甘肃两栖动物的保护研究

调查表明甘肃有两栖类动物24种,其中有尾目3科3属3种,无尾目6科21种.属于古北界的有5种和亚种,属东洋界的有14种,其余5种为两界兼有种.对引起甘肃省两栖类动物种群衰退、变异和灭绝的主要因素进行了初步分析,提出了若干针对甘肃两栖类动物的保护对策.     

应用蝌蚪快速检测环境变异的两种方法--微核试验和单细胞凝胶电泳

本文介绍了应用无尾两栖类动物的蝌蚪进行环境监测的两种方法——微核试验和单细胞凝胶电泳。此两种环境检测的方法与其他环境检测方法相比具有快速,简便,易操作,适于检测现场应用,可大面积推广等优点。     

江西省两栖类动物多样性与地理区划

本研究整合近年来江西省两栖类动物物种分布新纪录,对江西省两栖类动物多样性进行编目整理。结果表明,近年来江西省新增23种两栖类物种分布新纪录,两栖类动物累计达2目8科58种,包括2种国家Ⅱ级重点保护物种和40种中国特有种。江西省两栖动物区系组成以东洋界华中区和华南区共有种为主,无古北界种类。东洋界种类54种,占总种数的93.1%,广布种4种,占总种数的6.9%。生态类型以流水型最多,陆栖-静水型次之。对13个保护地两栖类动物物种组成的聚类分析将其分为4个聚类群：赣北、赣东北、赣南、赣西。聚类结果在一定程度上支持早期江西省两栖动物地理区划,我们建议将罗霄山脉划为单独的赣西（罗霄）山地省。     

雄激素对无尾两栖类鸣叫行为的调控及机制

鸣叫行为是无尾两栖类常见的行为,对其生存和繁殖具有重要意义.虽然目前没有一致的证据,但研究结果暗示了很多无尾两栖类动物的广告和攻击鸣叫行为与其体内雄激素水平密切相关.已有的研究表明,雄激素对无尾类发声器官的肌肉以及运动神经元有重要影响.另外,在无尾类脑部与发声的相关核团中发现雄激素受体的表达.注射精氨酸加压素(AVT)也可以增加蛙类的广告鸣叫及降低释放鸣叫.这些都暗示了激素对无尾类鸣叫行为具有重要作用,但其确切机制尚不清楚.本文通过对已做相关研究的所有物种进行系统发育分析,发现中枢神经与鸣叫行为相关的精氨酸加压素系统具有高度的进化保守性,而与鸣叫相关的性激素作用系统可能是多次独立起源的.     

四川资阳市两栖爬行动物资源调查初报

1996~2007年对四川省资阳市的两栖爬行动物资源进行了初步调查,发现两栖类7种,其中有尾目1种,无尾目6种;爬行类18种,其中龟鳖目2种,有鳞目蜥蜴亚目5种、蛇亚目11种,其中包括新记录1科3属5种。建议加强对该市两栖爬行动物物种多样性及其生境的保护,合理利用两栖爬行动物资源。     

重庆开县两栖爬行动物物种多样性及其保护

1999～2002年对开县的两栖爬行动物资源进行了大规模调查,初步发现有两栖类17种,其中有尾目2种。无尾目15种;爬行类23种,其中龟鳖目2种,有鳞目蜥蜴亚目8种、蛇亚目13种(含重庆市蛇类新记录1属1种)。建议加强对该县两栖爬行动物物种多样性及其生境的保护,合理利用两栖爬行动物资源。     

记云南巨两栖犀属一新种

本文记述了巨两栖犀属内的一个新种——马关巨两栖犀(Gigantamynodon maguanensis).它可能是两栖犀类动物中最大的一个种.其时代当为中、晚渐新世.     

九顶山两栖爬行类动物资源及保护

１９９７．４～１９９８．６在德阳市九顶山区对两栖爬行类运行进行了调查,基本查清了该区两栖爬行类动物的种类,分布及栖息环境,并对加强该区两栖爬行类动物资源保护和合理利用提出了建议。该区有两栖类动物１８种,隶２日６科１０属,爬行类动物１８种,隶１日７科１５属。     

两栖类动物抗菌肽活性研究

两栖类动物复杂的生存环境决定了其抗菌肽种类的多样性,抗菌肽种类及其结果的多样性则又决定了其作用的多样性。随着研究的深入,越来越多的抗菌肽从两栖类动物中发现,并得到研究。其中很多抗菌肽具有很好的生产使用价值。本文通过检索相关文献,对两栖类动物抗菌肽的活性进行了综述。     

中华大蟾蜍染色体标本制备的简便方法

中华大蟾蜍（Bufo bufo gargarizans)是我国特有的无尾两栖类动物该动物分布广、易捕捉,其循环系统和神经系统以及胚胎发育过程较为独特,故一直是医学生理学和发育生物学研究的重要实验动物,同时,中华大蟾蜍的染色体具有体积大、数目少、形态典型等细胞遗传学特点,是遗传学上进行染色体观察和研究的好材料,非常适于进行染色体的显微分离和单染色体文库构建等方面的研究。     

棘腹蛙生物学特性及资源保护研究进展

棘腹蛙(Quasipaaboulengeri)是无尾目(Anura)叉舌蛙科(Dicroglossidae)棘胸蛙属的两栖动物。因其以农业和森林害虫为食且对生存环境要求高的特点,故有保护和监测环境的生态功能。但由于生态环境恶化和过度捕捉等原因,造成野生棘腹蛙数量急剧下降,被《中国脊椎动物红色名录》列为易危种。本文从棘腹蛙的习性、生存环境特征、系统进化、人工养殖和资源保护等方面进行了综述,为进一步研究棘腹蛙提供基础资料和理论依据。     

重金属污染对蛙蟾类毒性的研究进展

基于近20年的大量相关资料,综述了重金属对蛙蟾类毒性影响方面的研究,介绍了实验动物和实验方法,综合了重金属对蛙蟾类在形态、器官、组织、细胞和分子水平上毒害的主要表现,从重金属致毒过程、环境因素、物种、发育、重金属积累、联合毒性等角度初步分析了重金属对蛙蟾毒性大小的影响因素和毒性作用的主要机理,归纳了蛙蟾的几种抗毒/解毒/避毒反应,对开展进一步的研究提出建议.     

甘肃有尾两栖动物资源现状及保护对策

甘肃地理与气候条件复杂,南部地区有尾两栖动物物种多样性较为丰富,共有3科、3属、3种.其中,文县疣螈为甘肃特有种.但由于滥捕乱猎、栖息地丧失、破坏、污染以及异种侵入等原因,已造成有尾两栖动物的渐危和濒危.针对这种情况,本文提出了一些保护举措和建议,希望能在维持有尾两栖动物资源储量的前提下,对其进行合理利用.     

人类活动对两栖动物群落结构的影响

本文报道了哀牢山徐家坝地区,山地水域环境植被的不同开发强度对两栖动物群落结构的影响。调查结果表明,水域环境植被未经破坏的原始常绿阔叶林生态类型其两栖动物群落结构由12种蛙组成,多样性指数2.41:原生植被曾被砍伐而演替为次生林生态类型由9种蛙组成,多样性指数1.97;原生植被曾遭受严重砍伐和火烧而演替为毛蕨草地和沼泽草甸生态类型,其两栖动物种数分别为6种和5种,多样性指数分别为0.70和0.57。由此可见森林植被破坏对两栖动物群落结构及动态都有决定性影响。     

Chromosome banding in Amphibia

The distribution and quantity of constitutive heterochromatin and of the nucleolus organizer regions (NORs) on the chromosomes of 22 species of bufonids and hylids (Amphibia, Anura) was investigated. Three different kinds of constitutive heterochromatin were found and the frequency of brightly fluorescing heterochromatic regions was remarkably high. On almost all chromosomes there is centric and telomeric heterochromatin. Quantitative estimates of heterochromatin demonstrate that large DNA differences among closely related species can not be attributed to differing quantities of constitutive heterochromatin. In all species investigated, only one homologous pair of NORs was found, which lies preferentially in the proximal and interstitial segments of the long chromosome arms. The NORs are always associated with constitutive heterochromatin on both sides. The size variability between homologous NORs is very high. In the euchromatic regions of the metaphase chromosomes, neither Q- nor G-bands can be demonstrated; this can be attributed to an extremely strong contraction of the anuran chromosomes. On the basis of these results various mechanism of the chromosomal evolution in Anura are discussed.     

Predation of frog eggs by the water strider Gerris latiabdominis Miyamoto (Hemiptera: Gerridae)

Water striders (Hemiptera: Gerridae) are predators found on the water surface that prey mainly on arthropods. The feeding on other organisms (dead vertebrates, fishes and tadpoles) is a rare event. To our knowledge, predation of frog eggs by water striders has not yet been reported. We observed that adult water striders, Gerris latiabdominis Miyamoto, 1958 (Hemiptera: Gerridae), preyed on the eggs of three frog species, Pelophylax nigromaculata Hallowell, 1861 (Anura: Ranidae), Rana japonica Boulenger, 1879 (Anura: Ranidae), and Rhacophorus schlegelii Günther, 1858 (Anura: Rhacophoridae). We found predation by the water striders affects the survival rate of frog eggs floating on the water surface. We suggest that this hunting event would occur in water bodies in which water striders and frogs coexist, especially the region where their phenology overlaps.     

Vascular supply to the ventral pelvic region of anurans as related to water balance

The ventral pelvic integument of anurans in hypervascular as compared to other skin regions. Recent studies indicate that this area is primarily responsible for water uptake and rehydration. Nine species representing four genera of terrestrial and aquatic Anura were dissected for comparison of vascularity in the pelvic area. Major differences in the ventral pelvic integumental vessels were found between aquatic and terrestrial genera. These variations are described, and names are suggested for previously unnamed vessels. Changes in vascularity are discussed and related to the literature on Anura pertinent to rehydration rates, tolerance of desiccation, resistance to desiccation, and habitat. Data from this study and previous studies suggest a correlation among the parameters discussed and habitat. The suggestion is made that when species are classified as xeric, mesic, or aquatic on the basis of the habitat in which they live, their responses to rehydration, tolerance to desiccation, and vasculatity should be considered, as these characteristics more accurately represent the micro-habitat.     

Clustered and interspersed repetitive DNA sequences in four amphibian species with different genome size.

We have compared the amount of clustered and interspersed repetitive sequences in the genome of four Amphibia with different DNA contents per haploid nucleus: two Anura (Xenopus laevis, 3 pg and Bufo bufo, 7 pg) and two Urodela (Triturus cristatus, 23 pg and Necturus maculosus, 52 pg). High molecular weight DNA of the four species was denatured and reassociated to the same Cot in order to obtain duplex sequences with a similar reiteration frequency. Single-stranded DNA was digested off with the Aspergillus S1 nuclease. DNA was then fractionated according to the molecular weight through an agarose A-50 column. We found that the amount of long repetitive sequences is roughly proportional to the genome size in the four species, while the number of short (about 300 base pairs) repetitive sequences is increased many-fold in the species with the larger DNA content, both in Anura and in Urodela.     

On the arrangement of chromosomes in the elongated sperm nuclei of Anura (amphibia)

The position of specific constitutive heterochromatic chromosome regions within the elongated sperm nuclei of eight species of Anura was examined with Q- and C-banding. These species differ widely with regard to the number, size and position of the brightly fluorescing heterochromatic regions. The empirical frequency distributions determined for the heterochromatic regions relative to the longitudinal axis of the sperm nuclei were compared with random frequency distributions calculated on the basis of two spatial models. None of the specifically stained heterochromatic regions occupy any definite preferential position within the sperm nuclei. In two instances, a specific sequence of the heterochromatic regions within the sperm nuclei could be excluded. The type of chromosomal arrangement within the elongated sperm nuclei of Anura is discussed on the basis of the distribution patterns obtained.