Orientobdelloides, Bolotov & Eliseeva & Kondakov & Coi & S & . & . & . & . & . & O. & . & O., 2022

Bolotov, Ivan N., Eliseeva, Tatyana A., Kondakov, Alexander V., Coi, S, ., .,., ., ., .,., O., .,. & O., 2022, A new freshwater leech genus from Southeast Asia (Hirudinea: Glossiphoniidae), Ecologica Montenegrina 56, pp. 1-9 : 2

Genus Orientobdelloides gen. nov.

Type species: Hemiclepsis siamensis Oka, 1917 . https://zoobank.org/ urn:lsid:zoobank.org:act:C1BC63F5-D3BE-498E-BD47-431C4F8B2187

Diagnosis: Medium-sized leeches; one pair of eyes on somite III; mid-body somites triannulate; mouth pore apical on the rim of oral sucker; salivary glands compact, esophageal glands present, ovate; seven pairs of crop caeca; six pairs of testisacs; male and female gonopores separated by two annuli: male gonopore on Xa3/XIa1 or XIa1/a2, female gonopore on XIa2/a3 or XIa3/XIIa1. Phylogenetically, the new genus represents a well-supported clade, which is distant from the African Placobdelloides , including its type species P. multistriatus .

Etymology: The name of the new genus is combined from two words: ‘ Orient ’ (reference to its range within the Oriental Region) and ‘ bdelloides ’ (reference to the former generic placement of this clade in the genus Placobdelloides ).

Species with new combinations: Orientobdelloides siamensis (Oka, 1917) gen. & comb. nov.; O. sirikanchanae ( Trivalairat, Chiangkul & Purivirojkul, 2019) comb. nov.; O. tridens ( Chiangkul, Trivalairat, Kunya & Purivirojkul, 2021) comb. nov.

Hosts: Freshwater turtles ( Trivalairat et al. 2019; Chiangkul et al. 2018, 2020, 2021a).

Distribution: Thailand and southeastern China.

Comments: Other Southeast and East Asian species currently placed in the genus Placobdelloides cannot be transferred to the new genus due to significant morphological differences. Generally, P. okadai , P. okai , and P. stellapapillosa lack esophageal glands. Moreover, P. okadai and P. okai share one pair of eyes in II or at II/III ( Moore 1930; Lai & Chen 2010), whereas P. stellapapillosa has one pair of eyes on somite I or II and prominent star-like papillae ( Govedich et al., 2002). The generic assignment of these taxa could be clarified in the future on the basis of DNA sequence data. A close relationship of African species with those from Australia and New Zealand is also rather doubtful. For example, P. bancrofti (Best, 1931) from Australia may also belong to a separate genus because it differs from other Placobdelloides species by having one annulus between gonopores ( McKenna et al. 2005). It is clear that the rest of the Placobdelloides species are still a paraphyletic assemblage, which needs future revision by means of an integrative taxonomic approach.