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对初始孵化到孵化后26d（变态前）的圆斑星鲽（Verasper vazriegatus Temminck et Schlegel）仔鱼的消化系统发生进行形态学和组织学研究。研究表明，在水温为12．5～15．5℃时，初始孵化仔鱼消化道细而直，两端封闭，位于卵黄囊背方。随着仔鱼发育，消化道延长，肝胰脏出现。孵化后6d，仔鱼开口，消化道贯通，开始摄食。孵化后10d，消化道明显分为口咽腔、食道、胃、小肠、直肠，黏膜上皮褶皱增多。孵化后14d，卵黄囊消失，仔鱼完全依靠外源性营养。孵化后26d，胃壁较厚处出现胃腺，但不发达，幽门盲囊尚未出现。由结果可见，孵化后6d仔鱼开口，可开始投喂轮虫；孵化后26d，消化系统的结构和功能逐渐完善，消化吸收能力增强，但由于胃的结构和功能尚不完善，此阶段还应以活体饵料为主，一方面可逐渐加大轮虫的投喂量，另一方面可适当投喂较大的卤虫无节幼体等。本研究旨为圆斑星鲽人工育苗中饵料种类及投喂时间的选择提供理论依据。 相似文献
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漠斑牙鲆胚胎及仔稚鱼发育的形态学观察 总被引：2，自引：0，他引：2
对漠斑牙鲆(Paralichthys lethostigma)胚胎及胚后发育进行观察,描述各发育时期的发育时序和形态特征.在水温18.5±0.5℃,盐度32～33的条件下,受精卵历时49 h脱膜而出,孵化后仔鱼在水温20.5±0.5℃时,4日龄开口摄食,26日龄进入变态期,45日龄左右完成变态成为幼鱼.漠斑牙鲆的卵子为浮性卵,油球一个.刚孵化仔鱼的消化道细直,3日龄肛门开通,4日龄卵黄囊消耗殆尽,开口摄食.在原肠期胚体下包约1/2时,在视囊和胚盘上出现点状星状的黑色素细胞.孵化后体两侧菊花状黑色素均匀分布;进入变态期后,体两侧的幼体色素逐渐收缩消失,同时在有眼侧出现个体较小的圆形成体色素细胞.在早期发育过程中,伴随着冠状鳍条的发生、伸长和缩短吸收.无鳔器官的发生. 相似文献
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以牙鲆(Paralichthys olivaceus)为母本,圆斑星鲽(Verasper variegatus)为父本进行科间远缘杂交,观察和记录了杂交受精卵胚胎及胚后仔鱼的发育情况,描述了各时期的形态特征。杂交受精卵为浮性卵,其受精率和孵化率分别为(71.18±0.14)%和(61.65±0.19)%,胚胎发育的畸形率为(17.00±0.06)%,4日龄仔鱼出苗率为(58.63±0.19)%,35日龄仔鱼的成活率为(57.08±0.20)%。在水温为(15±0.5)℃、海水盐度为29~30的条件下,受精卵经74 h孵化。孵化后4 d开口摄食,17 d开始变态,35 d完成变态。变态时,37%的仔鱼向右偏转,63%的仔鱼向左偏转。结果表明,牙鲆和星鲽杂交不存在配子不亲和,受精卵可以正常发育,杂交子代可以正常成活和生长。本研究旨为下一步杂交育种奠定基础。 相似文献
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为研究圆斑星鲽早期发育过程中色素细胞的形态和分布,实验对1~72日龄的圆斑星鲽鱼苗进行了连续的显微观察,并绘制了早期发育生长曲线。结果显示,圆斑星鲽从20日龄开始进入快速的增长期,在水温12~19.5°C时完成变态发育需要50 d,黑色素细胞最早出现,数量最多,黄色素细胞次之,虹彩细胞最后发育,数量最少。变态前黑色素细胞密度先升高后降低,在9日龄密度最大为1390个/mm~2,色素细胞逐渐密集鱼体两侧对称分布;变态开始后鱼体两侧色素不对称,有眼侧体表黑色素细胞逐渐溶解消退,由成体黑色素细胞代替,体色变深,黑色素细胞密度稳定在150个/mm~2;无眼侧黑色素细胞逐渐消溶退化,体色逐渐变白。白化个体在变态开始后出现,有眼侧不能形成成体黑色素细胞,形成白化。 相似文献
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褐牙鲆(♀)×犬齿牙鲆( ♂)杂交子一代胚胎发育及仔稚鱼形态学观察 总被引：2，自引：0，他引：2
杂交是目前水产育种中应用最为广泛、最有成效的育种途径,为了选育一个能够促进中国海水鱼类养殖业发展,改善目前养殖褐牙鲆发病严重的现状的牙鲆类养殖新品种,对褐牙鲆(Paralichthys olivaceus)(♀)×犬齿牙鲆(P.dentatus)(♂)的杂交进行了研究。在Nikon MS800解剖镜下对褐牙鲆(♀)×犬齿牙鲆(♂)人工杂交子一代的胚胎及胚后发育进行观察,并使用Nikon数码相机拍摄其发育特征,描述了各发育时期的发育时序和形态特征。杂交子一代胚胎发育可分为卵裂前期、卵裂期、囊胚期、原肠期、神经胚期、器官发生期、尾芽期、肌肉效应期、脱膜孵化期共9个时期,除克氏泡出现时期以及胚体开始扭动时期具有相对特异性外,胚胎发育过程与褐牙鲆相比无显著差异。在水温(16.5±0.5)℃,盐度32~33的条件下,受精卵历时67 h完成孵化。(19±0.5)℃水温下,仔鱼3 d以前营内源性营养(卵黄囊仔鱼),3 d开口摄食营外源性营养(前弯曲期仔鱼),20 d左右进入变态期(弯曲期仔鱼),40 d后基本完成变态进入稚鱼阶段,生活方式由浮游转为底栖生活,50 d左右全身被鳞。同时观察了自胚胎发育时期至幼鱼期体表色素的分布及形态变化过程,描述了仔鱼变态期冠状鳍条、眼位置和尾部的发育、变化过程。早期生活史无鳔器官发生。 相似文献
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本研究阐述了棕点石斑鱼(♀)×鞍带石斑鱼(♂)杂交子代(简称珍珠龙胆石斑鱼)的胚胎发育和仔稚幼鱼形态发育的特征及其养殖过程中的一些难点、要点,以期为今后苗种的规模化培育生产提供参考依据。通过对珍珠龙胆石斑鱼各个发育期连续取样,系统观察并记录各发育期的形态变化及生长特征。结果表明,1)在水温27-28℃条件下,历时25 h 25 min孵化出膜,整个发育过程划分为卵裂期、囊胚期、原肠胚期、神经胚期和器官形成期。2)在水温(27.0±0.5)℃、盐度30、p H 8的培育条件下,根据卵黄囊、第二背鳍棘和腹鳍棘的生长与伸缩及鳞片、体色的变化将胚后发育分为仔鱼、稚鱼、幼鱼3个时期。仔鱼期根据卵黄囊的有无分为前期仔鱼和后期仔鱼。初孵至孵化后4 d为前期仔鱼;孵化后5 d,仔鱼卵黄囊完全消失,成为后期仔鱼;孵化后32 d,50%的仔鱼进入稚鱼期;孵化后46 d,50%的稚鱼完成变态,成为幼鱼。初孵仔鱼的全长平均为(1.65±0.11)mm,发育至70 d时,幼鱼平均全长已达(75.47±0.19)mm。跟踪观察的结果发现,珍珠龙胆石斑鱼作为杂交子代,从受精到发育的各阶段均能健康正常地生长发育,且生长快速、抗病力强,具有"虎斑头、龙胆尾"的外型,具有明显的杂交优势。 相似文献
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绿鳍马面鲀胚胎和仔鱼早期发育的初步观测 总被引：1，自引：1，他引：0
利用显微数码摄像系统观测绿鳍马面纯受精卵的胚胎发育和初孵仔鱼的形态特征,结果表明:绿鳍马面纯的卵为球形沉性的粘性卵,卵径平均为644 μm,未受精卵及早期胚胎有油球多个;在18.7～19.2 ℃水温条件下孵化,受精后约40～50 min胚盘形成,1 h 10 min进入卵裂期,6 h 10 min进入高囊胚期,9 h 20 min进入低囊胚期,10 h后进入原肠胚,21 h 40 min后听囊形成,23 h 40 min后形成柯氏囊,41 h30 min后耳石形成,多数胚胎油球溶合为1个,50 h后胚体环绕卵黄达1.3周以上,73.5 h陆续孵出,孵化积温为1375～1411 ℃·h.初孵仔鱼呈前位抱卵方式,油球位于卵黄囊的前端,85 h后开口摄食,5～6 d卵黄囊和油球吸收完,8 d第1背鳍棘突出背鳍膜,18 d发育到稚鱼期. 相似文献
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对七带石斑鱼胚胎和仔稚鱼发育过程进行了观察,描述了从受精卵到仔稚鱼各发育时期的形态特征;在水温22±0.5℃、盐度30条件下进行七带石斑鱼仔鱼的饥饿耐受力实验,记录了饥饿条件下初孵仔鱼的存活与生长、卵黄囊与油球的利用情况。结果表明,胚胎发育可划分为卵裂期、囊胚期、原肠胚期、神经胚期和器官形成期。在水温20.5±0.5℃、盐度30.0条件下,受精卵历时38h45min孵化出膜。初孵仔鱼全长1.059±0.071mm,至4日龄全长2.27～2.36mm时,卵黄囊完全消失;16日龄,全长4.99mm时,鳔形成;至25～30日龄,尾鳍鳍条发育完整。在饥饿条件下,初孵仔鱼的死亡高峰出现在孵化后4～6d,半数死亡时间出现在5d,至7d饥饿仔鱼全部死亡。卵黄囊期仔鱼的生长可分为3个阶段:仔鱼初孵时的快速生长期,卵黄囊消失前后的慢速生长期,以及在不能建立外源性摄食后的负生长期。随着生长发育时间的延长,饥饿仔鱼与正常条件下仔鱼的生长差异显著(P<0.05)。饥饿仔鱼体长较短,头大且体瘦,长期饥饿后脑后部下陷。 相似文献
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对斜带石斑鱼(Epinephelus coioides)的胚胎及仔稚幼鱼形态发育进行了观察与研究,详细描述从受精卵到初孵仔鱼的28个具体发育时期的形态特征和发育时间。根据研究观察结果,将斜带石斑鱼胚胎发育划分为卵裂期、囊胚期、原肠胚期、神经胚期和器官形成期。在水温(25±0.5)℃、盐度31.0p、H 7.8的海水中,斜带石斑鱼胚胎历时28 h 30 min完成整个胚胎发育孵化出膜。胚后发育主要根据卵黄囊、腹鳍棘及第二背鳍棘、鳞片、体色的变化分为仔鱼期、稚鱼期、幼鱼期。仔鱼期根据卵黄囊的有无又分为早期仔鱼和晚期仔鱼。在水温24.5~29.2℃,盐度28.8~33.5,pH 7.5~8.5的海水中,培育至36 d,发育最快的斜带石斑鱼结束仔鱼期进入稚鱼期;培育至42 d,发育最快的稚鱼完成变态,成为幼鱼。斜带石斑鱼胚后发育过程中最明显的变化是腹鳍棘与第二背鳍棘以及鳍棘上小刺的长出与收回。 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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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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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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