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在鲍的人工育苗过程中,要求成熟亲鲍能在较短的预期的时间内集中排放精卵,集中采苗。而在生产实践中,即使亲鲍的性腺达到成熟的程度,在比较恒定的环境条件下很少能自行集中排放精卵。即使能集中排放,其排放的时间也难以人为掌握。采用刺激催产的方法,可使亲鲍预期集中产卵、排精。多年来,人们研究采用过阴干流水升温刺激法、紫外线照射海水刺激法、过氧化氢刺激法、雄鲍性腺搅碎 相似文献
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九孔鲍苗脱板病防治的几点建议 总被引：3，自引：0，他引：3
近年来,我国南方地区九孔鲍育苗连续出现严重脱板和剥离后暴发性死亡等现象,致使九孔鲍苗育苗量大幅度减少,已严重制约我国南方地区鲍鱼养殖业的发展。为此,笔者根据近年对海南省九孔鲍育苗病害调查及鲍苗病害防治试验结果,对九孔鲍苗“脱板病”的病因进行浅析,并提出几点病害防治的建议,以供科研与生产人员参考。一、应注重亲鲍的培育工作亲鲍培育是繁育优质鲍苗的一项极为重要的前提性工作,没有培育出性腺成熟的亲鲍,就不能获得优质的受精卵,而劣质的受精卵孵化出的幼体容易出现发育不良、大量死亡的现象。培育优质亲鲍可采取如下措施:1.… 相似文献
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四、亲鲍的催产、授精与洗卵、孵化1.催产雌雄亲鲍应当分开催产。把亲鲍阴干1.5～2个小时后直接放入新鲜海水中,每隔20～30分钟换1次水,1小时后雄性亲鲍就开始排精。只要亲鲍的生殖腺成熟,也可以使用以下方法进行催产:①亲鲍阴干1.5～2小时+升温刺激(每小时上升1℃)+强光刺激;②亲鲍阴干1～2小时+紫外线照射海水浸泡。使用该方法时应注意,紫外线照射剂量掌握在300毫瓦·小时/升左右为宜。采用以上方法催产时,仍不能排精放卵,说明亲鲍的生殖腺尚不够成熟,应继续升温培育。2.授精据观察,在排精放卵后1小时之内进行授精效果最好。授精时,精子数… 相似文献
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黑鲍原系皱纹盘鲍和日本盘鲍的杂交后代，壳形略似皱纹盘鲍，但体螺层高低明显，壳孔4个~5个与外面相通，是我国鲍鱼中个体较大的种类之一。黑鲍作为新引进的养殖品种，已逐渐在南方的一些沿海地区发展起来，成为南方鲍鱼养殖的新品种。本文报道了利用闽南九孔鲍育苗设施、海区渔排和浮筏，进行黑鲍生产性人工苗种培育技术。一、亲贝的选择10月中旬，水温20℃~24℃，挑选海区吊养或陆上养殖的鲍鱼，其壳长6cm以上，活力强且无损伤，性腺外观极为丰满，基部凸出壳缘，末端充满生殖腺而呈纯圆，雌鲍生殖腺多为绿色(少数为褐绿色)，雄鲍生殖腺… 相似文献
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闽南黑鲍苗种培育技术 总被引：1，自引：0，他引：1
黑鲍(原系皱纹盘鲍和日本盘鲍的杂交后代)壳形略似皱纹盘鲍,但体螺层高低明显,壳孔4~5个与外面相通,是我国鲍鱼中个体较大种类。现将黑鲍人工苗种培育技术介绍如下。一、亲贝的选择10月中旬,水温20~24℃,挑选海区吊养或陆上养殖的鲍鱼,壳长6厘米以上,活力强无损伤,性腺外观极为 相似文献
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海湾扇贝亲贝以３７．５个／ｍ＾３的密度在室内池越冬６０天，存活率９８％，平均性腺指数开始为１４．３％，最终为１３．９％。与自然海区越冬相比，亲贝存活率提高２５￣７５％，平均性腺指数提高５．６￣８．１％。 相似文献
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“配合饲料”以植物蛋白质和碳水化合物为主，加以适量各种添加剂，经科学调配混合组成。蛋白质含量２５－２６％，脂肪８４－１２９％，碳水化合物４３－５６％，并含有扇贝亲贝性腺成熟必需的微量元素和其他促进性腺成长发育的重要成分。经饲喂试验表明：亲贝性腺指数提高２０－３０％，亲贝成活率９８％，比对照提高２６％，亲贝产出优质精、卵，受精卵的孵化率９３％，饲料成本降低５０％，是一种完全可以代替单胞藻喂养扇贝亲贝的优良配合饲料。 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 
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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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Iciar Martinez Amaya Velasco Ricardo Pérez-Martín Eskil Forås Michiaki Yamashita Carmen G. Sotelo 《Journal Of Aquatic Food Product Technology》2013,22(4):289-297
The purpose of this work was to evaluate the suitability of a method based on the presence of two restriction sites (for Hae III and Hindf I) in the mitochondrial NADH dehydrogenase subunit 5 (mt ND5) gene to identify Scomber species. The evaluation was performed on 144 reference and market samples by sequencing of the entire 505-bp fragment of the mt ND5 gene and of a 464-bp fragment of the Kocher fragment of the cytochrome b gene (mt Cytb). Sequence analysis of any of the two fragments allows the identification of each of the four Scomber species, but S. japonicus and S. colias had the same restriction sites at the ND5 amplicon and would not have been differentiated by this analysis. Similarly, loss of the Hae III site in some S. scombrus individuals would have misidentified them as not being Scomber. All the market products were correctly labeled except one acquired in Spain labeled as originating in the Atlantic and containing S. japonicus. 相似文献
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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. 相似文献
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Effect of iodophor disinfection of non‐hardened Salmo trutta eggs on their bacterial and fungus load 下载免费PDF全文
下载免费PDF全文 Franz Lahnsteiner 《Aquaculture Research》2017,48(7):3901-3909
This study investigated the efficiency of iodophor disinfection (135 ppm active iodine for 15–30 min) of non‐hardened Salmo trutta eggs against different groups of bacteria and against fungus. Egg samples were taken from non‐disinfected and from disinfected eggs, microorganisms were cultured on specific nutrient media and their mass was measured by turbidimetric methods. Bacteria and fungus mass of non‐hardened eggs could be reduced but not eliminated by iodophor disinfection with 135 ppm active iodine for 15 min. The extent of reduction was 47–65% (Experiment 1). The efficiency of disinfection increased with disinfection time as the reduction in bacteria and fungus mass was 40–55% after 15 min and 58–74% after 30 min (Experiment 2). Disinfection efficiency of iodophor solution diluted in water (reduction 49–57%) and of iodophor solution diluted in sodium chloride solution iso‐osmolar to the oocytes (reduction 52–61%) was similar (Experiment 3). The reduction in bacteria and fungus mass was persistent as it was 39–72% lower in embryos deriving from disinfected eggs than in embryos deriving from non‐disinfected ones (Experiment 4). In conclusion, the tested disinfection method is inadequate to eliminate pathogens completely but it could positively influence immune defence of eggs and embryos. 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