A review on the morphology, molecular characterization, morphogenesis and pathogenesis of white spot syndrome virus

Since it first appeared in 1992, white spot syndrome virus (WSSV) has become the most threatening infectious agent in shrimp aquaculture. Within a decade, this pathogen has spread to all the main shrimp farming areas and has caused enormous economic losses amounting to more than seven billion US dollars. At present, biosecurity methods used to exclude pathogens in shrimp farms include disinfecting ponds and water, preventing the entrance of animals that may carry infectious agents and stocking ponds with specific pathogen-free post-larvae. The combination of these practices increases biosecurity in shrimp farming facilities and may contribute to reduce the risk of a WSSV outbreak. Although several control methods have shown some efficacy against WSSV under experimental conditions, no therapeutic products or strategies are available to effectively control WSSV in the field. Furthermore, differences in virulence and clinical outcome of WSSV infections have been reported. The sequencing and characterization of different strains of WSSV has begun to determine aspects of its biology, virulence and pathogenesis. Knowledge on these aspects is critical for developing effective control methods. The aim of this review is to present an update of the knowledge generated so far on different aspects of WSSV organization, morphogenesis, pathology and pathogenesis.     

中华绒螯蟹交配系统的形态功能

为深入了解中华绒螯蟹(Eriocheir sinensis)的交配过程,利用急速冷冻、扫描电镜、组织学等技术,对其交配系统的形态特征进行观察.结果表明,中华绒螯蟹交配系统具有短尾派蟹类的典型特征,即第一附肢(G1)比第二附肢(G2)长.G1整体粗壮光滑,由连接腹部的原肢和内肢组成.内肢长而挺直,呈三角柱状,两侧边缘融合...     

Scanning electron microscopic studies of the kidney glomerulus of Pudu pudu (Molina, 1782), and a comparison with that of cattle, goats, sheep and angora rabbits

The kidney's microvascularization of the Pudu pudu is mostly similar to that of domestic animals. The renal parenchymatous arteries do not give off capsular branches. The majority of the Pudu pudu's glomerula shows spherical shape. Glomerula next to the medulla have a diameter which is an average of 25 microns larger than the diameter of those situated more peripherally. Their volume is comparable to that of the angora rabbit. The capillaries form anastomosis in the inner and outer part of the glomerulus.     

Functional morphology of chloride cells in killifish Fundulus heteroclitus, a euryhaline teleost with seawater preference

ABSTRACT:   Recent advances in the functional morphology of chloride cells in killifish Fundulus heteroclitus , a euryhaline teleost with seawater (SW) preference, were reviewed. Immunocytochemical detection of chloride cells with anti-Na⁺/K⁺-ATPase revealed transitional processes of the chloride cell distribution during early life stages. Chloride cells first appear in the yolk-sac membrane at an early embryonic stage, followed by their appearance in the body skin in the later embryonic stages. The principal site for the chloride cell distribution then shifts from the yolk-sac membrane and body skin during embryonic stages to the gills and opercular membrane in larval and later developmental stages. Morphologically distinct SW- and freshwater (FW)-type chloride cells were identified in adult killifish adapted to SW and FW, respectively. Both types of chloride cells are equally active in the two environments, but exert different ion-transporting functions. Following direct transfer of killifish from SW to FW, SW-type chloride cells were transformed into FW-type cells as a short-term response, followed by the promotion of chloride cell replacement as a long-term response. In killifish acclimated to low NaCl (0.1 mM) FW, intense immunoreactivity for vacuolar-type proton pump (V-ATPase) was detected in the basolateral membrane of FW-type chloride cells, whereas the immunoreactivity was much weaker in fish acclimated to FW with higher NaCl concentrations (1.0 and 10.0 mM). These results suggest the occurrence of active ion absorption in FW-type chloride cells and the involvement of V-ATPase in ion-absorbing mechanisms. In view of recent advances in this field, future chloride cell research should be considered in relation to the functional diversity of chloride cells.     

水生动物防疫体系发展成就回顾

<正>水生动物疾病的预防、控制、治疗、修复可以采用行政管理、法律手段、技术措施三种措施,这三种措施的行为、效果不同,而且最有效、最直接的是第二种措施。水生动物疾病可分重大疾病、常规疾病,重大疾病中的传染性疾病、寄生虫病为疫病。《中华     

Atrial natriuretic peptide. I: Biochemistry, general pharmacology and physiology. A review

The recent discovery of the atrial natriuretic peptide (ANP) system and its possible physiological role in mammalians is discussed. The atrium is the major site of synthesis for ANP, where it is stored in specific secretory granules of atrial myocytes as a 126 amino acid precursor molecule (ANP 1-126). Upon adequate stimuli, such as atrial distension, the biologically active ANP (99-126) is released into the circulation. The hormone binds to specific receptors of the target organs, provoking natriuresis, diuresis, vasodilatation and exerts an inhibitory effect on the renin-angiotensin-aldosterone system. The peptide seems to play a role in cardiovascular regulation by both its renal and extrarenal actions.     

Functional palatability enhancer improved growth,intestinal morphology,and hepatopancreas protease activity,replacing squid paste in white shrimp,Litopenaeus vannamei,diets

Squid visceral paste is a popular attractant and feeding stimulator supplement in shrimp feeds in China, but it often faces problems with fluctuating availability, cost, composition, and quality. An 8‐week experiment was performed to test a proprietary palatability enhancer as an alternative to squid paste in white shrimp feed. Seven diets were tested: a control diet with no supplementations; S1 and S3 diets supplemented with squid paste at 1 or 3%, respectively; S1+PE0.1 and S1+PE0.15 supplemented with both 1% squid paste and the palatability enhancer at either 0.1 or 0.15%, respectively; and finally PE0.1 and PE0.15 supplemented only with the palatability enhancer at 0.1 or 0.15%, respectively. The results showed a trend for increased feed intake and weight gain when squid paste was added to the diet compared to the control, but this was worsened by raising the inclusion level from 1 to 3%. The inclusion of the PE, in combination with squid paste or alone at 0.15%, led to a significantly higher growth, and a feeding stimulation effect was also indicated, with PE0.1 and PE0.15 having a higher feed intake than the control. A further beneficial effect was a significant increase in protease activity in the hepatopancreas in the S1+PE0.15, PE0.1, and PE0.15 treatments compared to the control. In addition, a significant increase in the height of the intestinal mucosal folds was observed in PE0.15, followed by PE0.1. The results demonstrated the potential to replace or reduce squid visceral paste in shrimp diets by supplementing with a PE with functional effects beyond feeding stimulation.     

A new species of Goussia (Apicomplexa, Coccidia) in the kidney tubules of the cod, Gadus morhua L.

Abstract. Segments of the kidney tubules of about 16% of cod caught in the approaches to Halifax Harbour were found to contain a coccidian parasite. Macrogametes developed in an epicellular position, and microgamonts, unsporulated and sporulating oocysts, and free sporocysts, were found in the lumen of the kidney tubule. The epithelial cells of the kidney tubules were damaged and granulomas often formed around infected tubules. The presence of a suture dividing the sporocyst wall into two valves could only be determined using electron microscopy. Other coccidians which have been placed in the genus Eimeria because sutures could not be seen using light microscopy, although no Stieda body was present, may also belong to the genus Goussia. No other coccidians have been reported in the kidney tubules of marine fish, and the name Goussia spraguei sp. nov., is proposed.     

Genetic influences on reproductive system development and function: A review

This paper presents a current view of the genomic and neuroendocrine interaction based on our studies of the reproductive system in the platyfish (Xiphophorus maculatus). It also presents observations from basic research and applied biologists on natural and artificially reared fishes and indicates that there is a direct genetic involvement in the control of spawning, growth rates, size and age at maturation and final body size, similar to that described in platyfish. The past, present and future association of aquaculture and basic science, especially DNA technology, is discussed and potential directions for future research are presented.     

淮河水系沙塘鳢形态生物学研究

测量分析了淮河水系沙塘鳢(Odontobutis obscura)的外部形态特征和框架特征,为其形态种质标准和系统分类研究提供参考。(1)可数性状:背鳍Ⅶ,Ⅰ-9~10,尾鳍14~15,臀鳍Ⅰ-7~8,腹鳍Ⅰ-5,胸鳍14~15,纵列鳞36~41,横列鳞14~18,体侧感觉乳突线鳞28~30,第一鳃弓鳃耙数9~11,脊椎骨数28~29。可量性状:全长是体长1.23±0.03倍,体长是体高3.82±0.45倍、是头长3.08±0.49倍、是尾柄长5.19±0.54倍、是消化道长1.86±0.52倍、是肠长6.99±2.86倍,头长是吻长的2.94±0.42倍、是眼径6.09±0.87倍、是眼间距3.86±0.61倍、是口裂宽1.94±0.27倍,体高是体厚的0.96±0.11倍,尾柄长是尾柄高1.66±0.18倍。(2)体重与体长相关式为W=0.0454L2.7989,r=0.9790。肥满度系数K=2.90±0.32。通过形态性状比较和取样水系分析,认为淮河水系沙塘鳢与中华沙塘鳢的亲缘关系值得进一步探讨。     

中华鲟成体消化系统的形态学和组织学研究

中华鲟成鱼活体解剖后,对其消化系统的形态进行观察并绘图,且采用常规组织学方法对各个器官进行石蜡切片制作并在显微镜下观察.结果表明中华鲟具有口咽腔、食道、胃、幽门盲囊、十二指肠、瓣肠、直肠以及肝脏和胰脏.中华鲟消化系统中既有硬骨鱼类的幽门盲囊,又保留了软骨鱼类所特有的螺旋瓣肠,无论在外部形态和内部结构上,都充分体现了中华鲟典型的古老性和进化的不完全性.     

太门哲罗鱼消化系统形态学和组织学的研究

采用解剖和显微技术对哲罗鱼(Hucho taimen)消化系统形态学和组织学进行研究.结果显示:哲罗鱼口咽腔内除分布有味蕾和粘液细胞外,还着生有丰富的齿结构;食道粗而短,内壁有9～15个舌状粘膜褶皱,在粘膜层扁平上皮细胞间分布有大量的粘液细胞和少量梭型细胞;胃呈V型在粘膜层形成丰富胃小凹,柱状上皮下有发达的胃腺;肠分前...     

The impact of nutritional factors on the immune system in Atlantic salmon, Salmo salar L.: a review

Abstract Compared to the extensive number of studies in nutritional immunology in humans as well as in livestock, the evaluation of nutritional impact on fish health is in its infancy. The mechanisms by which single nutrient modulate immunity are frequently not understood, even if experiments give some indication of the mode of action. With current knowledge in fish nutrition, the methods and criteria for optimal nutrient recommendations should be reevaluated to include health factors such as immunolgy and disease resistance. By increasing knowledge of the role of different nutrients in the general metabolism and in immunity, and by improving rearing conditions, it may be possible to reduce losses due to diseases by retarding the progress of diseases, improving recovery and improving protection through vaccines. This review covers research on dietary level of carbohydrate, n-3 polyunsaturated fatty acids, vitamin E and vitamin C in salmonids, of which the vitamins have been by far the most studied.     

Effect of feed supplementation with kynurenic acid on the morphology of the liver,kidney and gills in rainbow trout (Oncorhynchus mykiss Walbaum, 1792), healthy and experimentally infected with Yersinia ruckeri

Kynurenic acid (KYNA) is an endogenous substance produced on the kynurenine pathway which is primarily known for its neuroactive properties. Recently, it has been proven that KYNA is a selective ligand for G protein‐coupled receptor (GPR 35), presented on immunocompetent cells such as T lymphocytes. This opens up new possibilities of its application as an immunostimulating substance in aquaculture. Thus far, no histopathological investigations in fish have been completed to evaluate influence of KYNA supplementation in feed. This study has been undertaken to determine the effect of feed supplementation with KYNA (2.5, 25, 250 mg kg^?1 of feed) for 28 days on the liver, gills and kidney in healthy fish and experimentally infected with Yersinia ruckeri. In a control group were observed a fatty liver, which is natural for this fish species in the autumn and winter season. As the dose of the supplement was increased, the fat liver changed, it decreased or completely disappeared. Additionally, inflammatory changes occurred in all the analysed organs, and their intensification was dose dependent. In the fish experimentally infected, KYNA caused aggravation of the signs in the liver, kidneys and gills, and the effect was dose dependent. The results implicate that KYNA may be a stressor for fish.     

泉州市渔船历史沿革及今后发展方向

渔船是渔民出海捕鱼的主要工具。从古至今,泉州海洋捕捞渔船的发展历程经历了三个阶段：木帆渔船时期、机帆渔船时期、钢质渔船时期。本文在对三种类型渔船发展历史沿革进行回顾的同时,重点对近20年来钢质渔船的发展变化进行总结,并对渔船目前存在的问题及今后的发展方向进行探讨。     

Haemorrhagic kidney syndrome of Atlantic salmon, Salmo salar L.

This report describes a new syndrome affecting farmed Atlantic salmon on the Canadian east coast that has resulted in increased morbidity and mortality in affected stocks. The major pathological findings are apparent only microscopically and include renal interstitial haemorrhage and acute tubular necrosis and tubular casting. As a result, the disease has become known as haemorrhagic kidney syndrome (HKS). Affected fish are lethargic and anorectic, and lack external lesions. Clinically, HKS fish are anaemic, hypoproteinaemic and hyperosmolalic, with increased serum concentrations of sodium and chloride. At necropsy, internal changes ranged from apparently normal to include one or several of the following: swelling and/or patchy reddening of the kidney, pale gills, exophthalmos, serosanguinous ascites, darkening of the posterior intestine and splenomegaly. Ultrastructurally, viral inclusions were found in the cytoplasm of erythrocytes of HKS fish, and there were unusual electron‐dense inclusions within the tips of renal tubular microvilli of HKS fish. The significance and relevance of the ultrastructural findings to HKS are unknown. Virus isolation was attempted using CHSE, RTG‐2, FH‐10, BB and EPC cell lines; no virus was isolated. Bacteriological analysis failed to reveal significant pathogens. Analysis of tissues for heavy metals and pesticides was negative. Assays for clostridial toxins, lipopolysaccharide and verotoxins were negative. The aetiology of HKS remains unresolved.     

养殖密度对鱼类福利影响的研究进展I．死亡率、生长、摄食以及应激反应

养殖密度影响鱼类福利是鱼类生理生态学、福利学和种群生态学研究中的关键问题,已受到各国学者的关注。文章综述了养殖密度影响鱼类福利的主要研究进展,讨论了鱼类死亡率、生长、摄食以及应激反应等福利指标随养殖密度变化的规律及其描述方法；在此基础上,对鱼类福利指标随不同放养密度变化规律的研究以及应用前景进行了展望。     

真鲷消化道的组织学和形态学研究

采用扫描电镜和光镜技术对真鲷的消化道进行了组织学和形态学研究。具发达颌齿的口咽腔之后，真鲷消化道由分化明显的食道、胃、小肠和直肠构成。口咽腔粘膜表面为复层上皮，其中含有怀状细胞和味蕾，表层细胞具微褶（脊）；食道粘膜也衬着复层上皮，由表层具微褶（脊）的扁平细胞、中层的怀状细胞及底部的基底细胞组成，食道粘部分区域 衬着单层柱状上皮；胃Ｖ形，粘膜表层为单层柱状上皮，贲门部和盲囊部上皮下有一厚层胃腺组织；