First Record of 𝑂𝑟𝑖𝑒𝑛𝑡𝑜𝑏𝑑𝑒𝑙𝑙𝑜𝑖𝑑𝑒𝑠 𝑡𝑟𝑖𝑑𝑒𝑛𝑠 (Hirudinea: Glossiphoniidae) from Indonesia, with Remarks on Its Taxonomic Characters

The freshwater leech genus 𝑂𝑟𝑖𝑒𝑛𝑡𝑜𝑏𝑑𝑒𝑙𝑙𝑜𝑖𝑑𝑒𝑠 Bolotov, Eliseeva & Kondakov, 2022, is reported for the first time in Indonesia. Morphological and mitochondrial DNA sequence data identified the specimens as 𝑂𝑟𝑖𝑒𝑛𝑡𝑜𝑏𝑑𝑒𝑙𝑙𝑜𝑖𝑑𝑒𝑠 𝑡𝑟𝑖𝑑𝑒𝑛𝑠 (Chiangkul, Trivalairat, Kunya & Purivirojkul, 2021), a species previously known only from Thailand. The external and internal morphological features of the Indonesian 𝑂. 𝑡𝑟𝑖𝑑𝑒𝑛𝑠 are provided in detail here, and the species diagnosis is amended based on our observations. Freshwater leech species from Africa, Asia, and Oceania, classified into the genus Placobdelloides Sawyer, 1986, are ectoparasitic to vertebrates (Sawyer, 1986). However, recent molecular phylogenetic studies revealed Placobdelloides to be polyphyletic (Siddall et al., 2005; Chiangkul et al., 2018; Bolotov et al., 2022). Consequently, 𝑂𝑟𝑖𝑒𝑛𝑡𝑜𝑏𝑑𝑒𝑙𝑙𝑜𝑖𝑑𝑒𝑠 Bolotov, Eliseeva & Kondakov, 2022 was established for turtle-specific species from the Indochinese region, with 𝑂𝑟𝑖𝑒𝑛𝑡𝑜𝑏𝑑𝑒𝑙𝑙𝑜𝑖𝑑𝑒𝑠 𝑠𝑖𝑎𝑚𝑒𝑛𝑠𝑖𝑠 (Oka, 1917) (syn. Hemiclepsis siamensis), designated as the type species. 𝑂𝑟𝑖𝑒𝑛𝑡𝑜𝑏𝑑𝑒𝑙𝑙𝑜𝑖𝑑𝑒𝑠 species are mainly characterized by a single pair of eyespots, esophageal glands, and male and female gonopores separated by 2 annuli (Bolotov et al., 2022). Currently, the genus comprises 3 turtle-associated species: 𝑂. 𝑠𝑖𝑎𝑚𝑒𝑛𝑠𝑖𝑠, 𝑂𝑟𝑖𝑒𝑛𝑡𝑜𝑏𝑑𝑒𝑙𝑙𝑜𝑖𝑑𝑒𝑠 𝑠𝑖𝑟𝑖𝑘𝑎𝑛𝑐ℎ𝑎𝑛𝑎𝑒 (Trivalairat, Chiangkul & Purivirojkul, 2019), and 𝑂𝑟𝑖𝑒𝑛𝑡𝑜𝑏𝑑𝑒𝑙𝑙𝑜𝑖𝑑𝑒𝑠 𝑡𝑟𝑖𝑑𝑒𝑛𝑠 (Chiangkul, Trivalairat, Kunya & Purivirojkul, 2021), all described from Thailand. 𝑂𝑟𝑖𝑒𝑛𝑡𝑜𝑏𝑑𝑒𝑙𝑙𝑜𝑖𝑑𝑒𝑠 𝑠𝑖𝑎𝑚𝑒𝑛𝑠𝑖𝑠 has a wider distribution, with records from China and Malaysian Borneo (Yang, 1996; Asad et al., 2021), whereas the remaining 2 species have not been recorded since their original descriptions.