异齿裂腹鱼胚胎发育与仔鱼早期发育的研究

对人工繁殖的异齿裂腹鱼Schizathorax oconnori胚胎发育和仔鱼的早期发育进行观察,描述了从受精卵到卵黄囊期仔鱼发育时期的时序和形态特征。异齿裂腹鱼的成熟卵近似于圆球形,呈淡黄色,卵径为(2.92±0.16)mm;受精后35 min卵膜吸水膨胀,卵膜径达(3.72±0.31)mm。在13.0～14.5℃条件下,孵化时间为193.22 h。异齿裂腹鱼胚胎发育速度存在明显的个体差异,孵化期历时92.83 h。初孵仔鱼全长为(8.97±0.31)mm。10日龄仔鱼初次摄食,进入混合营养期。     

拉萨裂腹鱼的胚胎及仔稚鱼发育特征

为探明拉萨裂腹鱼Schizothorax waltoni Regan的早期发育阶段特征和规律,采用显微观察法,对其胚胎及仔鱼发育各时期的形态特征和发育特点进行了研究。结果表明:拉萨裂腹鱼受精卵呈圆形、黄色,卵径为(2.53±0.10)mm;拉萨裂腹鱼胚胎发育水温不宜超过17℃,在(13±1)℃水温下,拉萨裂腹鱼胚胎发育历时225 h 10 min,积温为2838.79 h·℃,根据发育时胚胎的外部形态特征,将胚胎发育的过程划分为受精卵期、胚盘期、卵裂期、囊胚期、原肠期、神经胚期、器官分化期和出膜期8个阶段,33个时期;出膜仔鱼全长为(10.71±0.28)mm,出膜后11 d,仔鱼的鳃、口、胸鳍、尾鳍、鳔、肠道等功能器官先后形成,出膜23 d后卵黄囊消失,全长为(18.35±0.65)mm,出膜70 d时各鳍基本长成,体型和体色接近成鱼,进入幼鱼阶段。研究表明,拉萨裂腹鱼的早期发育特征与其生存的环境具有一定的适应性。     

欧洲舌齿鲈胚胎发育及仔鱼生长观察

为了解欧洲舌齿鲈Dicentrarchus labrax胚胎及仔鱼发育特点,采用人工催产获得受精卵,在人工孵化条件下观察了欧洲舌齿鲈胚胎发育及仔鱼的形态变化与生长特征。结果表明:欧洲舌齿鲈受精卵呈圆形,浮性,卵径为(1.287±0.025)mm;在(13.0±0.5)℃水温条件下,胚胎发育分别历经了受精卵(0 h)、2细胞期(1.5 h)、4细胞期(2.0 h)、8胚叶期(2.5 h)、多细胞期(4.0 h)、桑椹胚期(4.5 h)、囊胚期(9.0 h)、原肠胚期(22 h)、胚胎轴出现期(37 h)、肌节及视囊出现期(48 h)、脑泡形成期(56 h)、心脏形成期(62 h)、尾芽期(68 h)、心脏跳动期(70 h)和孵出期(71 h)等阶段,历时72 h完成孵化过程;初孵仔鱼全长为(3.98±0.02)mm,在(13.0±0.5)℃水温下,0～9 d处于早期仔鱼阶段,孵化0～5 d的仔鱼游泳能力差,心脏、肠道、鳍等各器官继续发育,卵黄囊占身体较大比例;孵化5 d后的仔鱼,眼囊内晶体颜色变黑,体表黑色素聚集,卵黄囊明显变小;孵化后7 d的仔鱼,口裂和胸鳍鳍条形成,少数仔鱼开始平游,但无法摄食,仍靠卵黄囊提供营养;9 d后进入后期仔鱼阶段,孵化9 d的仔鱼几乎全部进入平游状态,肠道内可见食物,卵黄囊未完全消失,属混合营养期;孵化11 d的仔鱼卵黄囊彻底消失,营外源性营养;孵化13～17 d的仔鱼游泳能力增强,肠道充满食物,进入快速生长期;孵化17～19 d的仔鱼个体开始出现明显的大小差异;孵化19 d后鱼体变黑,各鳍基本形成,继续发育将进入稚鱼期;欧洲舌齿鲈仔鱼的混合营养期短,具有异速生长特性。本研究初步阐述了欧洲舌齿鲈的早期生活史特征,为欧洲舌齿鲈在中国的人工苗种繁育工作提供了理论参考。     

欧洲舌齿鲈胚胎发育及仔鱼生长观察

为了解欧洲舌齿鲈Dicentrarchus labrax胚胎及仔鱼发育特点,采用人工催产获得受精卵,在人工孵化条件下观察了欧洲舌齿鲈胚胎发育及仔鱼的形态变化与生长特征。结果表明:欧洲舌齿鲈受精卵呈圆形,浮性,卵径为(1.287±0.025)mm;在(13.0±0.5)℃水温条件下,胚胎发育分别历经了受精卵(0 h)、2细胞期(1.5 h)、4细胞期(2.0 h)、8胚叶期(2.5 h)、多细胞期(4.0 h)、桑椹胚期(4.5 h)、囊胚期(9.0 h)、原肠胚期(22 h)、胚胎轴出现期(37 h)、肌节及视囊出现期(48 h)、脑泡形成期(56 h)、心脏形成期(62 h)、尾芽期(68 h)、心脏跳动期(70 h)和孵出期(71 h)等阶段,历时72 h完成孵化过程;初孵仔鱼全长为(3.98±0.02)mm,在(13.0±0.5)℃水温下,0～9 d处于早期仔鱼阶段,孵化0～5 d的仔鱼游泳能力差,心脏、肠道、鳍等各器官继续发育,卵黄囊占身体较大比例;孵化5 d后的仔鱼,眼囊内晶体颜色变黑,体表黑色素聚集,卵黄囊明显变小;孵化后7 d的仔鱼,口裂和胸鳍鳍条形成,少数仔鱼开始平游,但无法摄食,仍靠卵黄囊提供营养;9 d后进入后期仔鱼阶段,孵化9 d的仔鱼几乎全部进入平游状态,肠道内可见食物,卵黄囊未完全消失,属混合营养期;孵化11 d的仔鱼卵黄囊彻底消失,营外源性营养;孵化13～17 d的仔鱼游泳能力增强,肠道充满食物,进入快速生长期;孵化17～19 d的仔鱼个体开始出现明显的大小差异;孵化19 d后鱼体变黑,各鳍基本形成,继续发育将进入稚鱼期;欧洲舌齿鲈仔鱼的混合营养期短,具有异速生长特性。本研究初步阐述了欧洲舌齿鲈的早期生活史特征,为欧洲舌齿鲈在中国的人工苗种繁育工作提供了理论参考。     

哲罗鱼胚胎和仔鱼发育的研究

用活体观察和固定观察两种方法,首次对哲罗鱼Hucho taimen胚胎和仔鱼发育进行了系统观察,描述了哲罗鱼早期发育过程。哲罗鱼受精卵为沉性端黄卵,呈圆球形,含有大量卵黄,卵色呈桔黄色,吸水膨胀后卵径为(5.55±0.15)mm。在水温为4.8⁹.0℃下,受精卵历时839 h破膜,初孵仔鱼全长为(18.45±0.32)mm,卵黄囊体积为(0.074±0.009)cm3,经过60 d左右仔鱼发育基本完成。将哲罗鱼与几种鱼类进行了对比,探讨其卵径、孵化平均水温与破膜所需时间及初孵仔鱼大小之间的关系。     

北方须鳅人工繁殖与胚胎发育研究

为实现北方须鳅Barbatula barbatula nuda人工养殖和资源增殖,于2015—2019年采集野生北方须鳅亲鱼进行人工繁殖试验,探索了北方须鳅的繁殖季节、雌雄鉴别、人工催情、产卵、人工孵化等关键性技术。结果表明:通过催产北方须鳅雌亲鱼55 000组,获卵5 960万粒,平均催产率为45.0%,平均受精率为56.0%,平均孵化率为42.7%,水花鱼苗为1 840.3万尾;辽宁东部山区北方须鳅繁殖期主要集中在3月中旬—4月上旬,北方须鳅卵径为(2.15±0.07) mm,产卵最低水温为8.5℃,适宜水温为17～22℃,在此温度下,效应时间为23～26h,人工授精适宜雌雄比为2∶1;受精卵吸水后卵径为(2.35±0.05)mm,历经胚盘形成期、卵裂期、囊胚期、原肠期、神经胚、器官分化期和出膜期;从受精至仔鱼孵出积温为66.67℃·d,受精至仔鱼平游积温为126.5℃·d;初孵仔鱼全长为(4.9±0.8)mm,体质量为(0.6±0.1)mg。研究表明,通过生态调控(温度)和生理调控(复合催产药物)措施,可实现野生北方须鳅的规模化人工繁殖。     

齐口裂腹鱼的胚胎发育和仔鱼的早期发育

报道了齐口裂腹鱼Sclizothoraxprenanti胚胎发育和仔鱼早期发育的形态特征及发育特点。该鱼的成熟卵为微黏性,卵径2 9～3 0mm,授精后约1h,受精卵吸水膨胀达到最大,卵径4 2mm。试验期间水温为10 2～23 4℃,平均16 8℃。授精5h进入卵裂期,12h进入囊胚期,19h进入原肠期,40h胚孔封闭,86h肌节开始收缩,98h心跳开始,134h出膜。刚出膜的仔鱼全长11mm,出膜后第2天到第4天,胸鳍、鳃、口腔、鳍、眼色素、体内血管等器官相继发育完全;第5天仔鱼全长达15mm,鳔充气,鱼苗开始平游和觅食。齐口裂腹鱼卵裂前、原肠期、尾芽出现期前,发育相对较慢,尾芽出现后发育明显加快。     

扁吻鱼胚胎及仔鱼发育的形态学观察

2005年4月底在人工繁殖条件下,对扁吻鱼Aspiorhynchus laticeps精、卵的形态,胚胎和仔鱼发育进行观察。结果表明:扁吻鱼的成熟卵呈浅灰色,微黏性,成熟卵卵径为1.80¹.85 mm,受精后卵膜吸水膨胀,卵膜直径为3.301.85 mm,受精后卵膜吸水膨胀,卵膜直径为3.30³.45 mm。受精卵在水温213.45 mm。受精卵在水温21²2℃下,历经1 h40 min胚盘突起;2 h10 min出现第一次卵裂;历经7 h 15 min胚胎发育到多细胞期;12 h 4 min发育到囊胚期;16 h 36 min为原肠早期;30h 20 min发育到神经胚期;历经91 h 37 min器官形成,心脏搏动,胚体摆动;103 h后仔鱼孵出,全长为7.5 mm。孵出后的第6 d,全长为11.6 mm,卵黄囊基本吸收完毕,开口索食。孵出26 d后,全长为21.00mm,奇鳍、偶鳍发育完成,肌肉增生,但体尚未披鳞。观察发现:扁吻鱼受精卵不仅具有黏性,而且卵膜吸水膨胀,形成的膜径1.8倍于卵径,富有弹性;受精卵发育后期在微流水中能悬浮水中片刻,后逐渐沉水,因此加强水中氧量的供给有助于其发育;受精卵的胚盘隆起至第6次卵裂的时距大大快于青海湖裸鲤,且眼基和体节、嗅囊和尾芽同时发生;孵出前的胚体已超越卵膜内经,尾端超出头部的眼后。     

尖吻细鳞鲑胚胎及仔、稚、幼鱼发育的研究

通过活体观察和Bouin's液固定对乌苏里江尖吻细鳞鲑Brachymystax lenok的胚胎及仔、稚、幼鱼的发育进行观察,确定尖吻细鳞鲑的发育过程,详细描述了胚胎各发育时期的时序、形态特征以及仔、稚、幼鱼的发育特点,并将尖吻细鳞鲑与其它几种鱼类进行比较,探讨破膜所需时间与卵子性质和孵化水温的关系。结果表明:尖吻细鳞鲑成熟卵呈淡黄色,圆球形,卵径为(4.32±0.21)mm,含有大量卵黄,卵的比重大于水,属端黄卵,卵膜厚,无黏性,有弹性;受精卵在水温6.0¹0.7℃条件下,历时597 h孵出,有效积温为190.79℃.d;尖吻细鳞鲑胚胎发育过程包括受精卵、卵裂、囊胚、原肠胚、神经胚、器官形成等6个阶段、26个发育时期。初孵仔鱼全长为(10.67±0.02)mm,破膜第13天仔鱼出现鳔并开始上浮,第14天仔鱼卵黄囊吸收完全,仔鱼期结束,进入稚鱼期;破膜后第25天稚鱼体侧出现幼鲑斑,第35天各鳍发育完全,进入幼鱼期,此时鱼体外观与成鱼无异。     

舌鰕虎鱼的人工繁殖及其胚胎发育

为掌握舌鰕虎鱼Glossogobius giuris的人工繁殖技术及其胚胎发育特点,进行了舌鰕虎鱼人工繁殖试验和胚胎发育观察,研究了舌鰕虎鱼亲鱼强化培育、人工催产、产卵受精和胚胎发育过程,并描述了胚胎各发育时期的时序和形态特征。结果表明:性腺成熟的舌鰕虎鱼亲鱼经两次激素注射催熟催产,催产率为60%⁸0%,受精率为73.4%80%,受精率为73.4%⁸1.2%,孵化率为63.8%81.2%,孵化率为63.8%⁷7.2%;舌鰕虎鱼受精卵为纺锤形,呈黏性且半透明;胚胎发育分为胚盘形成期、卵裂期、囊胚期、原肠期、神经胚期、器官形成期和出膜期7个阶段,以及26个发育时期;在2577.2%;舌鰕虎鱼受精卵为纺锤形,呈黏性且半透明;胚胎发育分为胚盘形成期、卵裂期、囊胚期、原肠期、神经胚期、器官形成期和出膜期7个阶段,以及26个发育时期;在25²7℃条件下需要108 h完成孵化过程,初孵仔鱼体长为2.527℃条件下需要108 h完成孵化过程,初孵仔鱼体长为2.5³.5 mm,全长为2.73.5 mm,全长为2.7³.8 mm,肌节为263.8 mm,肌节为26²8对,心跳为5028对,心跳为50⁵5次/min。本研究结果可为舌鰕虎鱼资源的保护和人工繁殖提供理论指导。     

Vanadium in foods and in human body fluids and tissues

Using neutron activation analysis, vanadium was analysed in a range of foods, human body fluids and tissues. On the basis of these results and those of other workers, it was concluded that daily dietary intake amounts to some tens of micrograms. Analysis of body fluids (including milk, blood and excreta) and organs and tissues provided an estimate for the total body pool of vanadium in man of about 100 μg. Vanadium was not detectable in blood and urine at the level of 0.3 ng/g, while low levels were found in muscle, fat, bone, teeth and other tissues. The relationship between dietary intake to pulmonary absorption is discussed in relation to the occurrence of vanadium in man-made air particulates. The very low levels found in milks and eggs suggest minimal vanadium requirements in growth. The findings are discussed in the light of previous results and also in relation to the possible essentiality of vanadium.     

Iodine-129 in thyroid and urine in Ukraine and Denmark

Human thyroids collected from Gomel in Belarus, sheep thyroid from Jutland and human urine from Zealand in Denmark were analysed for 129I and 127I concentrations. The ratios of 129I/127I in human thyroid in Gomel are 2.65-11.0 x 10(-9) with an average of 7.21 x 10(-9), which is one order of magnitude higher than those from Asia and South America (10(-10)), but significantly lower than those observed in west Europe (10(-8)). A weak negative correlation (P < 0.05) between 129I/127I ratio in human thyroid and the age of the subjects was observed in Gomel. The average ratio of 129I/127I in sheep thyroids from Jutland of Denmark is 1.81 x 10(-7), which is two orders of magnitude higher than those in south hemisphere, and Asia. It is also significantly higher than those observed in other west European countries before 1984 and that in human thyroid in Gomel. The high thyroid 129I level in Jutland is attributed to the release of reprocessing plants in France and UK. The 129I/127I ratios in human urine in Zealand of Denmark are 0.86-2.86 x 10(-8). The possibility of using urine 129I to evaluate the thyroid exposure to 129I is investigated.     

儿童青少年近视的防控研究进展

儿童青少年近视率一直处于高位并持续上升,严重影响了我国儿童青少年的学习和生活,本研究通过查阅国内外治疗儿童青少年近视相关著作及文献,针对目前儿童青少年近视防控手段的进展,对各治疗方案进行分析和研究。     

德国城乡景观与中国景观问题

2003年,笔者获得德国DAAD(德国国际学术交流基金会)奖励资助,作为访问学者在德国逗留了4个月(4月～8月).在这期间,笔者还考察了法国、丹麦、瑞典和意大利,但我认为还是德国的景观最为优雅和美丽.     

广义文脉与规划设计教育

城市规划设计教育不仅应关注历史化,还应关注自然、社会和经济;不仅应关注地方和传统,还应关注全球和未来。城市规划教育应掌握正确的发展观和方法论,肩负起发展地万脉的历史使命,保护社会公众的利益,推动城市持续发展。     

Perchlorate in raw and drinking water sources in England and Wales

A well‐known use of perchlorate is as a rocket fuel propellant; however, more widespread uses include in munitions and fireworks, and it also occurs naturally. Perchlorate suppresses the thyroid, which can lead to a variety of adverse effects. It is a widespread contaminant in the United States, but limited occurrence data in the United Kingdom exist, and even less for drinking water. Monitoring of 20 raw and treated drinking water sites in England and Wales, covering four seasonal periods, showed that perchlorate is a low‐level background contaminant of raw and treated drinking water. Low concentrations (treated drinking water: <0.020–2.073 μg/L, mean 0.747 μg/L) were detected at every higher‐risk site. The concentrations were comparable in each of the four sampling exercises and no significant trends were apparent relating to the time of year, the type of risk or the method of chlorination. Limited data showed that removal by ion exchange and granular‐activated carbon may occur.     

Lead and cadmium contents in cereals and pulses in north-eastern China

It is known that, unlike Japanese, Koreans or southern Chinese who depend on rice as a major source of energy for daily life, people in north-eastern China rely not only on rice, but on wheat and other cereals and to a lesser extent also on pulses. Cereal and pulse samples were collected from open markets in north-eastern China, and analyzed by inductively-coupled plasma spectrometry (ICP-MS) for two potentially hazardous heavy metals — lead (Pb) and cadmium (Cd). The average Pb level in cereals (31.3 ng Pb/g as a geometric mean) and that of pulses (25.7 ng Pb/g) were similar to each other with no significant difference. Among the cereals, Pb contents were higher in foxtail millet (54.3 ng/g) and lower in maize (35.4 ng Pb/g; grain and flour in combination), wheat flour (28.8 ng Pb/g) and rice flour (22.7 ng Pb/g). Lead levels in two important types of pulses, kidney bean and soybean (24.6 and 30.8 ng Pb/g, respectively), were comparable to the levels in rice and wheat. In contrast, Cd levels were substantially higher in pulses (55.7 ng Cd/g) than in cereals (9.2 ng Cd/g), and among the pulses, Cd in soybean (55.7 ng Cd/g) was significantly higher than that in kidney bean (23.8 ng Cd/g). The possible public health implication of the Pb and Cd levels, especially the high Pb level in foxtail millet (54.3 ng Pb/g) and the high Cd level in soybean (73.5 ng Cd/g), is discussed.     

武汉城市景观文化生态保护建设的问题与对策

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