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中间球海胆(♀)×光棘球海胆(♂)F1代的生殖腺特征 总被引：2，自引：1，他引：2
对中间球海胆(♀)与光棘球海胆(♂)杂交F1代的生殖腺特征进行了研究,并与母本中间球海胆进行了比较。试验结果表明,中间球海胆的生殖腺颜色一般呈橙色或橘黄色(不同发育时期有所不同),结构致密;杂交海胆中有约90%表现为橙色和橘黄色,约10%呈黄色和浅棕色,约20%的个体生殖腺结构疏松,且和发育周期及色泽无关。杂交海胆的生殖腺指数与中间球海胆的变化基本一致,并且雌雄个体差别不明显。杂交海胆在生殖腺发育的整个过程中,生殖腺指数虽然也出现周期性的变化,但组织切片观察发现杂交海胆生殖腺发育不能象母本一样有明显分期,只有个别雌性个体能产生成熟卵细胞,雄性个体未见成熟精子。 相似文献
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对中间球海胆（♀）与光棘球海胆（♂）杂交F1代的生殖腺特征进行了研究，并与母本中间球海胆进行了比较。试验结果表明，中间球海胆的生殖腺颜色一般呈橙色或橘黄色（不同发育时期有所不同），结构致密；杂交海胆中有约90％表现为橙色和橘黄色，约10％呈黄色和浅棕色，约20％的个体生殖腺结构疏松，且和发育周期及色泽无关。杂交海胆的生殖腺指数与中间球海胆的变化基本一致，并且雌雄个体差别不明显。杂交海胆在生殖腺发育的整个过程中，生殖腺指数虽然也出现周期性的变化，但组织切片观察发现杂交海胆生殖腺发育不能象母本一样有明显分期，只有个别雌性个体能产生成熟卵细胞，雄性个体未见成熟精子。 相似文献
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中间球海胆与马粪海胆杂交家系早期生长比较和亲本配合力估计 总被引：1，自引：1，他引：0
为比较中间球海胆(Strongylocentrotus intermedius)与马粪海胆(Hemicentrotus pulcherrimus)杂交家系间的生长差异,评估杂交家系亲本在体重上的配合力,构建了种间杂交家系共42个。采用动物模型、约束性最大似然法(REML)和最佳线性无偏预测(BLUP)等方法估计了杂交海胆250、295和340日龄体重的育种值,以及各亲本的一般配合力(GCA)和各亲本组合的特殊配合力(SCA)。采用方差分析方法,比较了体重表型值和育种值在杂交家系间的差异。结果表明,3个生长阶段杂交家系间体重的表型值和育种值差异均达到极显著水平(P0.01),体重育种值在家系间的差异大于表型值,在50%家系留种率下,育种值选择和表型值选择的家系相同率介于88.89%~94.44%,育种值选择具有0.93%~4.83%的选择效率优势;250、295和340日龄各父本的一般配合力分别介于–0.22~0.33,–0.31~0.41和–0.29~0.31,各母本的一般配合力分别介于–0.24~0.33,–0.31~0.41和–0.28~0.28,各父母本组合的特殊配合力分别介于–0.07~0.09,–0.10~0.13和–0.32~0.32,M5、M6和M17等父本的一般配合力始终较高,F9、F11和F19等母本的一般配合力始终较高,M5F9和M6F11等杂交组合的特殊配合力始终较高。 相似文献
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球海胆属（Sh。楷叫优。ntrotu抓9海胆世界上共有十几种,光棘球海胆（S.n。;d u s）和中间球海胆（S.fll。。。。巾l。）是我国北方主要的经济品种,其营养价值和经济价值高,国际市场需求量大,开展海胆人工育苗和增养殖是海胆产业可持续发展的重要举措。而掌握其胚胎和幼虫生长发育的区别,不仪对苗种生产有帮助,而且对海胆资源的保护利用十分有利。 1卵及胚胎 光棘球海胆的卵径为106 pITI左右,黄色;中间球海胆90 pill左右,橙色,其卵径比光棘球诲胆小一点。受精膜举起后,光棘球海胆的卵径为 相似文献
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中间球海胆生长分化相关的AFLP标记 总被引：1，自引：0，他引：1
从同一遗传背景、同环境下培养的1龄中间球海胆(Strongylocentrotus intermedius)中,分别选择大个体50只、小个体30只,分别组成大小2组海胆,两组之间壳径、壳高2个指标均存在显著差异。共选用6对AFLP引物组合对2组海胆进行PCR扩增,发现43个标记在大小2组海胆间存在显著的频率差异(P0.05),其中29个位点差异极显著(P0.01)。所有存在显著频率差异的位点中,2个位点在大海胆组中缺失,4个位点在小海胆组中缺失,14个位点在大海胆组中出现的频率显著高于小海胆组(P0.05),而23个位点在小海胆组中出现的频率高于大海胆组(P0.05)。这一系列谱带可能与中间球海胆生长性状之间存在一定的相关关系。遗传多样性分析结果表明,大海胆组的平均Shannon氏指数、Nei氏杂合度2个指标均显著高于小海胆组(P0.05),提示杂种优势可能与中间球海胆的快速生长存在一定联系。 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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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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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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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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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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Qin-Cheng Huang Di‐Gen Qin Bei‐Ping Tan Tao Du Yuan-Zhi Yang Qi-hui Yang Shu‐Yan Chi Xiao-hui Dong 《Aquaculture Research》2020,51(2):816-827
A 5 × 3 factorial growth trial was conducted to evaluate optimal dietary protein and lipid levels (dietary protein level, DP; dietary lipid level, DL) for juvenile Sillago sihama (S. sihama) (2.0 ± 0.02 g, initial weight). Fish were fed 15 diets containing 5 DPs (350, 400, 450, 500 and 550 g/kg) and 3 DLs (60, 90 and 120 g/kg) for 8 weeks. The interaction between proteins and lipids significantly influenced the feed conversion ratio, condition factor, body composition, antioxidant indices and lipase activity (p < .05). DP 450 g/kg showed the highest average final body weight. DPs 500 and 550 g/kg significantly decreased the protein efficiency ratio (p < .05). DL 120 g/kg showed the highest percentage weight gain. The low feed conversion ratio was found in diets P45L12, P55L9 and P55L12. Diet P45L12 showed high superoxide dismutase activities. DP 450 g/kg showed the lowest average malondialdehyde content. Lipase activity was increased by increasing DP (p < .05) with a fall at DP 550 g/kg. Under the present experimental conditions, the optimal DP for S. sihama was 450 g/kg under the DL 120 g/kg. 相似文献
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Cholecalciferol (Vitamin D3) increased plasma inorganic phosphate concentration in American eels,Anguilla rostrata, in a dose-dependent fashion. This response was more marked in phosphate loaded fish. In control as well as phosphate loaded
eels the hyperphosphatemic response to D3 was associated with a sharp reduction in renal phosphate clearance relative to14C-polyethelene glycol (PEG) clearance. Glomerular filtration and urine flow rates were not affected by D3. As renal phosphate clearance, even in phosphate loaded eels, never significantly exceeded that of PEG, it is suggested that
D3 reduced the relative clearance rate of phosphate by increasing renal phosphate reabsorption rather than by reducing the tubular
secretion of phosphate. 相似文献