贵州疣螈骨骼系统的研究

本文运用硬骨-软骨双染色技术对贵州疣螈（Tylototriton kweichowensis）的骨骼系统做了较全面的观察研究，包括头骨、脊柱和前后肢带骨，并对各骨块的形状、位置以及与邻近骨块的关系都作了详细的描述。最后，将贵州疣螈与东方蝾螈、有斑肥螈的骨骼系统进行了比较，为揭示蝾螈科属间演化关系提供一定的依据。     

我国棘螈属(Echinotriton)和疣螈属(Tylototriton)的研究概况

棘螈属（Echinotriton）和疣螈属（Tylototriton）均属于两栖纲有尾目蝾螈科.两属主要分布于我国西南、亚洲西南部、东南亚及日本.棘螈属在我国已知3种：Echinotriton andersoni（琉球棘螈）、E. Chinhaiensis（镇海棘螈）、E. Asperrimus（细痣棘螈）.疣螈属在我国已知4种：Tylototriton kweichowensis（贵州疣螈）、T. Shanjing（红瘰疣螈）、T.taliangensis（大凉疣螈）、T. Verrucosus（棕黑疣螈）.本文回顾了棘螈属和疣螈属物种的命名史,阐明了两属之间的关系,并从形态学、生态学、细胞遗传学和分子生物学方面对这两属的研究工作进行了综述.     

中国疣螈属一新亚种

对采自河南省大别山区商城县的一种蝾螈科标本进行形态特征比较,发现与文县疣螈Tylototriton wenxianensis 相似,但存在明显差异;经与文县疣螈等4种蝾螈进行12S mt DNA部分序列比对,显示其与文县疣螈的遗传分化已达亚种级水平,因此定为1新亚种,文县疣螈大别亚种Tylototriton wenxianensis dabienicus ssp.nov..新亚种的主要鉴别特征为:头长远大于头宽;4肢较短,前后肢贴体相对指、趾端不相遇;前肢前伸,指末端达眼前角;泄殖腔孔周缘橘红色.     

富钟瘰螈和广西瘰螈骨骼系统的比较研究

采用硬骨-软骨双染色技术,研究我国广西产的富钟瘰螈和广西瘰螈骨骼系统,包括头骨、脊柱和附肢骨骼,并对各骨块的形状、位置以及与邻近骨块的关系都作了详细的描述;同时,比较了富钟瘰螈和广西瘰螈骨骼特征的差异,并将富钟瘰螈、广西瘰螈与有斑肥螈、贵州疣螈和东方蝾螈骨骼系统进行了比较,为揭示瘰螈属种间演化关系和蝾螈科属间演化关系提供一定的依据.     

文县疣螈早期胚胎发育

对湖南省怀化市黄岩地区的文县疣螈(Tylototriton wenxianensis)早期胚胎发育进行了观察。整个胚胎发育分为21个时期,在实验室19～21℃下,受精卵完成胚胎发育历时(513.30±7.93)h(n=8);本文描述了各时期的形态特征,并讨论了与其他有尾类胚胎发育的异同,以及怀化产文县疣螈与甘肃产文县疣螈的主要区别。     

降雨决定繁殖期红瘰疣螈的活动性

有尾两栖类的繁殖活动常常受到环境因子,特别是如温度、湿度和降雨等气候因子的限制。红瘰疣螈Tylototriton shanjing是适应云南山地环境的典型有尾两栖类动物。本研究期望通过对繁殖期红瘰疣螈活动个体数量的野外调查和气候因子的分析,弄清影响红瘰疣螈繁殖行为活动的关键气候因子。研究结果显示,繁殖期红瘰疣螈活动个体数量与气温呈显著的负相关关系,与空气相对湿度和降雨量呈显著的正相关关系。然而偏相关和多元回归分析则表明,红瘰疣螈繁殖行为活动与相对湿度和降雨量关系更密切。红瘰疣螈总是在降雨后引起空气湿度增加以及气温下降时进行各种繁殖行为活动,降雨是影响红瘰疣螈繁殖行为活动关键的气候因子。红瘰疣螈的繁殖行为活动与降雨节律保持一致是对云南山地环境的重要适应。     

文县疣螈在重庆境内分布的补充调查

2005～2008年在重庆云阳县和奉节县对文县疣螈 Tylototriton wenxianensis 进行了10处实地考察,其中9处看见或采集到标本,1处为寻访调查;在1处观察到其求偶行为.结合文献和标本查阅结果,更具体地了解到重庆市文县疣螈的分布情况和各地种群生存现状的信息,从而为该物种的地区性保护提供相关策略.     

甘肃白水江国家级自然保护区有尾两栖动物资源现状及保护对策

2007年6月～2009年5月对甘肃白水江国家级自然保护区有尾两栖动物进行了为期两年的调查研究,了解白水江自然保护区现存有尾两栖动物西藏山溪鲵Batrachuperus tibetanus、大鲵Andrias davidianus和文县疣螈Tylototriton wenxianensis的分布状况和资源现状.分析了大鲵和文县疣螈栖息地环境存在问题的原因,针对原因从加强宣传教育、加强科学研究、严格执法、加强社区发展项目和合理开发5个方面提出了相应的对策.     

从线粒体Cyt b基因探讨红瘰疣螈物种地位的有效性

疣螈属的红瘰疣螈(Tylototriton shanjing)和棕黑疣螈(T.verrucosus)的物种界限一直不清楚。测定了来自中国西南地区14个地点的T.shanjing和T.verrucosus共40只标本的线粒体DNACytb基因(753bp)。结果表明:(1)用邻接法、最大简约法和贝叶斯法等3种系统发育分析法分别重建棕黑疣螈种组系统发育树的拓扑结构不支持T.shanjing是单系群;(2)T.shanjing与T.verrucsus的mtDNA Cytb序列差异平均值仅为1.2%,未达到种级水平。因此,全部T.shanjing样品都属于同一个物种,即T.verrucosus,不支持T.shanjing的物种地位,T.shanjing为T.verrucosus的同物异名,并建议恢复T.verrucosus的中文名红瘰疣螈。根据基于40个样品Cyt b基因序列的系统发育树和遗传变异以及地理分布,这些红瘰疣螈(T.verrucosus)样品聚为3支,即中国西南地区的红瘰疣螈可分为片马、滇中滇西和滇东南3个地理居群。     

贵州疣螈繁殖生态

贵州疣螈(Tylototriton kweichowensis)为中国特有种,国家Ⅱ级重点保护野生动物,对生境变化具有重要指示意义。2018年9月至2019年10月,在贵州省毕节市撒拉溪石漠化综合治理示范区,对贵州疣螈栖息地、形态特征、繁殖行为进行了野外观测。调查显示,贵州疣螈栖息于山塘、山泉、蓄水池、临时性积水坑(塘)等水域,个体全长、尾长和体重雌螈均显著高于雄螈。贵州疣螈于4月18日雷雨天气后破眠外出活动,繁殖始于4月29日,最晚见于8月8日,高峰期为5至6月;繁殖期贵州疣螈的性比总体上偏雄,但在产卵期性比偏雌;雌、雄螈抱对时间几分钟到40min不等;抱对结束后开始排精、纳精;产卵活动在纳精后的1～2 d进行,卵产于繁殖场水底、草或石头上;卵的孵化率为55%,平均孵化期8d,幼体完成变态发育需130d。研究表明,贵州疣螈的繁殖与发育受降雨、水量、温度变化的影响较大,且繁殖场所相对较为固定,容易受到人类活动的干扰。因此,在石漠化治理和生态修复时注重贵州疣螈的栖息地保护,必要时应人工新建稳固繁殖场,保障其生态繁衍。     

A New Species of the Genus Tylototriton(Amphibia: Urodela: Salamandridae) from the Southern Dabie Mountains in Anhui Province

A new species of the genus Tylototriton is described,from Yuexi county,Anhui province,in the south of the Dabie Mountains.It is based on morphological and molecular analysis.The new species is identified as belonging to the Tylototriton asperrimus group and shares a number of similarities with T.wenxianensis,T.broadoridgus and T.dabienicus.The diagnostic characteristics of the new species are as follows: the head length is greater than the width of the head; bony ridges on the head are prominent and necked-in; the distal digit ends,ventral digits,peripheral area of the cloaca and the tail's lower edge are orange.The result from the molecular analysis of the genus Tylototriton(including the type specimen of the new species) based on three mitochondrial genes(ND1,ND2 and CYTB) indicated that the new species was close to T.wenxianensis,T.dabienicus,and T.broadoridgus,but formed an independent clade.This result was consistent with the morphological analysis above,which supports the theory that the population distributed in the south of the Dabie Mountains,namely in from Yuexi county,Anhui province,represented a distinct species,Tylototriton anhuiensis sp.nov.     

A New Species of the Genus Tylototriton(Amphibia: Urodela: Salamandridae) from Eastern Himalaya

A new species of the genus Tylototriton is described from eastern Himalaya based on molecular and morphological comparisons. The new species is diagnosable from the closely-related species by having light brown colouration in dorsal region in life, flat and blunt snout, greatly separated dorsolateral bony ridges on head and straightthick tailfin. In addition to head morphology, the new species is also morphologically distinguishable from its closelyrelated species Tylototriton shanorum by having 16 dorsal warts and average smaller Snout Vent Length(SVL).     

Mitochondrial genomes and divergence times of crocodile newts: inter-islands distribution of Echinotriton andersoni and the origin of a unique repetitive sequence found in Tylototriton mt genomes

Crocodile newts, which constitute the genera Echinotriton and Tylototriton, are known as living fossils, and these genera comprise many endangered species. To identify mitochondrial (mt) genes suitable for future population genetic analyses for endangered taxa, we determined the complete nucleotide sequences of the mt genomes of the Japanese crocodile newt Echinotriton andersoni and Himalayan crocodile newt Tylototriton verrucosus. Although the control region (CR) is known as the most variable mtDNA region in many animal taxa, the CRs of crocodile newts are highly conservative. Rather, the genes of NADH dehydrogenase subunits and ATPase subunit 6 were found to have high sequence divergences and to be usable for population genetics studies. To estimate the inter-population divergence ages of E. andersoni endemic to the Ryukyu Islands, we performed molecular dating analysis using whole and partial mt genomic data. The estimated divergence ages of the inter-island individuals are older than the paleogeographic segmentation ages of the islands, suggesting that the lineage splits of E. andersoni populations were not caused by vicariant events. Our phylogenetic analysis with partial mt sequence data also suggests the existence of at least two more undescribed species in the genus Tylototriton. We also found unusual repeat sequences containing the 3' region of cytochrome apoenzyme b gene, whole tRNA-Thr gene, and a noncoding region (the T-P noncoding region characteristic in caudate mtDNAs) from T. verrucosus mtDNA. Similar repeat sequences were found in two other Tylototriton species. The Tylototriton taxa with the repeats become a monophyletic group, indicating a single origin of the repeat sequences. The intra-and inter-specific comparisons of the repeat sequences suggest the occurrences of homologous recombination-based concerted evolution among the repeat sequences.     

A New Species of the Genus Tylototriton （Urodela： Salamandridae） from Northeastern Hunan Province,China

We describe a new species from the family Salamandridae from northeastern Hunan Province of China based on morphological and molecular genetic evidences.The new species,Tylototriton liuyangensis,is a member of the T.asperrimus group,and shares a number of similarities with T.wenxianensis and T.broadoridgus.The dorsal surface of the new Tylototriton species is completely black,with nodule-like warts distributed evenly along the lateral margin of dorsal body,and there is no transverse striae between the warts.There are several diagnostic characters of the new species that differ from those of T.wenxianensis and T.broadoridgus as follows：（1）the interorbital space（IOS）is comparatively wide;（2）there is a bony ridge present on the dorsal head surface,running along the upper eyelids;（3）the space between axilla and groin（AGS）is comparatively large,with the mean male AGS approximately equal to 50%of the snout-vent length（SVL）and the mean female AGS being 53%of SVL;and（4）there is a small genital armature on the anterior angle of labial folds present inside the anal fissure of adult males during the breeding season.The result from the molecular phylogenetic analysis of the genus Tylototriton（including the type specimen of the new species）based on the complete DNA sequence of the mitochondrial ND2 gene（1035 bp）indicated that the new species was similar to T.wenxianensis,T.dabienicus,and T.broadoridgus,but formed an independent clade.This result was consistent with the morphological analysis above,supporting that the Liuyang Population represented a distinct species.     

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。     

文县疣螈繁殖初探

2006年4～9月、2007年4～9月,在四川青川初步观察了文县疣螈(Tylototriton wenxianensis)的繁殖习性,并研究了其主要特点,包括繁殖期雌雄差异、繁殖迁徙、交配与产卵、幼体发育等,同时在甘肃文县观察了其幼体的生长发育过程.结果表明,文县疣螈的繁殖期一般为4月上旬至9月上旬,繁殖期成体性比不断变化.该螈具有繁殖迁徙现象,迁徙及求偶行为由雄性占主动.求偶、交配及产卵均在水塘周围岸边的陆地上进行,产卵集中在5月初至7月末,雌螈平均产卵数为42.8枚(n=6),卵的平均孵化期为26.8 d(n=119).卵群的平均孵化率为46.3%(n=6).随着气温的升高、相对湿度和降水量的增加,雌螈产卵量和孵化率升高,卵的平均孵化期缩短.     

四川马边大风顶自然保护区两栖爬行动物调查

2005年7月中旬至下旬对四川马边大风顶自然保护区的两栖爬行动物进行了调查.本次调查共采得两栖爬行动物标本17种,隶属于9科3目.结合文献资料,该保护区现已知有两栖爬行动物27种（亚种）,隶属于12科4目.其中,两栖动物13种（亚种）,隶属于7科2目;爬行动物14种（亚种）,隶属于5科2目.该保护区物种组成较丰富,没有古北界的成分,特有种所占比例较高.马边县新纪录9种,大鲵已被收入“濒危野生动植物种国际贸易公约（CITES）”附录Ⅰ,大凉疣螈和脆蛇蜥已被收入《中国濒危动物红皮书》,大鲵和大凉疣螈是国家Ⅱ级重点保护野生动物.该保护区和四川美姑大风顶自然保护区的两栖爬行动物Sorenson指数为36.7%.