鱼粉质量对中国对虾、真鲷、饲料转化率和蛋白质消化率的影响

IntroductionInherent to the practice of intensive aquaculture is the generation of wastes having immediate and verybroad effects on the aquatic environment.There is a growing consensus about the need to reduce waste pro-duction in aquaculture to minimize the negative impacts on the environment.Nitrogen(N) and phosphorus(P) wastes are major concerns for many aquaculture operations.In the past,formulation of diets in intensive aquaculture was often aimed at meeting requirements formaximum growt…     

线纹尖塘鳢的形态生物学与核型

This paper reports the morphological character and karyotype of Oxyeleotris lineolatus. Oxyeleotris lineolatus is native in Australia and call ed sleepy cod. It belongs to Oxyeleotris, Eleotridae, Gobioidei, Perciformes in taxonomy. Recently, it was introduced to China and local people were not familiar with it. So we carried out this study. 30 individuals have been observed and some data were recorded. It has a large mouth that is in front and up. The mandible stands out and is longer than the up jaw. There are many rows of thin teeth in up and down jaws. The pelvie fins are located in chest and pectoral fins are large and fanlike. There are two dorsal fins. The tail fin is circular. Gill rakers are sparse and the number of gill rakers is 8-12+3-4. The gas bladder belongs to physoclistaus and its stomach is strong and I-like. The intestine is thick and short and no pyloric caecas. The length of the digestive path is 48.1％-80.3% of the length of body. Its liver has two lobes and the liver weight is 4.1%-7.2% of the body weight. The digestive organs characters are same as the trait of flesheater fish. Its scale belongs to ctenoid scale and its body surface shows several long lines. There is not lateral line in the body. The number of vertebra is 26-27 and it has 10-11 pairs rib. The number of diploid chromosome is 2n=46 and the karyotype formula is 2sm+8st+36t，NF=48. The relative length of chromosome is from 1.37% to 3.48% and it is continuity. No strange size chromosomes relation to sex was observed. The karyotype of Oxyeleotris lineolatus is similar to that of Oxyeletris marmoratus Bleeker from South East Asia and both of them belong to Oxyeleotri. It testifies the correctness of traditional classification on cytology.     

西北太平洋柔鱼渔情速报系统的开发

The neon flying squid, Ommastrephes bartrami, is one of the most important jig fisheries in the northwest Pacific Ocean. In order to understand the movement of O. bartrami fishing-ground better and supply O. bartrami fishing-ground information for Chinese fishing boats in the northwest Pacific ocean, the fishing condition analysis and forecasting system of O. bartrami was developed successfully. The system was based on established comprehensive database, which included the catch data of O. bartrami (total yields, count of total fishing boats, fishing position etc. ) and oceanic environmental information (SST, SST gradient etc. ). Artificial intelligent technology about case-based reasoning was also combined with GIS component technology successfully in the system. The process and function of system establishment are composed of four parts: setting up of case database for central fishing-ground and its environmental factors, knowledge reasoning of fishery information, GIS visualization analyzing as well as trend forecasting of central fishing-ground and information production mapping. At last as an example of the results, an experimental central fishing-ground forecasting of O. bartrami from 9 to 15 in July 2002 in the northwest Pacific Ocean was given in the paper. The results showed that through three class similar searching forecasting central fishing-ground would move west, and indicating that forecasting of the system for O. bartrami central fishing-ground was correct by comparing to real fishing-ground from 16 to 22 in July 2002. Consequently, artificial intelligent expert system technology about case-based reasoning is a useful method for fishing condition and fishing-ground forecasting.     

鲍遗传育种研究进展

Abalones are important farming species with a high economic value. They have already been farmed for more than 50 years. As problems and new requirements rose continuously in culture industry of abalone, studies on genetic and breeding techniques are needed to improve characteristics and to gain new traits. This review concentrates on advances in genetics and breeding techniques in abalone. As for genetic studies, karyological analyses, allozyme, DNA markers and genetic diversity were reviewed. So far, karyological analyses in abalone have been performed in 12 species that can be divided into three groups according to the chromosome number. In some economically important species, loci of allozymes and. microsatellites have been isolated and applied to investigate the genetic structure of natural and hatchery populations and to identify the result of chromosome set manipulation, but the related reports are only a few yet. The resultsof investigation with DNA markers and allozymes showed that the genetic structure of natural populations presents two characteristics: excessive homozygosity and subdivision. Advances of various breeding techniques, including introduction, selection,hybridization, polyploidy, gynogenesis and gene manipulation, were reviewed in the other part. Although Haliotis discus discus, introduced from Japan, has become one of the most important culture species in China, the economic, social and environmental effects of introduction have been rarely studied. Selection is one of the most important and basic breeding techniques, but the studies on selection are only a few and preliminary, referring to the relations between genetic characteristics and the traits of growth and resistance, genetic diversity and heritability of quantitative traits, and the effect of selection. Interspecific hybridization was the first breeding program carded out in abalone. Experimental hybridization have been carded out for about 20 crosses. Heterosis,such as faster growth and high survival rate, has been observed in some crosses. Triploids have been successfully induced in many species of abalone with physical or chemical shock, e.g.H, discus hannai, H. rufescens, H.diversicolor diversicolor and H. rnidae. Field experiments were conducted in some species of triploid abalone. In comparison with triploid, the research on tetraploid is still in quest stage. The progress of induction of gynogenesis in abalone is quite slow. Conditions of sperm inactivation, diploid restoration and nuclear behavior of gynogenetically activated eggs have been researched on in H. discus han nai. Notwithstanding the gene transfer technology in abalone is in the quest stage, the research have already involved preparation of exogenic DNA,means of gene transfer, identification integration and expression of target gene, etc. Three research directions in these topics were proposed : to investigate the germplasm resources of abalone deeply and widely, to make use of traditional breeding methods and modem biotechnique synthetically, and to combine the science research with production practice.     

细角螺的繁殖生态条件及繁殖习性

Hemifusus ternatanus(Gmelin), a gastropoda living in the deep water areas of undertide,as well as a delicious seafood, was distributed mainly in Chinese southeast seas and Japanese seas near the coast. In this experiment Hemifusus ternatanus' breeding ecological conditions and its propagation habit were studied in order to provide an experimental foundation for the artificial breeding. The brood stocks of test animals collected from the waters in Taiwan Strait, and then were examinated their growing temperature， salinity, feeding and propagation habit in the laboratory. The re sults showed that the growing temperature for Hemifusus ternatanus ranges from 16 ℃ to 32 ℃, with an optimum temperature between 20 ℃ to 28 ℃ and between 23 ℃ and 28 ℃ for breeding. The optimum growth salinity was 18.3-32.3 though it much adapts to salinity from 13 to 35. They prefer to feed on bivalves particularly those with thin shells and byssusless. Hemifusus ternatanus is dioecious and fertilization finishes inside the body. It was called as egg vesicle procreation that the whole stages of embryo growth were developed within egg vesicle. Larva forms as soon as it leaves egg vesicle, which is called direct occurrence type. The larva became the juvenile after metamorphosis during 20-25 days development. It was first to obtained 233 juveniles with shell height 32-45 mm by an artificial breeding method.     

Differences in Major Ions Composition of Artificial Seawater from Aquarium Tanks at the New Jersey State Aquarium

Concentrations of major seawater ions were monitored in six aquarium tanks at the New Jersey State Aquarium over a three-year period. The ratios of these ions to chlorinity were compared to those in freshly prepared artificial seawater. The largest aquarium tank (Ocean Tank) exhibits statistically significant (p<0.01) relative enrichment of potassium, calcium and strontium, and relative depletion of magnesium and sulphate. The likely source of excess potassium is from potassium iodide added to prevent goiter in sharks. Based on the excess potassium, a total amount of 650 μmol/kg iodide added over the years was calculated for the Ocean Tank. The excess calcium observed in several tanks correlates with the presence of concrete or arbonaceous shells in these tanks. In Ocean Tank, a calcium leaching rate of 6.7 kg/month was calculated. Continuous formation of white carbonaceous precipitates serves as a sink for magnesium in Ocean Tank, and a magnesium removal rate of 5.1 kg/month was calculated. These and other results show that concentrations of major ions in artificial seawater aquaria are affected by leaching, precipitation and addition of food supplements, and these factors should be taken into account when preparing artificial seawater for aquarium tanks with long water residence time. This revised version was published online in August 2006 with corrections to the Cover Date.     

芝芪菌质对罗氏沼虾生长和免疫及中肌苷酸含量的影响

The purpose of this paper is to evaluate the effect of Zhiqi Fungal Substance on their performance, immunity , and meat quality in Macrobrachium rosenbergii. Macrobrachium rosenbergii were allotted into four groups randomly. The control group were fed with basal diet, the others were the treated groups fed with basal diet supplemented with 0.25% ,0.5% ,1% Zhiqi Fungal Substance for 35 days, respectively. The results showed Zhiqi Fungal Substance can imporve the production of shrimpand and the survival rate. Zhiqi Fungal Substance increased the LSZ and SOD level（P 〈 0. 05） compared to control. Addition of 0.5% and 1% Zhiqi Fungal Substance increased the AKP and the ACP level（P 〈 0. 05）. It is indicated that dietary Zhiqi Fungal Substance can improve the flavor of cultured shrimp.     

鱼类诺达病毒及其所导致的疾病

In recent years, piscine nodaviruses have emerged as major pathogens of a wide range of larval and juvenile marine finfish resulting in high mortality in aquaculture worldwide. Affected fish exhibit a range of neurological signs, such as erratic swimming behaviour with the associated microscopic lesions of necrosis and vacuolation of the central nervous tissues and retina. Numerous roundshaped, unenveloped and 25-30 nm in diameter virus particles were found in the cytoplasm of affected retinal and nerve cells. Nodaviruses have a bipartite genome of positivesense RNA,with RNA1 encoding the RNAdependent RNA polymerase and RNA2 encoding the capsid protein. Both RNA are capped, but not polyadenylated. The family Nodaviridae comprises two genera: Alphanodavirus and Betanodavirus, members of which primarily infect insects and fish, respectively. Therefore, betanodavirus is also named piscine nodavirus. At present, piscine nodaviruses are divided into four genotypes based on partial sequences of the coat protein gene. ELISA and RT-PCR amplification have been developed as specific diagnostic methods for the d etection of the virus. Antibodies to striped jack (Pseudocaranx dentex) nervous necrosis (SJNNV) were found in 65% of plasma samples collected from wild and domestic brood stocks of striped jack, suggesting that the virus is very prevalent. Viral antigens were detected in eggs, larvae, and ovaries of hatcheryreared and wild spawner fish, suggesting both horizontal and vertical modes of transmission of the virus. Selection of nodavirusfree spawners using ELISA for detection of antigens and RT-PCR techniques have successfully reduced incidences of the virus infections in juvenile sea bass (Dicentrarchus labrax),striped jack and barfin flounder (Verasper moseri). The SSN1 and GF cell lines have been successfully used in isolating piscinenodaviruses.Although there are many papers describing the molecular characteristics of betanodavirus, our knowledge of the genomic attributes of these viruses is still limited. Vaccination studies are being undertaken by a number of researchers and need to be fostered. In particular, the use of passive immunization of broodfish with homologous and heterologous, high titre antisera are worthy of investigation.     

盐度对黄鲷胚胎发育及早期仔鱼生长的影响

The effect of salinity on embryo and early larva development of Dentex tumiforns was discussed. Floating forms of egg in different salinities, optimal salinity for embryonic development and early larva growth was studied. The results showed: 1. In immobile condition, all eggs sank at salinity of 32.0, most of egg ssuspended in the middle of water at 34.0, and all eggs floated on the surface when salinity above 36.0. 2. Eggs did not hatch out at salinity of below 10.0 or above 60.0 and the death time of egg gradually moved up with increase or decline of salinity. Eggs hatched out at salinity range of 15.0 and 50.0, including abnormal larva. There was indistinct difference in speed of embryonic development (about 36-40h) within the salinity of 15.0 and 50.0. However the salinity had a great effect on larval survival after hatching and abnormal rate. The relation between hatching rate and salinity variation showed parabola but abnormal rate showed inverted parabola. The hatching rate was 81%-86% and abnormal rate of yolk sac larva was 27%-30% in suitable salinities of 27.0-39.0. The hatching rate was 89%-91% and abnormal rate was 13%-16% in optimal salinities of 33.0-36.0. The oil ball of abnormal larva was located in the central or front position. With increased extent of salinity, spondyle of larva bended and number of larva with arrhythmia increased. 3. The optimal salinities were 30.0-35.0 based on SAI. The test with SAI showed that SAI of early larvae was 41.25-47.53 at salinities of 30.0-35.0, the yolk and oil ball of 7-8 days larva was completely absorbed with a survival rate of 88%.     

水产食品特定腐败菌与货架期的预测和延长

Fresh fish and lightly preserved fish products are welcome by the global market, however, they are also among the most perishable food products. The research on specific spoilage organisms (SSO) reveals the spoilage process of aquatic product. This paper reviews the current knowledge (past ten years) on SSO of fresh fish and lightly preserved fish products with particular emphasis on characteristics of SSO and how to apply this concept to determine, predict and extend the shelf life of aquatic product. During storage, the microflora changes owing to different abilities of the microorganisms to tolerate the preservation conditions. SSO is defined as special microorganisms which can increase rapidly during preservation and has the ability to produce off- odours and off- flavours associated with spoilage, and spoilage metabolites. Identification of an SSO relies on comparison of the sensory and chemical characteristics of spoiled product with those of isolates from the spoilage microflora. Generally, the SSO of fresh fish may be a single species or genus, but the ones of lightly preserved fish products will be more complex. One exciting area for use of SSO aims to obtain quantitative knowledge about probable behavior of SSO and their function during the progression of spoilage. Thus mathematical models on the growth of SSO are established to evaluate the quality lost degree of product, which provide a sound information for the rational development of devices to monitor loss of products shelf life. Models for the growth of Pseudomonas spp, S. putrefaciens, P. phosphoreum have been established, and validated for shelf life prediction of seafood successfully. Another application field of SSO intends to develop the techniques to prolong the shelf life of food products by inhibiting SSO targetedly. Targeted inhibition of spoilage bacteria during preservation reduces their growth and results in a significant extension of shelf life in despite of the activity of non - spoilage organisms has not been influenced. Such techniques have been applied in perversion field of fresh fish and lightly preserved fish.     

福建省东山岛西埔湾港养斑鰶的繁殖生物学

本文研究了福建省东山岛西埔湾港养斑鰶性腺周期发育、成熟系数周年变化、个体生殖力以及雌雄同体。港养斑鰶能在半封闭式湾内发育成熟而且自然产卵。其卵细胞发育分为6个时相,精巢发育分为6期。卵膜由透明带、外放射带和内放射带组成,内有孔道结构。第4时相中期卵母细胞的内放射带有7～8层纤维状片层。产卵后鞘膜细胞和颗粒细胞分裂增殖变成游走的吞噬细胞。西埔湾港养斑鰶Ⅰ龄鱼初次性成熟,生殖季节从12月下旬至翌年3月下旬,生殖盛期为2月,雌鱼成熟系数高达17.88％。个体绝对生殖力为7575～72621粒,平均 35310粒,系属于分批产卵类型,第1批生殖力大于第2批。     

史氏鲟精子入卵过程的扫描电镜观察

史氏鲟(Acipenserschrencki)隶属鲟形目(Acipenseriformes)、鲟科(Acipenseridae)、鲟属(Acipenser),是黑龙江特产和重要的经济鱼类之一,为淡水定居种类。鲟鱼是古老的生物类型,世界上约有28种,仅分布于北半球。由于自然环境的改变和人类活动的影响,所有鲟鱼均处于不同程度的濒危状态,有的已近灭绝[1,2]。我国有8种鲟鱼,其中黑龙江2种,即史氏鲟和达氏鳇。近年来,随着人工养殖技术的提高和完善,史氏鲟成为国内最主要的鲟鱼养殖种类。有关史氏鲟人工养殖、基因组DNA含量、胚胎发育等国内有较多研究,而对受精生物学方面研究尚未见报道。特殊…     

花䱻卵母细胞发育的组织学和超微结构观察

2015年7月至2017年10月在河南省驻马店宿鸭湖水库采集花?(Hemibarbus maculatus Bleeker)雌鱼样本190尾,体长7.12～32.21 cm,体重10.55～330.22 g,采用组织学和扫描电子显微镜技术观察了花?卵母细胞发育各时期的特征。结果表明,花?卵母细胞发育可分为5个时相,第I时相卵母细胞处于卵原细胞增殖阶段;第Ⅱ时相卵母细胞处于初级生长阶段,出现滤泡膜;第Ⅲ时相卵母细胞出现皮质液泡,细胞质膜之间形成放射带;第Ⅳ时相卵母细胞处于大生长后期,卵黄颗粒增多。电镜下观察发现放射带表面形成微孔状结构,核仁外排,可能与卵母细胞内营养物质积累有关;第Ⅴ时相卵母细胞中细胞核消失,卵母细胞发育为成熟卵子,与卵膜脱离,准备排卵。繁殖季节,花?卵巢成熟系数达到13.78%～17.04%。研究结果可为花?人工繁殖和育种工作提供参考。     

黄、渤海区不同生态类型鱼卵卵膜和受精孔区亚显微形态

黄、渤海区分布的硬骨鱼类鱼卵几乎涵盖了所有鱼卵生态类型。本研究借助扫描电镜观察技术对近年来黄、渤海渔业资源监测调查期间采集的15种不同生态类型鱼卵卵膜和受精孔区亚显微形态特征进行观察,以阐明其亚显微结构并总结提炼可用于鱼卵形态分类的特征,同时将相应鱼种产卵场环境因子引入到卵膜形态特征的认识中,以揭示其生境适应性。结果显示不同生态类型或不同鱼种卵膜形态不尽相同,浮性鱼卵和口含鱼卵卵膜较薄,沉性鱼卵和具卵膜丝鱼卵卵膜较厚;浮性鱼卵卵膜表面壁孔密度、卵膜外表面呈现的蚀刻或特殊结构以及受精孔形状类型,沉性鱼卵卵膜黏膜层表面结构、受精孔形状类型,具卵膜丝鱼卵卵膜丝数量、着生位置及受精孔形状类型,口含鱼卵受精孔区形状及周边附着丝数量等均可用于鱼卵形态分类。鱼卵卵膜和受精孔区亚显微结构差异与鱼种系统分类地位、产卵场环境和地理分布区相关联。鱼卵卵膜表面结构可以作为区分鱼类科或属的性状,卵膜壁孔密度、表面呈现的蚀刻或奇异结构是鱼卵形态分类的重要依据;受精孔结构则一般具有物种特异性。卵膜结构与厚度可反映鱼卵对不同生境的适应性,而卵膜表面的许多特殊结构和装饰被认为是鱼卵应对产卵场环境的保护和适应性策略。本研究将为黄、渤海区硬骨鱼类早期生活史阶段个体发生和鱼卵形态分类研究积累基础资料。     

大菱鲆成熟精子、卵子及精子入卵早期过程的电镜观察

通过人工授精和电镜技术,观察和描述了大菱鲆Scophthalmus maximus成熟精卵的形态、精子入卵的早期过程及精子入卵过程发生的一系列形态结构变化。大菱鲆卵子表面均匀地布满纵横交错的网纹,并整齐地分布许多微小孔,在动物极有一个受精孔。大菱鲆精子为无顶体类精子,由头部、中片和尾部三部分组成,中片有9～14个圆形线粒体。大菱鲆精子入卵速度非常快,授精后0～5s已经有精子通过受精孔(Micropyle)进入卵子。精子入卵过程还伴随着其他一些结构的变化,如精孔管管壁边缘由锯齿状变为平滑的环状等。     

Early development of the silver catfish Rhamdia quelen (Quoy & Gaimard, 1824) (Pisces:Heptapteridae) from the São Francisco River Basin, Brazil

The silver catfish, Rhamdia quelen , is endemic to North, Central and South America with high aquaculture potential and wide acceptance in the market. Breeder fish were subjected to induced reproduction through hypophysation using a crude common carp pituitary extract. Egg characteristics, oocyte surface ultrastructure and histology of larval ontogenesis until whole yolk resorption were described for the first time for this species. Oocytes and semen were obtained by manual extrusion, and fertilization was conducted using the dry method. After fertilization, eggs were kept in incubators at 24 °C. The embryonic development was monitored using a stereomicroscope every 10 min until hatching. To analyse the larval development, larvae samples were collected from incubators daily until the fifth day, fixed in Bouin's fluid and subjected to routine histological techniques. The oocyte extrusion occurred 8 h after the second hormone dose at 26 °C. The oocytes were spherical, non-adhesive and yellow, with a diameter of 1471.75±47.63 μm. Scanning electron microscopy revealed a thin jelly coat covering the zona radiata in the animal pole around the micropyle. The blastopore closure occurred within 8 h after fertilization, and the fertilization rate was 79.9±5.2% at 24 °C. Embryonic development was completed within 25 h 30 min after fertilization. The complete resorption of the yolk and the formation of the digestive system organs and the mouth opening occurred on the fifth day, indicating a need for exogenous feeding. The results of this study provide information important for improvement in R. quelen culture and management.     

Ultrastructure of the oocytes of the Japanese eel Anguilla japonica during artificially induced sexual maturation

ABSTRACT: Morphological changes in the oocytes of the Japanese eel, Anguilla japonica , induced to undergo ovarian development by repeated injections of salmon pituitary homogenate, were examined using electron microscopy. Oil droplets were closely associated with organelles, especially mitochondria, and increased in number as oocyte growth proceeded. They fused at the migratory nucleus stage. During vitellogenesis, two types of cortical alveoli were distinguished, one having filamentous contents, the other having latticated contents. As oocytes reached maturity, the structure of the cortical alveoli was exclusively filamentous. Yolk globules were homogeneous and highly electrondense, but electrondensity decreased during hydration. The structure of the zona radiata of previtellogenic oocytes consisted of two layers, and an additional reticular network structure was formed on the inside of the zona radiata during the vitellogenic stage. The zona radiata lost the reticular network structure and assumed a layered structure of uniform electrondensity at the migratory nucleus stage. These structural changes during oocyte development were mostly comparable to those in other teleosts. Results of the present study should assist in developing improved methods for full control of artificial maturation in the Japanese eel.     

长江口纹缟虾虎鱼精子、卵子及受精过程扫描电镜观察

采用电镜对长江口纹缟虾虎鱼成熟精子、卵子及受精早期精子入卵过程进行了观察。结果显示:纹缟虾虎鱼成熟精子由头部和尾部两部分组成。头部呈圆形或近圆形,无顶体,细胞核长径为1.15±0.28μm,短径为0.97±0.22μm,尾部鞭毛长为8.17±1.12μm。核膜外具有双层质膜,质膜表面不平整,在核膜和双层质膜中间有较大空隙存在。中心粒复合体位于植入窝内。袖套两侧分布有2～3个较大的线粒体。鞭毛为典型的"9+2"结构,有侧鳍。成熟卵呈圆形,卵膜表面多沟和嵴,具单一受精孔,孔洞区外径约5μm,孔内壁呈螺旋嵴。在卵的植物极有一盘状突起,突起的中间为圆形,周边有呈网状结构的粘丝与卵壳膜连接。纹缟虾虎鱼精子入卵速度较快,受精过程较短,受精后10～18 s完成精子入卵过程。     

狭鳕早期胚胎发育的形态结构观察

利用显微数码摄像系统,活体观测、拍摄了狭鳕受精卵的早期胚胎发育过程,详细描述记录不同发育时相胚胎的形态特征、发育时间等。选取6个发育期(未受精、细胞分裂期、囊胚期、原肠胚期、胚体发育期、将孵化前期)的照片,利用Image J软件测量不同发育期的卵径,以探讨狭鳕早期胚胎发育过程中卵径的变化。此外,利用扫描电镜观察了4个胚胎发育期(未受精期、2细胞期、原口关闭期、孵化前期)受精孔及卵膜的形态结构。结果表明,狭鳕产浮性分离卵子,卵膜单层、透明光滑,卵黄均匀,无油球,卵径1.45~1.58 mm。在水温(6.3±1.24) ℃,盐度34时受精后约1 h胚胎形成,24 h后进入囊胚期,61 h后进入原肠胚期,134 h后进入器官形成早期,161 h后心脏开始跳动,319 h后开始孵化。在整个胚胎发育过程中,狭鳕卵子的直径呈现逐渐增大的趋势。亚显微观察显示,狭鳕受精孔为Ⅱ型,受精孔前庭平坦,但受精孔孔道较长。未受精时,受精孔开放,卵膜上多皱褶,卵膜壁孔不明显;2细胞期时,受精孔被卵周液分泌物阻塞,卵膜皱褶减少,卵膜壁孔明显;原口关闭期时,受精孔呈半开放状态,卵膜褶皱增多,卵膜壁孔不明显;即将孵化期时,受精孔完全塌陷,卵膜表面十分粗糙,卵膜壁孔明显。由此可见,狭鳕卵子卵径、受精孔和卵膜结构的动态变化都与整个胚胎发育过程紧密相关,其对提高卵子受精率、卵子在海底正常发育和散布,卵子发育过程中防止多精受精和细菌感染具有重要意义。     

黄鳝精子活力检测和精子入卵早期过程观察

采用Olympus3×51相差系统显微镜和SQIAS—1000彩色精液质量图文分析系统检测黄鳝精子活力。结果表明,在NaCl溶液浓度为0～0.3%时,黄鳝精子激活比例随溶液浓度升高而极显著增加(P<0.01);当NaCl浓度达到0.7%时,精子激活比例、直线运动速度和鞭毛摆动频率均显著(P<0.05)或极显著(P<0.01)降低。扫描电镜观察显示:黄鳝成熟卵卵壳膜上的精孔区呈漏斗状凹陷,其底部中央可见一精孔管外孔,口径约4.22±0.66μm;黄鳝精子入卵速度缓慢,受精过程较长,从精子附着于卵球表面到精孔管完全堵塞,约30s～5min。