Increased melanomacrophage centres in the liver of reproductively dysfunctional female greater amberjack Seriola dumerili (Risso, 1810)

The greater amberjack Seriola dumerili is a new aquaculture fish that may display reproductive dysfunctions. During extensive follicular atresia, which is a common reproductive dysfunction in females during vitellogenesis, part of the reabsorbed yolk returns to the liver to be metabolized and recycled. Melanomacrophage centres (MMCs) are aggregates of macrophage-like cells that play a role in the destruction, detoxification and recycling of endogenous and exogenous materials, and have been associated with systemic stress. Wild and captive-reared greater amberjack were sampled in the Mediterranean Sea during two different phases of the reproductive cycle. The liver of reproductively dysfunctional captive-reared females sampled during the spawning season showed a high density of both MMCs and apoptotic cells. A weak liver anti-cytochrome P450 monooxygenase 1A immunoreactivity was observed, suggesting that the examined fish were not exposed to environmental pollutants. We propose that the observed increase in MMCs and apoptosis in captive-reared fish was related to the hepatic overload associated to the metabolism of yolk proteins reabsorbed during extensive follicular atresia. Since follicular atresia is a frequent physiological and pathological event in teleosts, we suggest that the reproductive state should be always assessed when MMCs are used as markers of exposure to stress or pollutants.     

应用稳定同位素技术分析枸杞岛近岸海域褐菖鲉的食性

为获知褐菖鲉的食性,本研究应用碳、氮稳定同位素技术分析了不同季节和发育阶段褐菖鲉的摄食习性,并评估了浮游动物、端足类、虾蟹类和小型鱼类等饵料生物对褐菖鲉的营养贡献。结果显示,枸杞岛近岸海域4个季节褐菖鲉的δ~(13)C值为–18.2‰~–14.7‰,平均值为–15.6‰;δ~(15)N值为3.3‰~9.9‰,平均值为7.9‰;单因素方差分析显示,褐菖鲉的δ~(13)C值和δ~(15)N值在不同季节之间差异都不显著,说明不同季节之间褐菖鲉的食性差异不大。对褐菖鲉全长和碳、氮稳定同位素比值进行线性回归分析,显示其δ~(13)C值和δ~(15)N值随全长变化都极显著,表明不同发育阶段褐菖鲉的食性差异极显著。聚类分析将不同全长的褐菖鲉分为3组,其中0~19 mm为一组,20~79和80~109 mm为一组,110~199 mm为一组,ANOSIM分析3组之间的差异极显著。褐菖鲉的δ~(13)C值与虾蟹类和鱼类等饵料类群δ~(13)C值较接近,应用Iso Source软件分析饵料类群的营养贡献时发现,麦秆虫对褐菖鲉的的营养贡献均值最大,为22.3%,鱼类、虾蟹类等饵料类群的营养贡献均值都超过了12%。枸杞岛近岸海域褐菖鲉的平均营养级为3.18,属于低级肉食性鱼类,主要摄食麦秆虫、鱼类和虾蟹类,是底栖动物食性,而非浮游动物食性。     

褐菖鲉消化道的组织学和组织化学

褐菖鲉消化道的组织学和组织化学=Study on histology and histochemistry of digestive tract in Sebastiscus marmoratus[刊，中]/石戈（浙江海洋学院海洋科学学院，浙江 舟山 316004），王健鑫，刘雪珠，王日昕//水产学报.－2007，31（03）.－293～302 利用光镜技术对褐菖鲉消化道进行了组织学和组织化学研究。组织学研究表明：褐菖鲉消化道由口咽腔、食道、胃和肠4部分组成。口咽腔较大，上下颌，犁骨及腭骨均有细齿带,粘膜由复层鳞状上皮组成，并含有大量黏液细胞和少量杯状细胞；食道粗而短，上皮组织包括扁平上皮层区域和单层柱状上皮层区域，上皮含有大量杯状细胞和黏液分泌细胞，粘膜层的固有膜中含有腺体；胃呈Y型，包括贲门、胃体和幽门3个区域，胃粘膜由单层柱状上皮组成，在贲门和胃体部的粘膜层中有厚的结实层，上皮有大量的胃小凹和胃腺组织；胃幽门部括约肌明显，幽门上皮不含胃小凹；胃与肠相接处有8～9个指状幽门盲囊，其形态学和组织学特征与前肠类似；肠道上皮由单层柱状上皮细胞组成，丰富的微绒毛形成明显的纹状缘，上皮中含有大量杯状细胞，肠道系数为0.54。组织化学研究显示：幽门、幽门盲囊和肠上皮细胞顶端胞质和纹状缘具碱性磷酸酶活性；幽门盲囊及肠道上皮细胞顶端胞质中检测到酸性磷酸酶活性；在贲门部和胃体部的固有层以及幽门上皮还检测到酯酶活性，且酯酶定位于幽门柱状上皮细胞胞质的上半部。整个消化道的粘膜层中存在许多粘液细胞：食道上皮含大量酸性粘液细胞，胃上皮细胞均含有中性粘液，而肠道由前向后中性粘液物质逐渐减少，酸性粘液物质逐渐增多。组织学和组织化学的结果表明褐菖鲉食道有润滑和微弱的消化作用，胃有消化脂类和吸收糖类的功能；幽门和盲囊有较强的吸收脂类的功能；前肠、中肠和后肠有活跃的细胞内消化和吸收功能，整个消化道结构与其肉食性功能密切相关。图3参29     

粤东海域褐菖鲉种群线粒体DNA控制区序列变异及其在平鲉亚科中的分类地位

对捕自粤东海域的47尾野生褐菖鲉Sebastiscus marmoratus线粒体DNA控制区序列进行了扩增和序列变异分析,并结合GenBank中10种其他平鲉亚科的同源序列,分析了平鲉亚科的分子系统。结果表明,所获序列长度在538～544bp之间,具69个碱基替换位点和36个插入/缺失位点;控制区碱基组成中,A、T、C、G含量分别为34.5%、29.0%、15.8%、20.7%。共检测到38个单倍型。该种群的单倍型多样度(Hd)和核苷酸多样性(Pi)分别为0.978和0.0192。以鲉亚科棘鲉Hoplosebastes armatus作为外群构建的分子系统树显示,褐菖鲉为11种平鲉亚科中较早分化出的种,位于进化树的基部;平鲉亚科为单系群,分为4个分支,分别为平鲉属Sebastes、菖鲉属Sebastiscus、眶棘鲉属Hozukius和无鳔鲉属Helicolenus,与传统的分类地位一致。研究结果表明,控制区序列不仅适合褐菖鲉种群遗传多样性研究,同样也适合分子系统发育研究。     

云斑尖塘鳢精子的超微结构

采用扫描电镜和透射电镜观察了云斑尖塘鳢(Oxyeleotris marmoratus)的精子结构。结果显示:扫描电镜下云斑尖塘鳢精子由头部和尾部(鞭毛)组成。头部近似圆形,直径1.98～2.12μm,尾部鞭毛长23.22～32.92μm。透射电镜下云斑尖塘鳢精子由头部、中段和尾部三部分组成。头部细胞核呈扁卵圆形,前端不具顶体,染色质致密,细胞核内偶见小空隙;核膜与质膜间有间隙,其间分布有细胞质、囊泡、溶酶体,在细胞核后端,还分布有5～7个呈环形单层排列的线粒体;植入窝较浅,中段不明显,包括中心粒复合体和袖套;精子尾部的鞭毛细长,轴丝为典型的"9+2"型结构;轴丝外侧具有较发达的侧鳍。     

云斑尖塘鳢♀×线纹尖塘鳢♂杂交育种的初步研究

利用从国外引进的云斑、线纹尖塘鳢的自繁后代,经过强化培育、性腺促熟后,2009年5-9月开展人工杂交试验。试验结果:孵化水温28~30℃时,云斑尖塘鳢♀×线纹尖塘鳢♂孵化时间68h,受精率为90.0%,孵化率为83.6%,培苗出苗率为60.51%,研究证明尖塘鳢属种间杂交可以成功。     

Morpho-histology of head kidney of female catfish <Emphasis Type="Italic">Heteropneustes fossilis</Emphasis>: seasonal variations in melano-macrophage centers,melanin contents and effects of lipopolysaccharide and dexamethasone on melanins

In the catfish Heteropneustes fossilis, the anterior kidney is a hemopoietic tissue which surrounds the adrenal homologues, interrenal (IR) and chromaffin tissues corresponding to the adrenal cortical and adrenal medulla of higher mammals. The IR tissue is arranged in cell cords around the posterior cardinal vein (PCV) and its tributaries and secretes corticosteroids. The chromaffin tissue is scattered singly or in nests of one or more cells around the epithelial lining of the PCV or blood capillaries within the IR tissue. They are ferric ferricyanide-positive. Leukemia-inhibitory factor (LIF)-like reactivity was noticed in the lining of the epithelium of the IR cell cords and around the wall of the PCV and blood capillaries. No staining was observed in the hemopoietic cells. IL-1β- and TNF-α-like immunoreactivity was seen in certain cells in the hemopoietic tissue but not in the IR region. Macrophages were identified with mammalian macrophage-specific MAC387 antibodies and are present in the hemopoietic mass but not in the IR tissue. Pigments accumulate in the hemopoietic mass as melano-macrophage centers (MMCs) and are PAS-, Schmorl’s- and Perls’-positive. The pigments contain melanin (black), hemosiderin (blue) and lipofuscin/ceroid (oxidized lipid, yellowish tan), as evident from the Perls’ reaction. The MMCs were TUNEL-positive as evident from FITC fluorescence, indicating their apoptotic nature. The MMCs showed significant seasonal variation with their density increasing to the peak in the postspawning phase. Melanins were characterized spectrophotometrically for the first time in fish anterior kidney. The predominant form is pheomelanin (PM), followed by eumelanin (EM) and alkali-soluble melanin (ASM). Melanins showed significant seasonal variations with the level low in the resting phase and increasing to the peak in the postspawning phase. Under in vitro conditions, lipopolysaccharide (10 µg/mL) treatment increased significantly the levels of PM and EM levels both at 16 and at 32 h and the ASM level at 32 h. On the other hand, the synthetic glucocorticoid dexamethasone (100 nM) decreased significantly the levels of EM, PM and ASM time-dependently. The results indicate that the anterior kidney is an important site of immune–endocrine interaction.     

Liver melanomacrophage centres as indicators of Atlantic bluefin tuna,Thunnus thynnus L. well‐being

Melanomacrophage centres (MMCs), located in different organs of non‐mammalian vertebrates, play a role in the destruction, detoxification or recycling of endogenous and exogenous materials. Cytochrome P450 monoxygenase 1A (CYP1A) is involved in xenobiotics biotransformation, and its liver expression is considered as a biomarker for detecting exposure to environmental pollutants. Atlantic bluefin tuna (ABFT), Thunnus thynnus L., liver samples were collected from: wild animals caught in the eastern Atlantic; juveniles reared in the central Adriatic; juveniles reared in the northern Adriatic; adults reared in the western Mediterranean. The samples were processed for basic histology, histochemistry and for CYP1A immunodetection. An unexpected high density of MMCs, containing ferric iron and lipofuscin–ceroids, was detected in the juveniles sampled in the northern Adriatic Sea. These individuals showed also a strong anti‐CYP1A immunopositivity in hepatocytes and in the epithelium of bile ducts. This study supports the utility of MMCs as biomarkers of fish ‘health status’ and gives concern for a potential contaminant accumulation in ABFT.     

褐菖鲉不同地理群体的形态学比较研究

研究褐菖鲉群体间形态差异及与生境的关系,能够为我国近海海域鱼类物种多样性研究和资源保护提供基础资料。采用主成分分析、判别分析、聚类分析和单因素方差分析等多元统计分析方法对采集自我国浙江舟山、福建厦门、广东汕头及广西北海附近海域的4个褐菖鲉(Sebastiscus marmoratus)群体共112尾个体的8个分节特征和15个量度特征进行分析。研究结果显示,北海群体和舟山群体的形态特征指标分别与其他两个群体存在一定程度的分化。相比于北海群体,厦门群体尾柄更长,头部更小。生境差异以及褐菖鲉生活范围相对稳定的生活习性,使得被隔绝于相对独立的生活环境的群体产生了形态特征上的适应性分化。同时,由于我国东海海域和南海海域之间的联通性,不同海域的褐菖鲉群体之间因摄食、繁殖等出现的短距离迁徙出现短暂的基因交流,在一定程度上削弱了形态特征的分化。     

Susceptibility of cultured juveniles of several marine fish to the sevenband grouper nervous necrosis virus

Piscine nodaviruses (betanodaviruses) have been tentatively divided into four genotypes (SJNNV, RGNNV, TPNNV and BFNNV) and it is suggested that host specificity is different among these genotypes. In the present study, a betanodavirus [sevenband grouper nervous necrosis virus (SGNNV)] belonging to the redspotted grouper nervous necrosis virus (RGNNV) genotype, to which most betanodaviruses from warm water fish are identified, was evaluated for its pathogenicity to hatchery-reared juveniles of several marine fish species. When challenged with the virus by a bath method (10(5.1) TCID50 mL(-1)), sevenband grouper, Epinephelus septemfasciatus, Japanese flounder, Paralichthys olivaceus, and tiger puffer, Takifugu rubripes, displayed behavioural abnormalities and mortalities with distinct histopathological signs of viral nervous necrosis and heavily immunostained cells were observed in the central nervous tissues and retina. Bath-challenged rock fish, Sebastiscus marmoratus, and a hybrid of sevenband grouper and kelp grouper, E. moara, did not display any behavioural abnormality or mortality during the experimental period, although many fish showed slight signs of viral infection in nerve cells. Kelp grouper and red sea bream, Pagrus major, showed no behavioural abnormality, mortality or immunohistopathological changes after the virus challenge. These results are, in part, consistent with the natural host range of RGNNV, indicating the complexity in the host specificity of betanodaviruses.     

The genetic variability and population structure of the marbled rockfish Sebastiscus marmoratus in western Japan,as inferred by microsatellite DNA markers

Fisheries Science - Identification of the population structure of harvested species is the first step in the management of wild fisheries. Although the marbled rockfish Sebastiscus marmoratus is a...     

牙鲆免疫相关组织特征及抗体阳性细胞的免疫组化定位

应用抗牙鲆免疫球蛋白单克隆抗体(2D8、1H1)对牙鲆外周血系统、肾、脾、肝、胰、肠道组织中抗体阳性细胞进行了定位观察，并对其组织学特征进行了描述。两株单抗均能在外周血滴片和组织切片中成功地检测到抗体阳性细胞。外周血系统中的抗体阳性细胞主要为淋巴细胞，没有发现抗体阳性的巨噬细胞；牙鲆头肾中没有肾单位，肾小管、肾小球等主要存在于后肾中，脾脏和肾脏都含有巨噬细胞、粒细胞、淋巴细胞等免疫相关细胞，抗体阳性细胞存在方式也极为相似，成簇或单独分布于黑色素巨噬细胞中心和血管周围；牙鲆的胰组织镶嵌在肝上，形成肝胰脏，也参与免疫应答，抗体阳性细胞单个存在，分布于肝组织中，胰组织中没有发现抗体阳性细胞；肠道抗体阳性细胞主要存在于固有层中，有成簇存在现象，在上皮层也可见到单个存在的抗体阳性细胞。     

云斑尖塘鳢、线纹尖塘鳢及其杂交子一代间的遗传关系

应用RAPD技术研究云斑尖塘鳢、线纹尖塘鳢及其杂交子一代(F1)间的遗传关系。筛选得到25个随机引物均在亲本和杂交子一代间呈现多态,遗传相似性指数和遗传距离的计算结果显示,正交F1(云斑尖塘鳢♂×线纹尖塘鳢♀)与母本平均遗传相似系数(0.7090)高于与父本平均遗传相似系数(0.5948);反交F1(云斑尖塘鳢♀×线纹尖塘鳢♂)与母本平均遗传相似系数(0.6301)也高于与父本平均遗传相似系数(0.6089)。说明正反交子代在遗传关系上均偏向各自的母本,对扩增带和聚类图的分析均得到这一结果,表明F1所接受的双亲遗传物质并非完全对等的,所获得的遗传信息可能更多来自母本。     

石莼对褐菖鲉养殖水体的生态作用

在褐菖鲉（Sebastiscusmarmoratus）室内养殖条件下，以不换水作为对照组，设置2个石莼（Ulva lactuca）养殖密度梯度，研究了石莼对褐菖鲉养殖水体的生态作用。试验结果表明，石莼对褐菖鲉养殖水体中氮、磷营养盐的清除效果明显。在褐菖鲉养殖水体中分别加入石莼534和801g·m13共9d不换水，与对照组相比，养殖密度为534g·m-3的石莼组对硝态氮（NO3-N）、氨态氮（NH4-N）和无机磷（PO4-P）的清除率分别为83．7％、90．7％和86．5％；养殖密度为801g·m^-3的石莼组对NO3-N、NH4-N和PO4-P的清除率分别为90．1％、96．9％和92．7％。     

盐度对褐菖鲉仔鱼活力影响的研究

实验比较了5个盐度梯度(28、22、16、10、4)下褐菖鲉仔鱼在饥饿条件下的存活状况并测定其不投饵存活系数SAI。结果表明,褐菖鲉仔鱼最适的生存盐度范围在16~22之间,盐度过低或者过高均对褐菖鲉仔鱼的生存不利。     

饲料脂肪水平对褐菖鲉生长、肠道消化酶及主要脂代谢酶活力的影响

研究了不同脂肪水平饲料对褐菖鲉（Sebastiscusmarmoratus）生长、肠道消化酶及肝脏中主要脂代谢酶活力的影响,试验选用平均体质量为（27．56±0．19）g的褐菖鼬幼鱼225尾,随机分成5个组,分别投喂脂肪水平为6．1％、9．5％、12．4％、15．1％和18．5％的饲料,试验周期为60d。结果表明,1）褐菖铀的特定生长率和肥满度呈先升后降的趋势,在脂肪水平12．4％时达到最大（P〈0．05）,饵料系数则相反,呈先降后升的趋势,肝体指数随脂肪水平的升高而增大（P〈0．05）,成活率在各组问没有显著差异;2）鱼体肠道脂肪酶活力呈上升趋势（P〈0．05）,胃蛋白酶与淀粉酶活力在各组之间没有显著差异;3）褐菖鲉的脂肪酸合成酶活力呈先升后降的趋势（P〈0．05）,脂蛋白酶活力和肝酯酶活力也呈上升趋势,但各组间差异不显著。根据特定生长率与饲料脂肪水平的回归曲线计算得出,褐菖鲉幼鱼最适脂肪需求量为12．72％。     

Henneguya shaharini sp. nov. (Protozoa: Myxozoa), a parasite of marble goby, Oxyeleotns marmoratus (Bleeker)

Abstract. Henneguya shaharini sp. nov. is described from marble goby, Oxyeleotns marmoratus , collected in the State of Selangor, Malaysia. Cysts occurred in the gill filaments. The histopathological examination revealed intralamellar and inter-lamellar forms of infection. A host tissue response against the parasite was seen in some fish.     

Characterization of molecular variants of GnRH, induction of spermiation and sex reversal using salmon GnRH-A and domperidone in the protogynous diandric fish, Synbranchus marmoratus Bloch, (Teleostei, Synbranchidae)

This paper studies the molecular variants of gonadotropin-releasing hormone (GnRH) present in the brain of the protogynous swamp eel, Synbranchus marmoratus, and the effects of the administration of salmon GnRH analogue (sGnRH-A) and the dopamine receptor antagonist, domperidone (DOM) on final maturation and gamete release in this species. Evidence for the presence of two GnRH variants, sGnRH and cIIGnRH were obtained by reverse phase high-pressure liquid chromatography (RP-HPLC) and radioimmunoassay with different antisera. The effects of treatment with sGnRH-A+DOM were checked by three ways: oocyte and milt release by stripping, histological analysis of the gonadal tissue, and androgen serum levels at different times throughout the experiment. In males, spermiation was induced after three weeks of treatment. In the female group, sGnRH-A+DOM did not induce ovulation at the end of the experiment. Histological analysis of the gonads from the female group showed evidence of sex reversal. All the treated fish had elevated androgen serum levels from the third week, with respect to control fish. In all cases, serum estradiol levels were undetectable. These results suggest that treatment with sGnRH analog and DOM induce sex reversal in female and spermiation in males. This revised version was published online in July 2006 with corrections to the Cover Date.     

云斑尖塘鳢微卫星分子标记的筛选与检测

用磁珠富集法分离云斑尖塘鳢的微卫星序列,由所获得的1032个克隆中筛选出146个阳性克隆,经测序81个含有微卫星序列,52个为完美型,27个为非完美型,2个为复合型,其中43个微卫星序列重复次数在10以上。所获得的云斑尖塘鳢微卫星序列中除探针中使用的CA重复单元和GA重复单元外,还有TAC等其他类型的重复单元。设计合成38对微卫星引物,其中29对引物可稳定扩增出条带,使用这些引物对云斑尖塘鳢48个个体进行检测显示:观测杂合度平均值为0.63,期望杂合度平均值为0.43。29对引物中1对引物表现为单态,7对表现为高度多态,14对表现为中度多态,7对表现为低度多态,多态性较为丰富,说明本研究开发的绝大部分微卫星分子标记较为理想。     

云斑尖塘鳢池塘育苗研究

从商业化生产的目的出发,研究池塘云斑尖塘鳢(Oxyeleotris marmoratus)仔幼鱼的培育。育苗池经清塘、培水后,当幼小轮虫生物量达10 eggs/mL以上时,按225～375尾/m2放养刚开口的仔鱼,饲养30 d,长成全长约1.5 cm的稚鱼,开始驯食人工混合饲料,再池养30～35 d,育成全长2.75～3.35 cm幼鱼。2006年共放养仔鱼434万尾,育成早期幼鱼119.7万尾,成活率27.6%。在傍晚时拉网起捕,“三网率”达95%。