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1.
瘤背石磺的形态、习性和生殖行为   总被引:18,自引:1,他引:18  
2003年5月~2004年5月研究了上海崇明瘤背石磺(Onchidium struma)的形态特征、生活习性,分别对其消化、呼吸、循环、排泄、生殖、神经等六大系统进行了阐述。结果表明,瘤背石磺生活在潮间带高潮区滩涂的芦苇丛里,摄食泥滩上的有机质和单胞藻类;雌雄同体、异体交配、卵生。生殖系统包括生殖器和雌、雄交接器三部分:生殖器由两性腺、卵黄腺和蛋白腺组成;雄性交接器由输精管、附性腺、阴茎、刺激器等组成,雄性生殖孔位于右侧第一触角中部;雌性交接器由输卵管、受精囊、阴道等组成,雌性生殖孔位于肛门右侧约5.0mm处的腹足与外套膜的交界处。本文并详细描述了石磺的交配行为。  相似文献   

2.
不同体重瘤背石磺性腺发育规律   总被引:2,自引:0,他引:2  
利用组织学方法研究了瘤背石磺体重(2—28g)与性腺发育、性腺指数与肝胰腺指数或卵黄腺指数间的关系,不同体重瘤背石磺性腺内各期生殖细胞的组成与比例以及瘤背石磺卵子和精子发生的规律。结果表明,(1)瘤背石磺的性腺指数有随体重增加而增加的特点:10g以上个体性腺指数达到最高且基本无变化;不同体重瘤背石磺性腺指数与肝胰腺指数和卵黄腺指数有明显的正相关性(P<0.05);(2)6g以下组的瘤背石磺性腺滤泡管内未发现有雌性生殖细胞,6g以上组的性腺滤泡管内雄性与雌性生殖细胞并存;(3)所有瘤背石磺个体性腺内均有精子分布,6g以下个体雄性生殖细胞组成以次级精母细胞为主,而6g以上个体则以精子为主;6g以上组的雌性生殖细胞成熟程度随体重增加有明显增加,其中6—8g以卵原细胞为主(57%),8—10g开始出现外源性卵黄合成期的卵母细胞,10—14g时的外源性卵黄合成期的卵母细胞约为69%,且开始出现成熟卵母细胞。(4)卵子发生共经历6期:分别为卵原细胞期、卵黄合成前卵母细胞期、内源性卵黄合成期、外源性卵黄合成期、近成熟期和成熟卵母细胞期,成熟卵母细胞直径约为(59.36±3.88)μm。精子发生经历精原细胞、初级精母细胞、次级精母细胞、精子细胞和精子共5个阶段,精子长约(52.44±20.65)μm。石磺体重与性腺发育程度密切相关,10g以上的个体可做为亲本使用。  相似文献   

3.
瘤背石磺的生殖系统和性腺发育   总被引:24,自引:1,他引:24       下载免费PDF全文
2003年5~8月对瘤背石磺(Onchidium struma)的生殖系统结构和性腺发育进行了组织学研究。瘤背石磺生殖器包括两性腺、卵黄腺、蛋白腺。两性腺具有外管和内管,两管相连后通入蛋白腺,内管分支为收集管与腺泡相通。蛋白腺包括腺体部和分泌物两部分,中央为生殖输送管,蛋白腺具食指突和拇指突。性腺腺泡包括精子期腺泡、卵子期腺泡、精卵同泡和排空期腺泡4种类型。本文还对卵黄腺、受精囊、雄性交接器等结构进行了组织学观察,分析了精子和卵子的发育过程、运输路径。  相似文献   

4.
瘤背石磺(Onchidium struma)是雌雄同体、异体交配的腹足纲贝类,其生殖系统较为复杂,通过解剖学和组织切片技术对成体瘤背石磺的生殖系统及产卵前后的组织学变化进行了系统的研究.结果表明:(1)雄性生殖系统主要南阴茎囊、阴茎、雄性附性腺、两性腺(早期主要产生精于)和储精囊等部分组成,而雌性生殖系统则由两性腺(后期主要产生卵子)、生殖细胞输送管、蛋白腺、黏液腺、受精囊和阴道等组成;(2)雄性生殖系统的组织学结构在产卵前后变化较小,但两性腺、卵蛋白腺和黏液腺的组织学在产卵前后变化显著;(3)产卵后的两性腺由于成熟卵子的排放,整体结构松散,部分腺泡中有少量未排出的成熟卵细胞和卵黄合成早期的卵母细胞;(4)产卵前的卵蛋白腺中含有许多强嗜碱性的小颗粒(组织学结构类似于卵鞘中的胚胎外周蛋白),产卵后腺体中的颗粒相对较大,且呈嗜酸性;(5)产卵前的黏液腺中存在嗜碱性区、嗜酸性区和混杂区三种区域,但是产卵前黏液腺以嗜酸性细胞为主,而产卵后的黏液腺中以嗜碱性细胞区域为主,且分泌管道中有一些嗜碱性物质.由此可见,卵蛋白腺的主要功能是分泌卵蛋白包裹受精卵形成卵外周蛋白层,而黏液腺则在产卵过程中分泌黏液物质形成卵鞘结构及链状的卵带.  相似文献   

5.
瘤背石磺产卵前后脂类和脂肪酸组成的变化   总被引:7,自引:0,他引:7  
本研究测定了瘤背石磺产卵前后肌肉、肝胰腺、两性腺、卵蛋白腺、雄性附性腺和黏液腺指数、水分含量、总脂含量、脂类和脂肪酸组成.结果表明:(1) 瘤背石磺产卵后的肝胰腺指数(HIS)、两性腺指数(DGSI)和卵蛋白腺指数(EAGI)都显著下降(P<0.05), 其水分含量显著上升, 而脂肪含量显著下降; (2) 瘤背石磺各种组织总脂主要有磷脂(PL)、胆固醇(Cho)、游离脂肪酸(FFA)和甘油三酰(TG), 仅在肝胰腺中检测出少量甘油一酰(MG), 产卵后肝胰腺中的FFA含量和两性腺中的PL含量大幅度下降, 分别下降了41.36%和80.53%, 其它组织中的脂类成分变化幅度不大;(3) 产卵后瘤背石磺肝胰腺中的C16:1n7、C20:5n3(EPA)和C22:6n3(DHA)显著下降, 而饱和脂肪酸(∑SFA)含量显著上升.产卵后两性腺中的C20:2n6、C22:2n6和C22:5n3(DPA)显著下降, 而C20:4n6(AA)含量显著上升.产卵后雄性附性腺和黏液腺中的AA和EPA含量均有所下降, 而C16:0和C18:1n9却有所上升.结果表明:卵蛋白腺和黏液腺对于瘤背石磺产卵和胚胎的形成具有重要的作用, PL和多不饱和脂肪酸(PUFA)对瘤背石磺的两性腺发育具有十分重要的作用, 肝胰腺中的脂肪可能是瘤背石磺产卵过程中主要的能源物质之一, 性腺发育过程中肝胰腺中的PUFA可能被转运到两性腺中.  相似文献   

6.
运用常规组织学方法和NADPH-d组织化学方法,研究了薄背涡虫 Notoplana humilis 生殖系统的组织结构和一氧化氮合酶的分布.其雄性生殖系统包括精巢、储精囊、阴茎、雄性生殖孔,精巢壁由一薄层薄膜组成,每个精巢内都含有不同发育时期的雄性生殖细胞,且精子发育无明显同步性;储精囊呈螺旋状排列在雄性生殖孔附近,囊壁由单层扁平上皮组成;阴茎为粗大的球形,外壁由柱状上皮细胞和数层肌细胞组成.雌性生殖系统包括输卵管、生殖腔、雌性生殖孔和受精囊,但不形成集中的卵巢和卵黄腺.雌雄生殖孔、生殖腔、受精囊、阴茎等部位呈NADPH-d强阳性反应.  相似文献   

7.
钱静  沈和定  管菊 《动物学杂志》2015,50(4):600-606
雌雄同体贝类精子的储存和利用规律一直是国内外贝类生物学研究的难点之一,本文利用活体解剖、显微观察、组织切片和扫描电镜技术,综合研究了平疣桑椹石磺(Platevindex mortoni)的生殖系统及精子储存场所。结果显示,其生殖系统包括生殖器本部、雌性生殖部分和雄性生殖部分。生殖器本部由两性腺、两性输送管、蛋白腺、黏液腺、支囊组成;雌性生殖部分包括输卵管、受精囊、阴道,位于身体中后方体腔内;雄性生殖部分包括输精管、刺激器、阴茎、阴茎鞘和阴茎牵引肌,位于身体前端右侧体腔内;其阴茎有阴茎鞘,阴茎表面布满倒刺。平疣桑椹石磺阴茎为直线状,无雄性附属腺。未交配的性成熟个体支囊内充满细长精子,受精囊内无精子;而交配后充当雌性个体的支囊内均为细长的自体精子,受精囊内有大量活力较强的粗短精子,其支囊为自体精子的存储场所,而受精囊为异体精子的存储场所。其精子储运情况为:两性腺内精子成熟后暂存于支囊,交配时通过输精管运输至阴茎,由阴茎输送精子至对方的阴道,异体精子进入受精囊内存储待用。  相似文献   

8.
拟澳洲赤眼蜂(Trichogramma confusum)的体长约0.6mm,腹部长度约0.3mm.雌蜂生殖系统(包括卵巢、生殖腔、受精囊及三种附腺)位于腹部后端,约占腹腔的2/3.成熟的卵巢由两条多滋式的卵巢管组成.两条成熟卵巢的端段细长,扭卷成一条疏松索,基部膨大,内脏贮存大量卵粒.成对的侧输卵管较短,分别开口于生殖腔后方的两侧,中输卵管缺如.受精囊呈梨形,开口于生殖腔后方.雌性生殖系统三种附腺中,第一种附腺是成对的,呈锤状,分别连接于生殖腔前方两侧;第二种附腺,腺体呈球状,其前端以短曲的小管通进膨大的贮腺囊,贮腺囊端部成柄状的弯曲小管,连接于产卵管的基部开口处.第三种附腺的腺体呈棒状,前端为细长的小管,开口于第二种附腺贮腺囊的前端.雄性生殖系统由成对的睪丸,输精管、贮精囊、附腺及单一的射精管组成.蛹的早期到后期至成虫期睾丸的形态结构,各有不同变化.  相似文献   

9.
日本三角涡虫生殖系统组织结构的观察   总被引:3,自引:0,他引:3  
涡虫在动物系统演化史上占有十分重要的地位,雌雄同体,具有很强的再生能力,因此,对其生殖系统组织结构进行深入研究具有重要的意义.本文用3种染色方法(H.E染色、Masson染色、Van Gieson染色)显示了日本三角涡虫(Dugesiajaponica)生殖系统的组织结构并对其进行了光镜观察.结果表明.该类涡虫生殖系统为雌雄同体.雌、雄性生殖系均由生殖腺和生殖管道构成,雌性生殖腺包括卵巢、卵黄腺和交配囊,生殖管道包括输卵管、交配囊柄;雄性生殖腺主要是精巢,生殖管道包括输精囊、输精管、球腔、射精管4部分.交配囊由单层柱状上皮构成,胞质强嗜碱性,胞核位于上皮基底面,游离面胞质呈现很多泡状结构;卵黄腺为单细胞腺,灯泡状,其核较小,位于柄部.因此,可以确定交配囊具有外分泌的功能;卵黄腺的数目存在周期性.  相似文献   

10.
石磺科3种贝类皮肤显微结构比较   总被引:1,自引:0,他引:1  
应用石蜡切片和H.E染色技术,对石磺科(Onchidiidae)3个属的代表物种:瘤背石磺(Onchidium struma)、平疣桑椹石磺(Platevindex mortoni)和里氏拟石磺(Paraoncidium reevesii)的皮肤进行了组织学观察及参数测量比较。结果表明,3种石磺的皮肤虽然厚度不一,但基本结构相似,均由角质膜、表皮和真皮构成。角质膜是一层覆盖于表皮角质层上的蛋白质薄膜;表皮由多层上皮细胞构成,包括角质层、颗粒层和生发层;真皮包括疏松层和致密层,疏松层中嵌有颗粒腺和黏液腺两种腺体。3种石磺的皮肤厚度、各组织相对厚度及腺体数量等均存在差异。将结构差异与石磺的栖息环境进行比较分析后得到:陆栖为主的瘤背石磺皮肤表皮角质化程度高,颗粒腺发达;以水栖为主的里氏拟石磺表皮角质化程度相对低,黏液腺发达;而水陆两栖的平疣桑椹石磺,皮肤角质化程度介于前述二者之间,颗粒腺与黏液腺均不发达。研究结果体现了三者不同的生态适应特征,也为深入探讨海洋无脊椎动物从海洋向陆地进化的研究提供形态学依据。  相似文献   

11.
Reproductive Biology of the Pteridophyta   总被引:4,自引:0,他引:4  
Because of the homothallic nature of many pteridophytes, two categories of mating are possible: intragametophytic selling (the origin of both gametes from a single gametophyte) and inter-gametophytic mating (the origin of each gamete from a different gametophyte).Various morphological and genetical criteria (placement of the gametangia on the thallus, their sequence of ontogeny, the capacity for simple polyembryony and genetic self-incompatibility) can be used to indicate the relative probability of intragametophytic selfing or intergametophytic mating. Only the former has genetic significance (i.e.complete homozygosity); if the latter is evidenced, then detailed studies of population variability are required to ascertain the breeding system.
Three types of reproductive systems involve the gametophyte generation: intragametophytic selfing, intergametophytic mating and apogamy. Apogamy generally offers the shortest gametophyte generation and the least evolutionary potential, intergametophytic mating systems generally have the longest gametophyte generation and the greatest evolutionary potential, and intragametophytic mating systems are intermediate in both respectS. It is envisioned that the interaction between gametophyte ecology and evolutionary potential is important in the evolution of a taxon's reproductive system.  相似文献   

12.
The genus Oryx comprises one species already extinct in the wild and others that are rapidly disappearing. It is important to understand the reproductive physiology of these species in order to ensure their successful captive propagation. It was determined behaviorally and hormonally that the scimitar-horned oryx's 21–22 d estrous cycle very closely resembled that of the domestic cow. Four females of three species (Arabian, scimitar-horned, and fringe-eared oryx) were treated with prostaglandin (PG) and pregnant mares serum gonadotropin (PMSG) or follicle-stimulating hormone (FSH). All animals responded to prostaglandin treatment with shortened cycles and behavioral estrus. Ovulation occurred in all females but only one responded to gonadotrophin treatment with a mild superovulation. An embryo recovered from an Arabian oryx was frozen in liquid nitrogen for 6 months. Upon thawing, the normal-appearing morula was surgically transferred to a scimitar-horned oryx. The recipient failed to carry the embryo and returned to estrus within three weeks of the transfer. It was demonstrated that induction of ovulation and synchronization of estrus can be achieved in the three Oryx species with PMSG or FSH combined with prostaglandin treatment.  相似文献   

13.
The combination of a few factors, including poor captive reproduction, secession of importation from the wild and advances in hormone detection and ultrasonography, has contributed to the current knowledge on the elephant reproductive cycle. Several reproductive features in elephants differ markedly from other mammals. These include the urogenital tract anatomy, length and structure of the reproductive cycle, the formation of multiple corpora lutea and the type and secretion pattern of reproductive hormones. Being 13-18 weeks in length, the elephant estrous cycle is the longest amongst all studied non-seasonal mammals to date. Progesterone increases 1-3 days after ovulation, indicating the start of the luteal phase, which lasts 6-12 weeks. This is followed by a 4- to 6-week follicular phase that is concluded by two, precisely spaced and timed, LH surges. In general, the first, anovulatory LH surge occurs exactly 19-21 days before the second, ovulatory surge. Normally, a single follicle is ovulated. However, beside a corpus luteum (CL) forming on the site of ovulation, multiple accessory CLs can be found on the ovaries. Unlike many other species, the predominant progestagen secreted by luteal tissues is not progesterone, but rather its 5-alpha-reduced metabolites. The currently known aspects of the unique estrous cycle in Asian and African elephants, covering estrous behavior, circulating hormones, ultrasonography and anatomy of the reproductive organs as well as hormonal manipulation treatment possibilities, will be reviewed here.  相似文献   

14.
Reproductive seasonality was studied in 12 jennies in southern Wisconsin for 12 mo. The proportion of jennies ovulating differed (P < 0.05) among months due primarily to a lower proportion ovulating during December (64%) than during the other months (82 to 100%). Of 114 interovulatory intervals, eight were considered prolonged (>35 d) due to persistent corpus luteum (two intervals) and a follicular-related anovulatory period (six intervals). Four of the six follicular-related anovulatory periods were attributed to seasonal effects. The anovulatory season in these four jennies occurred in winter, was relatively short (39 to 72 d), and was terminated by a long period (17 to 41 d) of estrous behavior in the continued presence of large follicles (>20 mm). The prolonged estrus accounted for the lower incidence of ovulations during December and seemed similar to the transition between anovulatory and ovulatory seasons in mares. There was a significant effect of month on length of the interovulatory interval, even after removal of the eight prolonged intervals, due primarily to shorter intervals during May to September (means, 23.0 to 24.3 d) than during October to April (25.0 to 27.3 d). Length of estrus differed significantly among months due primarily to shorter periods during May to October (means, 5.7 to 6.9 d) than during November to April (7.4 to 15.2 d). These results indicated that this species is subjected to seasonal effects on reproductive function. However, contrary to the literature, the dramatic partitioning of the year into ovulatory and anovulatory seasons, as occurs in mares, was absent (eight jennies) or limited (four jennies).  相似文献   

15.
圈养小熊猫繁殖行为变化及繁殖行为对策   总被引:7,自引:1,他引:6  
In order to investigate the change of reproductive behaviors and understand reproductive strategies of both male and female red pandas, one-year behavioral observation was conducted through the focal sampling method in the Chengdu Research Base of Giant Panda Breeding from December 1999 to November 2000. Our results indicated that reproductive behaviors showed significant differences between the estrous and non-estrous seasons. Frequencies of the rubbing anogenital, sniffing and licking marking were much higher in estrus than in non-estrus. Bleating only appeared in the estrus and can be regarded as an estrous indicator.The result also demonstrated that both male and females applied different reproductive behavioral strategies. Frequencies of activity, rubbing anogenital, licking and sniffing marking, and bleat were much higher in the male than in the female. However, those of resting and investigating were much lower in the male than in the female. This indicated that the male was more active than the female during the estrus and might imply that the male acts mainly as an estrous message sender, and the female as a message receiver in the estrous season.  相似文献   

16.
动物的繁殖活动关系到整个种群的生存与灭绝,繁殖投入和繁殖成功率是繁殖生态学研究的重要内容。从繁殖投入的划分人手,综述了小型哺乳动物的繁殖投入和繁殖成功率之间的关系及其影响因素、分子生物学技术在繁殖生态学中的应用等,阐述了小型哺乳动物能够根据自身的状态调整每次繁殖活动中的时间投入和能量分配,采取不同的繁殖对策。这些繁殖对策是长期自然选择的结果,其目的都是为了最大限度地提高自身的适合度。并且指出分子生物学技术在繁殖生态学中的应用将大大加快这一研究领域的快速发展。  相似文献   

17.
18.
The reproductive cycle of the American alligator, Alligatormississippiensis, was studied using blood and tissue samplesfrom wild alligators, and blood samples drawn from a captivebreeding stock at the Rockefeller Wildlife Refuge in Louisiana.Generally the cycle commences in March as air and water temperaturesincrease. By early April the seminiferous tubules are full ofactively dividing spermatocytes and maturing spermatids. Testismass is greatest at this time and plasma testosterone is ata peak (>50 ng/ml), but mature spermatozoa do not appearuntil late April and mid May when mating takes place. Plasmatestosterone levels decline rapidly in June after spermiation,and are low to nondetectable in July and August when the testesare fully regressed. A second small peak in testosterone occursin September without any obvious changes in testicular histology.In the female a similar temperature dependent initiation ofthe ovarian cycle occurs in late March. Plasma estradiol levelsreach a peak (>600 pg/ml) in mid April, and ovarian folliclesincrease from 5 mm to 45 mm in diameter at ovulation in May.Plasma testosterone is also high in preovulatory females (ca.1.5 ng/ml). Plasma progesterone shows a periovulatory surgeto levels as high as 16 ng/ml, but declines rapidly during the3 wk between ovulation and oviposition. During egg incubation(66 days) when the female remains close to the nest, ovariansteroids remain undetectable.  相似文献   

19.
Four diploid plants and four tetraploid plants ofPhegopteris decursive-pinnata were investigated for determination of the reproductive characteristics of their gametophytes and two major features were recognized. First, gametophytes of the diploids showed an ontogenetic sequence of gametangium formation which is unfavorable for intragametophytic selfing, whereas those of the tetraploids showed that favorable for intragametophytic selfing. Second, 41 to 72% of the isolated gametophytes of the diploids produced sporophytes in the intragmetophytic selfing tests, whereas all of the isolated gametrophytes of the tetraploids produced sporophytes in the tests. Based on these developmental and genetic features of gametophytes, the dissimilar mating systems of the diploids and the tetraploids of this species are discussed.  相似文献   

20.
The author presents general data about the reproductive cycle of Selachian Fishes, chiefly based on species of Tunisian coasts. In this paper is also presented a discussion about the different modes of reproduction oviparity and viviparity (placental and non-placental) and their variations according to families, genus and species.  相似文献   

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