近日,中国科学院昆明动物研究所哺乳动物生态与进化学科组研究员蒋学龙、王应祥及博士研究生周昭敏和墨西哥生态研究所、加拿大安大略皇家博物馆等的研究人员,共同确定了楔鞍菊头蝠为翼手目(蝙蝠)菊头蝠科一新种。该成果已发表在今年2月出版的《哺乳动物学杂志》(Journal of Mammalogy)上。
据悉,菊头蝠是旧大陆的物种,分布于欧洲、亚洲、非洲和大洋洲,为单型科,现有79种,已有的形态分类系统将其分为15个种组。已有证据表明,菊头蝠起源于3700万年前的始新世中晚期,在1500万年前的早中新世晚期开始快速分化。现生的菊头蝠中,除了早期分化出的水菊头蝠支系(5种)和叶鼻菊头蝠支系(1种),其余物种分属于非洲—古北和亚洲两大支系。其中,东非菊头蝠种组的种类主要在非洲分布,其鼻叶形态与楔鞍菊头蝠相似,即有尖的角状联接叶和楔形鞍状叶,但体型明显较小,而同域分布的其他体型较大的菊头蝠都具圆钝的联接叶。因此,他们确定楔鞍菊头蝠为一新种。
本次发表的楔鞍菊头蝠标本共有5号(3雄2雌),其中3号于1963年采自中国贵州省金沙县,一号于2005年采自云南省永德县乌木龙镇,另一号于2006年采自中国贵州省绥阳县。该新种是一种形态独特的大体型菊头蝠,在以上3个受人为显著影响和被农田破碎化的林地生境中,45年间仅采集到了5号楔鞍菊头蝠标本,其保护地位值得人们关注。考虑到中国各哺乳动物标本馆中馆藏有过去50年中采自云南、贵州、四川和广西多山地带的约1200号标本,以及这些省份的菊头蝠标本记录相对于中国其他地区更为丰富,该新种可能是仅限于在云南和贵州山地分布的珍稀种类。但是,青藏高原的一些周边地区,如缅甸北部、印度阿萨姆邦和四川西部,并没有作过详尽的蝙蝠调查,该新种也有可能分布于更广泛的区域。为了评价其是否应列入IUCN濒危物种红色名录,还需要调查其地理分布和种群大小,以确定可能的保护策略和标准。
研究人员通过形态学和分子生物学的综合比较证实,楔鞍菊头蝠与非洲—古北支系有更紧密的亲缘关系。该新种是迄今发现的除了马铁菊头蝠外第二个在亚洲有分布,但在系统发育上隶属于非洲—古北支系的物种。它的发现丰富了人类对整个印度马来地区菊头蝠物种多样性的认识,揭示了1000万年前的晚中新世气候变暖使当时的撒哈拉、中东和印度次大陆北部地区比现今更适宜菊头蝠生活,并为菊头蝠在埃塞俄比亚界和古北界东西部间扩散提供了适宜条件。
楔鞍菊头蝠的发现,为人们了解菊头蝠非洲—古北支系的生物地理演化历史以及古代哺乳动物在非洲和亚洲东部间的迁移扩散情况提供了新的线索。今后,需要通过更长的线粒体序列和进化更慢的核基因序列来证实非洲—古北支系内部的分化过程和各物种的亲缘关系,并推测各分化事件的年代顺序和相应的生物地理假说。
论文原始出处:
Journal of Mammalogy,Volume 90, Issue 1,pp. 57–73,Zhao-Min Zhou,Xue-Long Jiang
A New Species from Southwestern China in the Afro-Palearctic Lineage of the Horseshoe Bats (Rhinolophus)
Zhao-Min Zhou1, 2, Antonio Guillén-Servent3, Burton K. Lim4, Judith L. Eger4, Ying-Xiang Wang1, and Xue-Long Jiang1
1. State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, The Chinese Academy of Sciences, No. 32 Jiaochang Donglu, Kunming 650223, Yunnan, China (Z-MZ, Y-XW, X-LJ), 2. Graduate University of the Chinese Academy of Sciences, Beijing 100039, China (Z-MZ), 3. Instituto de Ecología A.C., Km 2.5 Carretera Antigua a Coatepec #351, Xalapa 91070, Veracruz, México (AG-S), 4. Department of Natural History, Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario M5S 2C6, Canada (BKL, JLE)
A new species of horseshoe bat (Chiroptera: Rhinolophidae) is described from southwestern China. The presence of a wedge-shaped sella and pointed connecting process of the nose leaf aligns the new species to the landeri group in the Afro-Palearctic lineage of Rhinolophus. However, the new species is distinctly separable from these allopatrically distributed species by its noticeably larger body size. Other sympatric large-sized species of Rhinolophus have rounded connecting processes. Molecular systematic analyses based on mitochondrial cytochrome-b sequences confirmed the affinity of the new species to the Afro-Palearctic lineage, but in a clade most closely related to the ferrumequinum, fumigatus, and maclaudi groups. Of these species, only R. ferrumequinum ranges into Asia and overlaps in distribution with the new species. R. ferrumequinum is similar in general body size and external appearance; however, the new species is distinct in the characteristics of the nose leaf, skull, and baculum. The presence of a new species from southwestern China in the Afro-Palearctic lineage indicates a more complex historical biogeographic scenario within Rhinolophus than previously known. The difficulties found in allocating the new species to one of the phenetically described traditional species groups stress the convenience of using a phylogenetically based systematic organization of the genus Rhinolophus.