【作者】 管卫兵；

【导师】 王桂忠； 李少菁；

【作者基本信息】 厦门大学 ， 海洋生物学， 2003， 博士

【摘要】 锯缘青蟹(Scylla serrata)，是我国重要的经济海洋蟹类。本实验采用组织学、组织化学、超微和透射电子显微镜观察等技术对其生殖系统结构和功能进行深入的研究。重点集中在精荚的形成、转移、贮存及授精和产卵过程，主要结果如下。 1．锯缘青蟹精荚形成开始于精巢，精巢中最成熟的精子呈现游离状态，在此处开始形成初级精荚壁。前输精管和精巢紧密相联，为连续性结构。前输精管中的精荚进一步形成次级精荚壁，次级精荚壁为均质不嗜曙红物质，串联有嗜曙红精液颗粒的构造，逐渐形成大量椭圆形的完整精荚结构。前输精管后部分泌大量颗粒状精液。贮精囊为雄蟹精荚的贮存场所，具有内环外纵两层肌肉层，具有大量精液颗粒。后输精管为贮精囊和射精管之间的中间结构，其中精荚密度较高，精液开始液化。射精管壁为腺状上皮，相当于副性腺功能，具有强大环肌。 2．射精管末端存在促雄腺，促雄腺和胸神经团来源的支配第五步足(即游泳足)的神经紧密相联。该神经在游泳足基部的肌肉内部紧贴射精管并行，其分支支配着射精管周围肌肉，可能是控制精荚排放的神经。 3．青蟹精巢中成熟精子具有多个幅射臂，前输管处的精子团被分隔成精荚，明显可见精荚基质的沉积过程。贮精囊精荚有两层壁，内外电子密度有异。青蟹精荚椭圆形，精荚中精子致密分布，彼此间有精荚基质相联。青蟹精荚分为两种类型，一种表面具沟槽状结构，用于纳精囊中贮存之用，另一种渐趋平滑，用于立即受精之用。精荚之间有大量不同大小的颗粒状精液充填。贮精囊和射精管内表面存在大量微绒毛，微绒毛顶端有大量分泌物。 4．青蟹雄体输精管在第八胸节通向一个短的肌肉质的阴茎开口。第一腹肢由一个基部原肢和一个延长的内肢组成，表皮环包，形成一个交接管。第二腹肢吻合这个表皮管，而阴茎则放在内肢的基部侧面。交配时，阴茎在肌肉作用下，精液射到第一腹肢的射精管中，射出物在第二腹肢2的活塞样的泵作用下，沿着管腔向里推进。第一腹肢顶端侧扁状、具侧缝，前部表面具棘突状和腺体孔，弯曲部棘较大。侧缝处具细长的棘和羽状刚毛。刚毛基部为杯状凹陷。 5.青蟹雄性腹肢具有生殖肢腺体(GTG)。雄性第一腹肢向末端逐渐变细成一薄的弯曲突起。腺体主要集中于腹肢距基部长度的2/5处，即第二腹肢入口处的附近，末端也有少量分布。腺体在组织学上和玫瑰状的皮腺相似，群绕着射精管腔。经染色表明腺体含有中性粘多糖(NMPS)和酸性粘多糖(AMPS)，同一批腺体，甚至同一个腺体两种类型糖类的染色状况有异。腺体由分泌细胞和管细胞组成，管细胞含有一导管，多个导管形成网络。导管末端通向交接器内壁表皮开孔处，孔径约为2.5一3.5 pm，这些孔通向交接器管腔，孔中及开口处分泌物的染色性质和腺体中相似。第二腹肢也具有腺体，但分布较少，且不太集中。GTG分泌物可能具有几个复杂的功能，其中低粘度的NMPS可能有助于加速强粘性精液通过狭窄的交接器管腔作用，而高粘度的AN[PS功能则更为复杂。 6.青蟹精英的贮存器官为纳精囊。纳精囊由囊部的腺质部和后端的几丁质区组成，其后端与具几丁质内膜的阴道相联。未交配青蟹纳精囊很薄、呈现白色、经度方向为透明的扁平囊。性成熟青蟹纳精囊囊部膨大，腺质部增生，含有大量分泌物，腔中充满大量精液和精英。产卵后的纳精囊收缩，腺质部的分泌物几乎排空，上皮大量脱落。纳精囊腺上皮可分为三层，最内层为分泌层，中间为扩增层，外层为含有纤维的锚定层，上皮为全泌分泌方式。 7.青蟹纳精囊内壁充满凹凸不平的褶皱结构，形如胃壁。上皮细胞多层，核多样，具有胶原纤维。纳精囊上皮具有多核共质体结构，多层细胞相互呈现嵌套状，充满大量分泌颗粒。成熟阶段纳精囊中的大部分精英已失去膜，精子呈现游离状，部分游离精子被消化。纳精囊上皮对精子具有吞噬作用，部分精子进入上皮深层。纳精囊中具有大量泡状，均质状等多种类型的分泌物。 8.青蟹精子塞为雄性精液和纳精囊开口处的分泌物在短时间发生的剧烈反应的产物，短时间内从液态变为胶状结构。精子塞将精液颗粒、精英等紧密联系在一起，部分精英被拉伸破裂。 9.顶体酶是精子顶体部特有的胰蛋白酶，其在顶体反应、精子和透明带的结合及穿透中起重要作用。青蟹纳精囊精子顶体酶活力分别为3.566 p IU/1护 3和4.248 p IU/106。青蟹精子顶体酶活力和用同样方法测定的其它物种(如猪、人、马)相比较低。这反应了不同物种之间的精子顶体酶活力存在着显著的差异，也反应青蟹纳精囊中精子处于一种抑制状态，活力抑制方式可能有利于精子在纳精囊中的长期存活。 10.随着发育的进行，雌雄青蟹在形态上发生较大的变化。雌青蟹腹部变化较大，而雄青蟹成熟形态的变化主要表现在鳌足上。雌青蟹腹甲宽和腹甲长的比例呈现有规律的变化。雄青蟹成熟阶段鳌足大小相应发生明显变化，可以分为三种类型，小型鳌，中型鳌、大型鳌。测量了头胸甲宽(C钧、头胸甲长(CL)、更多还原

【Abstract】 Scylla serrata is a commercially important marine crab in China. To help elucidate its reproductive characteristics,the functional anatomy of the male reproductive system and the female spermathecae are investigated using the histological techniques, transmission and scanning electron microscopy, and microscopic observaion of fresh material, focusing on sperm transfer, sperm storage in the seminal receptacles, and spawning. The results were as follow:1. The development of spermatophore begins from testicular.The testicular secretes substance which agglutinates the dissociate mature spermatozoa or sperm cell and forms the primary spermatophore layer. Closed to testicular is the anterior portion of the proximal vas deferens which continues its agglutination of spermatozoa and separate the sperm mass gradually .The secretory nature changes in the distal part of the proximal vas deferens in that a granular substance is released to constitute the medium for storing the completed spermatophore. The middle vas deferens is membranous and acts as the storage region for the seminal products. The distal vas deferens interspace between middle vas deferens and ejaculatory duct. Following the short distal vas deferns is the long ejaculatory duct, its fluid-like secretion is not mixed with the rest of the semen stored in the mid vas deferens until the time of mating. In view of the mucoid nature of this secretion, it may function as the accessary gland.2. A pair of androgenic glands attach to the distal part of the ejaculatory ducts of Scylla serrata. Androgenic gland is connected to the fifth pereiopod nerve of thoracic ganglion directly. This nerve also concomitant with edjaculatory ducts between the muscles of fifth walking leg and may control the spermatophore expulsion.3. The sperm of Scylla serrata has several nuclear arms. Large numbers of sperm become clumped into aggregates which surrounded by an acellular wall secreted by cells of the anterior vas deferens. As the sperm move posteriorly,this thin wall becomes surrounded by yet another epithelial secretion which condenses against it .Together the two layers form the definitive spermatophore wall which apparently differ in electron density of the composing material. The spermatophores of Scylla serrata are ellipsoidal in shape and consists of sperm mass and matrix. Numerous spermatophores are stored in the median regions of the vas deferens where they become mixed with seminal fluids .The seminal fluid which surrounds the spermatophores appears flocculent and globular nature. The spermatophores show two different morphological types: one with an extremely wrinkled spermatophoric wall which are stored in the spermathecae and the other with smooth and thin spermtophoric wall which are used for immediate fertilization of oocytes at copulation. Many microvilli are seen on the inner surfaces of epithelial cells of median vas deferens and ejaculatory duct.There are many secretions on the top of the microvilli.4. The ejaculatory duct of Scylla serrata open on the coxae or sternum of eighth segment by short muscular penis. The first gonopod consists of a basal protopodite and elongated endopodite.in which the cuticle is infolded the entire length a tube which functions as an ejaculatory canal. The second pleopod fits into this cuticular fold, while the penis fits into a slit on the lateral side at the base of the endopodite. During coitus, seminal substances are ejected by muscular action through the penis into the ejaculatory canal of the first pleopod. The ejaculate is further pushed down the canal by the pumping action of the piston-like second pleopod. The first gonopod terminates in a recurved process, at the apex of which the ejaculatory canal opening forms a distinct spout, the cuticular fold are easily distinguished as outer and inner folds and form the lateral slot. Several types of setae are quite conspicuous on the first and second gonopod. There are also some long processes and setae on the lateral slot .Pinnate se更多还原