To explore the histological and ultrastructural changes of the annual development of the testis and spermatogenesis of Lutraria sieboldii in Beibu Gulf of Guangxi,the annual development of testis and ultrastructure of spermatozoa of L.sieboldii were studied through tissue section,scanning and transmission electron microscopy.Results showed that the testis completes a cycle in one year,which can be divided into proliferating stage,growing stage,maturing stage,spawning stage and resting stage.The spawning was from December to April of the following year,and the testis development of 5%～10%individuals in each stage was slightly delayed.Spermatogenesis can be divided into proliferation period,growth period,mature period and metamorphosis period.The male reproductive cell can be divided into Spermatogonia stage,primary spermatocyte stage,secondary spermatocyte stage,spermatocyte stage and mature sperm stage.The sperm of L.sieboldii belongs to the flagella type,whose total length is(39.76±0.50)μm.The sperm head was composed of a nearly subelliptic spermatic acrosome and nucleus,the bottom of the acrosome and the spermatozoa connected with the spermatozoa were depressed to form a subacrosomal cavity.The electron density in the nucleus was uniform,and there was a gap in the middle of the nucleus.There are four mitochondria around the centriole complex to form the middle part of sperm,and the mitochondria are nearly round with apparent internal ridge.The plasma membrane wraps around the axial filaments to form sperm tail,and the"9 + 2"doublet microtubule structure can be clearly observed in the transverse section of the tail.In addition,there are two different types of spermatogonia:type A spermatogonia has no nucleolus in the nucleus while type B spermatogonia has nucleolus in the nucleus,and type B spermatogonia is distributed in the testis at different stages.

In this study,ovarian development,reproductive cycle,egg development and its ultrastructure of Paphia textile in Beibu Gulf of Guangxi were investigated using anatomical observation,ovarian tissue sectioning and transmission electron microscopy techniques.The results showed that P.textile has one reproductive cycle in one year,and the ovarian development of P.textile can be divided into five stages:proliferating stage(May to July),growing stage(July to September),maturing stage(September to November),spawning stage(November to January of the next year),and resting stage(January to April of the next year).According to the relevant characteristics of the egg development and vitellogenesis of P.textile,it can be divided into four main stages:the first stage is the oocytes stage,the second stage is the phase of previtellogenesis oocytes stage,the third stage is the phase of vitellogenesis oocytes stage,and the fourth stage is the phase of postvitellogenic oocytes stages.The phase of vitellogenesis is an important stage of vitellogenesis,during which mitochondria,endoplasmic reticulum,golgiosome,lysosomes and other organelles form yolk granule in different ways.The water temperature in the sea area was closely related to the ovarian development of P.textile and was an important factor affecting the ovarian development of P.textile.P.textile is hermaphroditic,and no hermaphroditism has been found.The results of the study provide providing basic data for reproductive biology,artificial breeding,breeding and germplasm resources protection of P.textile.

文章采用组织切片、透射电镜技术对广西北海营盘海域钝缀锦蛤(Tapes conspersus)的卵巢发育、卵子发生的组织学及卵黄发生的超微结构进行研究.结果显示,钝缀锦蛤卵巢发育一年为一个繁殖周期,分为增殖期(6月底-7月)、生长期(7月中旬-10月中旬)、成熟期(11月-翌年2月底)、排放期(3月-4月)、休止期(5月-6月)共5个时期.钝缀锦蛤卵巢发育受水温的影响较大,个体间的性腺发育并不完全同步.在广西北海营盘海域,钝缀锦蛤每年在6月底-7月初性腺开始发育,在翌年3月-4月底成熟的卵子大量排放.依据钝缀锦蛤卵细胞发育的相关特点,可将其划分为4个主要阶段,第一阶段为卵原细胞期,第二阶段为初级卵母细胞期,第三阶段为次级卵母细胞期,第四阶段为成熟卵母细胞期.根据透射电镜观察钝缀锦蛤卵黄的发生,可将其分为3个主要时期,第一时期为卵黄合成前期,第二时期为卵黄合成期,第三时期为卵黄合成后期.

为了解广西北部湾海域钝缀锦蛤(Tapes conspersus)精巢周年发育情况、精子发生过程及成熟精子超微结构,本文采用组织切片、扫描电镜、透射电镜技术对钝缀锦蛤精巢发育过程、精子的发生及超微结构进行了研究.研究结果显示:目前广西北部湾钝缀锦蛤未见雌雄同体情况,观察的个体皆为雌雄异体.一周年的采样结果中,雌性个体138个、雄性个体102个,雌雄的性比约为1.35︰1.1年即为精巢发育的一个周期,发育时期可以划分为增殖期、生长期、成熟期、排放期、休止期共5个主要分期.精细胞的发育可以划分为5个主要分期,即精原细胞期、初级精母细胞期、次级精母细胞期、精细胞期、成熟精子期.精子全长约59.27μm,属于鞭毛型,由头部、中部、尾部3个部分共同构成,精子头部呈圆锥型,由细胞核和顶体组成,顶体呈倒"V"型.电子在顶体的分布是不均匀的,顶体前部电子分布少,后部分布多.中部主要由两部分构成,即5个圆形排列的线粒体和一个中心粒复合体.轴丝与质膜两个部分共同构成了尾部,轴丝的双联体微管结构横切面表现为"9+2"型.此外,本实验观察到少部分精子尾部呈双尾结构.