A revision of the Metaphire peguana species-group (Oligochaeta: Megascolecidae) from Vietnam Author Nguyen, Tung T. Department of Biology, School of Education, Can Tho University, Vietnam. Author Lam, Dang H. 0000-0002-1236-1087 Department of Biology, School of Education, Can Tho University, Vietnam. & lamhaidangct @ gmail. com; https: // orcid. org / 0000 - 0002 - 1236 - 1087 lamhaidangct@gmail.com Author Nguyen, Anh D. 0000-0001-9273-0040 Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology, 18, Hoangquocviet Rd., Caugiay, Hanoi. & ducanh 410 @ yahoo. com; https: // orcid. org / 0000 - 0001 - 9273 - 0040 & Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18, Hoangquocviet Rd., Caugiay, Hanoi. ducanh410@yahoo.com text Zootaxa 2023 2023-03-15 5255 1 113 135 http://dx.doi.org/10.11646/zootaxa.5255.1.15 journal article 10.11646/zootaxa.5255.1.15 694336af-f170-49b8-8f98-2788d5a759d8 1175-5326 7744555 3F27E81A-87C7-48CD-8DF7-6FFDA0CD4907 Metaphire peguana species-group Diagnosis. Members of the species-group can be recognized by the following characters: two pairs of accessory glands coelomic, strongly covered by muscular-walled bursae, septum 10/11 only present ventrally. In addition, the group members also have spermathecal pores usually three pairs in 6/7/8/9, sometimes four pairs in 5/6/7/8/9 or numerous in 6/7/8/9 or 7/8/9; two pairs of genital markings in 17/18 and 18/19 or on segment xvii and xix (if not within a copulatory pouch). Remarks. A total of seven species and subspecies were assigned to this species-group, namely M. bahli , M. doiphamon , M. dorsomultitheca , M. kiengiangensis , M. nhuongi , M. peguana peguana , and M. peguana laisonensis . Out of 7 species/subspecies, M. bahli and M. peguana peguana have been distributed widely, from South America ( French Guiana ), Australia , South Asia ( India , Bangladesh , and Sri Lanka ), East Asia ( Japan ), and found commonly in Southeast Asia ( Myanmar , Laos , Cambodia , Thailand , Singapore , Vietnam , Malaysia , Philippines , and Indonesia ) ( Fig. 3 ). Other five members have been recorded only in Southern Vietnam , so far ( Fig. 3 ) ( Michaelsen 1922 ; Gates 1925 , 1945 , 1972 ; Easton 1982 ; Thai & Do 1989 ; Ishizuka 1999 ; Shen & Yeo 2005 ; Blakemore et al. 2006 ; Csuzdi & Pavlíček 2010 ; Sarkar & Bandyopadhyay 2012; Prasankok et al. 2013 ; Ng et al. 2017 ; Narayanan et al. 2019 ; Nguyen et al. 2016 , 2020 , 2021a , 2021c ; Lam et al. 2021 ).