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采用大体解剖和光镜技术研究了海鳗(Muraenesax cinereius)消化道形态学和组织学。海鳗消化道分化为明显的食道、胃和肠。食道皱襞多且粗大，黏膜为复层上皮，部分区域为单层柱状上皮。上皮中含两种类型的杯状细胞，以杯状细胞层次多为显著特征，此外还有嗜酸性细胞。肌层厚。浆膜中纤维发达，伸人肌层并与黏膜下层相连。胃“Y”形，分为贲门部、盲囊部和幽门部，盲囊部发达。胃上皮为单层柱状上皮，贲门部和盲囊部胃腺发达，至幽门部胃腺逐渐消失。肠短，由具微绒毛的单层柱状上皮构成，小肠前段绒毛分支多且相互吻合，毛细血管丰富，平滑肌多。直肠单层柱状上皮与假复层纤毛柱状上皮共存。海鳗消化道组织结构特点反映了其凶猛、食肉、食量大的食性特点。 相似文献
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为了解斑鳠(Mystus guttatus)消化系统组织结构特征,采用形态解剖和组织学方法对斑鳠消化系统进行研究。结果表明,斑鳠为一种杂食性偏肉食性鱼类,解剖观察其消化道结构包括口咽腔、食道、胃、肠及肛门,肝脏和胰脏为其主要的外消化腺。组织学观察发现口咽腔上皮组织中有较为丰富味蕾和黏液细胞;食道粗而短,肌层发达,且含有丰富的黏液细胞;胃贲门部和盲囊部,体壁较厚,胃壁内侧有丰富的黏膜褶皱,黏膜层为单层柱状上皮,分布大量的分泌胃酸和胃蛋白酶原的管状腺体,胃幽门部内层为环肌层,外层为纵肌层;斑鳠肠道系数为(0.89±0.11),肠道分为前肠、中肠和后肠三部分,肠腔内有丰富黏膜褶皱,褶皱高度从前向后逐渐降低。肠黏膜上皮肠粘膜表层为单层柱状上皮,在黏膜上皮分布大量的黏液细胞。肝脏与胰脏分离,肝脏分为两叶,胰脏弥散分布于肠系膜上。斑鳠消化系统结构特征与其喜好摄食甲壳类动物密切相关。 相似文献
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河南华溪蟹消化系统的形态结构观察和组织学研究 总被引：1，自引：0，他引：1
为研究河南华溪蟹消化系统的形态结构及组织学特征,采用石蜡切片、H.E.染色和光镜等技术,对河南华溪蟹成蟹消化系统各组织器官的结构进行了观察。结果显示,河南华溪蟹的消化系统主要由消化道和消化腺组成。消化道主要包括食道、胃、中肠和后肠,消化腺为肝胰腺。胃包括贲门胃和幽门胃:贲门胃内有钙化的几丁质齿、隆嵴、短刺及刚毛等组成的胃磨,可磨碎食物;幽门胃内侧可见特殊形态的梳状结构,可过滤食物。在光学显微镜下,食道、中肠和后肠均由黏膜层、肌层和结缔组织层构成,其各段内表面均有由上皮细胞与基膜内凸形成的多级皱褶和嵴,有由环形、纵形和辐射状排列的肌层。仅中肠表面有典型微绒毛结构,无角质膜。食道与后肠上皮表面均有较发达的纤毛层。肝胰腺主要由基膜和4种上皮细胞构成,即吸收细胞(R细胞)、泡状细胞(B细胞)、纤维细胞(F细胞)和胚细胞(E细胞)。 相似文献
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中国龙虾早期叶状幼体消化道的组织结构观察 总被引：4，自引：0，他引：4
利用光镜和电镜对中国龙虾叶状幼体发育早期(Ⅰ～Ⅳ期)消化道的组织学、组织化学和超微结构进行了研究。消化道可分为前肠、中肠和后肠。前肠包括口、食道和胃。消化道壁由粘膜层、结缔组织层、肌肉层和外膜组成。除中肠外,其余消化管壁上皮均覆盖有几丁质层。消化道结构随幼体发育逐渐复杂化。口部的口器发达。食道壁内褶形成四个食道嵴。贲门胃的结构简单,至Ⅳ期幼体只有胃磨齿的雏形;幽门胃内具有由栉状刚毛组成的腺滤器,其结构与过滤功能逐渐完善。中肠上皮细胞具微绒毛,胞质中富含胞器。后肠有六个纵嵴。各段管壁上皮细胞内的胞器以线粒体与内质网居多。在各期幼体消化道中,几丁质层具较多的多糖类物质,中肠上皮细胞含少量糖原;肌细胞内含丰富蛋白质,幽门胃与中肠上皮的含量次之。还探讨了龙虾幼体消化道的结构与功能的关系。 相似文献
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采用解剖和光镜技术研究多鳞(鱼喜)消化系统的形态学和组织学.试验结果表明,多鳞(鱼喜)消化道由口咽腔、食道、胃、幽门盲囊、小肠和直肠构成.口咽腔较小,具绒毛状颌齿,舌三角形,黏膜上皮为复层鳞状上皮,上皮含少量味蕾和较多杯状细胞.食道黏膜也为复层上皮,从食道到胃,杯状细胞逐渐减少,上皮由复层上皮逐渐变为单层柱状上皮,肌肉层发达.胃为"Y"型胃,其盲囊部发达,黏膜上皮为单层柱状上皮,贲门部和盲囊部上皮下有一厚层胃腺组织.小肠短,肠道系数为0.56,上皮为具微绒毛的单层柱状上皮,杯状细胞前肠较多,中肠较少,后肠无,幽门盲囊4个,结构与小肠相似.直肠上皮为单层柱状上皮,上皮含少量杯状细胞,肌肉层较小肠发达.肝小叶不明显,肝细胞索明显.胰腺为弥散型,散布在肝脏组织中. 相似文献
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西伯利亚鲟消化道形态学和组织学的初步研究 总被引：1，自引：0，他引：1
对人工养殖2龄西伯利亚鲟消化道的形态解剖学和显微组织学结构进行了观察。研究结果表明,西伯利亚鲟的消化道从前至后分为口咽腔、食道、胃、幽门盲囊、十二指肠、瓣肠和直肠,食道与胃的分界不明显,形成一个"食道-胃过渡区",胃分为贲门部、胃体部和幽门部。组织学研究显示:西伯利亚鲟的消化道由内向外一般分为粘膜、粘膜下层、肌层和浆膜四层。其中食道粘膜上皮为复层扁平上皮,含杯状细胞和粘液细胞。"食道-胃过渡区"已有腺体存在。胃上皮细胞为单层柱状上皮细胞,无杯状细胞,胃的粘膜表面有许多上皮凹陷形成的胃小凹,幽门部的胃小凹较贲门部和胃体部深;贲门部和胃体部中含有大量的胃腺,幽门部无胃腺。幽门盲囊的管腔内被向内深入的肌层分割成许多完全或不完全的囊腔;粘膜褶皱和褶皱上的绒毛纵横交错,形成网状。肠上皮均为单层柱状上皮,上皮细胞间分布有大量的杯状细胞;粘膜褶皱的高度和数量、杯状细胞的数量从前至后递减:十二指肠粘膜褶皱细而高,上有许多绒毛;瓣肠粘膜和粘膜下层向管腔内突出并卷曲,形成螺旋瓣;直肠的粘膜褶皱矮且宽。 相似文献
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《渔业科学进展》2017,(1)
采用解剖学、组织切片、电镜观察和2种染色技术研究了半滑舌鳎(Cynoglossus semilavis)消化道的组织结构特征。半滑舌鳎消化道可分为口咽腔、食道、食道胃、前肠、后肠5部分,观察了各部分消化道的显微和超微结构,测定了消化道各部分的黏膜褶皱数、黏膜褶皱高度、肌肉层(纵肌和环肌)厚度、黏液细胞相对密度等指标。结果显示,半滑舌鳎不具备结构特征明显的胃,摄食后,食道后部与肠道连接部形成一个囊状膨大结构,称之为食道胃;食道前部开始出现杯状黏液细胞,整个食道以Ⅲ型黏液细胞为主,食道胃中黏液细胞以Ⅲ型为主,前肠黏液细胞以Ⅳ型为主,后肠黏液细胞以Ⅱ型为主。研究结果为认识半滑舌鳎消化与吸收生理机制及研制人工养殖用饲料提供参考资料。 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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Sandra García‐Garrido Ismael Hachero‐Cruzado Carlos Rosas Pedro Domingues 《Aquaculture Research》2013,44(11):1741-1751
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. 相似文献