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三疣梭子蟹促雄腺显微和亚显微结构的研究 总被引：1，自引：0，他引：1
采用解剖镜观察及组织切片和电镜技术,研究了三疣梭子蟹促雄腺的位置、形态、显微及亚显微结构。结果发现,三疣梭子蟹促雄腺1对,附着在左右射精管的表面,呈不规则索状。随着个体繁殖周期的变化,促雄腺结构各异,可划分为增殖期、合成期和分泌期3个发育时期。腺体进行全浆分泌,有A、B2种细胞类型,A型细胞具常染色质,粗面内质网和线粒体丰富,B型细胞具异染色质,细胞核固缩。处于增殖期的促雄腺量少,体积小,细胞界限清晰;合成期促雄腺体积大,呈索状,内质网和线粒体发达,A型细胞居多;分泌期分为分泌前期和分泌后期,分泌前期促雄腺体积较大,以B型细胞居多,分泌后期促雄腺体积小,部分有脱落现象,细胞器解体,细胞内存在大量空泡,有的细胞已经解体。 相似文献
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该论文首次报道了经由促雄性腺提取物的注射而在蟹类中引起的性逆转现象。此前关于蟹类促雄性腺活性研究的报道极少，而且蟹类的雄性化均是由促雄性腺的移植所产生。本实验中将锯缘青蟹和中华绒螯蟹的促雄性腺提取物分别注射到刚刚完成性别分化的中华绒螯蟹雌性幼蟹体内，此时幼蟹处于4至5期，壳宽为5～8 mm。注射之后，幼蟹经过大约1～2次蜕皮，此时在注射锯缘青蟹以及中华绒螯蟹的促雄性腺提取物的两组实验幼蟹中均能观察到雄性化现象，而注射生理盐水的对照组实验幼蟹中未能观察到相同现象。由此本实验可以证明促雄性腺确实是蟹类的一种雄性激素，注射促雄性腺提取物能引起雌性幼蟹发生性逆转；同时根据锯缘青蟹和中华绒螯蟹的促雄性腺提取物均能引起中华绒螯蟹雌性幼蟹发生性逆转的现象推测，锯缘青蟹和中华绒螯蟹两种间可能存在促雄性腺的交叉活性；不仅如此，性逆转还能在极低的注射剂量下获得，相当于中华绒螯蟹0.14促雄性腺当量和锯缘青蟹0.06促雄性腺当量。 相似文献
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中华绒螯蟹促雄腺的结构与功能 总被引：15，自引：0，他引：15
应用组织切片、组织化学、电镜及体外培养技术研究了中华绒螯蟹促雄腺的结构与功能。结果表明,中华绒螯蟹促雄腺１对,呈不规则索状,位于近阴茎基部射精管的表面,由许多实心腺泡组成;腺体结构与个体精巢发育周期密切相关,可明显划分为增殖期,合成和分泌期３个发育时期;腺细胞以全浆方式分泌激素,茚三酮－Ｓｃｈｉｆｆ反应、磷钼酸法反应呈阳性,推断分泌激素中主要含蛋白质和脂类２种化学成分;体外共培养实验证明,促雄腺具 相似文献
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采用组织学方法和透射电镜技术对性周期内不同阶段和不同季节的雌性长吻鮠(Leiocassis longirostris)脑垂体的超微结构进行较详细的研究，结果表明：长吻鮠脑垂体包括腺垂体和神经垂体两个部分，腺垂体组织中有6种分泌细胞，即促性腺激素(GTH)分泌细胞、生长激素(STH)分泌细胞、促甲状腺激素(TSH)分泌细胞、促黑色素细胞刺激激素(MSH)分泌细胞、催乳激素(PRL)分泌细胞、促肾上腺皮质激素(ACTH)分泌细胞。神经垂体组织中存在A型(A1、T2)和B型神经分泌纤维，A型分泌纤维轴突中具有不同类型的分泌颗粒，B型分泌纤维轴突中含有许多透明小囊泡。产卵前GTH细胞胞质中充满了电子密度较高的大、小两种分泌颗粒；TSH细胞胞质中分泌颗粒排空，电子密度降低，出现大空泡；STH细胞处于活跃的合成和分泌状态；MSH细胞粗面内质网相当发达，成层围核分布，分泌颗粒极少；PRL细胞电子密度高，具圆球形被膜的分泌颗粒；ACTH细胞分泌物颗粒数量少。产卵后GTH细胞中的分泌颗粒排空；TSH细胞出现空泡；STH细胞中的粗面内质网围核环状排列；MSH细胞分泌颗粒多但比较小，粗面内质网呈扁状或网状；PRL细胞分泌颗粒极少，分布不均匀；ACTH细胞内质网近核分布。秋季GTH细胞中发现GTH1和GTH2两种细胞，GTH1细胞具有大量围核分布的分泌颗粒，GTH2细胞胞质中分泌颗粒数量较少；STH细胞胞质中粗面内质网极发达，围核分布，线粒体数量增加；TSH细胞内质网膨大成泡状；MSH细胞有明显的双核结构，其中一核具核仁，胞质内分泌颗粒较产后增多；PRL细胞具有呈不均匀分布的圆球形分泌颗粒；ACTH细胞线粒体与内质网围核分布，分泌颗粒较少，不均匀分布于细胞质中。冬季GTH细胞内有少量分泌颗粒散布在核周围；TSH细胞含有较多的小型分泌颗粒，胞核外周有大量长条形的粗面内质网；STH细胞中分泌颗粒数量较少，合成和分泌活动微弱；MSH细胞粗面内质网呈泡化状，绕核排列；PRL细胞、ACTH细胞和秋季时的超微结构无明显差异。神经垂体中的分泌纤维各阶段也有一定的变化，产前阶段具有较多球形的无被膜分泌颗粒，产后阶段分泌颗粒呈现排空，秋季部分可见到分泌颗粒，但数量相对较少，冬季变化不明显。 相似文献
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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。 相似文献
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用酵母、水球藻、鱼油强化和豆油强化四种不同方式培养轮虫，再分别投喂锯缘青蟹幼体，分析测定轮虫和体的生化组成，结果显示，（1）不同方式培养的轮虫之间以及摄食这些轮虫的锯缘青蟹幼体之间的蛋白质含量都没有显著差异；（2）轮虫的脂类含量和脂肪酸组成与培养方式密切相关，小球藻轮虫的脂类含量最高，20：5n-3(EPA)占总脂肪酸的比例也最高 ，为18.05%，鱼油轮虫则含有最多的22：6n-3(DHA)，占总脂肪酸3.16%，脂类含量仅次于小球藻轮虫；（3）锯缘青蟹幼体的脂类含量和脂肪酸组成受相应饵料营养成分的影响。另外，幼体培育实验也发现，饵料营养成分影响幼体的存活率，结果表明，提高轮虫的EPA和DHA含量，尤其晨DHA含量，将有利于锯缘青蟹幼体的存活和发育。 相似文献
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Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean 
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下载免费PDF全文 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. 相似文献
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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. 相似文献
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Liping Li Rui Wang Wanwen Liang Xi Gan Ting Huang Yan Huang Jian Li Yunliang Shi Honglin Luo Ming Chen 《广西水产科技》2014,(1)
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. 相似文献
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Growth hormone (GH) and reproduction: a review 总被引：5，自引：0，他引：5
Florence Le Gac Odile Blaise Alex Fostier Pierre-Yves Le Bail Maurice Loir Brigitte Mourot Claudine Weil 《Fish physiology and biochemistry》1993,11(1-6):219-232
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. 相似文献
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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. 相似文献
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Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection 下载免费PDF全文
下载免费PDF全文 G Sharon M Pimenta‐Leibowitz M C L Vilchis N Isakov D Zilberg 《Journal of fish diseases》2015,38(1):67-74
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). 相似文献
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William King V David L. Berlinsky Craig V. Sullivan 《Fish physiology and biochemistry》1995,14(6):489-500
Plasma estradiol-17 (E2), testosterone (T), 17,20-dihydroxy-4-pregnen-3-one (DHP) and 17,20,21-tri-hydroxy-4-pregnen-3-one (20-S) levels were measured by radioimmunoassay (RIA) in white perch (Morone americana) and white bass (M. chrysops) that were induced to undergo final oocyte maturation (FOM) with human chorionic gonadotropin (hCG). Plasma DHP levels increased in females of both species in association with oocyte germinal vesicle migration (GVM) and germinal vesicle breakdown (GVBD) and decreased thereafter. Plasma 20-S levels also increased with oocyte GVM in white bass, but were several-fold lower than DHP levels. Circulating E2 and T levels were greatest during GVM and GVBD in both species and decreased to low levels during oocyte hydration and ovulation. Follicles from white perch and white bass which received a priming injection of hCG in vivo, produced both DHP and 20-S in vitro after exposure to hCG and their oocytes underwent GVBD. Ovarian incubates from unprimed fish of either species produced only E2 and T and their oocytes did not complete GVBD. Oocytes from unprimed bass, but not perch, matured when follicles were exposed to hCG in vitro. Both trilostane and cycloheximide blocked in vitro production of DHP and 20-S and oocyte GVBD by white perch follices. DHP and 20-S were equipotent inducers of FOM in the GVBD bioassay. None of several other structurally-related steroids tested were effective within a physiological range of concentrations. These results indicate a role for DHP and 20-S in the control of FOM in white perch and white bass. 相似文献
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Cardiac,ventilatory and metabolic responses of two ecologically dissimilar species of fish to waterborne cyanide 总被引：1，自引：0，他引：1
Changes in heart rate, ventilatory activity and oxygen consumption were determined in trout (Salmo gairdneri) and brown bullhead catfish (Ictalurus nebulosus) during exposure to a steadily increasing concentration of waterborne cyanide selected to produce death in 8–9 hours for each species. The lethal cyanide concentration for the bullheads was an order of magnitude higher than for trout. Trout developed an immediate and gradually increasing bradycardia throughout the exposure period. Cyanide produced tachycardia in the bullhead followed by a gradual onset of bradycardia as the concentration of cyanide was raised. Pericardial injection of atropine (a muscarinic cholinergic antagonist) indicated that bradycardia in the trout was due initially to increased vagal tone but later due to the direct effect of cyanide on the heart. Hyperventilation in the trout persisted throughout the exposure period, although the rate and amplitude fluctuated and was variable between individual fish. During the last hour of exposure (highest cyanide concentration), ventilation was characterized by rapid, shallow breaths followed by a sudden respiratory arrest. The bullheads exhibited hyperventilation during the first 3 hours of exposure followed by a gradual, linear drop in ventilation rate and amplitude until death occurred. Cardiac and ventilatory responses in both species were attributed to stimulation of central and peripheral chemoreceptors by cyanide. Evidence is presented which suggests the initial response in the bullheads was due, at least in part, to gustatory stimulation by the cyanide. Oxygen consumption of the trout remained above pre-exposure levels for the majority of the test period. Oxygen consumption in the bullhead paralleled the changes in heart and ventilatory rates. Whole-body lactate levels of fingerlings of both species during cyanide exposure were measured to estimate the extent of anaerobiosis. Whole-body lactate levels were much greater in the bullheads than the trout, indicating a higher capacity for anaerobiosis, possibly due to a greater fuel supply. Overall, the trout responded to cyanide in a manner similar to that produced by environmental hypoxia whereas the bullheads experienced a gustatory stimulus which masked the hypoxia-like response. 相似文献
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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. 相似文献