Laser scanning fluorescence microscopic measurement of the movement of cleaving egg surface of Rana Amurensis

By laser scanning fluorescence microscopy for quan-titative measurement of fluorescence intensity changes on egg surface stained with fluorescein isothiocyanate duxing cleavage furrow extending forward, it was found that in area of presumptive cleavage furrow the scanning curve became ∨ shape, indicating dark stripe appeared in that place. Then the fluorescence intensity increased at the place where the botton of ∨ shape had located, and the scanning curve tuxned to ∧ shape, indicating single stripe was formed. While enhanced fluorescence appeared on the borders of ∧ shape, an M shape curve was found, show-ing double stripe occurred. During the distance between two borders of M shape incresing from 50 μm to 100μm,a fluorescence peak came to sight in the middle of the M shape, which being the cleavge furrow bottom. The two lateral sides of furrow bottom with decreasing fluorescence were nascent membrane. At that time the curve became W shape. By the sides of cleavage furrow the the stress folds became conspicous after double stripe stage, showing the stretching of the egg surface being increased. With our[31, 33] and others[32] reports that polylysine could induce the appearance of nascent membrane and phyto-hemagglutinins could decrease or prevent the appearance of nascent membrane, we believed the idea of Schroeder[25] that increasing mechanical stress could initiate nascent membrane formation and thought that the stress lay to the outsides of cleavage furrow.

Prehibernation Energy Storage in Heilongjiang Brown Frogs(Rana amurensis) from Five Populations in North China

Energy storage is an important component in the life history of species that directly inlfuences survival and reproduction. The energetic demands of amphibian reproduction can differ between the sexes, with environmental conditions, reproductive pattern or process of the species, and depending upon the timing of breeding, and the reproductive season for a species. Surprisingly, comparative studies of pre-hibernation energy storage for anuran populations from different latitudes are relatively few in Asia, especially in China. Here we investigated the patterns of pre-hibernation energy storage of Heilongjiang brown frogsRana amurensis, based on ifve populations along a ifnely latitudinal gradient in north China （40.7–43.7°N）. We found that pre-hibernation energy storage of the frogs did not show a clear latitudinal cline, but differed strongly between the sexes, with males depositing more energy reserves into the muscle and liver, whereas females accumulate more energy in the gonads. The sexual differences in energy storage may result from differential timing of energy allocation for reproduction.

黑龙江蛤蟆Rana amurensis Boulenger的早期胚胎发育

黑龙江蛤蟆Rana amurensis又称黑龙江林蛙,通称哈士蟆。分布在东北各地。这种蛙的肉味鮮美,营养丰富,当地居民常常食用,有的单位正在研究养殖。同时,这种蛙在消灭农业害虫方面也具有一定作用。所以它是有益动物。可是,关于黑龙江蛤蟆生物学特征的研究还很少,尤其是早期的胚胎发育似乎还沒有人报导过。为了給今后的教学和科研等方面积累几許材料,我們做了一些有关黑龙江蛤蟆早期胚胎发育的工作。近年来許多学者对蛙形目早期胚胎发育的分期曾进行过不少研究,据我們初步所得的材料而言,国外有A. W. Pollister和J. A. Moore(1937)

Age and body size of Rana amurensis from northeastern China

Age and body size are two important demographic traits that determine the life history strategies of populations and species. We measured these two parameters ofRana amurensis, at a 900 m and a 500 m altitude site in northeastern China. At the two sites, age at first reproduction was 2 years for males and 3 years for females. The maximum age of males and females at the high-altitude site was 6 and 7 years, and 5 and 7 years at the low-altitude population, respectively. Females were significantly larger than males in both populations, due to greater age in both the high- and low-altitude sites, Body size of either males or fe- males did not differ significantly between populations; only males showed increased body size at the high-altitude site when age effect was statistically controlled for. The increased cline of male body size may be attributable to delayed maturation of the sex due to a shorter growing season at high altitudes