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1.
使用超声波技术检测了6只雌性四眼斑水龟的卵黄卵泡(包括生长卵泡和排卵前卵泡)、闭锁卵泡和输卵管卵的大小和数量.结果 表明:四眼斑水龟卵巢卵黄卵泡数目和大小呈明显的周期性变化,检测到的卵黄卵泡长径范围为4~24 mm(n=186).8月份卵泡数目开始增多,卵泡长径逐渐增大,至12月份排卵前期卵泡数量达最大值,卵巢发育成熟.排卵前期卵泡长径范围为19~24 mm(n=56),最大排卵前期卵泡出现于12月.排卵时间是1月至3月.闭锁卵泡长径范围在10~20 mm(n=14)之间,仅在10月至次年3月能检测到少数的闭锁卵泡.  相似文献   

2.
四眼斑水龟血浆生殖激素季节性变化   总被引:1,自引:0,他引:1  
为了进一步探讨四眼斑水龟(Sacalia quadriocellata)的繁殖生理周期和生殖激素分泌特征,使用放射免疫分析测定法(RIA)分别测定了8月(夏季)、10月(秋季)、1月(冬季)、3月(春季)四眼斑水龟血浆中卵泡刺激素(FSH)、促黄体生成素(IJH)、睾酮(T)、雌二醇(E2)、孕酮(P)五种生殖激素的含量.结果显示,四眼斑水龟生殖激素分泌呈现较明显的周期性,激素水平与环境温度的变化有关;雄性T含量夏季开始升高,秋季达到高峰,与精子的发生和成熟同步;雌性T水平升高促进其接受雄性爬胯,且作为雌激素合成的前体物质,间接作用于雌激素的合成;排卵会出现LH峰,E2含量排卵前几个月开始增长,刺激肝生成卵黄;排卵期间P含量较高,可能在排卵过程中发挥作用.  相似文献   

3.
为探讨光周期对四眼斑水龟(Sacalia quadriocellata)繁殖的影响,于2008年10月至2009年9月对其进行光周期实验.将39只成体分成短光照组、长光照组和对照组,每个组别中样本量均为7♀、66.每月用超声波技术对雌性个体进行卵泡数量、大小的检测,并用X光投射法确定硬壳卵数;每半月对雄性进行录像观察.结果表明:三个实验组卵泡数量和卵泡大小表现出明显的周期性,原始卵泡从8月份开始生长发育,卵泡数量在11月份最多,尺寸在12月份也达到最大值;光周期对雌性卵泡数量和卵泡大小的发育有影响,短光照组检测到的总卵泡数高于长光照组和对照组,其中短光照组卵泡数与对照组卵泡数差异显著(P<0.05),长光照组卵泡尺寸相对于另外2个实验组显著变小(P<0.01);光周期对雌性产卵数和雄性发情强度无影响(P>0.05).光周期对四眼斑水龟雌雄个体性腺发育的作用不同,缩短光照对雌性繁殖有促进作用,延长光照对雄性发情强度在特定阶段具有一定促进作用.  相似文献   

4.
海南岛黎母山四眼斑水龟种群密度与空间分布格局   总被引:1,自引:1,他引:1       下载免费PDF全文
2004年3~7月,采用系统抽样法在海南岛黎母山对四眼斑水龟(Sacalia quadriocellata)种群密度与空间分布进行了调查,采用Cassie指数、David&Moore指数、Morisita指数和Lloyd指数测定了四眼斑水龟种群空间分布格局。结果表明,(1)四眼斑水龟种群分布于海拔170~470m范围内,在垂直梯度上呈现不连续的分布状态;(2)在海拔170~470m范围内种群相对密度为0.011~0.050只/笼捕日;(3)种群空间分布呈现聚集分布格局;(4)资源的空间分布特点和人为干扰可能对四眼斑水龟种群密度及空间分布格局有重要影响。  相似文献   

5.
研究龟鳖的两性异形对理解形态适应具有重要意义。通过测量41只(21♀,20♂)成体四眼斑水龟(Sacalia quadriocellata)的20个形态特征指标,研究四眼斑水龟个体大小和体形的两性异形。结果表明:除头长、头宽、尾长和尾长肛前段长外,四眼斑水龟其他的形态特征均与背甲长呈正相关。雌性的背甲长、腹甲长、腹甲中线长、腹甲曲线长显著大于雄性;雄性的头长、头宽、后肢长、尾长和尾长肛前段长显著大于雌性;雌雄两性的体重、体周长、前肢长、腹甲宽、肛盾切口长、肛盾切口宽以及除背甲长外的所有背甲形态特征指标均无显著差异。研究结果表明,四眼斑水龟存在个体大小和体形两性异形。  相似文献   

6.
中国水龟类的核型与银带带型研究   总被引:3,自引:0,他引:3  
以血培养细胞为材料,研究了三种水龟的核型与NORs,结果表明,染色体数均为2n=52,核型模式9+5+12,属龟科核型中的原始类型,但眼斑水龟NF=76,而四眼斑水龟和黄喉拟水龟的NF=78。从核型结构看,眼斑水龟与四眼斑水龟相似,而黄喉拟水龟则有较大差别,作者还发现黄喉拟水龟核型的一些重要特征,即其A组No.3和No.6染色体有次缢痕,N.别,作者还发现黄喉拟水龟核型的一些重要特征,即A组这些是  相似文献   

7.
四眼斑水龟在海南岛的地理分布调查   总被引:1,自引:1,他引:0  
采用查阅文献、走访调查和野外调查三种方法相结合,对四眼斑水龟在海南岛的地理分布进行了调查。对18个市县的103个乡镇进行了走访调查;野外调查中采用系统抽样法和笼捕法,对黎母山、尖峰岭、霸王岭、南茂岭、万俄岭和文教河上游6个研究点进行了调查。结果表明:1)四眼斑水龟分布于海南岛中部和西南部山区以及丘陵地区,除了海口、文昌、临高、定安和澄迈5个市县没有分布外,其它13个市县均有分布,其中8个市县为本次调查的分布新记录;2)四眼斑水龟栖息于海拔170~640m的山区溪流环境,而在平原、台地、滩涂地区以及比较大的江河、水库和湖泊沿右分布。  相似文献   

8.
目的探讨正常SD雌性大鼠性成熟前不同日龄段的脏器与促黄体生成素(LH)、促卵泡素(FSH)、雌二醇(E2)等性激素的变化及其关系。方法从生产群中取出60窝密度状态一致的SD大鼠,在不同日龄随机选取雌性大鼠,检测15、25、32、40日龄时大鼠体重、主要脏器指数,子宫、卵巢组织变化和15、25、32、40、60日龄大鼠血清LH、FSH、E2水平。结果记录了SD雌性大鼠性成熟前各脏器指数和卵巢、子宫组织变化,结果显示大鼠卵巢、子宫的增长速度大于体重的增长,而其他脏器增速大都小于体重的增长。本研究还记录了血清LH、FSH、E2水平在不同日龄段的变化规律,表明血清LH、E2浓度在32日龄时出现较为明显升高。结论不同日龄大鼠脏器指数的动态变化提示大鼠性器官在性发育早期得到机体的优先发育。血清LH、E2水平在32日龄时有了明显升高,提示性腺轴功能已经激活。60日龄大鼠血清性激素水平的波动类似于动情周期的规律性变化,推测大鼠在60日龄前即已进入性成熟,这些结果将为大鼠性发育的相关研究提供重要的参考数据。  相似文献   

9.
海南岛黎母山四眼斑水龟对春季生境的选择性   总被引:11,自引:1,他引:10  
2004年3—4月,在海南岛黎母山采用系统抽样法对四眼斑水龟春季生境选择进行了初步研究。在海拔170~1170m设196个研究样点,共1392个笼捕日。其中在海拔170~470m的26个布笼点共捕获四眼斑水龟36只,而在海拔470~1170m未捕获到四眼斑水龟。采用Kruskal Wallis检验,对海拔500m以下四眼斑水龟利用样地(n=26)和海拔500m以上的对照样地(n=26)的生态因子差异显著性进行检验。结果表明,两类样地的海拔、植被类型、植被盖度、落叶厚度、土壤类型、坡度、水面宽、水深、水面流速、基底类型、露石率、食物丰度、干扰距离13个生态因子差异均显著,仅石洞数目差异不显著。说明海拔500m以上和以下的环境差异较大。主成分分析结果表明,影响四眼斑水龟生境选择的主要生态因子依次为海拔、干扰距离、植被盖度、土壤类型、水深和落叶厚度。而植被类型、食物丰度、露石率、基底、石洞数目、坡度、水面宽和水面流速8个生态因子的影响不明显。保护好近河岸植被和提高当地群众对龟类的保护意识对四眼斑水龟的保护十分重要。  相似文献   

10.
四眼斑水龟低温胁迫条件下体重与形态特征的初步研究   总被引:1,自引:0,他引:1  
在海南的正常温度下,四眼斑水龟(Sacalia quadriocellata)在人工饲养环境中无冬眠现象,也未观察到繁殖行为。为研究冬眠对四眼斑水龟繁殖的影响,于2004年12月~2005年2月对其进行低温胁迫实验。选取29只成体四眼斑水龟分成2组,实验组9♀5♂共14只进行低温处理,在8·46±1·61℃干燥环境中保持32天;对照组10♀5♂共15只在正常条件下饲养。结果表明:低温胁迫后,实验组平均体重减小8·68±2·45%,雌雄差异不显著;雄性个体背甲宽从8·55±0·26cm减小到8·46±0·22cm,差异显著(P<0·05);雌性个体背甲长从12·97±0·80cm减小到12·94±0·81cm,差异显著(P<0·05);雌雄四眼斑水龟甲壳表面积相对低温胁迫前均减小;对照组龟养殖于常温下,甲壳无显著变化,两组龟体重变化量差异极显著(P<0·01)。影响失重率主要因素是胁迫时间,环境温度对失重呈显著线性正相关(r=0·811,P<0·05);形态特征的变化可能与繁殖机制、代谢有关。  相似文献   

11.
2007年7月至2009年6月间,分别于北江中上游及流溪河上游支流采集侧条光唇鱼样本358尾及522尾,对两种群的繁殖生物学特征的差异进行了研究。研究结果显示,两种群雌鱼及雄鱼的最小性成熟年龄均为1 龄,北江种群雌性由1 ~5 龄组成,雄性由1 ~4 组成,性比为雌性:雄性=1:1.73;而流溪河种群雌性由1 ~4 龄组成,雄性由1 ~3 组成,性比为雌性:雄性=1:1.40。北江种群繁殖群体的各年龄组体长及体重均较显著大于流溪河种群。北江种群的繁殖期约为2~10月份,高峰期为3~7月份;而流溪河种群繁殖期为2~8月份,高峰期约为每年的5~7月份;繁殖期内,北江种群雌性及雄性的成熟系数均高于流溪河种群。北江种群各年龄组或体长组的绝对生殖力、体长相对生殖力与体重相对生殖力均极显著地大于流溪河种群。本文结合北江和流溪河在营养状况、捕捞压力及溪流级别上的差异对研究结果进行了分析和讨论。  相似文献   

12.
The annual reproductive cycle of 27 female Mauremys mutica was observed by radiography and ultrasonography from April 2006 to August 2007. Radiography was used to monitor clutch size and ultrasonography was used to monitor changes in the ovarian follicles. The follicles started to enlarge in September and became preovulatory in January. The mean maximum follicle diameter of ovulation was 18.30±1.44 mm, and ovulation occurred from March through August. Eggs were laid between April and August. Turtles entered latent period in early August and the maximum follicular size was at a low of 13.22±2.36 mm in late September. The vitellogenesis of the next reproductive cycle began in October. The 24 adult females laid 56 clutches containing a total of 227 eggs. Average clutch size was 4.05 eggs (range 1–8) and there were 2.33 clutches (range 1–4) per female. Egg shell images were first observed on the sixth or seventh day after ovulation. The oviductal period averaged 6.9 weeks (range 2–16 weeks) on the first clutch, 3.4 weeks (range 2–8 weeks) on the second, and 2.75 weeks (range 2–6 weeks) for the third. Radiography and ultrasonography are non‐invasive and convenient methods to evaluate the reproductive cycle of female M. mutica. They should be applicable to other turtles and should greatly enhance knowledge of reproductive physiology. Zoo Biol 29:50–58, 2010. © 2009 Wiley‐Liss, Inc.  相似文献   

13.
The present study aimed at assessing the annual reproductive cycle of female Arabian carpetshark, Chiloscyllium arabicum from the Persian Gulf by a macroscopic and microscopic evaluation of the reproductive tract. The annual cycle of gonadal steroids [17β-estradiol (E2), progesterone (P4) and testosterone (T)] was also assessed in this shark. In total, 130 female C. arabicum were collected from the Bahrakan Creek (located northwest of the Persian Gulf) between January 2018 and March 2019. Females were oviparous with an external-type ovary and only one functional ovary. Five sexual maturity stages were recognized based on macroscopic and microscopic evaluation: Immature I (August–October), Immature II (November–January), Mature (February–March), Pregnant (April–May) and Spent (June–July). The structural changes in the oviducts, oviducal glands and uterus throughout the annual reproductive cycle were consistent with their roles in the egg movement, the egg capsule production and sperm storage. The plasma levels of the gonadal steroids were associated with morphological changes in the reproductive tract. E2 showed two detectable peaks during March (close to ovulation) and June (just before mating). P4 and T displayed a peak just before ovulation.  相似文献   

14.
Chen TY  Lee YT  Chi CH 《Zoo biology》2011,30(6):689-698
This study presents a combination of radiography and ultrasonography to observe the reproductive cycle of 24 captive female yellow-margined box turtles in Taiwan. Radiography was mainly used to monitor clutch size, whereas ultrasonography was applied to detect changes in the follicles throughout the year. The observation of the 24 female turtles was performed from April 2007 to June 2008. Their average carapace length was 16.62 ± 1.66 cm and their average body weight was 812 ± 164.98 g. The mean clutch size was three (87 eggs/29 clutches) and the reproductive frequency was 95.83% (23/24). Double clutches were detected in 79.2%, and 20.8% had single clutches. Ovulation occurred from March through August, and the average follicular diameter was 2.16 ± 0.18 cm. Follicles entered the latent period in October (at 1.54 ± 0.26 cm), and vitellogenesis of the next reproductive cycle began in November. Using radiography, the eggshell could be detected on the ninth day after ovulation. The average period of the single clutch group was 6.9 weeks (range 5.1-8.5 weeks). In the double clutch group, the average period of the first clutch was 5.5 weeks (range 4-7.8 weeks) and that of the second clutch was 5.2 weeks (range 4-7.8 weeks). This study has advanced the understanding of reproductive physiology of yellow-margined box turtle and established a valuable and practical model for comparative study of the reproductive physiology of other chelonians.  相似文献   

15.
嘉庚蛸雌性生殖系统组织学观察   总被引:2,自引:0,他引:2       下载免费PDF全文
对象山港自然海区中的嘉庚蛸(Octopus tankahkeei)雌性生殖系统的组织学结构进行了研究.结果表明,雌性生殖系统由卵巢、输卵管、输卵管腺组成.卵巢单个、球形,内包裹滤泡细胞围成的卵子,输卵管1对,开口于外套腔中部,每条输卵管中部膨大形成圆球状的输卵管腺.近端输卵管内具两瓣蘑菇状突起,上有不规则短指状分枝,突...  相似文献   

16.
In this study, sexual dimorphism, reproductive cycles, litter size and offspring size of a population of the little‐known species Sceloporus palaciosi in central Mexico were analysed. Significant male‐biased sexual size dimorphism was recorded in snout–vent length (SVL), head length, head width, forearm length and tibia length. Both sexes showed asynchronous reproductive cycles, and males reached sexual maturity at a smaller SVL (33 mm) than females (37 mm). Testes volumes were small from January to February, testicular recrudescence began from March to June, and decreased in July, but increased again in August and September, followed by a second decrease from October to December. In females, vitellogenesis began from May until ovulation in December. Embryonic development extended from November to March, and a small number of females carried embryos through July. Mean litter size was 4.0 and was positively correlated with female SVL. The length of the reproductive period in S. palaciosi recorded in this study is longer than that recorded for other populations in other parts of this species range. Further studies are needed to clarify reproductive cycles in the other isolated populations of S. palaciosi, and then extended to other species and chromosome races in the Sceloporus grammicus complex.  相似文献   

17.
The relationship between ovarian activity and circulating steroid concentration was studied in the female sheath-tailed bat, Taphozous longimanus. T. longimanus breeds twice in rapid succession during the year at Varanasi, India. Ovarian recrudescence was observed during September, and antral follicles were first observed during the month of October. Circulating androstenedione concentration showed an increase beginning in October, reaching a peak in December. This increase in androstenedione concentration correlated with the period of heavy accumulation of adipose tissue and increase in body mass. Antral follicles grow slowly during the period of high circulating androstenedione concentration from October to December. There was a sharp decline in androstenedione concentration during January. Simultaneously with the decline in androstenedione concentration, a sharp increase in size of the antral follicle and circulating estradiol concentration was noticed. Soon thereafter, one of the follicles ruptures, followed by fertilization and the commencement of the first pregnancy. During the second pregnancy, antral follicles first appeared during late pregnancy in March in the contralateral ovary that lacked the corpus luteum. One follicle developed rapidly and quickly attained a preovulatory stage in April. This is reflected in a sharp increase in estradiol concentration during this period. Ovulation was observed immediately following the first pregnancy in May. During this period, androstenedione concentration remained low. The results of the present study suggest that high androstenedione concentration during October to December (winter dormancy) may be responsible for slow follicular development and delays ovulation in T. longimanus. It is further hypothesized that the geographical variation in reproductive pattern of T. longimanus could be due to variation in the duration of fat storage and associated changes in the androstenedione concentration.  相似文献   

18.
Observations relating testes size to body weight in growing and adult Polish Merino rams were performed during 3 consecutive years in a flock of 1700 pedigree ewes. October-born ram lambs were measured for testis diameter (TD), scrotal circumference (SC), and body weight (BW) at 100 (January), 150 (March), 180 (April), 240 (June), 365 (October), and 480 d (February) of age. In adult rams (n = 63 to 73 per year) BW and SC were measured in March, May (prior to breeding), August and October. Semen quality was evaluated before each breeding season, and the results of controlled reproductive performance (2 natural services to designated rams) were analyzed. Indices were applied to relate testis size to body weight: TD BW , SC BW and TW BW . Heritability estimates of testes indices in ram lambs at 100 to 240 d and at 480 d of age ranged from 0.21 to 0.36 (SE = 0.067 to 0.090). In adult rams SC measurements within months in consecutive years were repeatable (r = 0.55 to 0.68; P相似文献   

19.
大鳞裂峡鲃繁殖生物学特征   总被引:1,自引:2,他引:1  
2009、2010和2013年在云南省西双版纳自治州勐腊县境内的南腊河共收集大鳞裂峡鲃(Hampala macrolepidota)样本438尾。研究结果表明:大鳞裂峡鲃雌性群体初次性成熟体长228 mm、体重270.3 g,雄性群体初次性成熟体长205 mm、体重172.5 g,对应年龄均为4龄。大鳞裂峡鲃雌、雄繁殖群体的成熟系数年度变化趋势基本一致。成熟系数值在1月、3月、4月呈逐渐增大趋势,5月显著上升,6月达到最高峰,7月急速下降,8月至9月趋于平缓。繁殖活动每年4月开始,一直可持续至10月,主要集中在5~6月。大鳞裂峡鲃雌雄性比为1︰1.19,与鲃亚科其他部分鱼类雌性数量多于雄性的情况相反;繁殖盛期则雌性数量多于雄性。繁殖群体由4~8龄共5个年龄组组成,雌、雄群体均以5龄组所占比例最大。大鳞裂峡鲃属单次产卵鱼类。平均卵径1.18 mm;绝对繁殖力为63 393粒,相对繁殖力为70.04粒/g。与鲃亚科其他部分鱼类比较,大鳞裂峡鲃的卵径相对较小而繁殖力较大。  相似文献   

20.
The reproductive biology of three introduced Poeciliidae, Gambusia affinis holbrooki Baird and Girard, Xiphophorus helleri (Günther) and X. maculatus (Heckel) was studied over a 14-month period in Brisbane, Queensland. Photoperiod and water temperature determined the length of the breeding season in G. affinis , which produced up to nine broods between August and March, with the peak of reproductive activity in October. Fecundity was linearly related to body weight in G. affinis (mean fecundity = 22.78 ± 1.02, range = 3–108 offspring per brood).
Xiphophorus helleri bred from August to May, producing eight to nine broods, with peak reproductive activity from October to December. Fecundity was curvilinearly related to body weight (mean fecundity = 60.15 ± 3.8, range = 7–183 offspring per brood. Xiphophorus maculatus bred between September and March, producing five to six broods during the study period. Fecundity was linearly related to standard length (s.l.) (mean fecundity = 27.27 ± 2.4, range = 3–92 offspring per brood). Although the reproductive strategy of the three species differs, all have the capacity to build up large populations in south-eastern Queensland. Their present distributions and relative abundance are discussed.  相似文献   

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