广西棱皮树蛙Theloderma kwangsiensis生物学初步研究

2010年至2012年对海南鹦哥岭两栖类动物进行了调查,野外采集到广西棱皮树蛙Theloderma kwangsiensis的蛙卵,对蛙卵进行了人工孵化,对蝌蚪与幼蛙进行了人工饲养。结果显示:该蛙繁殖时间为3月中旬,蛙卵孵化时间为14 d,6个月左右完成变态,蝌蚪唇齿式为Ⅰ∶2+2/1+1∶Ⅱ。该蛙种群数量极其稀少,建议加强保护。     

昆嵛林蛙胚后发育的初步观察

昆嵛林蛙（Rana kunyuensis,Lu et Li2002）是新近在山东文登昆嵛山发现的蛙科（Ranidae）蛙属（Rana）林蛙群（Wlld-frogs）的一新种。我们在23.7-26.0℃的条件下,观察了其胚后发育全过程中的形态变化。该蛙胚后发育可划分为19期,历时约49d。唇齿式多为Ⅰ：1-1/Ⅲ、少数Ⅰ：1-1/Ⅱ：1-1,为昆嵛林蛙这一新种的确立提供了形态学依据。     

粤北山区饰纹姬蛙胚后发育的初步观察

初步观察记录了饰纹姬蛙Microhyla ornata胚后发育过程。饰纹姬蛙的卵采于广东韶关小坑国家森林公园,置于人工实验缸中自然孵化,在23.0～28.7℃水温条件下观察饰纹姬蛙蝌蚪胚后发育的过程。该蛙的胚后发育可以分为19期,历时31.1d,对其后肢芽、趾、前肢的发育,以及肛管及尾的变化等方面做了系统的描述,饰纹姬蛙蝌蚪的头长、体长、尾长和后肢长度随发育时间的增加而显著增长。     

小弧斑姬蛙胚后发育的初步观察

初步观察记录了小弧斑姬蛙Microhyla heymonsi胚后发育的过程。在22.9～27.3℃的温度条件下,观察了其胚后发育全过程中的形态变化。该蛙胚后发育可划分为19期,历时35.7d。小弧斑姬蛙蝌蚪的头长、体长和后肢长度随发育时间的增加而增长。对其胚后发育各个阶段的后肢芽、趾、前肢的发育,以及尾的变化等方面做了系统的描述。讨论并比较了该蛙和其他蛙胚后发育的特点。     

云南昆明地区4种蝌蚪形态比较研究

作者比较了采自昆明东北郊的滇蛙Rana pleuraden、昭觉林蛙Rana chaochioensis、华西蟾蜍eufo andrewsi和云南小狭口蛙Calluella yunnanensis的蝌蚪。结果表明,4种蝌蚪口部形态、尾形、出水孔和肛管开口位置在第Ⅰ、Ⅱ期稳定。滇蛙蝌蚪唇齿式为Ⅰ：1—1／1—1：Ⅱ;有一出水孔位于体左侧,肛管开口于下尾鳍基部右侧,尾末端尖、短。昭觉林蛙蝌蚪唇齿式为Ⅰ：2—2／1—1：Ⅲ;有一出水孔位于体左侧,肛管开口于下尾鳍基部右侧,尾末端为尖、短。华西蟾蜍蝌蚪唇齿式为Ⅱ／Ⅲ;有一出水孔位于体左侧,肛管开口于下尾鳍基部正中,尾末端钝,几乎呈半圆。云南小狭口蛙蝌蚪无唇齿及唇乳突,口位于吻端,口缘膜状,口部马蹄形,出水孔位于腹部后端中线处;肛管开口于下尾鳍基部正中;尾末端尖,细长。肛管在下尾鳍基部的开口位置可作为蝌蚪分类特征。     

介绍一种蛙类胚胎及蝌蚪发育的分期

以蛙类发育过程中的形态结构或生理特征为标志,对蛙类胚胎及胚后发育进行分期,便于对它们的发育进程进行描述,以及对发育与外界条件的关系进行比较研究。在恒温条件下培育蛙胚,可以作出能为今后重复验证的发育时刻表。比较不同蛙种的发育时,也应在相同的恒温条件下进行,才具可比性。分类学上描述蛙种时,蝌蚪也是被描述的对象。但过去描述蝌蚪,多数采用“当后肢长度若干毫米时,蝌蚪全长为若干毫米。”应用这一方法,很难与其他蛙种作比较,因为发育的水温不同和营养物丰歉不同,蝌蚪的生长速度差别很大,后肢与全长的比例关系也会产生变化。因此,制订一个比较适合多数蛙种通用、又易于掌握的蛙     

山东昆嵛山蛙属林蛙群一新种(两栖纲:无尾目:蛙科)

在山东省胶东半岛昆嵛山采集到林蛙类及其蝌蚪标本,与中国林蛙Raha chensinensis具背侧褶弯曲等特征极相似,但有以下主要区别;无声囊,无雄性线,雄性第1指婚垫分2团,蝌蚪唇齿式多为Ⅰ：1-1/Ⅲ,少数为Ⅰ：1-1/Ⅱ：1-1。此蛙与已知林蛙其它种有明显区别,故定为新种,即昆嵛林蛙Rana kunyuensis sp.nov。     

中国蛙类一新种(无尾目,蛙科)

描述了1种采自广西猫儿山国家级自然保护区的蛙类1新种,模式标本保存于沈阳师范大学自然博物馆.猫儿山林蛙,新种Rana maoershanensis sp.nov.(图1～17)正模:SYNU 06020120,雄性成体,李丕鹏和王绍能于2006年2月采集自广西壮族自治区猫儿山国家级自然保护区,海拔1 980 m.配模:SYNU 06020091,SYNU 06020122和SYNU06020124,雄性成体;SYNU06020121,SYNU06040153,SYN 0604154和SYNU 06040155,雌性成体.李丕鹏和王绍能于2006年2月和4月采集,采集地点与正模相同.蝌蚪:SYNU0602001和SYNU 0604001系列,采集信息与配模标本相同.新种具有如下主要鉴别特征:1)体略大;2)头宽略大于头长;3)背侧褶明显且略弯曲;4)胫跗关节前达眼角;5)雄性婚垫2团,无内声囊,腹部无雄性线;6)蝌蚪唇齿式多为Ⅰ:3-3/Ⅲ:1-1,少数为Ⅰ:3-3/Ⅳ.新种在头型上与中国林蛙相似,在体形上与昭觉林蛙相似.但与已知林蛙均有明显不同.新种的背侧褶略显弯曲,这一特点明显不同于主要分布于中国北方的黑龙江林蛙种组Rana amurensis group和中国林蛙种组R.chensinensis group的成员.新种与长肢林蛙种组R.longicrus group的镇海林蛙R.zhenhaiensis在背侧褶的弯曲特点上相似,但前者有别于后者的主要特点有:头型较宽扁,雌蛙后腿相对较长,蝌蚪唇齿式多为Ⅰ:3-3/Ⅲ:1-1.新种与长肢林蛙种组的其他林蛙不仅在背侧褶和头型等方面明显有别,而且蝌蚪唇齿式也显著不同.通过对四川、贵州和云南的昭觉林蛙R.chaochiaoensis成体和蝌蚪标本(包括地模标本)的核查和比较,新种的胫跗关节前达眼角,皮肤光滑,缺乏疣粒,雄性腹侧无雄性线,蝌蚪下唇乳突排列规则,中央无缺刻;而昭觉林蛙胫跗关节前达鼻孔或超过吻端,体侧和背部有圆疣或长疣,雄性背腹侧均有雄性线,蝌蚪下唇中央乳头排列稀疏或有缺刻.     

桓仁林蛙蝌蚪胚后发育的初步观察

本文对桓仁林蛙蝌蚪胚后发育的过程和形态特征进行了观察、测量和描述,并与中国林蛙和昆嵛林蛙进行了比较.胚后发育可分为19期,对其后肢芽、趾、前肢的发育,唇齿的变化过程,口、鼻、眼的位置与形状,以及肛管与尾的变化等方面做了系统的描述.     

Rana johnsi的生物学初探

从保护生物学角度对广西大瑶山Rana johnsi Smith,1921的的栖息地和繁殖地生境、 繁殖生物学及蝌蚪的特点等进行了初步探讨。该蛙在大瑶山主要分布在海拔800m左右的一个狭窄区域,10月至次年1月下山繁殖,有效性比为5：1。蝌蚪唇齿式为Ⅰ：5—5／1—1：Ⅳ和Ⅰ：4—4／1—1：Ⅳ,越冬后在5～6月完成变态。由于人为和自然因素的影响,该蛙种群受到严重威胁,应加强保护管理和宣传教育。     

Morphological variation and age-class determination in overwintering tadpoles of the tailed frog, Ascaphus truei

The morphological variation and development of different age classes of Ascaphus tadpoles is described for a subalpine population in the North Cascade Mountains. Adult females lay eggs in mid July, and embryos develop into hatchling tadpoles in late August. The torrent-adapted tadpoles develop in cold waters, overwinter in ice-covered streams and complete metamorphosis in four years. In September/October there may be five age-classes of tadpoles: cohort 0, hatchling tadpoles (total length (ToL) = 11 mm); cohort I, one-year tadpoles (ToL = 32 mm); cohort 2, two-year tadpoles (ToL = 36 mm); cohort 3, three-year tadpoles (ToL = 42 mm); and cohort 4, metamorphosing tadpoles or recently transformed frogs (ToL = 20 mm). Determination of these age-classes is based upon total length, body weight and hind limb and forelimb differentiation. The limb buds appear in the first year of tadpole development, but the forelimbs are hidden by the body wall and branchial chamber, and the hind limbs are concealed by the anal fold.
Arguments are presented from the data of total size-frequency and morphological differentiation and a review of the literature that the larval life period in montane populations is not two or three years, as is commonly accepted, but is approximately four years.     

密度对中国林蛙蝌蚪生长发育的影响

将中国林蛙（Rana chensinensis）蝌蚪分别饲养在40只／L、80只／L、120只／L、160只／L、200只／L和240只／L6个不同的密度条件下,通过定时定量喂食及测量其全长、尾长、体宽、体重和死亡率的变化,分析密度对中国林蛙蝌蚪生长发育的影响。实验结果表明：（1）饲养密度和生长发育时间及两者的交互作用对中国林蛙蝌蚪的生长发育影响都极其显著;（2）在40只／L的密度下,中国林蛙蝌蚪的全长、尾长、体宽、体重的增长速率最快,在240只／L的密度下,中国林蛙蝌蚪的全长、尾长、体宽、体重的增长速率最慢;（3）在相同时间内,40只／L的密度条件下中国林蛙蝌蚪的存活率最高,在240只／L的密度条件下中国林蛙蝌蚪的存活率最低;（4）中国林蛙蝌蚪的生长发育速度随饲养密度的升高而减慢。     

Effects of light intensity on activity in four sympatric anuran tadpoles

Though light conditions are known to affect the development and anti-predation strategies of several aquatic species, relatively little is known about how different species react to light, or how light can affect these species during different points in their life-cycle. In this study, we used four sympatric anuran tadpoles(Bufo gargarizans, B. melanostictus, Pelophylax nigromaculatus and Microhyla fissipes) as animal system to examine species-specific activities of the underdoing different light intensity treatments, so as to better understand how they respond to light. We exposed four different species of tadpoles to 1660 and 14 lux light intensity treatments and then measured several parameters including development stage, body length and tail length, and as well as their basic activities. The results of this observation and analysis showed that the activities of tadpoles were significantly greater in B. gargarizans and B. melanostictus than in P. nigromaculatus and M. fissipes; and were also significantly greater during times of high light intensity as compared to during low light intensity. Moreover, the observed relationship between species and light intensity was significant. The activities of B. gargarizans and B. melanostictus tadpoles were greater in high light, while the activity of P. nigromaculatus tadpoles was greater in low light intensity, while M. fissipes tadpoles showed no differences in either low or high intensity light. Furthermore, the activities of B. gargarizans, B. melanostictus and M. fissipes tadpoles in terms of developmental stage, body size or tail length did not seem to differ with light intensity, but during early larval developmental period of P. nigromaculatus, the activity of tadpoles was negatively correlated with development stage, but irrelevant to either body size or tail length in different light intensities. These results lead us to conclude the observed activities of the four sympatric anuran tadpoles are closely correlated with their specific anti-predation strategies.     

Simultaneous induction of ectopic pelvic zone and duplication of regenerated limbs in tadpoles of Polypedates maculatus by vitamin A

With a view to determine ectopic limb developing capacity along with normal hind limb regeneration in response to vitamin A palmitate in well-differentiated hind limb stage tadpoles of P. maculatus, higher doses of vitamin A (30 IU/ml and 20 IU/ml) were administered for a longer period (120 hr) to the tadpoles following tail amputation through middle and hind limb amputation through middle of thigh. Simultaneous development of ectopic pelvic zone was observed along with hind limbs from the cut end of tail and duplication of regenerated hind limbs in the same tadpole for the first time. Besides, development of double ectopic pelvic girdle was also reported in one case. Results also indicate that induction of pelvic zone and duplication of regenerated limbs are concentration dependent.     

Analysis of tadpole growth following gamma-ray irradiation

This investigation reports observations on the growth of Rana cyanophlyctis tadpoles following a whole body gamma-ray exposure. The effect on the body and hind limb size is perhaps the most significant of the period of latency. A dose of 2,000 R serves as a stressor and activates ACTH secretion in the tadpoles. The resultant somatotrophic hormone (STH) inhibition and subsequent recovery during the following days seem an integral part of the radiation syndrome.     

Effects of hydroperiod duration on developmental plasticity in tiger frog(Hoplobatrachus chinensis) tadpoles

While developmental plasticity can facilitate evolutionary diversification of organisms,the effects of water levels as an environmental pressure on tiger frogs remains unclear.This study clarifies the relationship by studying the responses of tiger frog(Hoplobatrachus chinensis)tadpoles to simulated hydroperiods(i.e.,constant low water levels,constant high water levels,increasing water levels,decreasing water levels,rapid changes in water levels and gradual fluctuations in water levels)in a laboratory setting.ANOVA analysis showed that none of the water level treatments had any significant effect on the total length,body mass,or developmental stages of H.chinensis tadpoles half way through development(11 days old).Tadpoles raised in rapidly fluctuating water levels had protracted metamorphosis,whereas tadpoles raised under low and gradually fluctuating water levels had shortened metamorphosis.None of the water level treatments had a significant effect on the snout-vent length(SVL)or body mass of H.chinensis tadpoles at Gosner stage 42,or on the body mass of tadpoles at Gosner stage 45.However,the tadpoles raised in high levels and rapidly fluctuating water levels,significantly larger SVL at Gosner stage 45,while ones under gradually fluctuating water levels had smaller SVL than the other groups.Time to metamorphosis was positively correlated with body size(SVL)at metamorphosis in H.chinensis tadpoles.H.chinensis tadpoles under constant low water level had the highest mortality rate among all the treatments(G-test).Moreover,ANOVA and ACNOVA(with body length as the covariate)indicated that water levels had no significant effect on either the morphology(i.e.head length,head width,forelimb length,hindlimb length and body width)or the jumping ability of juvenile H.chinensis.These results suggest that the observed accelerated metamorphosis and high mortality of H.chinensis tadpoles under decreasing water level treatment was driven by density-induced physical interactions among increasing conspecifics.     

黑斑侧褶蛙蝌蚪断尾后的补偿生长和发育研究

动物在经历不利的生长条件或环境后往往出现补偿生长。研究了黑斑侧褶蛙(Pelophylax nigromaculatus)蝌蚪经历来自食蚊鱼(Gambusia affinis)捕食造成断尾损伤后的补偿生长模式、断尾损失对蝌蚪游泳能力以及变态时间与大小的影响。结果表明,经历捕食压力后,全尾组和1/3断尾组蝌蚪的体长显著大于1/2断尾组蝌蚪的体长,全尾组和1/3断尾组之间的蝌蚪体长差异不显著;第19天时,1/2断尾组蝌蚪经过补偿生长后体长显著大于全尾组蝌蚪,1/3断尾组与全尾组和1/2断尾组之间的蝌蚪体长差异均不显著;三个实验组之间蝌蚪尾长差异不显著;全尾组蝌蚪的疾游速显著大于1/2断尾组蝌蚪的疾游速,1/3断尾组蝌蚪的疾游速与全尾组和1/2断尾组之间差异不显著,表明严重断尾对蝌蚪疾游速产生了消极影响。三个实验组蝌蚪的变态时间和变态前后形态差异均不显著。黑斑侧褶蛙蝌蚪能够在变态前调整生长轨迹补偿早期捕食风险造成的生长损失,断尾损失并不影响变态时间与大小,断尾超过一半的蝌蚪经过补偿生长后仍要付出一定的运动代价。     

The Influence of Oxygen on the Development of Nanorana parkeri Tadpoles

Ectothermic animals are tolerant of variable oxygen availability, whether low-oxygen levels constrain the fitness of ectotherms remains unclear. Nanorana parkeri, an anuran endemic to the southern Tibetan plateau, is an excellent model with which to answer this question. In this study, we raised tadpoles of N. parkeri in oxygenated water(high-oxygen group) and deoxygenated unchlorinated tap water(low-oxygen group) and monitored their growth, mortality, and telomere length. The growth rate for body length and body weight was higher in the low-oxygen group than in the high-oxygen group. However, dissolved oxygen did not affect development time, mortality, and telomere length of the tadpoles. These results suggest that although the oxygen concentration influenced some phenotype traits of plateau tadpoles, but it didn't influence the telomere length and survival rate, potential explanations are the local adaptation and N. parkeri tadpoles' wide oxygen tolerance, and fluctuant toxic content that resulted in little oxidative stress on tadpoles. These results indicated that low oxygen was not a stress to N. parkeri tadpoles' fitness and survival. This study is helpful in understanding the adaptation mechanisms of Tibetan plateau amphibians.     

Hypergravity susceptibility of ventral root activity during fictive swimming in tadpoles (Xenopus laevis)

1. Fictive swimming is an experimental model to study early motor development. As vestibular activity also affects the development of spinal motor projections, the present study focused on the question whether in Xenopus laevis tadpoles, the rhythmic activity of spinal ventral roots (VR) during fictive swimming revealed age-dependent modifications after hypergravity exposure. In addition, developmental characteristics for various features of fictive swimming between stages 37/38 and 47 were determined. Parameters of interest were duration of fictive swimming episodes, burst duration, burst frequency (i.e., cycle length), and rostrocaudal delay. 2. Ventral root recordings were performed between developmental stage 37/38, which is directly after hatching and stage 47 when the hind limb buds appear. The location of recording electrodes extended from myotome 4 to 17. 3. Hypergravity exposure by 3 g-centrifugation lasted 9 to 11 days. It started when embryos had just terminated gastrulation (stage 11/19-group), when first rhythmical activity in the ventral roots appeared (stage 24/27-group), and immediately after hatching (stage 37/41-group). Ventral root recordings were taken for 8 days after termination of 3 g-exposure. 4. Between stage 37/38 (hatching) and stage 47 (hind limb bud stage) burst duration, cycle length and rostrocaudal delay recorded between the 10th and 14th postotic myotome increased while episode duration decreased significantly. In tadpoles between stage 37 and 43, the rostrocaudal delay in the proximal tail part was as long as in older tadpoles while in caudal tail parts, it was shorter. During this period of development, there was also an age-dependent progression of burst extension in the proximal tail area that could not be observed between the 10th and 14th myotome. 6. After termination of the 3 g-exposure, the mean burst duration of VR activity increased significantly (p < 0.01) when 3 g-exposure started shortly after gastrulation but not when it started thereafter. Other parameters for VR activity such as cycle length, rostrocaudal delay and episode duration were not affected by this level of hypergravity. 7. It is postulated that (i) functional separation of subunits responsible for intersegmental motor coordination starts shortly after hatching of young tadpoles; and that (ii) gravity exerts a trophic influence on the development of the vestibulospinal system during different periods of embryonic development leading to the formation of more rigid neuronal networks earlier in the spinal than in the ocular projections.