粗糙沼虾卵巢发育的组织学

利用组织切片技术,对粗糙沼虾的卵子发生和卵巢发育周期进行了组织学研究。根据细胞的大小、细胞核和核仁的大小形态及卵黄积累等情况,将卵子发生划分为4个时期,卵原细胞、卵黄合成期的卵母细胞、成熟前期和成熟期。卵黄合成期的卵母细胞又可细划分为3个时期。粗糙沼虾卵巢发育具有一定的规律性。根据卵巢的大小和颜色及每种雌性生殖细胞在卵巢中所占的比例,将卵巢发育划分为7个时期。并通过卵巢发育规律的探讨,对粗糙沼虾的人工养殖提出了合理的建议。     

切除眼柄对加速克氏原螯虾卵巢发育进程的组织学研究

应用组织切片和透射电镜技术研究眼柄切除对加速克氏原螯虾(Procambarus clarkii)卵巢发育进程的影响。实验分成4组,选取眼柄切除15 d和30 d两个时间点进行。切除眼柄30 d后,雌虾体长增长显著,从(11.50±2.30)cm增长至(18.20±3.40)cm(P0.05),性腺指数(GSI)从4.56%±2.81%增长至8.05%±2.51%(P0.05),体重和螯肢长也有所增长(P0.05)。电镜观察发现卵母细胞从发育Ⅱ期迅速度过Ⅲ期进入到Ⅵ期阶段,卵母细胞体积变大,变圆;液泡压缩变小;卵黄颗粒加速积累,逐渐占满整个胞内空间;滤泡细胞胞质从黏稠变稀薄。这些结果表明,切除眼柄在短期内显著加快卵母细胞内卵黄颗粒的积累,并且加快个体生长。     

洞庭湖克氏原螯虾肌肉成分分析及品质特性分析

通过对洞庭湖克氏原螯虾肌肉成分进行分析, 并与其他产地克氏原螯虾进行比较, 进而较为科学的评定其品质特性。结果表明: 克氏原螯虾含肉率为20.21%, 水分和灰分含量分别为79.46%和1.17%, 粗蛋白和粗脂肪含量分别16.67%和0.77%; 对肌肉的质构特性分析表明克氏原螯虾肌肉硬度小, 易咀嚼; 肌肉中含18种氨基酸, 其中包括8种必需氨基酸, 必需氨基酸指数为80.02%, 氨基酸总含量为16.06%, 鲜味氨基酸含量为5.98%; 依据氨基酸化学评分, 克氏原螯虾的第一限制性氨基酸是含硫氨基酸(甲硫氨基酸和胱氨酸), 第二限制性氨基酸是缬氨酸。测定了克氏原螯虾肌肉中15种脂肪酸占肌肉鲜质量的含量, 其总脂肪酸含量为6.66‰, 其中不饱和脂肪酸含量为4.94‰, n-3与n-6多不饱和脂肪酸比值为1.73。综上所述, 洞庭湖克氏原螯虾具有较高的食用价值和养殖价值。     

桂林地区克氏原螯虾对泽蛙蝌蚪的捕食

克氏原螯虾（Procambarus clarkii）已入侵我国江苏、湖北、江西、安徽等多个省（市）。为研究克氏原螯虾对其生境中主要两栖动物泽蛙（Rana limnocharis）的影响,我们于2006年5-6月对广西桂林地区自然生境中克氏原螯虾和泽蛙蝌蚪的数量和密度进行了调查,7月在室内进行了克氏原螯虾对泽蛙蝌蚪和饰纹姬蛙（Microhyla ornata）蝌蚪的捕食实验。野外调查结果表明克氏原螯虾的密度与泽蛙蝌蚪的密度呈显著负相关。室内实验结果表明克氏原螯虾对泽蛙蝌蚪的捕食强度与克氏原螯虾体长呈显著正相关,且对泽蛙蝌蚪的捕食强度高于饰纹姬蛙蝌蚪。表明克氏原螯虾对两栖类幼体有比较严重的危害,应加强监测,采取相应措施预防和控制其危害。     

克氏原螯虾的入侵生态学研究进展

克氏原螯虾(Procambarus clarkii)原产于美国南部和墨西哥北部,是一个著名入侵物种,作为一种水产经济资源物种在世界各地扩散。克氏原螯虾抗逆性强,所具有的广泛生境适应性、生长迅速、高生殖率等特点使它们迅速建立野生种群。近10余年的研究认为,克氏原螯虾通过捕食和资源竞争等机制严重威胁引入地的水生植物、无脊椎动物、两栖类等的生存,显著降低引入地的生物多样性。当前,由于克氏原螯虾的经济价值高,它会借助于人力的作用而继续扩散。为认清和减少克氏原螯虾对引入地的生态影响,应加强以下方面的研究:1)在中国开展克氏原螯虾的生态危害的调查和研究;2)克氏原螯虾种群调节和控制对策研究;3)被入侵地的生态恢复工作。     

稻虾田黄鳝的食物组成及其对克氏原螯虾捕食强度研究

文章研究了稻田黄鳝(Monopterus albus)天然饵料生物资源、稻田黄鳝对克氏原螯虾(Procambarus clarkii)捕食选择及不同投喂策略下黄鳝对克氏原螯虾的捕食强度,旨在为构建与优化稻-虾-鳝综合种养模式提供依据。结果表明,稻田中黄鳝天然饵料生物种类丰富,达16种(属);克氏原螯虾是黄鳝最喜猎物,其次为米虾,再次为蚯蚓和水生寡毛类;稻田黄鳝自然生长期间,其胃和肠前端食物团中,克氏原螯虾重量百分比均显著高于其他猎物,其中8月份占比最大,达93.90%, 4月份占比最小,为76.85%;当克氏原螯虾为唯一食物时,每尾大规格成鳝(≥200 g)日均捕食量为(1.63±0.065) g;当克氏原螯虾、米虾和蚯蚓作为食物时,黄鳝主要捕食克氏原螯虾且不捕食蚯蚓,对三者的选择指数分别为0.066、–0.266和–1;若以克氏原螯虾、鱼糜-饲料为食物时,黄鳝主要摄食鱼糜-饲料,极少捕食克氏原螯虾,对两者的选择指数分别为–0.846和0.591。     

不同施肥模式对克氏原螯虾稻田养殖水体浮游植物群落结构的影响

为探讨在克氏原螯虾(Procambarus clarkii)稻田养殖水体中施用不同肥料对浮游植物群落结构的影响,以湖北省荆州市太湖农场稻虾模式试验基地为场所,于2019年4—5月进行试验,设置施化肥、施有机肥和施有机-无机复混肥3个处理.每块稻田中克氏原螯虾的放养密度为2.30ind/m2.结果发现,施化肥、施有机肥和...     

对虾白斑综合征病毒新株型WSSV-CN-Pc的毒力研究

对虾白斑综合征病毒(white spot syndrome virus,WSSV)是一种能够感染虾类并且造成其大面积死亡的环状双链DNA病毒。WSSV有多种分离株,其毒力有所差异。从克氏原螯虾(Procambarus clarkii)中分离得到1株WSSV新分离株WSSV-CN-Pc,其毒力尚不清楚。本研究采用肌肉注射和经口注射的方法,以WSSVTW型作为阳性对照,分别对克氏原螯虾(P.clarkii)和罗氏沼虾(Macrobrachium rosenbergii)进行活体实验。实验结果显示:肌肉注射WSSV-CN-Pc和WSSV-TW的克氏原螯虾均在第6天出现100%的死亡;罗氏沼虾在肌肉注射WSSV-TW后未出现死亡,但在注射WSSV-CN-Pc后的第9天死亡率达100%。经口注射WSSV-CN-Pc和WSSV-TW的克氏原螯虾均在第16天出现100%的死亡;罗氏沼虾经口注射WSSV-CN-Pc后的第19天死亡率为100%,但注射WSSV-TW的实验组并未出现死亡。结果表明,对于克氏原螯虾,WSSV-CN-Pc具有和WSSV-TW相似的毒力,而对罗氏沼虾存在明显的毒力差异。提示克氏原螯虾是WSSV传播途径中的重要因素。     

基于生态位模型的外来入侵种克氏原螯虾在中国的适生区预测

克氏原螯虾在20世纪初作为重要的水产品引入中国,但因其繁殖能力强、生长迅速、适应性强、喜掘洞穴,对农作物、池埂及农田水利有一定破坏作用,降低入侵地区当地物种多样性,对当地生态系统造成严重危害。因此,研究未来气候情景下克氏原螯虾适生区的变化,可为其监控和管理措施提供关键信息,有效预防和控制其蔓延。本研究基于克氏原螯虾的分布点,应用最大熵(MaxEnt)模型和规则集遗传算法(GARP)模型模拟了当前气候条件下克氏原螯虾在中国的潜在适生区,并预测了2041—2060年和2061—2080年克氏原螯虾在4种气候变化情景下(RCP 2.6、RCP 4.5、RCP 6.0、RCP 8.5)的分布,采用ROC曲线对预测结果进行检验和评价。结果表明: 在当前气候条件下克氏原螯虾集中分布在上海、江苏、浙江、安徽等长江沿岸地区;最冷季平均温度、最冷月最低温度对克氏原螯虾分布影响最大,其次是温度季节性变化、最暖月最高温度和最干月降水量。在未来气候情景下,2061—2080年克氏原螯虾的适生区面积有不同程度的变化,在RCP 2.6和RCP 4.5情景下总适生面积增加,但在RCP 8.5情景下呈先增后减趋势,而在RCP 6.0情景下无明显变化;克氏原螯虾适生区在空间分布上不仅有纬度方向上的扩散,也有向海拔较高地区迁移的趋势。     

克氏原螯虾洞穴的生态特征及其对水利工程安全影响的初步研究

在分类学上,克氏原螯虾(Procambarus clarkia(Girard))隶属于节肢动物门,甲壳纲,十足目,爬行亚目,螯虾科,原螯虾属[1]。克氏原螯虾为外来物种,原产于北美洲,主要分布在美国南部和墨西哥北部,1930年引入日本,约在20世纪40年代由日本引入我国南京[2],由于食性广、繁殖快、生长迅速、适应性强,现在已成为分布于长江中下游地区一些水域虾类资源的优势种群。克氏原螯虾具有掘洞的习性,洞穴在其生活史中是重要的环境要素,因此人们一直担心其对江河大堤和水库大坝会造成危害[3]。国外对克氏原螯虾的穴居行为以及对农田的危害作过一些研究[4—6],但国内类似的研究以及有关克氏原螯虾对水利工程影响的研究尚属空白。作者就克氏原螯虾掘洞生态习性及其对堤坝工程安全影响开展了初步研究,以期为有关部门采取有效措施来降低其不利影响和根除隐患,确保水利工程的安全提供一些科学的决策依据。1材料与方法1·1研究区域研究区域为长江中下游地区的湖南、湖北、江西、安徽、江苏和上海五省一市,该区域克氏原螯虾种群分布较多,洪水发生频率较高。研究水体为江河、湖泊、水库、塘堰和沟渠,重点研究长江干流荆江段、鄱阳湖、洞庭湖、三湖连江水库...     

Gross morphology of ovarian changes during the reproductive cycle of Indian lizards (Calotes versicolor and Hemidactylus flaviviridis).

A comparative study has been made of the reproductive cycle and gross ovarian changes in two species of Indian lizards (Calotes versicolor and Hemidactylus flaviviridis), which are oviparous. They exhibit a single, short breeding season that extends over a few months. Calotes ovalutes 10 to 32 eggs per clutch (the highest number recorded so far for lizards belonging to the family Agamidae) from last week of June to the first week of September, with July through August being the months of highest reproductive potential when monsoon occurs. From October to May, there occur reduced ovaries containing small previtellogenic follicles which begin to increase in size with the approach of June when heavy yolk deposition occurs. Hemidactylus ovulates from mid-March to mid-May, with a peak in April when there occurs an appreciable increase in day length and temperature. It usually ovulates two eggs per clutch (one from each ovary). From June to the 3rd week of February, the ovaries remain small whitish bodies, each containing 3 or 4 small previtellogenic follicles of variable size which, with the approach of March, begin to increase in size by accumulating yolk. Various indirect evidences suggest that both the lizards lay more than one clutch of eggs during the breeding season.     

雅鲁藏布江黑斑原鮡繁殖生物学研究

对2004-2006年采集于雅鲁藏布江拉萨河的190尾黑斑原鮡进行了繁殖生物学研究。雄性最小性成熟(精巢Ⅳ期)个体体长141.7mm,体重45.2g,性体指数1.09%,雌性最小性成熟(卵巢Ⅳ期)个体体长146.8mm,体重66.7g性体指数11.52%,相应年龄均为5龄。初次性成熟年龄(L50):♂,170.1mm相应年龄为7龄;♀,150.2mm,相应年龄5龄。通过组织切片法和GSI的周年变化分析,繁殖时间集中在5-6月,每年繁殖一次,繁殖之后的6-8月卵巢从Ⅵ期回复到Ⅲ期,9月卵巢发育到Ⅳ期越冬。卵径频率分布显示,卵巢发育类型为分批同步型,卵巢中至少存在2批卵径,每年成熟一批卵并同时产出,产卵类型为完全同步产卵。卵黏性,成熟卵卵径在2.04-3.37mm之间,平均(2.83±0.16)mm。对19尾产卵前夕(体长为151.0-210.0mm)的标本进行统计,其绝对繁殖力范围在525-2058粒之间,平均为(1244±346)粒,相对繁殖力为(14.7±5.8)粒/g。绝对繁殖力与体长呈直线正相关,表达式为F=13.624L-1187。       

湖南沅水下游?繁殖期内繁殖力和卵径的变化研究

为分析鱼类繁殖期内繁殖力和卵径变化趋势, 研究于4—10月在沅水下游逐月采集180尾?(Hemiculter leucisculus), 分析81尾雌性成熟个体的繁殖力。研究结果表明: ?的性体指数在5、6月最高, 其次在7、8和9月, 在4和10月最低。绝对繁殖力平均值为(30116±19390)粒, 以10000—30000粒为主, 相对繁殖力的平均值为(650±324)粒/g, 以400—800粒/g为主。绝对繁殖力与体长、空壳重呈幂函数关系(P<0.05)。绝对繁殖力和相对繁殖力在5和6月最大, 7、8和9月次之, 在4和10月最小。不同月份成熟卵子的卵径无显著差异, 补充卵子的卵径在5和6月最大, 暗示5和6月分批繁殖次数较多。不同繁殖时期的分批繁殖力、繁殖次数不一样, 对评估种群的繁殖潜能具有重要的指导意义。比较不同水系繁殖力发现, 湖泊种群的个体繁殖力普遍大于河流种群, 沅水种群的个体繁殖力跟湖泊种群的相似, 可能与其具有类似湖泊的缓流水或静水生境有关。研究揭示了?的基本繁殖特征, 为渔业资源管理提供了基础数据资料。     

The testicular cycle of Gambusia affinis holbrooki (Teleostei: Poeciliidae)

Fifteen male mosquito fish ( Gambusia affinis holbrooki ) were collected in 1989 on the 15th of each month to perform a quantitative histologic study of the annual testicular cycle including a calculation of the gonadosomatic index, testicular volume, and the total volume per testis occupied by each germ cell type. The cycle comprises two periods: spermatogenesis and quiescence. The spermatogenic period begins in April with the development of primary spermatogonia into secondary spermatogonia, spermatocytes and round spermatids. In May, the first spermatogenic wave is completed and the testicular volume begins to increase up to June when the maximum testicular volume and gonadosomatic index are reached. Germ cell proliferation with successive spermatogenetic waves continues until August. In September germ cell proliferation ceases and neither secondary spermatogonia nor spermatocytes are observed. However, spermiogenesis continues until October. In November, spermiogenesis has stopped and the testis enters the quiescent period up to April. During this period only primary spermatogonia and spermatozoa are present in the testis. In addition, a few spermatids whose spermiogenesis was arrested in November are observed. Testicular release of spermatozoa is continuous during the entire spermatogenesis period. The spermatozoa formed at the end of this period (September-October) remain in the testis during the quiescent period and are released at the beginning of the next spermatogenesis period in April. Developed Leydig cells appear all year long in the testicular interstitium, mainly around both efferent ducts and the testicular tubule sections showing S₄ spermatids.     

Oviductal sperm storage structure and their changes during the seasonal (dissociated) reproductive cycle in the soft-shelled turtle Lissemys punctata punctata

The oviduct of the Indian fresh water soft-shelled turtle Lissemys punctata punctata was examined throughout the year under light and scanning electron microscopes to determine the location, histomorphological characteristics, and function of sperm storage structure, as well as their changes at different phases of the seasonal reproductive cycle. Sperm storage structures in the form of tubules were observed in the wall of isthmus throughout the year. These tubules developed either by folding or fusion of the oviductal mucosal folds and were lined by both ciliated and nonciliated epithelial cells. The height and secretory activities of the epithelia were markedly high during the breeding phase (August to September) but low in the nonbreeding phase (October to June). A few short tubules lined by cuboidal epithelium appear in the wall of infundibulum only during the breeding phase. Following mating (May), inseminated sperm were stored within the tubules of isthmus up to the pre-ovulatory stage (August). Thereafter, sperm associated with PAS-positive materials secreted from the epithelium (referred to as a carrier matrix) moved forward to the infundibulum and were stored within the storage tubules of the infundibulum for a short time. Subsequently, sperm evacuated the storage tubules and entered the oviductal lumen to fertilize the subsequently ovulated eggs during or prior to ovulation. The isthmus-tubules become shorter and narrower in the regressive phase (October to November) and remained so until the early preparatory phase (April). Sperm release might have been stimulated by estrogen secreted from the ovarian follicles of pre-ovulatory turtles. Stored sperm not utilized for fertilization remained viable not less than six months in the present turtle species.     

Seasonal changes in plasma testosterone concentrations and Leydig cell and accessory gland activity in the Cape horseshoe bat (Rhinolophus capensis)

Male Cape horseshoe bats were studied in the Cape Province of South Africa (33 degrees 17'S, 26 degrees 25'E) between January 1983 and June 1985. The reproductive cycle is characterized by reactivation of the seminiferous tubules in early summer (October) after a 4-month (June to September) period of winter inactivity. Spermiogenesis occurred between January and April, and spermatozoa were released to the epididymides in April and May. Spermiogenesis was associated with Leydig cell activity and increasing plasma testosterone concentrations. At this time components of the reproductive accessory glands became secretorily active or showed increasing secretory activity. During winter Leydig cells were secretorily inactive and plasma testosterone concentrations dropped, but components of the accessory complex remained active. There was a second period of Leydig cell secretory activity and increasing and peak plasma testosterone values in late winter/early summer which may be associated with copulation or the initiation of a new cycle of spermatogenesis.     

Seasonal reproductive cycle in relation to tolerance to high temperatures in the terrestrial slug Lehmannia valentiana

Abstract. Seasonal maturation of the gonad (hermaphrodic gland) was examined in the terrestrial slug Lehmannia valentiana in Osaka, Japan. The ratio of the gonad weight to body weight was low in June–September, rapidly increased in October, and gradually decreased thereafter. In May–September, most slugs had only spermatogonia and spermatocytes, and all slugs had mature sperms in October–April. The oocyte size increased in September and large oocytes were observed in late October–April. Under natural temperature and photoperiodic conditions in Osaka, slugs laid eggs in early November–May. Therefore, this species reproduces from late autumn to spring, in contrast to many terrestrial slugs. In January–early February, however, the number of laid eggs was small and oviposition activity showed a bimodal seasonal pattern. In contrast, the hatching pattern was unimodal and most hatching was observed in spring. After a 1-h exposure to 33°C, the survival rate was 100% in juvenile slugs but 0% in eggs. Although hatching success was >85% at 15°–20°C, no eggs hatched when they were maintained at 25°C. The heat susceptibility of eggs in this species may be one of the key factors restricting oviposition from late autumn to spring.     

c-fos和c-myc在北方山溪鲵精子发生中的表达

用免疫组织化学方法检测原癌基因cf-os和c-myc蛋白在北方山溪鲵(Batrachuperus tibetanus)精子发生中的表达定位。结果显示,在精原细胞缓慢增殖期,8、9月,FOS阳性反应物出现在精原细胞的胞质及核膜外,10、11月,FOS在少量精原细胞的胞核中表达。在精原细胞快速增殖期,即翌年4月,FOS定位在精原细胞的胞质中;5月,FOS在大量的胞核中强阳性表达;6月,FOS定位于部分精母细胞核质和核膜下;7月,FOS在一些精子细胞的核质和核膜下表达。MYC在8、9月的部分精原细胞胞质中表达较弱,在101、1月阳性反应出现在个别精原细胞的核质中。翌年4月,MYC在精原细胞核周围的胞质中表达;5月在大量的精原细胞核膜下有强表达;6月,MYC在一些精母细胞核膜下表达;7月,MYC在部分精子细胞的核膜下弱表达。结果表明,北方山溪鲵的原癌基因cf-os和c-myc表达大强度在生精细胞发育中呈阶段性,表达的强度和细胞数量与细胞增殖的速度相一致。FOS和MYC在精原细胞内从胞质向胞核的转移与细胞快速增殖的时期相吻合。说明cf-os和c-myc对精原细胞有丝分裂有促进作用,并参与精母细胞成熟分裂的调控。     

Ovarian and behavioral cyclicity of the laboratory maintained cat

This study examined the sexual behavior-ovarian activity relationship of the laboratory cat maintained under consistent environmental conditions. Mean (±SEM) lengths of estrus for nonovulating, mated ovulating, and human chorionic gonadotrophin (HCG)-induced ovulating queens were 5.8 ± 0.17, 6.5 ± 0.75, and 10.0 ± 0.65 days, respectively. The duration of estrus was significantly (P < 0.01) longer in HCG-treated queens in comparison to the nonovulating or mated ovulating groups. No differences were observed in the number of behavioral estrous periods detected monthly. Duration of estrus was affected by season with significantly shorter periods of estrus observed in June (P < 0.05), September (P < 0.05), October (P < 0.05), and November (P < 0.01) compared to the March, April, May, August, or December averages. Length of estrous cycle (from Day 1 of estrus to Day 1 of next estrus) was variable (range: 6–120 days); however, 49.8% of the estrous cycles were 12 to 21 days in length. Although the ovaries of queens displaying sexual receptivity always contained developing or mature foilicles, ovaries of cats showing no estrous behavior also showed patterns of follicular development and regression at 14- to 19-day intervals. These results suggest that the estrous cycle of the laboratory maintained cat varies from 2 to 3 weeks in duration and that reproductive behavioral patterns alone are not always an accurate indication of ovarian activity or duration of the reproductive cycle.     

Reproductive cycles ofSebastes taczanowskii,compared with those of other rockfishes of the genusSebastes

Synopsis Seasonal reproductive cycles were examined in both sexes ofSebastes taczanowskii, captured in southern Hokkaido, Japan. The reproductive cycle in females was divided into four periods: recovery (July–August), vitellogenesis (September–March), gestation (April–May) and parturition (June). Spermatozoa were first observed in November in the ovarian cavity, where no structural specialization was present for sperm storage. Fertilization of oocytes appeared to occur in April, when the oocytes underwent a rapid process of final maturation. Embryos developed in the ovary quite synchronously and were released in June; empty ovaries indicated the rockfish has a single parturition. The reproductive cycle in males comprised five periods: resting (December–July), early maturation (February–May), mid-maturation (June–August), late maturation (September–October) and functional maturation (November). In November when active spermatogenesis had been completed, a large amount of spermatozoa was preserved in the sperm duct, and the males were therefore ready for mating. A comparison was made of the reproductive cycles of four species of the genusSebastes inhabiting southern and northern waters of Japan. It suggests that the northern species tend to prolong gametogenesis in both sexes while the southern species have the opposite tendency. Sperm storage in the ovary also tends to be longer in the northern than in the southern species.