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卵黄囊期是鱼类早期发育中的一个重要阶段，是鱼类由内源营养向外源营养转化的一个关键时期。在此期间，游离氨基酸、蛋白质、脂肪酸、总脂和碳水化合物等基本生化成份的变化表现出一定的规律性，并具有种的特异性。从能量学的角度来分析，则表现为主要能源物质在发育过程中有规律的变化，各能量物质是按一定顺序被利用的。
鱼卵是一个高度特化的自组织系统，它在发育过程中，用于细胞活动的物质基础主要是卵黄。在卵黄期，卵细胞的代谢过程可描述为依生化成份变化的生化代谢过程和依能量转移和释放的能量代谢过程。从受精到卵黄囊消耗完全的卵黄囊期，以开口摄食为标志分为前后两个阶段，开口之前为全部利用自身营养的内源营养阶段，开口之后为利用自身营养和外源营养相结合的混合营养阶段。探素卵黄囊期海洋硬骨鱼类的能量转化规律，定量分析发育过程中生化成分和能量物质的变化，预测维持仔稚鱼生命活动和提供生长所必需的合适饵料营养成分，已成为鱼类早期发育生物学研究的热点课题。 相似文献
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Are assemblages of black bream (Acanthopagrus butcheri) in different estuaries genetically distinct?
J.A. Chaplin G.A. Baudains H.S. Gill R. Mcculloch I.C. Potter 《International Journal of Salt Lake Research》1997,6(4):303-321
Samples of the estuarine-spawning teleostAcanthopagrus butcheri were collected from nine estuaries and a coastal lake, located in the Pilbara and South-western drainage divisions of Western
Australia and distributed along a coastline covering a distance of nearly 2,000 km. The patterns of allozyme variation in
these samples were used to explore the extent to which there was variation in the genetic compositions of black bream assemblages
in geographically-isolated estuarine systems, and whether or not any such variation could be related to the geographical location
or type of estuary. Although only three of 36 scorable loci (Gpi-1, Ldh andMdh-2) exhibited variation that could be used for analysis, there was considerable variation in allele frequencies at these loci
among the different samples (mean FST=0.166). Much of the detected variation was attributable to differences between the samples collected from the two drainage
divisions, which are located in very different climatic regions. Furthermore, the genetic compositions of samples from neighbouring
estuaries were typically more similar to each other than to those of samples collected from more distantly-located systems.
However, the assemblages in one west coast and two south coast estuaries, that are closed to the ocean for extensive periods
of time during the year, all showed very similar genetic compositions. Nevertheless, it is crucial to recognise that, pairwise
comparisons of samples collected from the different estuaries, both within and between the two drainage divisions, almost
invariably showed statistically significant differences in allele frequencies at one or more loci. Thus, our results indicate
that the local populations of black bream in individual estuaries are genetically distinct, which is probably a consequence
of both a limited movement by individuals between estuaries and the effects of differences in regional and local environmental
conditions. 相似文献
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甲状腺激素在鱼类生长发育、变态、生殖、渗透调节以及摄食和营养代谢中发挥着重要作用,外源化合物对硬骨鱼的甲状腺干扰作用会导致发育和孵化延迟、运动性降低。本文首先对鱼类甲状腺激素的中枢调控、合成、转运、代谢和发挥作用的相关过程进行简要介绍,随后从核受体介导途径、非受体介导途径两个方面综述了外源污染物对硬骨鱼甲状腺的干扰作用机制,最后从物种特异性、检测指标、膜受体介导途径三个方面提出了目前研究的不足之处以及解决方法,以期为今后探究外源污染物对鱼类甲状腺系统干扰作用机制的研究提供更多的参考。 相似文献
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AL Mackintosh CC Reed MAI Nunkoo PH King CD van der Lingen 《African Journal of Marine Science》2018,40(3):245-252
The angelfish Brama brama is a mesopelagic species distributed circumglobally in temperate to warm-temperate waters, including continental-shelf-edge and upper-slope waters of the Benguela Current ecosystem. Little is known about the parasite assemblage of Benguela B. brama, with only three parasite taxa having previously been documented from this species in the southern Benguela. This study describes the macroparasites recorded from 35 B. brama collected during research surveys off the west coast of South Africa in 2015 and 2016. A total of six macroparasite taxa were documented, including the nematode Anisakis pegreffii, the copepod Hatschekia conifera, the cestode Hepatoxylon trichiuri, an acanthocephalan from the genus Rhadinorhynchus, a monogenean from the family Diclidophoridae, and an unidentified species. Three of these (He. trichiuri, Rhadinorhynchus sp. and the unidentified species) had not previously been found to infect B. brama. The most prevalent macroparasite taxa were A. pegreffii (94%), the unidentified species (71%) and Ha. conifera (60%). Two of the parasites, Ha. conifera and He. trichiuri, showed seasonal variation in infection, and infection with the latter was positively correlated with host length. These findings increase our knowledge of B. brama biology and contribute to our understanding of the biodiversity of the southern Benguela ecosystem. 相似文献
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硬骨鱼类精子超微结构及其研究前景 总被引：11，自引：1，他引：11
对近几年国内外硬骨鱼类精子超微结构的研究进行了综述。硬骨鱼类精子结构比较原始 ,可明显地分为头部、中段和尾部 ,但各部分结构在不同种属的硬骨鱼体中有一定差异 ,尤其是精子头部顶体有无植入窝及其发达程度 ,精子中段中心粒复合体的组成、“袖套”结构的对称性、线粒体的分布和形态及精子尾部侧鳍的有无及其发达程度等在不同种属的硬骨鱼体中有一定差异。通过分析这些精子结构的差异 ,可以明显看出种间亲缘关系 ,因此 ,精子超微结构研究在生殖进化生物学研究中具有广阔的前景。对不同硬骨鱼类精子表面大分子物质的分布、精子鞭毛的运动机制、侧鳍与受精率的关系及精子各结构的特征和功能的研究将有利于对硬骨鱼类受精生物学的研究。 相似文献
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Short-term effects of fishing on life history traits of fishes 总被引：4，自引：4，他引：4
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刺激隐核虫生活史的光镜观察 总被引：5，自引：0，他引：5
本文对寄生于海水硬骨鱼体表组织的纤毛虫刺激隐核虫(Cryptocaryonirritans)的生活史进行了描述。该寄生虫生活史分3个阶段,即滋养体,包囊体和幼虫。滋养体主要营寄生生活。成熟的滋养体离开宿主后,在数小时内就发育成包囊体。包囊体的特点是具多层结构的囊壁,而且此阶段虫体的繁殖方式为不等分裂。每个成熟的包囊平均可形成273±64个幼虫。由于囊壁坚硬,幼虫游离后,包囊壁仍保持原样。进入水体的幼虫游动极快,不摄食,一旦遇到合适的宿主即侵入,并在宿主体内发育成滋养体。文中还将结果与淡水多子小瓜虫生活史进行了比较。 相似文献
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Recent work has established that marine teleost (bony) fish represent a prolific source of mud grade, mainly high‐Mg calcite, carbonate sediment by means of primary precipitation within the intestine. Previously documented crystalline products display a diverse array of morphologies, many unique in shallow tropical marine settings, and have a wide range of magnesium contents (from 18 to 39 mol% MgCO3). This study utilizes scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, X‐ray diffraction and liquid ion chromatography to provide a more extensive and expansive morphological, mineralogical and chemical characterization of the crystalline forms produced by a wider range of piscine functional groups (covering 21 different fish species common in The Bahamas). Several crystal morphologies not previously described in fish‐derived carbonates are documented, and chemical composition is found to be more variable than previously reported: in addition to high‐Mg calcites with >18 mol% MgCO3, high‐Mg calcites with lower MgCO3 contents and low‐Mg calcites are identified. From the expanded species range, MgCO3 content in fish‐derived carbonates ranges from ca 0˙5 to > 40 mol%, and particle length is in the range 0˙1 to >50 μm (typically <2 μm for individual crystals). Amorphous Mg‐carbonates (with detectable CaCO3 of <2 mol%) are also found to varying extent in the precipitates of many species. Dominant mineralogy and MgCO3 content varies with producing species and crystal morphology (itself a species‐dependent variable). Given the very small grain size and often high MgCO3 contents of these carbonates, interesting questions arise about their preservation potential. Thus, the extent to which carbonates produced by different species may follow different post‐excretion preservation pathways is considered. 相似文献