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1.
灰鲳仔稚鱼消化系统的发育   总被引:1,自引:1,他引:0  
对出膜后1~35 d灰鲳仔稚鱼的消化系统进行了形态学和组织学观察。初孵仔鱼具有很大的卵黄囊,消化管为一简单的直形盲管。2日龄仔鱼消化系统中肠区首先开始分化,内面可见纹状缘。3日龄仔鱼胃区膨大,卵黄消失,肠道分化出小肠和直肠。侧囊在4日龄仔鱼时出现分化。5日龄仔鱼观察到幽门盲囊的初始结构,油球消失,从内源性营养向外源性营养过渡基本完成。6日龄仔鱼摄食主动。14日龄稚鱼肝脏分为两叶,体积增大,胰脏体积增大,胃弯曲呈"U"形,幽门盲囊指状分支已增加到几十个。22日龄稚鱼肠道弯曲更多,在胸腹腔中肠道盘曲程度已接近幼鱼。28日龄稚鱼侧囊背腹形成一纵隔,出现角质剌。35日龄稚鱼胃腺已十分丰富,侧囊结构也已完善,标志着灰鲳消化系统更趋完善。  相似文献   

2.
在水温22~24℃,pH7.0左右的人工培育条件下,对密斯特黄彩鲶(Mystus sp.)仔、稚、幼鱼的形态特征和生长发育进行了观察与研究。密斯特黄彩鲶的鱼苗发育分为卵黄囊期仔鱼期(初孵至第5天)、晚期仔鱼期(第6~10天)、稚鱼期(第11~20天)和幼鱼期(第20天以后)。初孵仔鱼平均全长5.12 mm,卵黄囊体积1.63 mm3;仔鱼第3天开始摄食,第5天卵黄囊被完全吸收,鱼苗主要外部器官主要集中在晚期仔鱼阶期和稚鱼期内形成。仔鱼在饥饿状态下最高初次摄食率出现在出膜后第6天,为84.0%,其饥饿的不可逆点则为出膜后第8天,第8天以后即进入不可逆PNR期,至第11天绝大部分饥饿仔鱼死亡。  相似文献   

3.
文中对大西洋牙鲆仔、稚、幼鱼各期发育时间及特征进行观察记录,并对各发育阶段进行显微摄像。大西洋牙鲆室内人工育苗水温18℃~22℃,盐度30,pH8.2,光控500Lx左右。饵料为强化的轮虫、卤虫无节幼体和配合饲料。初孵仔鱼肠道细而直,孵化后3d~4d肛门开通并开口摄食,6d~7d卵黄囊吸收完毕,仔鱼前期阶段结束。仔鱼后期阶段,消化道弯曲,冠状幼鳍完全形成,右眼开始上升。稚鱼期右眼完全迁移至左侧,变态完成,营底栖生活。幼鱼期基本具有成鱼的外部形态和习性。  相似文献   

4.
云纹石斑鱼胚胎发育及仔、稚、幼鱼形态观察   总被引:1,自引:0,他引:1       下载免费PDF全文
对云纹石斑鱼Epinephelus moara胚胎发育及仔、稚、幼鱼形态进行了观察与研究,详细描述了各发育期的形态特征和发育时间。结果表明:1)在水温22±0.2℃、盐度30、溶氧7.8mg/L、pH8.25的条件下,云纹石斑鱼的受精卵历时38h 17min开始孵化出膜。胚胎发育可分为受精卵、卵裂、原肠、神经胚和器官形成及出膜6个阶段,受精、胚盘形成、2细胞等28个时期。2)在水温23±1℃,盐度30±3,DO≥5mg/L,pH8.0±0.5的海水中,培育至5d,卵黄囊完全消失,成为后期仔鱼;培育至27d,发育最快的云纹石斑鱼结束仔鱼期,进入稚鱼期;培育至65d,发育最快的稚鱼完成变态,成为幼鱼。胚后发育过程主要是根据卵黄囊、鳍膜、鳞片、体色及第1腹鳍棘与第2背鳍棘相对长度的变化分为仔鱼、稚鱼和幼鱼3个时期。其中仔鱼期又根据其卵黄囊的有无划分为前期仔鱼和后期仔鱼。  相似文献   

5.
半滑舌鳎消化系统器官发生的组织学   总被引:15,自引:0,他引:15  
常青 《水产学报》2005,29(4):447-453
利用形态学和连续组织切片技术,对出膜后1~30d的半滑舌鳎消化系统胚后发育的组织形态学进行了系统观察和研究。研究表明,试验水温为20.0~22.0℃时,孵化后第3天,仔鱼开口摄食,消化道上皮细胞出现分化,肝脏和胰脏开始出现,鱼体开始由内源性营养转向外源性营养。孵化后第5天,卵黄囊完全被吸收,消化道明显分化成口咽腔、食道、胃、前肠和后肠,仔鱼消化系统具备了摄食和消化外源性食物的能力。此后随着鱼体的生长,粘膜层的褶皱增加,消化道上皮细胞进一步分化,肠道分段、盘旋,消化系统从功能和结构上逐步地完善成熟。开口摄食之后,先后发现在后肠出现嗜曙红颗粒,在前肠出现空泡,表明肠上皮细胞吸收了蛋白质和脂肪。继而糖元在肝脏中不断地储存。在出膜后第23天,出现胃腺,标志着稚鱼期的开始。  相似文献   

6.
采用连续石蜡切片、苏木精-伊红染色技术, 对湘华鲮[Sinilabeo decorus tungting (Nichols)]出膜后 2~80 d 的仔稚鱼消化系统发生进行研究。结果表明, 2 日龄的仔鱼口、咽腔、肠腔、肛门形成, 但口咽腔未贯通; 肝细胞紧紧围绕着前肠周围, 形成肝细胞索。4 日龄, 消化道上皮细胞开始功能性分化; 肝细胞团增多, 填充于卵黄囊与消化道间, 胞质着色较浅初现肝血窦; 消化道贯通, 仔鱼由内源性营养向混合性营养转变。6 日龄口裂加深, 呈“>” 形, 吻部初具形状, 初现黏液细胞; 咽喉胼胝垫出现角质化, 鳃弓黏膜上皮增厚, 初现黏液细胞和味蕾; 食道肌层变厚, 环形肌为主; 肝细胞间形成大量空泡, 肝细胞变小; 肠表皮出现皱褶和纹状缘, 前肠到后肠皱褶逐渐变短, 杯状细胞增多。9 日龄咽后部的胼胝垫处肌层发达, 胼胝垫对侧的黏膜层开始凹陷形成皱褶; 食管环肌发达, 纵肌不明显; 肠道均分布有杯状细胞, 后肠段最多。10 日龄, 唇部细胞出现角质化趋势, 胼胝垫表面形成梳状突起。13 日龄, 卵黄囊完全消失, 混合性营养转变为外源性营养。37 日龄, 稚鱼肝胰脏、食管组织结构均似成鱼, 发育基本完成。43 日龄, 口咽腔、鳃与肠道组织发育基本完成。本研究将湘华鲮仔稚鱼消化系统的发育分为 3 个阶段, 即卵黄期、混合性营养及外源性营养阶段。研究发现, 湘华鲮消化器官组织结构的发育和变化, 始终是与食性的转变相适应的。湘华鲮其仔稚鱼消化系统组织学研究可为湘华鲮苗种培育中饵料管理提供理论依据, 对提高湘华鲮人工养殖的存活率和生长性能具有重要意义。  相似文献   

7.
银鲳仔鱼消化系统的组织学研究   总被引:10,自引:0,他引:10       下载免费PDF全文
对出膜后1~12 d银鲳(Pampus argenteus)仔鱼的消化系统进行了形态学和组织学观察。在水温为22~24℃和盐度25~28情况下,初孵仔鱼具很大的卵黄囊,消化管为一简单的直形盲管,管腔狭窄,口和肛门尚未与外界接通。3 d仔鱼消化系统分化加快,在卵黄囊凹陷部位出现2~3个弯曲,已初步分化出食道、胃、肠和肝脏,肠管也变粗。4 d仔鱼消化系统各器官初步形成。5 d仔鱼出现侧囊,并见部分卵黄囊和油球。7 d卵黄囊和油球基本被完全吸收,仔鱼主动摄食轮虫和小球藻,从内源性营养向外源性营养的过渡基本完成。12 d以后仔鱼肝脏明显分为两叶,体积增大;幽门盲囊指状分支已增加到几十根;食道、胃和肠的黏膜皱褶明显增多和加深,肠黏膜上皮细胞高度增加,游离面纹状缘发达;胃黏膜的单层柱状上皮高度和胃腺细胞数量也明显增加;但整个消化道的黏膜下层、肌肉层均不发达,说明12 d仔鱼已具初步消化和吸收功能  相似文献   

8.
利用形态学和连续组织切片技术,对出膜后1~30d的高体革(鱼刺)消化系统胚后发育的组织形态学进行了系统观察和研究。结果表明,培养水温在26.6~29.7℃条件下,高体革(鱼刺)初孵仔鱼消化管为一柱形盲管,管腔狭窄,口、肛门尚未与外界接通。出膜30h仔鱼,口开始张开,消化管相通。出膜2d仔鱼肠壁出现皱褶,肠瓣将肠道分为前肠和后肠,在显微镜下可见消化管蠕动。出膜3d仔鱼可以开口摄食,消化管上皮分化,食管中出现黏液细胞,肝脏和胰脏出现,鱼体由内源性营养转入混合营养阶段。混合营养阶段仔鱼消化道明显分为口咽腔、食道、胃、前肠、直肠等,消化腺肝脏和胰脏也已形成,各部分已经有初步结构和一定的消化吸收能力。随着仔鱼的发育,仔鱼消化系统各器官也趋于完善。出膜21d稚鱼的胃壁出现胃腺,标志着稚鱼期开始。  相似文献   

9.
对驼背鲈(Chromileptes altivelis)的胚胎发育及仔、稚、幼鱼的形态特征进行了详细的观察与研究,描述了从受精卵到仔、稚、幼鱼各发育期的时间和形态特征变化。结果表明,在水温25-26℃、盐度30的海水中,受精卵历时27 h 25 min完成整个胚胎发育过程,经历从卵裂、囊胚、原肠、神经胚到肌节形成、各器官的逐渐形成、变化、完善等一系列的胚胎发育和变化过程;根据其卵黄囊消长情况、鳞片的覆盖状态、体色发生的不同变化以及第二背鳍和腹鳍的消长,将胚后发育分为仔、稚、幼鱼3个阶段。在水温22-26℃、盐度29-31、DO≥5 mg/L的条件下,2-3 d仔鱼卵黄囊消失,开口摄食;生长发育至31 d,仔鱼已变态进入稚鱼期;培育至57 d,稚鱼完成变态,成为幼鱼。第二背鳍棘和腹鳍棘的生长与收缩等石斑鱼类早期发育的共性生长特征及其体表特性体色变化特征为驼背鲈胚后发育过程中最明显的特征。  相似文献   

10.
对驼背鲈(Chromileptes altivelis)的胚胎发育及仔、稚、幼鱼的形态特征进行了详细的观察与研究,描述了从受精卵到仔、稚、幼鱼各发育期的时间和形态特征变化。结果表明,在水温25-26℃、盐度30的海水中,受精卵历时27 h 25 min完成整个胚胎发育过程,经历从卵裂、囊胚、原肠、神经胚到肌节形成、各器官的逐渐形成、变化、完善等一系列的胚胎发育和变化过程;根据其卵黄囊消长情况、鳞片的覆盖状态、体色发生的不同变化以及第二背鳍和腹鳍的消长,将胚后发育分为仔、稚、幼鱼3个阶段。在水温22-26℃、盐度29-31、DO≥5 mg/L的条件下,2-3 d仔鱼卵黄囊消失,开口摄食;生长发育至31 d,仔鱼已变态进入稚鱼期;培育至57 d,稚鱼完成变态,成为幼鱼。第二背鳍棘和腹鳍棘的生长与收缩等石斑鱼类早期发育的共性生长特征及其体表特性体色变化特征为驼背鲈胚后发育过程中最明显的特征。  相似文献   

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Anguilla luzonensis and A. huangi were each described in 2009 using eels obtained from northern Luzon Island. We examined the taxonomic status of these two groups of eels using morphological and molecular genetic characters. There were no significant differences in two vertebrae counts between eels of A. luzonensis and A. huangi. Mitochondrial 16S ribosomal RNA and cytochrome b genes sequences were obtained and compared among 28 specimens of A. luzonensis, the holotypes of A. luzonensis and A. huangi, and one specimen of the other 15 anguillid species. The specimens of A. luzonensis exhibited almost identical sequences, including the holotype, with only a few site differences, and the genetic difference between the holotypes of A. luzonensis and A. huangi was within the range of differences of specimens of A. luzonensis. The other anguillid species were genetically very different from A. luzonensis and A. huangi, although A. interioris is a closely related species. It is clear that A. luzonensis and A. huangi are the same species, and according to the principle of priority in zoological nomenclature, A. luzonensis Watanabe, Aoyama, and Tsukamoto, 2009 is the valid species name, and A. huangi Teng, Lin, and Tzeng, 2009 is a junior synonym of A. luzonensis.  相似文献   

13.
The effects of exposing the eggs of Pacific threadfin and amberjack eggs (AEs) to different concentrations of hydrogen peroxide for 5 min on hatch rate and survival were assessed in a series of experiments using a petri dish model rearing system. Despite significant inter‐batch variation in hatch rate, it was shown that eggs of both species could be safely exposed to up to 11 340 mg L−1 H2O2 for 5 min. Exposure to 34 230 mg L−1 H2O2 for 5 min was shown to be lethal to AEs at a late stage of development. In two further experiments, it was demonstrated that Pacific threadfin eggs were resistant to all tested concentrations of a range of polyvinylpyrrolidone iodine (PVP‐I) concentrations and contact times (up to 1000 mg L−1 PVP‐I for 10 min). The level of bacteria adhering to the eggs of both species was highly variable. Where eggs were heavily colonized (>104 cfu egg−1), hydrogen peroxide concentrations of at least 11 340 mg L−1, or PVP‐I concentrations higher than 500 mg L−1 for 10 min, were required for effective sterilization. In less colonized batches, rinsing in sterile seawater or exposure to lower (550 mg L−1) concentrations of H2O2 was sufficient to result in high apparent levels of surface sterility (<1 cfu egg−1).  相似文献   

14.
Mulloway (Argyrosomus japonicus) occur in estuarine and coastal waters surrounding Australia, Africa, India, Pakistan, China, Korea and Japan, where they are important in fisheries. This study identified that mulloway in south-eastern Australia had similar growth rates, but matured at smaller lengths and younger ages, to those in South Africa and Western Australia. Growth of both sexes was similar to about 5 years, after which females grew faster and attained a greater maximum length than males. Female mulloway matured at 4–5 years of age with a L50 of 68 cm, whereas males matured at 2–3 years of age with a L50 of 51 cm. The commercial fishery in New South Wales was characterised by declining catches and a reduction in the proportion of mulloway of mature lengths in landings. During 2002–2005 commercial landings were dominated (83%) by fish within 15 cm of the current minimum legal total length of 45 cm and aged 2 and 3 years (>80%), even though mulloway can attain lengths of 200 cm and live >30 years. Estimates of the rates of instantaneous total mortality ranged between 0.34 and 0.45, whilst the rate of instantaneous natural mortality (M) was estimated to be approximately 0.12. Yield-per-recruit analyses indicated that mulloway in New South Wales are being growth overfished and substantial increases in yield could be achieved by increasing the length at first harvest. Values of the spawning potential ratio were below 0.2 under a range of mortality estimates, suggesting that mulloway are at risk of recruitment overfishing. These results suggest that the spawning stock of mulloway in south-eastern Australia has been depleted and that remedial management action is required to protect this iconic species.  相似文献   

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Mosquitofish, Gambusia sp., have been spread throughout the world to biologically control mosquitoes. However, the fish has gained a reputation as an invasive species and has been implicated in displacing native aquatic species. Gambusia affinis are native to the southeastern United States and commonly occur in commercial channel catfish, Ictalurus punctatus, production ponds. We investigated effects of mosquitofish presence on zooplankton populations, water quality, disease occurrence, and fish production in experimental ponds. There were no differences between ponds with or without mosquitofish in numbers of calanoid copepods, cyclopoid copepods, total copepods, Bosmina sp., Ceriodaphnia sp., Moina sp., Daphnia sp., or total cladocerans. There were also no differences in copepod and cladoceran sizes. Copepod nauplii were more numerous during the summer months in ponds with mosquitofish. There were no differences in water quality variables (soluble reactive phosphorus, nitrate, nitrite, ammonia, total nitrogen, total phosphorus, pH) or phytoplankton density between ponds stocked with and without mosquitofish. Catfish production and disease occurrence were also similar between ponds with and without mosquitofish. Although mosquitofish may cause problems when stocked outside their native range, there does not appear to be any adverse effects of mosquitofish presence in catfish production ponds.  相似文献   

18.
Adult common bullies, Gobiomorphus cotidianus McDowall, are small (total length =  30–120 mm), benthic fish commonly found in the littoral zones of New Zealand lakes where they are a major prey species for trout and eels. Differences in their relative abundance (CPUE) were determined between 21 shallow North Island lakes. Mean CPUE ranged from 2 to >  1000 fish net− 1 night− 1 and was inversely related to water transparency. The abundance of bullies was not reduced in lakes containing rainbow trout, Oncorhynchus mykiss (Walbaum), but was reduced in all lakes containing self-recruiting populations of eels, Anguilla spp. Mean densities of planktonic larval bullies in the limnetic zone were also inversely related to water transparency. Since low water transparency is related to increased trophic status for these lakes, the abundance of bullies is likely to be related to lake productivity, rather than turbidity.  相似文献   

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