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1.
本研究采用石蜡组织切片和H.E.染色法对军曹鱼原始性腺的形成、分化及精巢和卵巢首周年发育的组织结构变化进行观察。结果显示,军曹鱼原始生殖细胞在7孵化日龄(days post hatching,dph)时迁移到达生殖嵴,随后体细胞出现聚集和分裂,并于15 dph将原始生殖细胞完全包绕形成原始性腺。军曹鱼卵巢分化的时间要早于精巢,34 dph的稚鱼性腺组织尚未分化,但可观察到两种存在明显组织学差异的性腺类型,其中一种类型的性腺出现卵原细胞群,而另一种类型的性腺横切面较狭长,生殖细胞数量明显较少,因此推定为未分化精巢;卵巢的解剖学分化开始于44 dph,其标志为卵巢腔的形成;50 dph时精巢开始细胞学上的分化,此时精原细胞由基底膜包被形成囊泡状的细胞团。在首周年发育期间 (60~360 dph),军曹鱼的精巢发育包含I、II、III、IV、V 5个时期,而卵巢发育只包含I、II、III 3个时期。60 dph时,精巢和卵巢均处于I期;90 dph时,精巢发育至II期,卵巢仍处于I期;120 dph时,超过半数的精巢已发育至 III期,仅少部分卵巢发育至II期;150 dph时,精巢已发育至III期,而大部分卵巢发育至II期;185 dph时,精巢仍为III期,卵巢均已发育至II期;210 dph时,大部分精巢发育至IV期,卵巢仍处于II期;360 dph时,精巢已发育至V期,大部分卵巢发育至III期。上述研究结果可丰富军曹鱼的繁殖生物学研究基础,阐明其早期性腺发育规律,还可为其人工繁殖提供理论依据。  相似文献   

2.
日本蟳的性腺发育和生殖周期   总被引:2,自引:0,他引:2  
对日本蟳(Charybdis japonica)的性腺发育、生殖周期、繁殖习性和性比等进行了研究。根据其性腺的组织学和外部形态特征,将卵巢发育分为6个发育期:形成期、小生长期、大生长期、成熟期、排放期和恢复期;将精巢发育分为5个发育期:形成期、生长期、成熟期、排放期和恢复期。根据成熟系数的周年变化规律并结合性腺组织切片的观察结果,认为在连云港海区的日本蟳性腺发育为1年1个周期,繁殖期为5~9月,交配产卵盛期在5月中旬~6月下旬(水温17.5~23.5℃)。日本蟳为分批产卵类型,但第二批卵的数量远少于第一批卵。雌、雄性腺发育基本同步,雄性发育略快,雌雄比约为1∶1。  相似文献   

3.
性腺发育是罗氏沼虾(Macrobrachium rosenbergii)个体生长及繁育的重要生物学过程,是良种培育的基础。采用外部形态观察及常规石蜡切片的方法,分析了罗氏沼虾初次性成熟过程中性腺外部形态及内部组织学变化的规律。结果表明,性腺颜色、体积及细胞组成、分布均随性腺发育表现出规律性变化,卵巢发育划分为8个时期,精巢发育分为4个时期。卵巢外部形态发育与内部组织学变化同步性高,随卵巢成熟度增加,不同阶段生殖细胞由生发区向外形成环状分区, Ⅰ~Ⅲ期卵巢体积、生殖细胞大小及性腺指数(GIS)增长缓慢,主要进行生殖细胞数量积累, Ⅳ~Ⅶ期卵巢体积、生殖细胞大小及GIS增长迅速,生殖细胞在增殖同时,营养物质积累迅速。可根据卵巢颜色、体积、色素分布等推测其内部组织细胞的发育情况。精巢形态发育和组织发育同步性较差,精巢体积、生殖细胞大小、种类及GIS在精巢成熟过程中变化较小, Ⅰ期精巢主要进行个体生殖功能的完善, Ⅱ期、Ⅲ期、Ⅳ期精巢则整体表现为个体生殖能力的强化过程。研究结果丰富了罗氏沼虾繁殖生物学内容,从形态及组织学方面初步探明了罗氏沼虾性腺的基本发育过程,可为其良种选育和虾苗繁育提供参考依据。  相似文献   

4.
青岛文昌鱼(Branchiostoma japonicus)采自于青岛沙子口海区,在室内进行周年培育。每月采集样品,经测量、固定以及组织切片观察,研究了其周年卵巢和精巢的发育规律。结果表明,室内培育的文昌鱼一周年内全长没有明显变化,仅体质量在繁殖期即其性腺发育至Ⅴ期时有明显增大(P0.05=,精卵排空后则恢复原来体质量。文昌鱼1 a内在夏季6~7月繁殖1次,能自行排放卵和精子,排空后个体的卵巢或精巢,在适宜的条件下,经历Ⅰ、Ⅱ、Ⅲ、Ⅳ和Ⅴ期的发育过程,进行下一轮的性腺发育。文昌鱼精巢在Ⅳ期前先于卵巢发育,两者在Ⅳ期前发育都不同步,精巢处于Ⅳ期时间较长,一般从3月持续到5月,而卵巢处于Ⅳ期一般是在4月~5月。  相似文献   

5.
港养黄鳍鲷性腺发育和性转变研究   总被引:4,自引:2,他引:4  
洪万树  黄振池 《台湾海峡》1991,10(3):221-228,T002
本文利用光镜和电镜显微技术研究了福建东山县西埔湾黄鳍鲷性腺发育过程和性转变规律。结果表明,港养黄鳍鲷雌性性腺不能向产卵状态过渡,因而不能自然产卵,其卵细胞发育可分为5个时相,卵巢发育也可相应地分为5期。雄性性腺在港养条件下能够发育成熟,其精巢发育可分为6期。Ⅰ龄组雄性个体和雌雄同体并存;Ⅱ龄组大多数个体为雌雄同体,少数个体已转变为雌性鱼;Ⅲ龄组和Ⅳ龄组的个体均为雌性鱼。本文还对卵黄的形成、卵母细胞的退化吸收以及排卵的机制等问题进行了讨论。  相似文献   

6.
毛蚶的性腺发育和生殖周期   总被引:7,自引:0,他引:7  
根据毛蚶性腺的组织学和外部形态特征,可将其性腺发育分为:增殖期、生长期、成熟期、排放期和休止期五个时期。根据肥满度的周年变化规律并结合性腺组织切片的观察结果,认为在连云港海区的毛蚶性腺发育为一年一个周期,排放期为7月至9月,繁殖盛期在7月中旬至8月中旬。毛蚶为分批产卵类型,集中排放需要满足一定的水温、盐度等理化因子的刺激。雌、雄性腺发育基本同步,雄性发育略快,雌雄比为1.2:1。  相似文献   

7.
厦门皱瘤海鞘性腺发育的组织学研究   总被引:1,自引:0,他引:1  
方永强  冯涛 《台湾海峡》1997,16(3):275-279,T002
皱瘤海鞘雌性同体。性腺组织学观察结果表明,在厦门皱瘤海鞘卵巢和精巢发育和成熟可分为5人时期,在同一人体中,卵巢和精巢的发育不同步,因而不发生自体受精,另外,根据性腺发育的季节性观察,皱瘤海鞘常年都可繁殖,但生殖旺季在6月。  相似文献   

8.
通过常规生物学测定、解剖观察和组织切片方法,对2011年6月~2012年5月采自青岛浮山湾海域的多棘海盘车(Asterias amurensis)样本进行繁殖生物学研究。结果表明:青岛近海多棘海盘车的繁殖季节为10月至次年1月;雌雄发育同步,性比为1.05∶1;根据卵巢和精巢的外观特征、组织学结构特点和性成熟系数,可将两者的发育分为Ⅰ~Ⅵ期,每个分期具有不同的性腺结构特点和配子特征;海水温度和日照长短会影响性腺发育,温度降低会刺激个体繁殖;性腺生长由消化腺提供能量,性成熟系数和消化腺指数在一周年内呈负相关关系。  相似文献   

9.
为了解日本囊对虾(Marsupenaeusjaponicus)性腺发育及分化的分子机制,本研究采用改良的引物退火控制技术克隆到了共8个精巢、卵巢的差异表达基因.其中4个为已知基因,分别为凝血酶敏感蛋白基因、皮质棒蛋白基因、增殖细胞核抗原基因和泛素缀合酶基因;4个为未知基因,分别命名为MjACP3-T、MjACP4一T、MjACPl5一T和MjACP4一O基因.采用实时定量PCR方法分析了4个未知基因在性腺发育过程的表达谱,结果表明:MjACP3一T、MjACP4.T和MjACPl5,T基因在日本囊对虾精巢和卵巢中的表达量有显著差异,且在各个时期精巢的表达量均高于卵巢,说明这3个基因可能在精巢的发育中起到某些重要作用.卵巢MjACP4一O基因的表达量变化较大,第5期卵巢的相对表达量达到最高(为1.38),而其他各个阶段的变化较大,在第4期卵巢的相对表达量最低(为0.03).在精巢中,MjACP4一O基因的表达量随着精巢逐渐发育成熟呈下降趋势.定量PCR结果与引物退火控制技术的结果有着很好的一致性.研究结果表明,引物退火控制技术是一种简单高效的克隆差异表达基因的技术.采用该技术所克隆到的8个精巢、卵巢的差异表达基因,为进一步了解日本囊对虾性腺发育分化的分子机制提供了基础材料.  相似文献   

10.
采用常规石蜡切片,H-E组织染色法对同一批次松江鲈鱼性腺发育周期进行了观察。结果表明,松江鲈鱼性腺发育按其组织学特征均可分为5个时期,4月出膜的同一批次仔鱼,在同年7月精巢处于Ⅰ期,8月发育到Ⅱ期,9月达到Ⅲ期,10~11月持续处于Ⅳ期,12月和次年的1月,进入Ⅴ期;卵巢在7~9月处在Ⅱ期,10月的卵巢发育到Ⅲ期,11月,卵巢发育到Ⅳ期,12月和次年1月,卵巢持续处于Ⅴ期。松江鲈鱼为一年性成熟。  相似文献   

11.
鳚亚目 4 科 33 属 95 种,鰕虎鱼亚目 5 科 98 属 259 种,刺尾鱼亚目 5 科 11 属 65 种,鲈形目 19亚目 104 科 535 属 1799 种。  相似文献   

12.
Soil-sized particulates have been collected on board ship by a mesh technique from the lower troposphere of the North, Equatorial and South Atlantic Ocean, northern and southern Indian Ocean, South and East China Sea and various coastal localities.Spectrographic analysis reveals that, on average, the particulates have concentrations of Mn, Ni, Co, Ga, Cr, V, Ba, and Sr which are of the same order of magnitude as those in average crustal material. In contrast, the average concentrations of Pb, Sn, and Zn are one order of magnitude higher than those in average crustal material.Within this “world-wide” average there are significant geographical variations in the distributions of Pb, Sn, and Zn which may be related to anthropogenic sources.On the basis of trace-element distributions lower tropospheric soil-sized marine particulates have been divided into four genetic components; local, zonal, inter-zonal, and global. The proportions of these components vary geographically, and each component may have both a natural and an anthropogenic fraction.  相似文献   

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14.
Tautog, Tautoga onitis, is an abundant species of fish in estuaries of the northeastern United States. Planktonic tautog larvae are abundant in summer in these estuaries, but there is little information on rates of growth of tautog larvae feeding on natural assemblages of food in the plankton. We examined abundance and growth of larval tautog and environmental factors during weekly sampling at three sites along a nearshore‐to‐offshore transect in Buzzards Bay, Massachusetts, USA during summer 1994. This is the first study of a robust sample size (336 larvae) to estimate growth rates of field‐caught planktonic tautog larvae feeding on natural diets, using the otolith daily‐growth‐increment method. The study was over the entire summer period when tautog larvae were in the plankton. The sampling sites contrasted in several environmental variables including temperature, dissolved oxygen (DO), and chlorophyll a concentration. There was a temporal progression in the abundance of tautog larvae over the summer, in relation to location and temperature. Tautog larvae were first present nearshore, with a pronounced peak in abundance occurring at the nearshore sites during the last 2 weeks in June. Larvae were absent at this time further offshore. From late June through August, larval abundance progressively decreased nearshore, but increased offshore although never approaching the abundance levels observed at the nearshore sites. The distribution and abundance of tautog larvae appeared to be related to a nearshore‐to‐offshore seasonal warming trend and a nearshore decrease in DO. Otoliths from 336 larvae ranging from 2.3 to 7.7 mm standard length had otolith increment counts ranging from 0 to 19 increments. Growth of larval tautog was estimated at 0.23 mm·day?1, and length of larvae prior to first increment formation was estimated at 2.8 mm indicating that first increment formation occurs 3–4 days after hatching at 2.2 mm. Despite spatial and temporal differences in environmental factors, there were no significant differences in growth rates at any of three given sites over time, or between sites. Because larval presence only occurred at a narrow range of temperature (17–23.5 °C) and DO (6.5–9.3 mg·l?1), in situ differences in growth did not appear to be because of differences in larval distribution and abundance patterns relative to these parameters.  相似文献   

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16.
Concentrations of dissolved nutrients (NO3, PO4, Si), germanium species, arsenic species, tin, barium, dimethylsulfide and related parameters were measured along the salinity gradient in Charlotte Harbor. Phosphate enrichment from the phosphate industry on the Peace River promotes a productive diatom bloom near the river mouth where NO3 and Si are completely consumed. Inorganic germanium is completely depleted in this bloom by uptake into biogenic opal. The GeSi ratio taken up by diatoms is about 0·7 × 10?6, the same as that provided by the river flux, confirming that siliceous organisms incorporate germanium as an accidental trace replacement for silica. Monomethylgermanium and dimethylgermanium concentrations are undetectable in the Peace River, and increase linearly with increasing salinity to the seawater end of the bay, suggesting that these organogermanium species behave conservatively in estuaries, and are neither produced nor consumed during estuarine biogenic opal formation or dissolution. Inorganic arsenic displays slight removal in the bloom. Monomethylarsenic is produced both in the bloom and in mid-estuary, while dimethylarsenic is conservative in the bloom but produced in mid-estuary. The total production of methylarsenicals within the bay approximately balances the removal of inorganic arsenic, suggesting that most biological arsenic uptake in the estuary is biomethylated and released to the water column. Dimethylsulfide increases with increasing salinity in the estuary and shows evidence of removal, probably both by degassing and by microbial consumption. An input of DMS is observed in the central estuary. The behavior of total dissolvable tin shows no biological activity in the bloom or in mid-estuary, but does display a low-salinity input signal that parallels dissolved organic material, perhaps suggesting an association between tin and DOM. Barium displays dramatic input behavior at mid-salinities, probably due to slow release from clays deposited in the harbor after catastrophic phosphate slime spills into the Peace River.  相似文献   

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Three years of temperature data along two transects extending to 90 m depth, at Palau, Micronesia, show twice-a-day thermocline vertical displacements of commonly 50–100 m, and on one occasion 270 m. The internal wave occurred at a number of frequencies. There were a number of spectral peaks at diurnal and semi-diurnal frequencies, as well as intermediate and sub-inertial frequencies, less so at the inertial frequency. At Palau the waves generally did not travel around the island because there was no coherence between internal waves on either side of the island. The internal waves at a site 30 km offshore were out-of-phase with those on the island slopes, suggesting that the waves were generated on the island slope and then radiated away. Palau Island was thus a source of internal wave energy for the surrounding ocean. A numerical model suggests that the tidal and low-frequency currents flowing around the island form internal waves with maximum wave amplitude on the island slope and that these waves radiate away from the island. The model also suggests that the headland at the southern tip of Palau prevents the internal waves to rotate around the island. The large temperature fluctuations (commonly daily fluctuations ≈10 °C, peaking at 20 °C) appear responsible for generating a thermal stress responsible for a biologically depauperate biological community on the island slopes at depths between 60 and 120 m depth.  相似文献   

20.
以苯酚和4—溴苯甲酸为原料,合成一种尚未见文献记载的新化合物——4—溴苯甲酸—2,3,4,5,6—五溴苯酯,用无水三氯化铝催化苯酚的全溴化。此产物可望在阻燃剂方面得到应用。  相似文献   

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