中国鲎黄色结缔组织营养细胞超微结构观察

利用透射电镜对中国鲎营养细胞进行超微结构观察．营养细胞为鲎黄色结缔组织的主要构成细胞．营养细胞往往外包基膜，胞质中含有丰富的营养颗粒和脂肪颗粒．营养细胞由结缔组织中的营养母细胞分化而来．营养母细胞的细胞质膜特别发达。胞质少；原始营养细胞胞质增大许多，核质比变小。细胞器增多，特别是线粒体和内质网数量增多；随着营养细胞的发育，胞质中形成大量的营养颗粒和脂肪颗粒．营养颗粒和脂肪颗粒是鲎机体营养的储存库．营养颗粒被消化过程中。形成结构各异的残余体．     

The diets of juvenile horseshoe crabs,Tachypleus tridentatus and Carcinoscorpius rotundicauda (Xiphosura), from nursery beaches proposed for conservation in Hong Kong

Once common as a fishery resource, adult horseshoe crabs of two species occur in Hong Kong. A third, Tachypleus gigas, can no longer be found. Once common too were breeding and nursery beaches for horseshoe crabs in Hong Kong but overfishing of adults, pollution and coastal reclamation have reduced these to but three identified sandy mudflats and only one where juvenile Tachypleus tridentatus and Carcinoscorpius rotundicauda are sympatric. Nothing is known, however, of the conservation requirements of these two species locally and this study of the diets of these juvenile horseshoe crabs on two such nursery beaches aimed at providing information on this most elementary aspect of their biology. Gut contents of juvenile horseshoe crabs, i.e. nine Tachypleus tridentatus (8.5–67?mm prosoma width) and two Carcinoscorpius rotundicauda (50 and 52?mm prosoma width), were analysed and compared with the composition of the ambient assemblage of meiobenthos on a nursery beach at Pak Nai, Hong Kong. The obtained data suggest that juvenile horseshoe crabs of both species are selective benthic feeders and subsist mainly on insect larvae, polychaetes, oligochaetes, small crabs and thin-shelled bivalves. A strong, positive, preference for insect larvae (Chironomous sp.: Diptera: Chironomidae) was recorded, but with no preference for meiofauna over macrofauna.     

鲎保育的三赢策略

鲎有活化石之称,不仅是古生物学的重要研究对象,亦是医药试剂的原料,保育鲎不仅维系了人类生存,更是促进人类文明的跃升。但近年来,鲎被人类大量捕食、采血及破坏栖息地,种群大规模下降,迫切需要得到保育。根据世界自然保护联盟(IUCN)指南,鲎的物种保育工作以划设鲎保护区、增加鲎的种群量以及促进大众参与保育为重点。研究结果显示:在中国南部沿海,中国鲎(Tachypleus tridentatus)与圆尾鲎(Carcinoscorpius rotundicauda)的稚鲎共同栖息在有红树林分布的河口,这两种鲎的食物中大约60%的碳源来自海草衍生的食物;在户外养殖条件下,稚鲎与方斑东凤螺(Babylonia areolata)混养能够加速稚鲎脱壳率并提高存活率,因而可以获得大量适合放流的稚鲎(3龄)。本文在现有的研究成果基础上提出鲎保育的三赢策略:支持有效的海岸及河口保护区经营管理,在保护区内维系鲎的种群,对大众与小区进行鲎资源的明智利用宣教。     

中国鲎血蓝蛋白研究

应用超离心和柱层析结合聚丙烯酰胺凝胶电泳（ＰＡＧＥ）及电镜技术，研究中国鲎血蓝蛋白的结构特点．结果表明，经ＳｅｐｈａｄｅｘＧ－１００纯化的血蓝蛋白在ＰＡＧＥ电泳中出现４条带．纯化的血蓝蛋白再经ＤＥＡＥ－３２纤维素柱层析得到５个洗脱峰，每个峰在ＰＡＧＥ电泳下可分辨出４条带．在电镜下，血蓝蛋白分子出现环形、五角形、十字形和蝴蝶结形等构型并与其他解离的中间的构型同时存在．     

中国鲎卵黄粒形成铁蛋白标记的研究

从中国鲎（ＴａｃｈｙｐｌｅｕｓｔｒｉｄｅｎｔａｔｕｓＬｅａｃｈ）卵巢中分离出未成熟的卵子，在标有铁蛋白的培养液中进行培养，３～６ｄ后对材料分别进行固定，透射电镜观察，证明铁蛋白分子可以透过卵母细胞的基膜，并通过微绒毛的直接吸收和质的微吞饮活动进入卵质，然后在内质网膜囊中沉积，形成卵黄粒。     

中国鲎鲎素对人胃癌BGC—823细胞增殖的抑制作用

应用从中国鲎血细胞中提取的鲎素处理人胃癌BGC－823细胞,研究海洋生物活性物质的抗肿瘤作用。实验结果显示,经2．0μg/ml鲎素处理的BGC－823细胞生长缓慢,倍增时间延长,细胞集落形成能力减弱,细胞生长抑制率达62．67％,细胞分裂指数下降40．91％,处理后细胞碱性磷酸酶细胞化学反应减弱、分布改变、碱性磷酸酶和乳酸脱氢酶活力分别下降40．59％和76．05％。结果表明,鲎素能有效地抑制胃癌细胞的增活动,具有与癌细胞诱导分化物相似的抗肿瘤效果。     

中国鲎脑神经节5-羟色胺免疫组化的定位观察

中国鲎(Tachypleus tridentatus)是一种具有特殊研究意义的海洋动物.本研究应用免疫组织化学方法对中国鲎脑神经节中5-羟色胺(5-HT)的分布进行了定位观察,发现5-HT免疫阳性主要分布在视神经层和视神经髓的神经纤维,中间体以及蕈形体周边的细胞群中,而蕈形体中未发现免疫阳性.经比较,中国鲎5-HT的分布与美洲鲎(Limulus polyphemus)相似,而与昆虫、甲壳类存在一些区别.本研究可为中国鲎的神经生物学提供基础资料.     

中国鲎脑神经节的组织学观察

采用组织切片和H-E染色法观察了中国鲎(Tachypleus tridentatus)脑神经节的组织形态结构.研究发现中国鲎的脑神经节分为前脑和后脑.前脑由视神经系统、蕈形体以及蕈形体周围的细胞群组成,后脑由腹面侧后方第一细胞群、侧后方神经纤维网和部分的中央神经纤维网组成.中国鲎的蕈型体比其他节肢动物都发达得多,可能承担着更多的生理功能.研究确认和区分了其脑神经节的细胞群和神经纤维网,同时构建了中国鲎脑神经节的组织形态学图谱,旨在为中国鲎的神经生物学的研究积累资料.     

中国鲎黄色结缔组织的研究——Ⅰ.黄色结缔组织显微结构观察

中国鲎黄色结缔组织充满整个机体内部,填充于内脏器官之间,呈浅黄色或棕褐色,为鲎体内重要的组织结构,黄色结缔组织由多种类型的细胞和丰富的细胞间质组成,构成细胞主要有营养细胞、血细胞、类巨噬细胞以及干细胞等,营养细胞是其主要的组成细胞,内含丰富的营养颗粒和脂肪颗粒,鲎的黄色结缔组织分布有大量的造血组织,前体部的黄色结缔组织中分布有数量众多的中肠盲囊。     

Population structure of Tachypleus tridentatus (Chelicerata: Merostomata) at a nursery beach in Puerto Princesa City,Palawan, Philippines

This study aimed to determine the population structure of juvenile Tachypleus tridentatus, one of two species of horseshoe crabs found in Palawan, at Aventura Beach, Puerto Princesa City, Palawan. Surveys to assess the population in terms of size, density, size‐frequency, age structure, sex ratio and distribution were conducted from June to October 2002. The habitat was mapped and physical/chemical parameters taken to further describe it. The position of population members was plotted on the map. Individuals were measured, marked, sexed and released. Prosoma width was measured for living individuals and exuviae. Postembryonic stages were identified based on histograms with different interval size. The normal distribution of the animals per instar stage was tested with the Kolmogorov–Smirnov test. After the 5‐month survey a total of 125 juveniles was recorded and 40% of them were recaptured. Population size was estimated to be 150 individuals. Seven postembryonic stages were identified based on their prosoma width. Male: female ratio was 1:1.8 and the age of the first five postembryonic stages ranged from 5.4 months to 17.6 months. The population density was 1.47 individuals per?100?m². The majority of the animals of all postembryonic stages were found between 0 and 50?m from the mean high tide level. Further studies on the population structure of T. tridentatus with regards to the adult population are seen as a necessity.