PATTERNS OF REPRODUCTION IN FOUR LITTORINA SPECIES

The reproductive periodicities of four Iittorinids, Littorinaneglecta, L. nigrolineata, L. saxatilis and L. arcana were examinedin sympatric populations at Porth Swtan, Anglesey, North Wales.Three species, L. neglecta, L. nigrolineata and L. arcana, werefound to show marked reproductive periodicity. L. saxatilisshowed no periodicity and large numbers of animals were foundin breeding condition throughout the year. The oviparous speciesL. nigrolineata and L. arcana, came into reproductive conditionin the late summer or early autumn, L. nigrolineata in Augustand L. arcana in September, and their populations at Porth Swtanhad few individuals in breeding condition in the late springand early summer. L. neglecta, however, showed a periodicitywith high numbers of breeding animals throughout the springand summer and very low numbers in the autumn. For L. neglectathe basis of reproductive periodicity is shown to be the synchronizedannual life cycle of individuals of this species. It is thereforebelieved to differ from the other three species in which individualsare longer-lived and are supposed to undergo seasonal periodsof reproductive inactivity. (Received 2 March 1982;     

ELECTRON AND PHASE-CONTRAST MICROSCOPY OF SEXUAL REPRODUCTION IN CHLAMYDOMONAS MOEWUSII1

The sexual process of C. moewusii from gametic activation through germination of the zygote has been studied with phase-contrast and electron microscopy. Long strands emerging from the gametic flagellar tips are the site of early flagellar attraction which is followed by union of compatible flagella within common flagellar sheaths. The gametic connecting strand is formed by coordinated elongation of the plasma papillae of a gametic pair and the penetration of the former through their wall papillae while the flagella are in intimate association. After the free-swimming period, the gametic pairs aggregate in a second period of clumping. The connecting strand is abscised and extruded during plas-mogamy as are the flagellar basal bodies. Evidence is presented which suggests union of the gametic plastids, and stages in karyogamy are illustrated. Formation of the wall layers, accumulation of starch and lipids, and changes in plastid organization in the maturing and germinating zygote are described as is the formation of the gonal walls.     

新疆四种螽斯雄性鸣声结构的比较研究

比较分析了新疆短翅姬螽Metrioptera brachyptera(Linnaeus)、疣谷盾螽Decticus verrucivorus(Linnaeus)、灰螽斯Platycleis grisea (Fabricius)和长瓣螽斯Tettigonia caudata(Charpentier)雄性鸣声结构.研究结果表明,短翅姬螽和疣谷盾螽雄性鸣声具单一脉冲序列,灰螽斯和长瓣螽斯雄性鸣声具有多个脉冲序列组成.短翅姬螽脉冲组持续时间为0.290 s ～0.525 s,间隔时间较长,每个脉冲组有6～7个脉冲构成.疣谷盾螽脉冲组持续时间为0.080 s±0.003 s,有6个脉冲构成.灰螽斯的脉冲序列数较多,脉冲序列持续时间为0.20 s～0.27 s,间隔时间较短,为0.20 s～0.40s,有3～4个脉冲组组成,脉冲组持续时间为0.066 s±0.003 s,脉冲组重复率为13.2次/s.长瓣螽斯脉冲序列持续时间为2.590 s ～6.670 s,脉冲组持续时间为0.009 s-0.018 s.     

A COMPARATIVE STUDY OF CHROMOSOMES IN FOUR SPECIES OF THEODOXUS (GASTROPODA: NERITIDAE)

Karyological analysis was performed on Theodoxus baeticus (Lamarck,1822), T. valentina (Graells, 1846), T. velascoi (Graells, 1846)and T. fluviatilis (Linne, 1758), collected from freshwaterbodies of eastern Spain. Cells possessing diploid chromosomenumbers of 2n 5 25 were most common in the tissues of males,whilst 2n 5 26 was most prevalent in females. The sixth pairof chromosomes had only one homologue in mitotic cells of males,indicating the XO/XX sex-determining mechanism. The absolutelength of chromosomes ranged from 1.65 to 6.33 mm. The relativesizes of chromosomes varied from 3.92 to 13.33% of the totalhaploid set length. In all species chromosome pairs no. 1, 4,7-13 were composed of metacentric, pairs no. 5 and 6of submetacentricchromosomes. Pairs no. 2 and 3 were submetacentric, subtelocentricor submeta- subtelocentric according to the species studied.There were significant differences (P, 0.05) among the relativelength, as well as centromeric indices of different chromosomepairs across the species. Karyological differences were greatestbetween T. fluviatilis and three other Theodoxus species. (Received 6 March 2000; accepted 8 May 2000)     

壁虎属四种壁虎微皮纹的比较研究

由于扫描电镜技术的发展,有关蜥蜴类微皮纹结构已有一些研究报道（马克勤等,１９９０;Ｈａｒｖｅｙ,１９９３;Ｉｒｉｓｈ等,１９８８;Ｍａｄｅｒｓｏｎ,１９６６;Ｒｕｉｂａｌ,１９６８;Ｓｔｅｗａｒｔ等,１９７２,１９７３）,并且部分学者尝试将微皮纹特征...     

贵州四种蝾螈科动物的核型和C-带比较研究

我国蝾螈科已知共约5属18种(亚种)(叶昌嫒等，1993)，国内已有一些有关其核型的报道(朱季美等，1981；杨玉华等，1992；谷晓明等，1997)，涉及到大约1/3的种类，其中作了C-带研究的仅我国东南和贵州的3个种及产于日本的2个种(朱季美等，1981；Seto et al，1982；谷哓明等，1997)。本文报道蓝尾蝾螈、无斑肥螈、细痣疣螈和贵州疣螈的核型和C-带。     

光强对四种亚热带树苗生长特征影响的比较

鼎湖山亚热带森林优势树种藜蒴、荷木、黄果厚壳桂和马尾松2－3年生树苗,盆栽于16％、40％和100％的自然光下生长16个月．3种阔叶树无论在全自然光还是在弱光下均能较好地存活,遮光下的马尾松则出现不同程度的死亡．全光下的马尾松、黄果厚壳桂树苗的基径和树高生长大于遮光下的树苗．4个树种的侧枝数均随光照的减弱而下降．在不考虑新老叶更新的情况下,全光下的藜蒴、黄果厚壳桂单株叶片数大于弱光下的树苗,而荷木则相反．如果以全光下单株树苗干物质量为100％,那么在相对光照为40％和16％下生长的马尾松、黄果厚壳桂、荷木和藜蒴单株树苗的干物质量分别为57．4％和32．7％、73．8％和62．1％、78．0％和78．6％、93．9％和76．2％．不同光强下的藜蒴、荷木地上部分干物质量的变化不大,地下部分则随光照的减弱而下降,马尾松、黄果厚壳桂无论地上还是地下部分干物质量均随光强的减弱而明显减少．遮光下生长的3个阔叶树种树苗的冠根比（CRR）、叶重比（LWR）、叶面积比（LAR）和比叶面积（SLA）均高于全光下的树苗．马尾松为喜光树种,对阴生环境的适应能力极为有限;黄果厚壳桂为耐阴树种,在全光下仍然比遮光条件下生长较快．     

贵州北部四种两栖类乳酸脱氢酶同工酶的比较研究

本文采用聚丙烯酰胺凝胶电泳方法,研究了贵州北部的四种两栖类动物:细痣疣螈、棘指角蟾、绿臭蛙和小弧斑姬蛙的心、肝、肾等组织的乳酸脱氢酶(LDH)同工酶,发现LDH具有明显的种族特异性和组织特异性,不同种的动物和同种动物的不同组织都有各自的LDH同工酶谱型,可以用它们作为识别物种的附加指标。本文初步探讨了生化分类学与系统分类学的关系。     

桔梗科4种植物分离配囊的比较研究

应用酶解技术分离出桔梗科四种植物(桔梗、轮叶沙参、杏叶沙参和羊乳)的胚囊。对胚囊的形态结构和贮藏物质的变化作了观察比较。它们的成熟胚囊结构基本相同,均由卵细胞、一对助细胞和中央细胞组成。反足器退化较早。但形态、大小等有一定差异。桔梗胚囊狭长,细胞质浓密;沙参(包括轮叶沙参与杏叶沙参)的胚囊也较狭长,细胞质不如前者浓密;羊乳胚囊非常宽大,而细胞质相当稀薄,与前三种植物的差异较大。它们均含有贮藏物质,显微化学反应表明主要系多糖物质。多糖颗粒的形状、大小各有特点,在胚囊受精前后的消长变化也有不同。其中羊乳与其它三种植物之间的差别较大。     

几种鱼肝细胞核小RNA的比较研究

1968年国外多次报道了哺乳动物细胞核内存在一类代谢稳定的小分子RNA7,8,11,通常称为细胞核内小RNA(简称SnRNA)。       

COMPARATIVE SENSITIVITY OF THREE SPECIES OF CHLAMYDOMONAS TO ANALOGS OF METABOLITES1,2

Twenty-five analogs of metabolites were tested for their ability to inhibit the growth of Chlamydomonas eugametos, C. moewusii, and C. reinhardii. Eleven of the tested analogs were inhibitory to 1 or more species, but only 3 compounds were inhibitory to all 3.     

四种蝗虫前肠形态的比较研究(直翅目:斑腿蝗科)

采用体视显微摄影技术对斑腿蝗科Ｃａｔａｎｔｏｐｉｄａｅ３属４种（亚科）蝗虫前肠形态进行了分析,并对分布于不同地区的同一亚种进行了观察。结果表明,斑腿蝗亚科几种前肠特征同一性很高,同种不同亚种之间略有差异,相同亚种不同地区之间不存在明显差异。     

四种蜡蝉雌性生殖系统比较研究(半翅目,蜡蝉总科)

描述了缘蛾蜡蝉Salurnis marginella(Guérin-Meneville)、八点广翅蜡蝉Ricania speculum(Walker)、斑衣蜡蝉Lycorma delicatula(White)及中华彩象蜡蝉Raivuna sinica(Walker)等4种蜡蝉的雌性生殖系统,并提供了相应的形态特征图。研究结果表明:4种蜡蝉的雌性内生殖系统均为双孔类型;交配管通过阴道与交配囊相连,不直接与交配囊相连;卵巢管为端滋式;阴道、交配囊和受精囊均为双层膜质结构,而卵巢管、侧输卵管则为单层膜质结构。明确了蜡蝉总科昆虫总输卵管与侧输卵管的连接方式,总输卵管为一端固定于阴道内膜,另一端游离于阴道内膜与外膜之间,朝向侧输卵管合并处的透明膜质管状结构。此外,雌性生殖系统中的交配囊、第1产卵瓣、阴道附腺、内生殖突、内生殖瓣等形态特征差异较大。研究标本保存于西北农林科技大学昆虫博物馆。     

THE HORMONAL INTEGRATION OF SEXUAL REPRODUCTION IN OEDOGONIUM

Rawitscher -Kunkel , Erika , and L. Machlis . (U. California, Berkeley.) The hormonal integration of sexual reproduction in Oedogonium. Amer. Jour. Bot. 49 (2) : 177–183. Illus. 1962.—Sexual reproduction in a heterothallic, nannandrous species of Oedogonium was investigated cytologically and physiologically. Several new observations are reported. Oogonial mother cells release a substance which attracts androspores to them. The androspores, when attached to the oogonial mother cells, grow in well-defined directions apparently in response to a hormone originating in the oogonial mother cells. An oogonial mother cell divides into an oogonium and a suffultory cell only after the attached androspores complete their development into dwarf males, each bearing an antheridium. Presumably the developing dwarf males provide a chemical stimulus for the division of the oogonial mother cell. During development, the oogonia become enveloped in a massive gel which also encases the antheridia cut off at the apical ends of the dwarf male plants. The gel appears to function as a sperm trap, preventing the dissemination of the sperm into the surrounding liquid. The sperm are attracted to the protoplasmic papilla which briefly protrudes through the oogonial pore indicating the operation of a second chemotactic agent.     

四种网翅蝗鸣声结构分析(直翅目,蝗总科)

分析了网翅蝗科4种蝗虫雄性的鸣声。研究结果表明,宽翅曲背蝗Pararcyptera microptera meridionalis(Ikonn.)具有2类脉冲组,脉冲组持续时间分别为0.016~0.028s,0.20±0.01s;隆额网翅蝗Arcyptera coreanaShiraki有3类脉冲组,脉冲组的持续时间分别为0.11±0.02s,0.034±0.005,0.885±0.020s。曲线越度蝗Podismopsis sinucarinataZhengetLian每1脉冲序列含4~7脉冲组,脉冲组持续时间为0.023~0.030s;二声越度蝗Podismopsis bisonita Zheng etal.每1脉冲序列含2~4个脉冲组,脉冲组持续时间为0.119~0.140s。     

四种蝗虫雄性鸣声的比较研究(直翅目,蝗总科)

应用计算机技术分析了肿脉蝗Stauroderus scalaris scalaris(Fischer-Waldheim)、宽须蚁蝗Myrmeleotettixpalalis(Zubowsky)、邱氏异爪蝗Euchorthippus cheui Hsia、西伯利亚蝗Aeropus sibiricus(Linnaeus)雄性的鸣声特征.这4种蝗虫雄性鸣声特征差异显著.肿脉蝗雄性鸣声具有脉冲序列的分化,每个脉冲序列分为两种不同的脉冲组,第1种脉冲组持续时间约0.081 s,有7个脉冲串组成,每个脉冲串有7个单脉冲构成;第2种脉冲组持续时间不等,有13～18个脉冲串组成,脉冲串持续时间为0.021 s,间隔为0.010 s.鸣声的主能峰频率约8.62 kHz.宽须蚁蝗雄性鸣声的脉冲组持续时间为0.23 s,脉冲组间隔为0.35 s,每个脉冲组由28～31个单脉冲组成,主能峰频率为6.89 kHz、12.75 kHz.邱氏异爪蝗雄性鸣声的脉冲组持续时间为0.22 s,脉冲组间隔为0.76 s,每个脉冲组由6～7个脉冲串组成,每个脉冲串内含有1～5个单脉冲,主能峰频率为9.65 kHz.西伯利亚蝗的脉冲组持续时间约为0.092 s,脉冲组间隔为0.08 s,每个脉冲组分化为5～6个脉冲串;主能峰频率为7.58 kHz.     

四种菊头蝠染色体组型分析

本文分析了皮氏菊头蝠(R. pearsoni chinensis),鲁氏菊头蝠(R.rouxi sinicus),角菊头蝠(R.cornutus pumilus)及中菊头蝠(R.affinis)的常规核型,现报道如下。