Systematic revision of the Southeast Asian macrophagous leeches, with the description of two new gastrostomobdellid species (Hirudinida: Arhynchobdellida: Erpobdelliformes)

The systematic status of salifid macrophagous leeches inhabiting Southeast Asia, especially those from Sundaland, remains uncertain. No study has yet revisited their taxonomic accounts to determine whether they possess the diagnostic characteristics of Salifidae. In this study, we clarified the taxonomic status of the four known salifid species using a morphological examination of their type specimens. Additionally, we elucidated the systematic accounts of the species newly collected from Thailand and Borneo with morphological and molecular investigations. Based on the results, we classified all of them as within the Southeast Asian erpobdelliform family Gastrostomobdellidae. Two species, Gastrostomobdella extenta sp. nov. from Thailand and Gastrostomobdella ampunganensis sp. nov. from Borneo, are described herein. We placed the Bornean macrophagous species previously assigned to the salifid genus Mimobdella within Gastrostomobdella as Gastrostomobdella buettikoferi comb. nov. We retained the genus Scaptobdella as a distinct genus, but placed it within Gastrostomobdellidae. We placed the Sumatran a € Mimobdella' species, Scaptobdella thienemanni comb. nov., within this genus along with Scaptobdella horsti and Scaptobdella sumatrensis. The present findings of G. extenta from Thailand reveal that gastrostomobdellid species are indigenous not only to Sundaland, but also to Indochina.