生物多样性 ›› 2022, Vol. 30 ›› Issue (12): 22224.  DOI: 10.17520/biods.2022224

• 研究报告 • 上一篇    下一篇

海南岛蚯蚓物种组成及其系统发育分析

赵琦1,2, 蒋际宝1,2, 张曾鲁1,2, 金清1,2, 李佳丽1,2, 邱江平1,2,*()   

  1. 1.上海交通大学农业与生物学院, 上海 200240
    2.上海长三角区域生态环境变化与综合治理国家野外科学观测研究站, 上海 200240
  • 收稿日期:2022-04-26 接受日期:2022-08-30 出版日期:2022-12-20 发布日期:2022-12-17
  • 通讯作者: *E-mail: jpq@sjtu.edu.cn
  • 基金资助:
    国家自然科学基金(42077028);国家自然科学基金(41771279);国家自然科学基金(31401967);科技基础资源调查专项(2018FY100300)

Species composition and phylogenetic analysis of earthworms on Hainan Island

Qi Zhao1,2, Jibao Jiang1,2, Zenglu Zhang1,2, Qing Jin1,2, Jiali Li1,2, Jiangping Qiu1,2,*()   

  1. 1. School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240
    2. Shanghai Yangtze River Delta Eco-Environmental Change and Management Observation and Research Station, MST&ME, Shanghai Urban Forest Ecosystem Research Station, the National Forestry and Grassland Administration, Shanghai, 200240
  • Received:2022-04-26 Accepted:2022-08-30 Online:2022-12-20 Published:2022-12-17
  • Contact: *E-mail: jpq@sjtu.edu.cn

摘要:

海南岛独特的地理位置和复杂的古地理事件使其成为我国生物多样性的热点地区。已有的海南岛蚯蚓资料显示, 该岛的蚯蚓区系十分特殊, 且与大陆地区蚯蚓存在扩散与迁移。然而, 当海南岛与周围大陆断开形成独立岛屿后, 海南岛蚯蚓如何为适应海南岛的环境而逐渐形成现在岛内的分布与区系, 仍然是一个值得研究和探讨的问题。因此, 本研究在海南岛全面调查和采集蚯蚓标本, 整理海南岛地区的蚯蚓物种组成及其地理分布特征, 并联合5个线粒体基因COⅠCOⅡND112S rRNA和16S rRNA构建海南岛蚯蚓的分子系统发育树, 推测其分化时间和祖先分布区域, 探讨海南岛蚯蚓在岛内的分化与扩散过程。研究结果表明: (1)海南岛共有蚯蚓6科9属122种, 巨蚓科蚯蚓为优势科, 且全部为环毛类蚯蚓, 其中103种为海南岛特有种。蚯蚓物种数沿海拔呈先增加后减少的趋势, 在800‒1,000 m最大; (2)海南岛环毛类蚯蚓不同水平的遗传距离与我国巨蚓科蚯蚓的遗传距离区间基本一致。物种水平上, 美丽远盲蚓(Amynthas scitulus*)与纬向远盲蚓(A. zonarius)的基因遗传距离最小。在亚种水平, 保宁腔蚓指名亚种(Metaphire magna magna)和保宁腔蚓小型亚种(M. magna minuscula)的遗传距离均接近整体的物种水平。在种群水平, 等毛远盲蚓(A. homosetus)不同种群间遗传距离均接近整体的亚种水平; (3)海南岛环毛类蚯蚓可划分为7个类群, 其祖先于68.26 Ma开始分化, 可能起源于吊罗山。在新生代, 7个类群均得到较大发展。通过对海南岛蚯蚓组成及系统发育的梳理, 不仅为我国蚯蚓物种多样性研究提供基础资料, 也为岛屿蚯蚓物种系统发育关系分析提供科学参考。

关键词: 蚯蚓, 巨蚓科, 物种组成, 系统发育分析, 海南岛

Abstract

Aim: Because of its unique paleogeographical history and geographical location, Hainan Island is a major diversity hotspot in China. Previous research has shown that the earthworm fauna on Hainan Island is distinctive, and migration between Hainan Island and mainland China has occurred. However, how the earthworm fauna on this island formed is still unknown. Thus, this study aims to: (1) systematically assess earthworm diversity and their geographical distribution on Hainan Island; (2) improve understanding of the differentiation and dispersal of earthworms on Hainan Island using phylogenetic analysis.
Method: First, we collected earthworms on Hainan Island, especially from nature reserves, between 2006 and 2009 either by digging by hand or using an electric machine. We used both morphology and molecular techniques to identify earthworm species. Then, the molecular phylogenetic analysis was conducted using 5 mitochondrial genes—COI, COII, ND1, 12S rRNA and 16S rRNA using MEGA 5, jModelTest 2.1.10 and MrBayes 3.2.7. Their ancestral distribution area was reconstructed, and their differentiation time was speculated using the RelTime method and GTR model.
Results: (1) There were a total of 122 earthworm species, including 103 endemic species, belonging to 9 genera and 6 families. Megascolecidae is the dominant family, and all of the Hainan earthworms in this family belonged to pheretimoid species. The number of species varied by altitude, initially increasing before decreasing at higher altitudes. The highest number appeared in the altitude range of 800‒1,000 m. (2) The changes of genetic distance of the Hainan pheretimoid earthworm in species, subspecies and population levels were basically the same as those on mainland China. The shortest genetic distances appeared between Amynthas scitulus* and A. zonarius at the species level. The genetic distance between subspecies Metaphire magna magna and M. magna minuscula was close to that between two species. Furthermore, the genetic distances between A. homosetus populations were comparable to those at the subspecies level. (3) The pheretimoid earthworms of Hainan Island could be grouped into 7 clusters. The results suggested that they may have originated from the Diaoluo Mountain about 68.26 Ma years ago. All the earthworms appeared in the Cenozoic era.
Conclusion: Our results suggest that the earthworm fauna on Hainan Island including their composition, geographical distribution and genetic distances are unique, which indicate that they are affected by the environmental factors, such as altitude. This study not only provides information on earthworm biodiversity in China, but also serves as a reference for future genetic analyses of earthworms on islands.

Key words: earthworm, Megascolecidae, species composition, phylogenetic analysis, Hainan Island