中国科学院昆明动物研究所机构知识库

全球生物多样性丧失的速度不断增加，另一方面，大量的新物种不断地被发现，这就造成了很多物种可能还没有来得及发现就已经灭绝；此外，还存在一些物种的错误鉴定，这些因素都强调需要使用一个快速、准确和有效的物种鉴定方法。目前，DNA条形码技术在两栖爬行动物中已经被广泛地应用，特别用于物种鉴别和隐存多样性的发现。然而，此类工作对于肯尼亚两栖爬行动物的研究仍十分有限。肯尼亚拥有较高的环境异质性，是两栖爬行动物种类非常丰富的国家，然而两栖爬行类生物多样性的研究仍停留在基于传统形态学进行物种鉴定。因此，使用DNA条形码技术揭示该区域的物种多样性存在巨大的机遇，尤其是隐存多样性的发掘。为了获得对肯尼亚辛巴山国家保护区Shimba Hills和察沃Tsavo这两个区域两栖爬行动物较为全面的物种多样性名录，我们分别在雨季和干季对该区域进行了科学考察和取样。在野外中，我们首先对获得的标本进行了形态学的初步鉴定。随后，在实验室中，我们基于两段线粒体基因片段：细胞色素氧化酶I（COI）和 16S核糖体 RNA(16S rRNA)进行了DNA条形码鉴定。在本研究中，共测定了235个两栖类个体和168个爬行类个体的细胞色素氧化酶I（COI）和16S核糖体 RNA(16S rRNA)序列。通过使用基因片段构建NJ树（邻接法）、计算遗传距离对目标区域采集到的两栖爬行类样品进行物种鉴定。总的来说，初步形态鉴定出两栖类共15个属32种，爬行类共34 属62种。在这基础上，使用DNA条形码的方法分别在Ptychadena、 Arthroleptis 和Panaspis 3个属中发现了4个潜在的新种（2种两栖类和2种爬行类）。此外，在Chiromantis, Tomopterna, Xenopus, Phrynobatrachus, Ptychadena, Pellomedusa, Panaspis, 和 Psammophis 属中发现了7种形态和分子鉴定不一致的情况。本研究证实使用分子和形态相结合的方法，有助于揭示肯尼亚地区的两栖爬行动物的隐存物种多样性和新物种的发现。此外，本研究中产生辛巴山国家保护区Shimba Hill和察沃Tsavo两个区域的两栖爬行动物条形码数据将丰富全球生物条形码数据库，为物种的鉴定和保护提供基础数据。

The rate of biodiversity loss, unprecedented species discovery and possible species misidentification in amphibian and reptile species underscore the need for a faster and precise species characterization approach. A global inventory of these species is far from being realized. Application of DNA barcoding on amphibians and reptiles has aided in species identification and uncovering of cryptic lineage diversity. However, very little has been on DNA barcoding of Kenyan amphibians and reptiles. Kenya has a wide range of environmental clines teeming with highly diverse amphibians and reptiles, whose characterization has been greatly hampered by poor taxonomic technology. Hence, great opportunities exist for new species discovery, especially among cryptic species, as well as validation of those already characterized and reconstructing their phylogenetic relationships. To create a comprehensive inventory of herpetofauna of Shimba Hills and Tsavo ecosystems in Kenya, extensive sampling of amphibians and reptiles targeting both wet and dry season was conducted using standard herpetology field sampling techniques. Preliminary species and genera level classifications were based on morphology. Further, genetic identification using two mitochondrial genes, CO1 and 16S rRNA was carried out. Partial sequences of these two genes were obtained for 235 amphibians and 168 reptile samples. Using the derived 16S rRNA partial sequences, Neighbor-joining trees were constructed for species identification and further, to establish the genetic distinctness and phylogenetic divergence of amphibians and reptiles in these two ecosystems. Based on morphology, 32 species and 15 genera of amphibians, and 62 species and 34 genera of reptiles were identified. However, DNA barcoding approach aided in the discovery of four potential new species (two amphibians and two reptiles) in the genus Ptychadena, Arthroleptis and Panaspis. Additionally, eight cases of mismatch between morphology and molecular based taxonomy were encountered in the genus Chiromantis, Tomopterna, Xenopus, Phrynobatrachus, Ptychadena, Pellomedusa, Panaspis, and Psammophis This study demonstrates the need for integration of molecular and morphology based methods in species identification as it would aid in unveiling cryptic lineage diversities and possible novel species of amphibians and reptiles in Kenyan ecosystems. Further, this study avails comprehensive reference barcoding information for amphibians and reptiles of the two ecosystems that will enrich the global inventory of these species and facilitate their conservation.