生物胺对锯缘青蟹精巢发育的调控作用

采用活体注射和体外培养方法,以精巢指数、精巢生精小管的成熟节段比例和促雄腺B型细胞比例为量化指标,观察3种生物胺对雄性锯缘青蟹生殖神经内分泌的调控作用.活体注射实验表明:5-HT组锯缘青蟹精巢发育和促雄腺分泌活动具有显著的促进作用;DA组精巢发育受到抑制,但促雄腺细胞的分泌活动不受影响;OA组与同步对照组差异不显著.离体实验表明:5-HT刺激了脑和胸神经团的分泌活动,从而促进促雄腺分泌活动;OA和DA对脑和胸神经团分泌活动没有明显影响.视神经节的生殖内分泌活动几乎不受3种生物胺的影响.本实验首次报道了体外条件下生物胺对雄性甲壳动物生殖神经内分泌的调控作用,支持了5-HT首先刺激脑和胸神经团分泌GSH,再通过促雄腺活动从而促进精巢发育的观点.     

东方扁虾卵巢和滤泡结构的研究

卵巢包括4种形态的组分:(1)卵巢壁,(2)生殖上皮,(3)卵母细胞(早期卵巢还包括卵原细胞)一滤泡细胞层,(4)卵巢壁内突.卵巢壁及壁内突均含有血管、血窦、肌细胞等成分,卵巢壁内突延伸至每个滤泡的外层基膜处.滤泡由内至外由卵母细胞、卵周隙、滤泡细胞及基膜等4部分组成.卵母细胞膜表面向卵周隙内伸出许多微绒毛,并具有许多微吞饮凹.随着滤泡的发育,卵周隙内含物电子密度越来越大,成熟滤泡的卵周隙内含物演变为卵壳.卵壳由两部分构成:外层较薄,而内层较厚且含电子致密的颗粒物质.滤泡细胞一般为单层,具较强的合成活性,其合成产物系卵周隙内含物的一部分.东方扁虾卵巢和滤泡的结构特征表明外源性(卵母细胞外及卵巢外)的卵黄合成在卵黄发生上起重要的作用.     

孔鳐卵壳形成及其排卵的初步观察

孔鳐(Raja porosa Gnther)属软骨鱼类板鳃纲(Elasmobranchii)下孔总目(Hypot-hemata)鳐目(Rajiformes)鳐科(Rajidae)。俗名“老板鱼”为习见种类,主要分布于黄海、东海,产量很大,尤其是黄海,为具有经济价值的近海底栖鱼类。Clark(1922)曾报道过英国普利茅斯港产11种鳐卵的形态、排卵与孵化。石山礼藏(1950)就日本北海道产10种鳐类的卵壳形态、组织学结构,及其与地理分布的关系作了比较观察和报道。被誉之为“水手的钱袋”和“人鱼的别针箱”的鳐卵,它的卵壳在     

鱼类甲状腺轴对胚胎发育、仔鱼变态及性别分化的调控作用研究进展

鱼类甲状腺轴由下丘脑、垂体、甲状腺组成,下丘脑通过分泌促甲状腺激素释放激素、促肾上腺皮质激素释放激素调节垂体促甲状腺激素的合成和分泌,促甲状腺激素促进甲状腺滤泡合成并释放甲状腺激素(主要为甲状腺素—T4),T4运输至肝脏等外周组织中,经过脱碘转化形成生物活性更强的三碘甲腺原氨酸(T3),T3主要通过同核受体结合发挥生物学功能。甲状腺激素对鱼类胚胎发育、仔鱼变态及性别分化等早期生长发育过程具有重要调控作用:甲状腺激素为鱼类胚胎发育期所必须,外加适量甲状腺激素能够提高胚胎或仔鱼存活率;仔鱼变态过程中,某些外部形态变化及相关组织分化依赖甲状腺激素的调控,牙鲆等仔鱼变态期体内甲状腺激素水平及其受体表达量会显著升高;性腺发育期,甲状腺激素对调控鱼类性别分化方向可能具有一定作用。     

莫桑双克非鲫卵壳膜形成的电镜观察

于１９８６年９－１２月对取自湖北省水产研究所实验鱼网箱中的莫桑比克非鲫，运用透射电镜观察卵子发生中卵壳的形成过程。结果表明，随着卵母细胞的生长，在卵母细胞和颗粒细胞之间先后出现３层结构，即Ｚ１，Ｚ２，Ｚ３；初步确定：Ｚ１可能由颗粒细胞分泌形成，Ｚ２和Ｚ３由卵母细胞分泌形成，最终Ｚ１，Ｚ２，Ｚ３融为一体成为卵壳膜。对卵壳膜的结构特征及其与特殊的生殖习性－衔卵孵化的关系的分析认为，衔卵孵化导致卵壳膜的     

皱瘤海鞘神经递质和性类固醇激素含量与性腺发育成熟的关系

运用免疫组织化学和化学发光免疫分析方法研究了皱瘤海鞘(Styela plicata)神经递质多巴胺(DA)、5-羟色胺(5-HT)及其受体以及性类固醇激素含量与性腺发育成熟的关系.结果显示,DA和5-HT免疫活性定位在脑神经节中大小2种类型的神经细胞,DA免疫活性还定位在不同发育时期神经腺上皮细胞.5-HT受体免疫活性存在于脑神经节小型神经细胞和大生长期神经腺上皮细胞.在小生长期和大生长期性腺中均检测到DA、5-HT及其受体,提示DA和5-HT可能参与调节皱瘤海鞘的性腺发育.皱瘤海鞘为雌雄同体,化学发光免疫分析证实,海鞘性腺能够合成和分泌性类固醇激素,大生长期性腺中雄激素、孕激素和雌激素的含量分别为25.8±0.0、38.9±0.2和14.3±0.6pg/mg,提示性腺既是生殖组织也是内分泌组织.上述发现为证明尾索类海鞘可能像头索类文昌鱼一样,具有原始的生殖内分泌调控轴(脑神经节-神经腺-性腺)提供科学依据.     

中国软骨鱼类资源概述及其利用问题的商榷

鱼类可方便地分为软骨鱼类和硬骨鱼类两大类。软骨鱼类包括鲨鱼、鳐鱼与银鲛等鱼类。本文主要叙述中国软骨鱼类的资源概况,特别是它们的种类成分、分布情况、生活习性、质量和数量以及一般捕捞情况;同时也商讨一下它们的利用和增产等问题。为便于读者了解起见,现在先把软骨鱼类简要地介绍如下。     

条纹斑竹鲨雌性生殖系统的初步研究

条纹斑竹鲨为小型体内受精、卵生种类 ,是闽南近海常见鲨类。其雌鱼仅具右侧卵巢 ,呈葡萄状裸露型 ,怀卵量约二三百个 ,卵细胞不同步发育 ,成熟卵径为20～30mm ,卵中含大量卵黄。条纹斑竹鲨卵壳腺的大小随鱼体的生长而增大 ,达到性成熟时约80mm×50mm。卵经过卵壳腺时受精 ,受精卵外被一厚而坚韧的卵鞘 ,为黄褐色、椭圆四角形     

中国软骨鱼类资源概述及其利用问题的商榷

一.引言鱼类可方便地分为软骨鱼类和硬骨鱼类两大类。软骨鱼类包括鲨鱼、鳐鱼与银鲛等鱼类。本文主要叙述中国软骨鱼类的资源概况,特别是它们的种类成分、分布情况、生活习性、质量和数量以及一般捕捞情况;同时也商讨一下它们的利用和增产等问题。为便于读者了解起见,现在先把软骨鱼类简要地介绍如下。1.软骨鱼类的形态特征软骨鱼类的主要特征有以下几点:(1)内骨胳完全由软骨组成,没有真骨;(2)体被盾鳞,或光滑无鳞;(3)鳃裂5—7对,个别开口于体外(银鲛例外,具有一膜状鳃盖和一外鳃孔);(4)雄性的腹鳍里侧具一交接器,或称鳍脚;(5)尾常为歪形;(6)鼻孔腹位;(7)卵大而数少,体内受精。此外,还有许多内部特征,这里从略了。     

中国对虾XO-SG复合体及其分泌物的初步研究

X器官-窦腺(XO-SG)复合体是甲壳动物重要神经内分泌器官，类似哺乳动物的下丘脑-垂体系统，它能分泌多种神经肽类激素，调控甲壳动物的生殖、发育和蜕皮等重要生理功能(Cooke et al.，1982； Keller，1992)。对XO-SG复合体的研究一直是甲壳动物内分泌学的重点内容。XO由视神经节内一群相互无连接的单轴突分泌肽神经细胞组成，它们的轴突末梢在血窦附近膨大形成窦腺，XO内胞体形成的神经肽类激素经轴突运输到窦腺储存和释放。近20年来，一些学者对10余种甲壳动物眼柄内X器官-窦腺复合体进了形态及超微结构研究，发现X器官神经内分泌细胞胞体的分布位置和结构特征各不相同，区分出2至7种不同类型的神经内分泌末梢，并观察到多种神经内分泌物质释放方式(Fingerman，1992； Dircksen，1992； Castany，1997； Weatherby，1981)。我国对甲壳动物神经内分泌系统的研究刚刚开始(蔡生力，1998)，仅对锯缘青蟹(Scylla serrata)、罗氏沼虹虾(Macrobrachium rosenbergii)和中华绒螯蟹(Eriocheir sinensis)XO-SG复合体进行了显微和超微结构观察(上官步敏等，1994，1995；姚泊，1995；孙金生等，2000)。中国对虾(Penaeus sinensis)是我国重要经济甲壳动物，在育苗过程中往往采用切断或灼烧眼柄的方法来加速亲虾性腺发育和产卵，而对XO-SG复合体却了解甚少，仅进行了组织学观察(康现江等，1998)。为此作者对中国对虾眼柄XO-SG复合体显微和超微结构及其分泌物特征进行了初步研究，为进一步研究对虾神经分泌细胞的离体培养和神经分泌调控机制打下基础。     

台湾东风螺的生殖系统及其组织结构

本文报道了台湾东风螺(Babylonia formosa)雄性和雌性生殖系统的解剖学以及各器官的组织学研究结果,并与一些狭舌目种类的生殖系统作了比较。     

鱼类甲状腺功能研究进展

本文介绍了近十多年来,鱼类甲状腺功能的新进展。现已证实甲状腺所分泌物质甲状腺素参与鱼类性腺发育成熟和生殖活动。甲状腺素对鱼类受精卵发育、孵化和幼体生存着重要的生理作用。     

孔鳐雄性生殖系统解剖学与组织学观察

本研究对成年雄性孔鳐(Okamejei kenojei)的生殖系统进行解剖学和组织学观察,结果表明,孔鳐的生殖系统主要由精巢、附睾、输精管、储精囊、间质腺、鳍脚腺和鳍脚组成。其中孔鳐的精巢中的精小囊,按照成熟度依次由中心向小叶外周辐射状排列,其精子发育成熟过程根据精巢支持细胞的位置、精小囊的大小和精小囊中的生精细胞所处的状态可划分为7个时期:精巢支持细胞未迁移期、精巢支持细胞迁移期、精巢支持细胞定植早期、精巢支持细胞定植晚期、精子变形期、精子迁移期、精子聚拢期。变态成熟的精子最终每59~64根精子组成精子束进入附睾。精子束在附睾中经历“游离-聚拢-游离”3个过程后,最终储存在储精囊中。鳍脚是孔鳐的外生殖器,主要有鳍扇、扇盾等结构组成,它与储精囊相连,是将精液输送至体外的器官。     

疣荔枝螺(Thais clavigera)性畸变现象的解剖学和组织学研究

以解剖学和组织学的方法研究了有机锡污染生物指示种——疣荔枝螺的正常雄、雌和性畸变个体的生殖系统。结果表明，性畸变个体除具有正常的雌性器官外，还有输精管或阴茎。当性畸变程度严重时，性畸变不育个体的卵囊腺组织出现破损，并具有不规则块状的不育卵囊和未排出的正常卵囊。虽然性畸变个体的雄性器官具有表现出雄性功能的潜能，但由于缺少精巢或完整的前列腺，不可能发展成为具有雄性功能的个体，这与性逆转有着本质上的区别。有机锡污染引起的性畸变已对疣荔枝螺种群生存构成了潜在的威胁，深化此类负面生态效应的研究是人类面临的重要课题。     

Do fecundity‐time models really predict extreme optimal egg sizes?

In 1973, Vance published a mathematical model that explains differences in reproductive strategies such as planktotrophy and lecithotrophy found in marine invertebrates. The original model Vance (The American Naturalist, 107 , 339–352) traded fecundity against development time and resulted in a U‐shaped fitness function suggesting that only extreme levels of egg provisioning (referred to as egg size) are evolutionarily stable. Several later models independently predicted evolutionary stability of extreme egg sizes, and this has been commonly interpreted as a proof that the Vance model, albeit oversimplified, reflects the fundamental evolutionary principle of disruptive egg size evolution in marine invertebrates. However, empirical studies of the last several decades have illustrated that intermediate levels of egg provisioning are commonly observed in nature. As a result, the recent modifications of the original Vance model have attempted to explain evolution of such intermediate strategies. Here we re‐examine the earlier fecundity‐time models of the ‘Vance family’ and show that only Vance and its minor modification by Grant (The American Naturalist, 122 , 549–555) invariably predict evolutionary stability of extreme egg sizes. Most modifications of the original Vance model in fact can predict at least some intermediate optimal egg sizes and reproductive strategies. There is no reason to assume that selection towards extreme egg sizes is the driving force in the evolution of marine invertebrate life histories.     

Do endocrine disrupting chemicals threaten Mediterranean swordfish? Preliminary results of vitellogenin and Zona radiata proteins in Xiphias gladius

Endocrine Disrupting Chemicals (EDCs) have the potential to alter hormone pathways that regulate reproductive processes in wildlife and fishes. In this research the hypothesis that Mediterranean top predator species (such as large pelagic fish) are potentially at risk due to EDCs is investigated. These marine organisms tend to accumulate high concentrations of EDCs such as polyhalogenated aromatic hydrocarbons (PHAHs). The potential effects of EDCs on a fish species of commercial interest, the top predator Xiphias gladius (swordfish), were investigated using vitellogenin (Vtg) and Zona radiata proteins (Zrp) as diagnostic and prognostic biomarkers. Dramatic induction of typically female proteins (Vtg and Zrp) was detected by ELISA and Western Blot in adult males of the species. These results are the first warning of the potential risk for reproductive function of Mediterranean top predators, and suggest the need for continuous monitoring of this fragile marine environment.     

栽培羊栖菜(Sargassum fusiforme)成熟藻体不同器官的组织结构显微观察及其生理生态学功能剖析

为全面了解栽培羊栖菜(Sargassum fusiforme)成熟藻体假根、茎、叶(气囊)和生殖托(雌托和雄托)四类器官的组织形态特征,运用石蜡切片法,对栽培羊栖菜成熟藻体各器官进行了组织形态学观察和讨论分析。结果表明,不同器官横切组织的形态、结构和宽度差异显著;假根,茎,叶,雌、雄生殖托的横切面由外向内分别为表皮、近表皮、皮层和髓部组织,而气囊无髓部组织结构,但具有内皮层。此外,雌、雄生殖托还包括生殖窝、卵和精子结构。栽培羊栖菜各器官表皮细胞均呈栅栏状排列,宽度顺序为:雄生殖托茎雌生殖托气囊叶假根;表皮和近表皮细胞含淀粉粒最多,内含色素体;皮层和髓部细胞的淀粉粒含量相对较少;皮层组织的细胞腔最大,具有典型植物细胞形态和发达的胞间隙;髓部细胞致密,细胞腔多数较小。有关文献报道表明,羊栖菜不同器官响应光照、水温、干出与沉水及低盐胁迫等环境信号表达的生理生态学特征差异显著。研究结果可为深度解析栽培羊栖菜各器官之间的亚细胞结构差异,不同器官生理代谢响应环境信号表达差异,不同器官组织对微量元素或重金属离子的吸收、转运和储藏机制分析等研究提供基础数据和理论参考。     

Reproduction,hatching success,and early naupliar survival in Centropages typicus

The broadcast spawner, Centropages typicus, is a very successful copepod species in many coastal areas of the Mediterranean Sea and North Atlantic Ocean. This review assembles the large amount of information on the reproduction and early life history of C. typicus that has emerged since the 1970s and has made this species one of the best-studied copepods, similar in that regard to species of Acartia and Calanus. Observations on mating behavior and the female gametogenic and oogenic cycles are presented, together with information on seasonal cycles of egg production rates in Mediterranean and Atlantic populations from various regions. These studies indicate a strong latitudinal gradient, with continuous reproduction and the main spawning season occurring earlier (late winter/spring) in warmer waters such as the Mediterranean Sea, compared to northern areas such as the North Sea and in the Kattegat, where C. typicus actively reproduces mainly in late summer and fall with reproduction ceasing altogether in winter in the German Bight. These observations strongly suggest that temperature is the controlling factor for reproductive activity in this species. Egg development times are also temperature dependent but do not vary with latitude, and there is as yet no conclusive evidence that diapause egg production occurs in C. typicus. Laboratory experiments have shown that food quantity and quality both affect fecundity and offspring fitness, but most of these studies have focused on diatom and dinoflagellate diets and non-algal prey have been strongly underrepresented, despite their importance for this omnivorous copepod. Large fluctuations in hatching success and naupliar survival have been reported in field surveys and have subsequently been related to maternal feeding history and food quality or toxicity in laboratory experiments. We identify future lines of research that will help to explain the interannual variability in breeding intensity and recruitment of C. typicus in the field based on better understanding of the species’ reproductive biology.     

茎柔鱼(Dosidicus gigas)脂肪积累对其4个组织能量积累贡献的研究

茎柔鱼(Dosidicus gigas)是重要的大洋性经济头足类,其性腺组织发育滞后于个体生长,但在性腺发育开始后生殖能量积累显著。为研究茎柔鱼脂肪积累对组织能量积累的贡献,采用组织能量密度测定技术和组织脂肪萃取技术对茎柔鱼卵巢、输卵管卵子、肌肉和消化腺4个组织脱脂前后的组织能量密度、单位质量脂肪含量及脂肪能量进行测定和分析。结果显示,脱脂前各组织的能量密度以消化腺最大,为(27.34±0.85) kJ/g;脱脂后的能量密度则以输卵管卵子的最大,为(20.01±0.56) kJ/g。各组织脱脂后的能量密度值均下降显著,尤以消化腺的下降最大,达31%。消化腺的单位质量脂肪含量最高,为(413.83±96.81) mg/g,其次为输卵管卵子和卵巢,肌肉组织的最低。在生理性成熟后,卵巢组织脂肪积累较大,输卵管卵子、肌肉和消化腺等组织则维持较稳定的脂肪积累水平。4个组织的脂肪能量占比的平均值在10%~32%之间。综上研究表明,脂肪是茎柔鱼卵巢、输卵管卵子、肌肉和消化腺等组织的重要能量物质,在组织能量积累过程中起着重要的作用。     

Reproductive success of Calanus pacificus during diatom blooms in Dabob Bay, Washington

While numerous laboratory studies in the last decade have shown that diatoms can induce reproductive failure in copepods, field evidence for a negative diatom effect is equivocal. To unambiguously elucidate the effects diatoms have on copepod reproduction in situ, we undertook a study of the abundance, distribution, grazing rates, and reproductive success of Calanus pacificus in Dabob Bay, Washington, USA, during two spring bloom periods. We simultaneously measured the phytoplankton composition, abundance, and distribution. Here we present results for the reproductive success of C. pacificus using four measurements: egg production rate, clutch size, egg hatching success, and naupliar survival (to the first feeding stage). Egg production rate was positively correlated with chlorophyll a concentration, and egg hatching success and naupliar survival were usually greater than 80%. However, in February 2002 and 2003 – during blooms of diatoms of the genus Thalassiosira – either egg hatching success, naupliar survival, or both were significantly depressed compared to other times in spring and summer. These effects, combined with evidence that C. pacificus was grazing aldehyde-producing Thalassiosira at the time of their blooms, indicate that diatoms can negatively affect copepod reproduction in the field, albeit only under specific circumstances and for brief periods.