜕皮激素受体基因（Ers-EcR）的克隆和组织表达分析

蜕皮激素受体(ecdysteroid receptor,EcR)介导调控甲壳动物蜕皮生长、附肢再生等重要生命活动。为了解EcR在人工控制甲壳动物的繁殖和生长中的作用,采用RACE方法结合同源克隆技术,首次从中华绒螯蟹Y-器官中克隆得到蜕皮激素受体基因全长cDNA序列(Ers-EcR,登录号:KF736985),并进行了结构解析和组织表达分析。结果发现,Ers-EcR编码基因全长2 176 bp,开放阅读框为1 638 bp,编码545个氨基酸,具有DNA结合域(DBD)和配体结合域(LBD)等典型的核受体超家族结构域,但不具有信号肽结构。其中,DBD含有8个保守的Cys残基,可以形成2个锌指结构(C156-C159-C173-C176、C192-C198-C208-C211),是典型的DBD特征。多重序列比对分析表明,Ers-EcR氨基酸序列与拳手招潮蟹同源性最高,达到91%。荧光定量PCR结果显示成体中华绒螯蟹ErsEcR基因在Y-器官和肌肉组织中表达量最高,在血液、肠道、卵巢、眼柄、心脏和肝胰腺中有一定表达,在鳃、胸神经节和精巢表达量较低。这表明Ers-EcR基因在中华绒螯蟹各组织器官中的表达不具有典型的特异性,提示Ers-EcR基因可能参与体内多种生命活动的调控。     

精养团头鲂池塘沉积物微生物群落的结构特征及组成多样性分析

为了研究精养团头鲂池塘冬季不投饵期间沉积物不同层次细菌群落结构的特征,实验分层次采集池塘沉积物,采用PCR-DGGE(变性梯度凝胶电泳技术)及基因测序技术,对池塘沉积物垂向空间分布的微生物群落特征及多样性的组成进行分析。结果显示:精养团头鲂池塘的整个停饵期间沉积物微生物群落的丰富度(平均为38)和多样性指数(平均为3.18)均较高,说明精养池塘沉积物中微生物数量多、种类丰富。上层(0~10 cm)和中层(10~20 cm)沉积物的微生物群落Shannon指数(3.29、3.27)略高于下层(20~30 cm)的Shannon指数(3.17),底层沉积物样品的指数最小(2.96),说明在底层沉积物中微生物群落结构趋于稳定,菌群多样性变化较小。精养团头鲂池塘的整个停饵期间沉积物样品中上层(0~10 cm和10~20 cm)微生物的群落结构相似性较高(80%以上),而底下层(20~30 cm和30~40 cm)与中上层微生物的群落结构相似性较低(63%以上),说明通过微生物群落结构的相似性程度可以大致看出样品的空间顺序。微生物群落组成多样性的结果显示:精养团头鲂池塘沉积物在整个停饵期间包含的菌群分属于8个门:变形菌门(β-、γ-、δ-亚群)(33.33%)、绿弯菌门(19.05%)、拟杆菌门(14.29%)、蓝细菌门(9.52%)、螺旋体门(9.52%)、硝化螺旋菌门(4.76%)、酸杆菌门(4.76%)、厚壁菌门(4.76%);结果表明变形菌门为精养团头鲂池塘沉积物在停饵期间的优势菌群,δ-变形菌亚群(14.29%)是变形菌门中的优势菌群。本实验以期得到不同种类微生物的分子信息从而为以后筛选有益菌群奠定基础,并为团头鲂精养池塘微生态环境的人工调控提供依据,从而为适时监测养殖生态环境运营状况建立快速的分子生物学分析方法。     

不同施肥方法对鱼蚌综合养殖池塘浮游植物群落结构的影响

通过155 d围隔实验检验了不同施肥条件下鱼蚌综合养殖水体中的浮游植物群落结构。实验设3个处理:施鸭粪、施化肥、兼施鸭粪和化肥。放养种类为三角帆蚌、草鱼、鲫、鲢和鳙,放养量分别为每围隔20、15、5、5和5个。结果发现,围隔内浮游植物生物量平均值为(2.1~6.0)×108个/L。不同施肥方法对浮游植物种类组成和优势种、叶绿素a(Chl.a)、生物量以及蓝藻在浮游植物生物量中的比例无显著影响。浮游植物群落变化表现出较明显的季节性特点,影响围隔浮游植物群落的理化因子为TN、NH3-N和DO。研究表明,采用不同施肥方法的围隔内浮游植物群落结构未表现出显著差异,难以从浮游植物角度解释兼施鸭粪和化肥的围隔珍珠产量高于施鸭粪或施化肥的围隔的事实,也难以确定珍珠产量与浮游植物群落结构之间存在必然的联系。     

传染性皮下及造血组织坏死病毒NJ株ORF3基因的原核表达及生物信息学分析

为探究本实验室分离的传染性皮下及造血组织坏死病毒NJ株(IHHNV-NJ)ORF3基因编码蛋白的结构特征,本实验根据ORF3基因序列设计引物,利用PCR方法克隆ORF3基因序列,并构建至原核表达载体p ET-32a(+)中。对成功构建的p ET32a-ORF3重组表达载体进行原核表达,获得49 ku的融合蛋白,符合预期大小。通过生物信息学软件对ORF3基因编码蛋白序列进行分析,结果显示,ORF3基因序列长度为990 bp,编码329个氨基酸;ORF3基因编码蛋白理论分子质量为37 385.2 u,等电点为7.22,为亲水性蛋白;该编码蛋白序列不存在跨膜区、信号肽切割位点;二级结构含有55.9%的α-螺旋、52.0%的β-折叠以及13.4%的β-转角;抗原表位分布较广泛,抗原性强;该编码蛋白序列不存在潜在的N-糖基化位点,存在13个潜在的O-糖基化位点和17个潜在的磷酸化位点。进化树结果表明,NJ株的ORF3基因编码蛋白序列与6株IHHNV序列同源性均高于96%,与厄瓜多尔株同源性最高,为99.7%。研究表明,ORF3基因编码IHHNV衣壳蛋白;O-糖基化位点可参与衣壳蛋白的组装过程及细胞侵染过程,磷酸化位点可参与病毒在对虾细胞内的增殖过程;ORF3编码蛋白序列保守性强,不影响病毒毒力和个体间感染能力。     

Chicken-derived IgY recognizes developing and mature stages of Loma salmonae (Microsporidia) in Pacific salmon, Oncorhynchus spp.

A polyclonal IgY preparation, purified from yolk of immunized hens, is shown to be useful for the detection of Loma salmonae in Pacific salmon. Purity of the IgY was confirmed by SDS-PAGE and western blots of yolk protein extracts. Reactivity of the IgY preparation to L. salmonae was determined through indirect-fluorescent antibody tests on purified spores and by immunohistochemistry. Developing xenomas in histological sections of heart and gill tissue of infected chinook salmon (Oncorhynchus tshawytscha) were visualized as early as 4 weeks post-exposure (PE). Non-lethal detection of L. salmonae was obtained by indirect-fluorescent microscopy of acetone-fixed gill smears. The IgY preparation was shown to react with another Loma sp., L. branchialis. In contrast, no reactivity was observed with other microsporidian parasites of fish such as Pseudoloma neurophilia and Glugea anomala. Yolk derived IgY may be useful in the detection of other fish pathogens.     

Growth variation and fin damage in Atlantic cod (Gadus morhua L.) fed at graded levels of feed restriction

Atlantic cod (initial weight 55, 250 and 450 g) were deprived of feed for 1 month or fed one of two diets differing in crude protein and lipid levels at rations corresponding to about 25, 50, 75 or 130% of group satiation for two months. The fish were individually weighed at the start, mid and end of the experiment and growth variation and fin damage were registered. The fin damage patterns differed between size groups; 55 g cod had most wounds on the dorsal fins whereas the pectoral fins were the most damaged in the 250 g fish. The incidence of damage in these groups was high and increased significantly when feeding was restricted. In the 450 g cod there was little fin damage and the incidence did not seem to depend on diet treatment.In the 55 and 250 g cod groups, fast growing fish had lower incidence of fin damage than fish that grew slowly, suggesting that the fish that received most aggression were prevented from feeding. However, a similar trend was registered in non-fed fish, showing that the recipients of aggression also suffered other disadvantages.The variation in individual growth rates increased when feeding was restricted and the distribution was differently skewed depending on feeding level. The data provide evidence that competition is an important factor limiting growth of individual cod held in groups in culture.     

团头鲂营养需求与健康研究进展

团头鲂是我国主要的大宗淡水养殖品种之一,其养殖规模在近10年不断扩大。团头鲂的营养物质需求主要以生长和营养缺乏症为评价指标。而营养物质对鱼类健康,如免疫反应和抗病力等影响的研究尚不充分。一般认为,饲料中营养物质搭配合理、品质优良有利于维持鱼类生理健康,并能保护养殖水环境。此外,一些营养物质如维生素,在鱼类的免疫机制中发挥重要作用。未来水产饲料应具有促进水产动物生长和维持健康的双重作用,通过营养调控预防鱼类疾病是保证水产养殖可持续发展的重要策略之一。本研究综述了团头鲂对蛋白质、脂肪、碳水化合物、维生素和矿物质营养需求的研究进展,以及饲料营养元素对团头鲂免疫力及抗病力影响的最新报道,以期为团头鲂高效配合饲料的开发提供科学参考。     

金钱鱼抗缪勒氏管激素基因克隆及其在性腺发育不同时期mRNA表达水平的分析

为了解抗缪勒氏管激素基因(AMH)在金钱鱼性腺发育中的作用,本研究利用RACE技术克隆了AMH的cDNA序列全长,为2324 bp(GenBank登录号:KP718479),其开放阅读框为1631 bp,编码543个氨基酸。同源性分析显示金钱鱼AMH与花鲈相似性最高,为71.16%,与斑马鱼相似性仅为29.83%。系统进化树分析表明,该基因与鲈形目紧密聚为一支,与金钱鱼进化地位一致,说明AMH在进化中有一定保守性。氨基酸结构分析表明其1~28为信号肽序列,69~426为AMH-N区域,444~543为TGF-β结构区。实时荧光定量研究表明,金钱鱼成鱼中AMH基因在精巢中表达量显著高于其他组织,在肝和卵巢中也有表达。性腺不同发育时期分析表明,AMH基因在精巢发育Ⅰ、Ⅱ和Ⅲ期均维持高水平表达,IV期表达水平有所降低,H.E染色结果显示这一时期精巢发育逐渐成熟,推测该基因在精巢发育和精子产生过程中有重要作用。在卵巢中,AMH在Ⅰ、Ⅱ期卵巢发育初期表达量较低,在Ⅲ、Ⅳ期卵母细胞大生长期及卵黄积累期表达量升高,推测其在卵母细胞的发育和功能维持上发挥作用。提示AMH基因在金钱鱼精巢、卵巢发育过程中均发挥重要作用。     

Effect of replacing fish meal with soybean meal on growth, feed utilization and carcass composition of cuneate drum (Nibea miichthioides)

The effect of replacing fish meal with soybean meal (SBM) in practical feeds for cuneate drum was evaluated in an 8-week net pen trial. The cuneate drum fingerlings (initial body weight 29.8 ± 1.3 g fish^− 1) were fed six isonitrogenous and isocaloric feeds containing 39% digestible protein and 16 MJ kg^− 1 digestible energy. The control feed was formulated to contain 40% herring meal, whereas in the other five feeds SBM was included at 11.3, 22.5, 33.8, 45.0 and 56.3% to replace 20, 40, 60, 80 or 100% of the fish meal. There were no significant differences in feed intake between fish fed the control feed and feeds in which SBM replaced 20 to 80% of the fish meal, but fish fed the fish meal free feed had higher feed intake than the other treatments. Weight gain linearly declined with the decrease of fish meal level. Final body weight (FBW) of fish fed the feeds in which SBM replaced 20% of the fish meal did not significantly differ from fish fed the control feed. Replacing 40 to 100% of the fish meal resulted in lower FBW and nitrogen retention efficiency (NRE), and higher feed conversion ratio (FCR) than those of fish fed the control feed. Fish fed the feeds in which SBM replaced 60 to 100% of the fish meal had lower condition factor and hepatosomatic index than those of fish fed the control feed. No significant differences in carcass protein content was found among the treatments, but fish fed the feeds in which SBM replaced 60 to 100% of the fish meal had higher moisture and lower lipid content in carcass than those of fish fed the control feed. Results of the present study appear to indicate that cuneate drum has a limited ability to utilize SBM as a protein source in practical feeds.     

四种不同添加物对仿刺参非特异性免疫力和肠道免疫基因Aj-p105、Aj-p50、Aj-rel和Aj-lysmRNA表达的影响

本实验研究了饲料中添加酵母多糖(6.3 g/kg)、马氏副球菌(109 cfu/kg)、大黄(25.0 g/kg)和氟苯尼考(15.0 mg/kg)4种添加物对仿刺参[初始体质量(4.68±0.36)g]非特异性免疫力以及肠道组织免疫相关基因Aj-p105、Aj-p50、Aj-rel和Aj-lys mRNA表达的影响.每个处理分别设置5个重复,以投喂未添加上述任何成份的基础饲料组作为空白对照,养殖实验周期为60 d.结果发现,饲料中添加马氏副球菌能显著提高仿刺参体腔细胞的吞噬活性和呼吸爆发活力,而添加酵母多糖可以显著提高仿刺参体腔细胞的吞噬能力,但是添加氟苯尼考显著降低了仿刺参体腔细胞的呼吸爆发活力;而在仿刺参中肠肠道组织中,酵母多糖和马氏副球菌处理组免疫基因Aj-p105和j-p50 mRNA的表达均大幅上调,显著高于对照组.其中,酵母多糖添加组增幅分别为43.2％和63.1％,马氏副球菌添加组的增幅分别为49.8％和48.0％.马氏副球菌添加组中免疫基因Aj-lys的表达显著高于对照组,增幅为46.4％;大黄添加组中Aj-p105 mRNA的表达量显著高于对照组,而氟苯尼考添加组中Aj-p50、Aj-rel和Aj-lys的mRNA表达量相对于对照组均显著下降.研究表明,饲料中适当添加酵母多糖和马氏副球菌可有效提高仿刺参非特异性免疫力,而饲料中抗生素氟苯尼考的添加会降低仿刺参非特异性免疫力.