锯缘青蟹促雄腺进行全浆分泌的证据

采用透射电镜技术，对锯缘青蟹(Scylla serrata)促雄腺细胞的分泌活动进行了观察。结果表明，腺细胞具有2种类型：A型细胞核内常染色质丰富，具有大量的扁平嵴的线粒体、粗面内质网与核糖体，A型细胞进行分泌时，细胞质大量排出，属于全浆分泌方式；B型细胞异染色质绕核内膜分布，仅见极少量的细胞器或细胞质完全消失。B型细胞为A型细胞完成分泌后的存在形式。本研究为甲壳动物促雄腺的全浆分泌活动提供了直接的证据。     

锯缘青蟹促雄腺和胸腹神经团的直接联系

采用组织学、扫描电镜方法对锯缘青蟹(Scylla serrata)促雄腺和胸腹神经团之间的关系进行观察。结果表明，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)的神经紧密相连。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，可能也是控制精荚排放的神经。本研究可为促雄腺对性别控制的机制及蟹类精荚电促排的深入研究提供理论依据。     

锯缘青蟹卵巢发育的组织学观察

根据锯缘青蟹卵巢的外部形态和内部组织学特征,卵巢发育可以划分为六个时期:未发育期、发育早期、发育期、将成熟期、成熟期和排卵后期。在发育早期,多数卵母细胞胞质中有多个嗜酸性液泡,这种结构在其他十足类卵母细胞中较少见。少数个体在发育早期发生卵母细胞全面退化,这种现象可能是缺乏交配或饥饿造成的。     

温度对锯缘青蟹幼体存活与发育的影响

锯缘青蟹溞状幼体生长发育的适温范围为25—30℃。在该范围内,随着幼体发育,其生存最适温度逐渐上升。各期溞状幼体的发育均随温度的提高而加快,从孵化至第一次变态,30℃时平均发育时间比 25℃时短 6天。温度对溞状幼体的变态过程亦有明显影响,水温大于或达到 30℃时不利于变态的进行,但变态后的大眼幼体对高温适应力增强,35℃时仍可正常生长发育。不同批孵化的幼体在相同温度下存活与发育有明显差异。在对后期溞状幼体相对不适的 25℃下,溞状幼体发育期数变异的出现率较高。     

菲律宾的锯缘青蟹养殖

就东南亚的锯缘青蟹（ＳｃｙｌａｓｅｒｒａｔａＦｏｒｓｋａｌ）养殖而言,以菲律宾的产量最高,１９９３年产量为５６５３ｔ,１９９４年为４０８５ｔ,１９９５年为２７８２ｔ。鉴于菲律宾养殖锯缘青蟹的产量名列世界前茅,本文简要介绍其养殖及研究进展。一、锯缘青蟹...     

锯缘青蟹的几种养殖方式

锯缘青蟹(Scylla serrata)又称青蟹,分布于温带、亚热带和热带海域。我国浙江、福建、台湾、广东及广西沿海均有分布。青蟹肉味鲜美,是优良的食用蟹,也是我国出口创汇的珍贵海产品。温州地区70年代初的年产量约100吨,主要是捕捞产量。近十多年来,由于各种原     

锯缘青蟹人工育苗试验

<正> 锯缘青蟹(Scyua seiiate),俗称青蟹,属广温、广盐性的底栖甲壳动物,是我国的珍贵水产品之一。其肉质鲜美、营养丰富,具有很高的经济价值。但由于海区捕捞过度,青蟹的资源量日趋减少,不能满足人们的需求,因此,在我国东南沿海已兴起了青蟹人工养殖热。青蟹人工育苗在国内外虽有报道,但育苗技术还没有取得根本性突破,从而阻碍了青蟹养殖的进一步发展。     

锯缘青蟹养殖技术经济探讨

本文对岛屿村四年来青蟹育肥所采取约技术要点及其经济效益进行探讨、分析。     

锯缘青蟹的人工育苗试验

本文报道在室内水缸中进行锯缘青蟹人工育苗的试验结果,通过对拖卵蟹的培育,孵出蚤状Ⅰ期幼体300万只,蚤状幼体从第Ⅰ期培育到第Ⅱ期的成活率最高的达66.7%,并从其中两个试验缸中,培育出稚蟹995只     

锯缘青蟹促膏育肥增效技术

锯缘青蟹又称青蟹，俗称“蟳”。青蟹适应性强，生长快，经济价值高，是开展人工养殖的极好对象。而采用人工促膏育肥技术培育“红膏蟳”，不仅养殖周期短，而且经济效益十分显著。现将主要技术总结如下：     

Ovarian maturation stages of the mud crab Scylla serrata

Ovarian maturation in adult wild‐sourced and pond‐grown Scylla serrata (Forsskål) was determined based on gross morphology and histological appearance. There were no significant differences noted in the histological features of both wild and pond‐reared S. serrata females. Ovarian maturation was classified into five stages: immature, early maturing, late maturing, fully mature and spent. The immature ovaries are thin and translucent to off white and contain oogonia, primary oocytes with large nuclei. The follicle cells were found around the periphery of the lobes and an area among groups of oogonia and oocytes. The follicle cells gradually enclosed the oocytes. The early‐maturing ovaries were yellow and small yolk globules started to appear in larger oocytes. In late‐maturing ovaries, the colour became light orange and lobules were apparent. Yolk globules occurred in the cytoplasm with larger globular inclusions towards the periphery, while follicle cells were hardly recognizable. Fully mature ovaries were orange to deep orange and had swollen lobules. Large yolk globules were apparent in the entire cytoplasm. Follicle cells were hardly seen. Spent ovaries were similar to the early‐maturing and late‐maturing stage in partially spawned females. The ovarian development was correlated closely to the gonadosomatic index, oocyte diameter, and ovarian histology. The classification of ovarian maturation provides baseline information for further studies on reproductive biology. Likewise, the information provides a guide for broodstock management in the hatchery.     

锯缘青蟹苗种培育的科技进展

锯缘青蟹是我国南方沿海各省传统养殖的海水蟹类,在当前农业产业结构调整中被列为主要发展品种之一。鉴于苗种是限制青蟹养殖业发展的主要因素,本文根据目前的研究现状对青蟹的种质、性成熟机制,产卵、孵化条件,幼体培育过程中营养条件、盐度、温度、光照、疾病等,以及从大眼幼体到仔蟹的中间培育技术等作了简要归纳,并对研究现状和进入产业化急需解决的问题进行了探讨。     

影响锯缘青蟹幼体成活的几个因素

本文对海捕和养殖的锯缘青蟹抱卵及胚胎发育情况进行了观察,并对幼体饵料营养强化、适口性、幼体的培育方式等进行了研究。结果表明：自然诲区捕获的亲蟹其抱卵率和幼体质量要好于人工养殖的亲蟹;胚胎发育的最适盐度为28～33,最适温度为26～30℃;幼体\期和大眼幼体时期摄食的饵料以边缘毛状的活体为佳,便于抱握;涵状幼体、期起应降低苗池中的直射光,投饵多餐少量．增加附着面积．可降低相互残杀率。     

利用AFLP技术筛选锯缘青蟹性别差异DNA片段

采用高盐和酚氯仿异戊醇 (PCI)结合法提取DNA ,利用AFLP技术 ,应用 5 2个引物组合 ,检测了锯缘青蟹 (Scyllaser rata)雌雄基因组DNA的多态性 ,筛选与锯缘青蟹性别相关的分子标记。实验中共扩增出 4 312条带 ,筛选出候选差异DNA片段 74 8条。这些差异DNA片段的获得 ,为研究锯缘青蟹性别的分子标记奠定了基础     

锯缘青蟹血细胞的形态及分类

对锯缘青蟹（Scylla serrata）血细胞染色的抗凝剂、染色方法进行筛选。蟹样品体质量约250g。采用亚甲基蓝、瑞氏法染色后，在Olympus油镜下观察、记数、测量，再结合电镜超薄切片观察结果对锯缘青蟹血细胞进行分类。根据血细胞质中颗粒的有无、大小、折光性、染色特性及细胞的大小、核质比等，将锯缘青蟹血细胞分为4种：（1）无颗粒细胞，细胞质中无颗粒；（2）小颗粒细胞，细胞质中有深蓝色小颗粒；（3）中间型细胞，细胞质中既有深蓝色小颗粒，又有折光性红色大颗粒；（4）大颗粒细胞，细胞质中充满了具有折光性的红色大颗粒。4种血细胞的大小顺序从小到大依次为无颗粒细胞、小颗粒细胞、中间型颗粒细胞、大颗粒细胞；核质比则相反，分别为54．01％、37．13％、25．37％、17．49％；其数量百分比分别占20．92％、40．30％、19．39％、19．39％。根据伪足的多少。对4种血细胞在机体的免疫防御机制中所起的不同作用进行了简单探讨。     

Effects of tank colour on larval survival and development of mud crab Scylla serrata (Forskål)

Hatchery culture of mud crabs has not yet achieved commercial viability despite decades of research efforts. Further research is therefore needed to better understand larval culture requirements of the crab. Based on anecdotal observations, an experiment was carried out to test whether the background colour of the culture vessel affected larval culture success. Newly hatched larvae of Scylla serrata were reared in culture vessels of five colours, i.e., black, dark green, maroon, sky blue and white. Larval survival and development were monitored daily until all of them either moulted to the first crab stage or died. The results showed clear effects of background colour on larval survival. A general tendency of higher larval survival in darker‐coloured backgrounds was evident. In particular, overall zoeal survival for larvae reared in black vessels was significantly higher than those reared in white ones. Background colour also appeared to affect larval development. Larvae reared in darker backgrounds generally had shorter development times and more synchronized moulting. A significant delay in zoeal development was observed in larvae reared in white vessels. Dark backgrounds possibly facilitated more efficient feeding, reduced settlement of larvae at the bottom of the vessels as well as minimized stress. This result appears to be the first to demonstrate that background colour can significantly affect larval survival and development of a crustacean species.     

Ingestion of Brachionus plicatilis and Artemia salina nauplii by mud crab Scylla serrata larvae

Two feeding experiments were conducted to determine if Brachionus plicatilis and Artemia salina nauplii were ingested by mud crab Scylla serrata larvae. In the first experiment, larvae were fed with increasing densities of Artemia nauplii with or without Brachionus to determine consumption with increasing densities of Artemia and with increasing zoeal stage. This experiment also aimed to determine if the presence of Brachionus as an alternative prey influenced the intake of Artemia by the crab larvae. There was generally an increase in intake with increasing densities of Artemia and increased consumption of Artemia as the larvae grew. Consumption of Brachionus was consistently high in all zoeal stages. There was a significant reduction in the intake of Brachionus with increasing consumption of Artemia in the early zoeal stages (Z1, Z2, Z3), but at later stages (Z4, Z5) the intake of Artemia was no longer affected by the presence of Brachionus. In the second experiment, daily ingestion within instar of zoeal stages and megalopa were compared. There was an increased consumption of Artemia nauplii on the day before molting and increased ingestion of Brachionus on the day after larvae had molted, except at Z3. Megalopae exhibited a decline in Artemia nauplii intake on the days before metamorphosis to crablet.     

Effect of selected feed meals and starches on diet digestibility in the mud crab,Scylla serrata

The present study examined the capacity of the mud crab, Scylla serrata to digest experimental diets that contained different animal and plant‐based feed meals or different levels or types of starch. The apparent dry matter digestibility (ADMD) coefficients for all feed meals tested in the first part of this study, except meat meal, were similar (78–88%). Crude protein digestibility (ACPD) coefficients for all feed meals were relatively high, with values ranging from 86% to 96%. Cotton seed meal, poultry meal, canola meal, fishmeal, soybean meal and lupin meal had similar gross energy digestibility (AGED) values (P>0.05) ranging from 84% to 89%. In the second part of this study, the impact of selected starches on the digestibility of fishmeal‐based formulated diets was assessed. The apparent starch digestibility (ASD) of wheat starch decreased significantly as the inclusion level was increased from 15% to 60%, however, there was no significant effect on ACPD values. At a 30% inclusion level, the ASD of diets containing different starches decreased in the order corn>wheat>potato=rice. Moreover, ACPD values were significantly higher (P<0.05) in the diets containing corn or rice starch than in those containing wheat or potato starches.