共查询到20条相似文献,搜索用时 62 毫秒
1.
魁蚶(Scapharcabroughtonii),俗称赤贝,是一种大型、经济价值较高的贝类,其软体部的加工品“赤贝肉”,具有较高的出口创汇价值。近几年,我们利用夏秋季育苗场相对空闲时间进行魁蚶常温育苗,取得了较好效果。一、亲贝选择1.亲贝的采捕时间因不同海区水温和饵料条件的差异,魁蚶的性腺发育程度也不尽相同,一般在海区底层水温升至20~25℃时性腺逐渐进入成熟排放期。我国的黄海北部海区7~8月份为产卵盛期,故常温育苗多在7~8月份采捕亲贝。2.亲贝的选择方法选择壳长7~10厘米、外形完整无损伤的魁蚶作亲贝。解剖检… 相似文献
2.
为探究性类固醇激素合成相关基因17β-羟类固醇脱氢酶14(17β-hydroxysteroid dehydrogenase 14,17β-HSD14)在魁蚶(Scapharca broughtonii)性腺发育过程中的作用,本研究从魁蚶转录组中筛选并验证了17β-HSD14基因序列,通过原位杂交和实时荧光定量PCR检测了该基因在魁蚶中的组织定位及性腺发育过程中表达变化规律。结果显示:17β-HSD14基因的编码区序列长度为822 bp,编码273个氨基酸;原位杂交实验在魁蚶卵巢的成熟卵细胞、滤泡壁和精巢中的精原细胞、精子以及其他组织的细胞中都检测到了17β-HSD14基因的阳性杂交信号;qRT-PCR结果表明,17β-HSD14基因的表达随其性腺发育而产生变化,在形成期(Ⅰ期)到增殖期(Ⅱ期)的过程中呈上升趋势,成熟期(Ⅲ期)至耗尽期(Ⅴ期)呈下降趋势,且在卵巢组织中的表达量显著高于精巢组织。综上,17β-HSD14基因与魁蚶的性腺发育密切相关,可能对其性腺发育、功能维持和成熟具有重要的作用。 相似文献
3.
魁蚶亲贝控温促熟试验 总被引:4,自引:0,他引:4
首次研究了魁蚶亲贝性腺室内控温促熟技术,3月中旬亲入池,人工控温,强化饲育25-28天,4月中下旬性腺成熟,排放精卵,比自然界提前3个月左右,水温16℃以上是魁蚶亲贝性腺成熟的迅速期。1991年11月专家鉴定认为,本研究属国内首次,居国内先进水平。 相似文献
4.
文蛤的性腺发育和生殖周期 总被引:13,自引:0,他引:13
应用组织学方法对浙南池塘养殖的文蛤的性腺发育、生殖周期和肥满度进行了周年变化的研究。结果表明,文蛤的性腺发育具有典型双壳贝类特征,性腺发育过程可分为增殖期、生长期、成熟期、排放期、休止期5个时期,并对上述5期的宏观肉眼观察特征及微观切片观察特征进行了描述。浙南池塘养殖的文蛤性腺发育过程以1年为1个周期,成熟排放期在5月下旬至8月中旬,水温21.8~31.0℃,繁殖盛期为6月下旬至7月下旬,水温为25.0~30.0℃。月平均肥满度最高为6月份的8.84%,最低为1月份的3.21%。论文还讨论了1龄文蛤性腺发育、文蛤性腺成熟和排放与积温的关系。 相似文献
5.
山东沿海魁蚶繁殖周期与生化成分的周年变化 总被引:4,自引:4,他引:4
自2010年10月至2011年9月,对山东省鳌山卫海区魁蚶的繁殖周期、生化成分的季节变化及其与环境因子的关系进行了研究。每月采集样品1次,测定采样点水温和叶绿素a含量,采用组织学方法分析性腺的季节变化,并分别测定外套膜、闭壳肌、性腺—内脏团和足组织的生化成分(糖原、脂肪和蛋白质)含量。结果表明,该海区魁蚶雌雄比例为1∶1,雌雄性腺发育同步,全年只有1个繁殖期;配子发生始于2月,分别有25.0%和53.9%的雌雄个体性腺进入形成期,随水温和叶绿素a含量的升高而发育,6月大部分个体成熟并有部分进入排放期,至8月配子集中排放(雌:58.3%;雄:69.2%)。生化分析显示,脂肪含量在性腺—内脏团中随性腺发育积累储存,产卵后显著降低;所有组织中的糖原含量在3—7月显著高于其它月份,并且性腺中的含量高于其他组织,于5月达最大值64.2%,表明糖原在魁蚶繁殖活动中具有重要作用;蛋白质含量在除闭壳肌外的其他3种组织中出现冬季和产卵盛期两个低谷,暗示蛋白质能够弥补糖原的供能不足,与繁殖活动存在密切联系。 相似文献
6.
7.
8.
魁蚶(Scapharca broughtonii)是一种大型、经济贝类,在我国主要分布于渤海及黄海北部。近几年由于过度捕捞,野生资源遭到破坏,自1989年以来,山东、辽宁沿海有关科研和生产单位开始了魁蚶室内人工育苗。笔者自1993年开始从事魁蚶苗种生产,积累了一些经验,现将采取的主要技术措施总结如下:1亲贝选择及采捕挑选壳长7 ̄12cm的魁蚶做为亲贝,将壳面有蚀孔和受伤的魁蚶剔除,视个体大小,一般每立方水体准备亲贝2 ̄6个。升温培育在3月中、下旬亲贝入池,室内强化促熟40 ̄50d,待海湾扇贝出池后产卵。常温培育在5月中、下旬以后进亲贝,亲贝室内促熟20 ̄… 相似文献
9.
10.
11.
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
12.
13.
14.
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
15.
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
16.
Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection
下载免费PDF全文
![点击此处可从《Journal of fish diseases》网站下载免费的PDF全文](/ch/ext_images/free.gif)
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
17.
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
18.
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
19.
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
20.
Effect of iodophor disinfection of non‐hardened Salmo trutta eggs on their bacterial and fungus load
下载免费PDF全文
![点击此处可从《Aquaculture Research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
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