杂色鲍的血细胞

通过光镜、电镜技术,比较了正常状态和受到细菌刺激后杂色鲍血细胞的变化.结果显示,正常状态下的杂色鲍血细胞分为三种类型:颗粒细胞、透明细胞和小细胞;杂色鲍血细胞具有很强的免疫功能,对外界刺激敏感;受到细菌刺激后杂色鲍的血细胞在结构和形态上均发生显著的变化.并推测,颗粒细胞的颗粒中含有大量的水解酶类和抗菌肽等免疫因子,发挥主要的免疫作用.     

皱纹盘鲍血细胞的亚显微结构及分类研究

通过对皱纹盘鲍血细胞的超微结构的观察，将其血细胞分成5种类型：大颗粒细胞、小颗粒细胞、特殊颗粒细胞、透明细胞和淋巴样细胞。根据胞核的形态和胞质中细胞器的结构特征，研究认为大、小颗粒细胞是同一类细胞的不同发育阶段，而特殊细胞则是大、小颗粒细胞的原始细胞；透明细胞和淋巴样细胞是两类完全分化了的细胞。     

凡纳滨对虾不同类型血细胞的活性氧水平和酯酶活性

应用流式细胞术(FCM)测定凡纳滨对虾(Litopenaeus vannamei)不同类型血细胞(透明细胞、小颗粒细胞和大颗粒细胞)的非诱导性和诱导性活性氧(ROS)含量以及非特异性酯酶活性,探讨不同类型血细胞的免疫功能.结果显示,透明细胞的非诱导性ROS含量最低,显著低于小颗粒细胞和大颗粒细胞(P＜0.05),大颗粒细胞的非诱导性ROS含量最高;经脂多糖(LPS)刺激后,透明细胞的ROS含量没有显著变化(P＞0.05),小颗粒细胞和大颗粒细胞的ROS含量显著提高(P＜0.05);大颗粒细胞的酯酶活性显著高于小颗粒细胞和透明细胞(P＜0.05).研究表明,3类血细胞在活性氧含量和酯酶活性的功能上存在差异,两类颗粒细胞的活性氧水平较高,大颗粒细胞的酯酶活性较强.     

中华绒螯蟹的血细胞组成、分类及免疫学功能

为了解中华绒螯蟹血细胞组成、分类及其在免疫应答过程中起到的重要作用,本研究通过细胞化学和细胞酶学分析,并结合细胞形态观察,对中华绒螯蟹血细胞的组成、分类进行了研究。同时,通过人工感染嗜水气单胞菌后血液的总血细胞数(THC)和不同类型血细胞数(DHC)的变化,研究不同类型血细胞在免疫应答过程中所发挥的作用。结果显示,依据本实验分类方法,中华绒螯蟹血细胞可以分为4类:大颗粒细胞(G)、中间型颗粒细胞(IG)、小颗粒细胞(SG)和透明细胞(H)。其中小颗粒细胞数量最多,约占33.54%±0.98%,中间型颗粒细胞最少,仅占15.31%±2.01%。4种类型细胞中均含有多糖成分而不含脂质,只有大颗粒细胞在酸性磷酸酶、碱性磷酸酶、β-葡萄糖醛酸酶以及酚氧化酶染色中发现阳性反应。此外,嗜水气单胞菌感染后中华绒螯蟹总血细胞数在3 h后明显升高,在6 h达到峰值,约9.57×106个/m L,并显著高于未处理组和生理组;在感染过程中,大颗粒细胞数量明显下降而透明细胞数量明显上升,这种现象在6 h时达到顶峰并随着时间延长而逐渐恢复至正常水平。研究表明,在中华绒螯蟹非特异性免疫应答过程中,透明细胞主要通过大量增殖执行吞噬功能来参与免疫应答,而大颗粒细胞主要通过裂解释放胞质中所含免疫相关酶参与免疫反应。其中,各类型细胞之间可能存在相互转化作用,而中间型颗粒细胞为这种转化中的过渡类型。     

杂色鲍血细胞中一氧化氮合酶活性的鉴别

一氧化氮合酶(Nitric oxide synthase,NOS)是催化L-精氨酸与O_2产生一氧化氮(Nitric ox- ide,NO)的一种合成酶,它广泛存在于生物体的各个器官和组织中,其活力大小可通过测定NO合成量的多少来决定。NO作为一种新型生物信使分子、效应分子和免疫调节分子,参与机体多种重要的生理病理活动,可以通过非特异性地杀伤细菌、真菌、寄生虫及病毒等。增强机体的非特异性免疫。本文采用生物化学法,以副溶血弧菌和脂多糖为刺激因子.并采用硝酸盐还原酶法测定了NO的水平,对杂色鲍血细胞中的NOS活性进行了初步鉴别。结果表明,加入副溶血弧菌组或LPS组NO水平显著高于对照组(P<0.05),孵育4h后分别为对照组的1.84和1.92倍,孵育8h后分别为对照组的2.38和3.05倍,而且这一反应能被NOS抑制剂L-NAME所阻断,说明杂色鲍血细胞中存在NOS活性。     

锯缘青蟹血细胞的形态及分类

对锯缘青蟹（Scylla serrata）血细胞染色的抗凝剂、染色方法进行筛选。蟹样品体质量约250g。采用亚甲基蓝、瑞氏法染色后，在Olympus油镜下观察、记数、测量，再结合电镜超薄切片观察结果对锯缘青蟹血细胞进行分类。根据血细胞质中颗粒的有无、大小、折光性、染色特性及细胞的大小、核质比等，将锯缘青蟹血细胞分为4种：（1）无颗粒细胞，细胞质中无颗粒；（2）小颗粒细胞，细胞质中有深蓝色小颗粒；（3）中间型细胞，细胞质中既有深蓝色小颗粒，又有折光性红色大颗粒；（4）大颗粒细胞，细胞质中充满了具有折光性的红色大颗粒。4种血细胞的大小顺序从小到大依次为无颗粒细胞、小颗粒细胞、中间型颗粒细胞、大颗粒细胞；核质比则相反，分别为54．01％、37．13％、25．37％、17．49％；其数量百分比分别占20．92％、40．30％、19．39％、19．39％。根据伪足的多少。对4种血细胞在机体的免疫防御机制中所起的不同作用进行了简单探讨。     

杂色鲍与九孔鲍消化酶活力的比较

对人工养殖的、不同体长的杂色鲍与九孔鲍消化酶活力大小进行了研究。酶学分析表明，无论是杂色鲍还是九孔鲍，其纤维素酶随着鲍的体长的增大活性逐渐增强；淀粉酶随着其体长的增大活性逐渐减弱；脂肪酶活性均很小；九孔鲍的纤维素酶活力和淀粉酶活力均大于相同体长的杂色鲍。     

杂色鲍自然海区人工放养的初步试验

本文报道了杂色鲍标志放养和人工造礁试验的方法和结果．试验表明，杂色鲍的最适放养壳长为2．5—3．0厘米；2龄的杂色鲍，平均壳长为4．8厘米，这一龄段的鲍生长最快，3龄的杂色鲍平均壳长为6．3厘米，最大的个体可达7．0厘米；4龄以后，其生长明显减慢。据此，似可将3—4龄，壳长超过6．0厘米的杂色鲍定为上市规格。此外，本文还对杂色鲍对自然环境的适应、生长、移动，以及人工造礁的方法和效果作了介绍。     

几种免疫促进剂对中国对虾血细胞数量、形态结构以及酚氧化酶产量和活性的影响

为了弄清免疫促进剂增强对虾自身免疫力的作用机理,利用脂多糖(LPS)、β-葡聚糖(β-1,3-glucan)、灭活哈维氏弧菌和灭活鳗弧菌对中国对虾血细胞的数量、形态结构以及酚氧化酶(phenoloxidase,PO)的产量与活性在刺激前后的变化进行了研究。研究结果表明,经β-葡聚糖、脂多糖、灭活哈维氏弧菌和灭活鳗弧菌刺激后,中国对虾总血细胞的数量分别增多了83．4％、52．0％、73．4％和111．3％,其中,小颗粒细胞的数量分别增多了100．4％、67．3％、57．2％和102．9％,大颗粒细胞的数量分别增多了47％、10％、127％、和173％;同时,PO的产量分别提高了81．3％、104．7％、29．2％和40．4％,但PO的单位酶活性在刺激前后没有显著变化。透射电镜(TEM)观察结果显示,中国对虾血细胞的超微结构在免疫刺激前后发生了不同程度的变化。在β-葡聚糖和脂多糖刺激下,小颗粒细胞和大颗粒细胞内糙面内质网(RER)和游离核糖体数量明显增多,线粒体数量增加,细胞内分泌颗粒的数量大幅度减少;而透明细胞的超微结构在多糖刺激前后除RER及线粒体数量略有增加、核孔复合体数量明显增加外没有显著差异。经灭活哈维氏弧菌刺激后,对虾大颗粒细胞中RER增生显著并发生泡状化,核质比明显降低;小颗粒细胞中的RER也发生增生且呈泡状化,核质比略有降低;透明细胞中RER数量明显增加,线粒体数量显著增加,核质比明显下降;在灭活鳗弧菌刺激下,对虾透明细胞中游离核糖体和线粒体的数量明显增加,核质比下降;小颗粒细胞内RER的数量明显增多、潴泡体积扩大,细胞质中分泌颗粒的数量比对照组略有减少,核质比明显下降;大颗粒细胞的超微结构除游离核糖体数量有所增加外,变化并不显著。β-葡聚糖和脂多糖主要用于小颗粒细胞和大颗粒细胞;而灭活鳗弧菌和哈维氏弧菌对大颗粒细胞、小颗粒细胞和透明细胞均有作用。     

流式细胞术在克氏原螯虾血细胞的分类、活性和免疫功能研究中的应用

应用流式细胞术(FCM)对克氏原螯虾(Procambarus clarkii)血细胞的分类、活性和免疫功能进行了研究。结果显示:血细胞可分为透明细胞、小颗粒细胞和大颗粒细胞三个亚群,组成比例分别为(26.25±5.29)%、(51.44±7.02)%和(11.20±1.82)%;螯虾血细胞的平均总凋亡率约为3.12%;血细胞对荧光大肠杆菌的吞噬活力显著(P<0.05)高于荧光微球,吞噬率分别为17.04%和14.57%;血细胞在自然生理状态下含有一定量的活性氧,其在两类颗粒细胞的含量显著(P<0.05)高于透明细胞,在大颗粒细胞中最高。结果表明,FCM能较好地应用于虾类的血细胞分类和功能研究。     

Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean

The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna.     

Rare serotype occurrence and PFGE genotypic diversity of Streptococcus agalactiae isolated from tilapia in China

Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China.     

Growth performance,digestive enzyme activity and immune response of Japanese sea bass,Lateolabrax japonicus fed with fructooligosaccharide

In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg.     

Growth hormone (GH) and reproduction: a review

Interaction between growth and reproduction occurs in many vertebrates and is particularly obvious at certain stages of the life cycle in fish. Endocrine interactions between the gonadotropic axis and the somatotropic axis are described, the potential role of GH being emphasised. A comparative analysis of these phenomena in mammals, amphibians and fish, suggests a specific role of GH in the physiology of puberty, gametogenesis and fertility. It also shows the original contribution made by studies on the fish model in this field of investigations.     

Purification and partial characterization of GtHs (cfLH and cfFSH) from Indian walking catfish (Clarias batrachus) (L.) and development of a homologous ELISA for cfLH

Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL^?1 (1.25 ng well^?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation.     

Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection

Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg^?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality).     

Nitrogenous waste excretion and accumulation of urea and ammonia inChalcalburnus tarichi (Cyprinidae), endemic to the extremely alkaline Lake Van (Eastern Turkey)

The endemic, anadromous cyprinidChalcalburnus tarichi is the only fish species known to occur in alkaline Lake Van (Eastern Anatolia, Turkey). EightC. tarichi were maintained individually in Lake Van water (17 – 19°C; pH 9.8; 153 mEq·I^–1 total alkalinity; 22 total salinity) and tank water samples analyzed for 24 h in 2 to 4 h intervals. At zero time, < 1µM ammonia was present and urea was undetectable in the tank water; at 24 h, total ammonia and urea made up 114±32 and 35±25µM, respectively. Over the experimental period, ammonia-N and urea-N excretion averaged 1041±494 and 607±169moles·kg^–1 fish·h^–1, respectively. The extent of urea excretion was highly variable between specimens. Uric acid excretion was not detectable.Urea was present at high concentrations in all tissues and plasma (25 – 35moles·g^–1·ml^–1) of freshly caughtC. tarichi; total ammonia content of the tissues was by a factor of 1.9 (liver) to 3.0 (brain) lower. High arginase activity (2.4±0.2 U·min^–1·g^–1) was detected in the liver ofC. tarichi but ornithine carbamoylphosphate transferase, a key enzyme of the ornithine-urea-cycle, was absent. Ureagenesis is likely through degradation of arginine and/or uricolysis. High glutamine synthetase activity (11±0.6 U·min^–1·g^–1) and low ammonia content in brain suggest that, like other teleosts,C. tarichi has an efficient ammonia detoxification in the brain, but in no other tissue.Nitrogenous waste excretion at alkaline pH is discussed. The ability ofC. tarichi to excrete high levels of ammonia at extremely alkaline pH is unique among teleosts studied so far. The mechanism of ammonia excretion under Lake Van conditions remains to be elucidated.     

Protein and amino acid composition from the mantle of juvenile O ctopus vulgaris exposed to prolonged starvation

Protein and amino acid composition of the mantle of juvenile O ctopus vulgaris (Cuvier, 1797) during fasting for 27 days were determined. Average protein content of octopus mantle was of 711.19 ± 46.80 g kg^?1 DW, and it decreased with increasing fasting days. The non‐essential amino acids content was higher (486.18 ± 11.08 g kg^?1 protein) than essential amino acids (425.82 ± 9.15 g kg^?1 protein) at the start of the experiment (unstarved animals). The results suggest that the amino acid profile of the mantle where the most abundant amino acids are Arg, His, Lys, Gly, Leu and Pro could indicate a prolonged fasting condition (>20 days) or poor nutrition of O . vulgaris. This study supports the idea of using mantle for metabolic needs of starved O . vulgaris suggesting that the degradation pathway of amino acids to pyruvate and tricarboxylic acid cycle intermediates was favoured contrary to the degradation pathway of ketogenic amino acids. Special considerations should be taken concerning Thr, Ile, Ser, Ala, Asx (Asp, Asn), Glx (Glu, Gln) (because of their fast intake) and Lys and His (due to their stable contents) during a prolonged period of fasting.     

Imported ornamental fish are colonized with antibiotic‐resistant bacteria

There has been growing concern about the overuse of antibiotics in the ornamental fish industry and its possible effect on the increasing drug resistance in both commensal and pathogenic organisms in these fish. The aim of this study was to carry out an assessment of the diversity of bacteria, including pathogens, in ornamental fish species imported into North America and to assess their antibiotic resistance. Kidney samples were collected from 32 freshwater ornamental fish of various species, which arrived to an importing facility in Portland, Oregon from Colombia, Singapore and Florida. Sixty‐four unique bacterial colonies were isolated and identified by PCR using bacterial 16S primers and DNA sequencing. Multiple isolates were identified as bacteria with potential to cause disease in both fish and humans. The antibiotic resistance profile of each isolate was performed for nine different antibiotics. Among them, cefotaxime (16% resistance among isolates) was the antibiotic associated with more activity, while the least active was tetracycline (77% resistant). Knowing information about the diversity of bacteria in imported ornamental fish, as well as the resistance profiles for the bacteria will be useful in more effectively treating clinical infected fish, and also potential zoonoses in the future.