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1.
红螯螯虾胚胎发育的研究:Ⅱ.消化系统的发生   总被引:4,自引:0,他引:4       下载免费PDF全文
应用组织切片技术 ,研究了红螯螯虾胚胎发育过程中消化系统的发生。红螯螯虾的消化系统由前肠、中肠和后肠 3部分组成 ,前肠和后肠由外胚层形成 ,而中肠源自原肠期由胚胎表面向囊胚内迁移的中内胚层细胞团。前无节幼体期前肠开始发生 ,至后无节幼体期先后形成口道、食道和胃等结构 ;中肠起始于后无节幼体期的次级卵黄锥 ,包括管状中肠和 1对囊状消化腺 -中肠腺 ;后肠端部是前无节幼体期形成的肛道 ,肛道不断向胚胎前端延伸逐渐形成后肠  相似文献   

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应用组织切片技术,研究了红螯螯虾胚胎发育过程中消化系统的发生,红螯螯虾的消化系统由前肠,中肠和后肠3部分组成,前肠和后肠由外胚层形成,而中肠源自原肠期由胚胎表面向囊胚内迁移的中内胚层细胞团,前无节幼体期前肠开始发生,至后无节幼体期先后形成口道,食道和胃等结构,中肠起始于后无节幼体期的次级卵黄锥,包括管状中肠和1对囊状消化腺-中肠腺;后肠端部是无节幼体期形成的肛道,肛道不断向胚胎前端延伸逐渐形成后肠。  相似文献   

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饥饿对中华绒螯蟹(Eriocheir sinensis)幼体发育的影响   总被引:3,自引:0,他引:3  
对刚孵化的中华绒螯蟹第一期的蚤状幼体经不同时间的饥饿后再投喂,发现饥饿可以明显降低幼体的存活率和延长幼体的发育期。实验表明:对中华绒螯蟹第一期的蚤状幼体的饥饿时间(t)和发育期长(D)呈线性关系(D=4.6303+1.3226t r=0.970p<0.01)。对于中华绒螯蟹第一期的蚤状幼体,当起始饥饿时间超过了4d,再予以投饵,幼体均不能恢复正常的发育和蜕皮功能,得出中华绒螯蟹的不可恢复点(the point of no-return,PNR)大约为4d。通常以产生50%的幼体死亡的饥饿期即PNR50,来表明幼体对饥饿的抵抗能力,实验得出中华绒螯蟹第一期的蚤状幼体的PNR50大约为48h。  相似文献   

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克氏原螯虾幼体发育的初步研究   总被引:35,自引:0,他引:35  
郭晓鸣  朱松泉 《动物学报》1997,43(4):372-381
在实验条件下观察了克氏原螯虾的幼体发育。详细描述了第一至第三龄幼体发育的形态特征。  相似文献   

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建立了间接竞争酶联免疫吸附反应(ELISA)方法,对红螯光壳螯虾(Cherax quadricarinatus)胚胎及仔虾发育过程中的卵黄磷蛋白含量及其亚基组分进行了研究。该方法对卵黄磷蛋白具有良好的特异性,有效检测范围为31.25~250 ng/ml。结果表明,在发育初期胚胎先降解分子量比卵黄磷蛋白大的蛋白;亚基中,分子量较大和较小的亚基都先被消耗;胚胎内卵黄磷蛋白含量总体上呈下降趋势,其中在卵裂囊胚阶段后略有上升(3.19%),至后无节幼体期卵黄磷蛋白含量达最高(4.67%),之后不断下降,到仔虾离开母体独立生活时,含量只剩下卵裂期的1/4。  相似文献   

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采用聚丙烯酰胺凝胶电泳技术,对中华绒螯蟹(Erlocheir sinensis)不同发育时期胚胎及流产胚胎的6种同工酶(乳酸脱氢酶、醇脱氢酶、苹果酸脱氢酶、酯酶、淀粉酶和过氧化物酶)进行了研究。结果表明,不同发育时期胚胎的乳酸脱氢酶、醇脱氢酶、苹果酸脱氢酶、酯酶及淀粉酶酶谱表现出一定差异。受精卵中未检测到乳酸脱氢酶同工酶活性,卵裂期和囊胚期出现4条酶带,无节幼体及溞状幼体期只有2条酶带;醇脱氢酶同工酶在中华绒螯蟹胚胎发育的各阶段均有表达,但表达的酶带数和活性有区别;在受精卵和溞状幼体期无苹果酸脱氢酶酶带显示,卵裂期酶带数最多,酶活性相对也最强,以后随着发育的进行,酶带数和酶活性都有减弱的现象;酯酶同工酶的变化较为复杂,特别是囊胚期,酯酶酶带突然全部消失;淀粉酶有两种类型:α-淀粉酶和R-淀粉酶。从受精卵发育到幼体其酶带数不增反减。不同发育阶段均检测不到过氧化物酶的活性。第二次抱卵胚胎的酶活性和酶带数低于或有别于第一次抱卵的卵裂期胚胎。流产胚胎中醇脱氢酶、乳酸脱氢酶、淀粉酶与第一次抱卵胚胎不同发育时期的酶谱相比略有变化,而苹果酸脱氢酶、酯酶酶带数迅速减少。  相似文献   

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克氏原螯虾   总被引:10,自引:1,他引:9  
从形态、习性、繁殖和幼体发育等7个方面介绍了克氏原螯虾的生物学特性,指出它对人类有益的方面,以及对水利、农业、淡水养殖业的危害及其可能造成食用者食物中毒的不利方面。  相似文献   

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绒螯蟹触角形态特征及其在分类中的应用   总被引:6,自引:3,他引:3  
基于光镜和扫描电镜的观察,研究了绒螯蟹触角的形态结构,分析了绒螯蟹第1触角内、外肢节的组成,以及外肢节内侧感觉毛的特点;第2触角内肢节的形状以及极长感觉毛和表面鳞片的特征.探讨了在绒螯蟹系统分类中,触角形态特征作为新的分类性状的可能性.  相似文献   

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闫启仑  陈红星 《生态学报》1999,19(4):495-498
日本大螯蜚(Grandidierellajaponica)生长发育的适温范围为20~26℃,不同发育期耐受温度范围不同,刚孵化幼体温度下限为11℃,上限32℃,以后随着幼体发育,其对低温的适应力逐渐增强,雄性个体对极限温度的忍耐力低于雌性,耐受温度范围内,幼体的生长发育随温度的提高而加快,研究结果表明,日本大螯蜚实验室培养温度宜选择在20~26℃,用其进行的沉积物急性和慢性毒性生物检验的实验温度均  相似文献   

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红螯螯虾繁殖习性的研究   总被引:8,自引:2,他引:6  
对红螯螯虾的繁殖习性进行了较为详细地描述。性成熟的雌虾通常经过生殖蜕皮后交配、产卵,受精卵粘附于腹肢的刚毛上;在水温28℃左右的条件下,幼体孵出的约需39天,性成熟雌虾能多次产卵。  相似文献   

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Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.  相似文献   

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Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.  相似文献   

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Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.  相似文献   

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正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases  相似文献   

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