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| Placobdelloides sirikanchanae (arrows) on the Asian leaf turtle (Cyclemys dentata (Gray, 1831)) (left) and the dark-bellied leaf turtle (C. enigmatica Fritz et al., 2008) (right). |
Abstract
A new species of glossiphoniid leech, Placobdelloides sirikanchanae sp. nov., is reported in the Asian leaf turtle (Cyclemys dentata) and the dark-bellied leaf turtle (C. enigmatica) from Songkhla Province, southern Thailand. The examination of morphological characters revealed that this new species is similar to P. siamensis (Oka, 1917), a common turtle leech species found in Thailand. Placobdelloides sirikanchanae sp. nov. demonstrates distinct morphological characters, with an elongated, narrow body, 13–17 well-developed knob papillae on each annulus, dark brown to greenish dorsal color with a crimson median line, the absence of a scarlet dot, different male and female gonopore distributions, a rough posterior sucker with a random pit distribution, and 104–115 eggs per clutch. The phylogenetic relationships of COI-ND1 genes were clarified and shown to be distinct from those of P. siamensis. Additionally, habitat preferences tended toward low oxygen conditions such as puddles or water patches on rubber plantations.
Keywords: Clitellata, Cyclemys, Glossiphoniidae, Hirudinea, leaf turtle, Songkhla
Placobdelloides Sawyer, 1986
Type species: Placobdelloides multistriata (Johansson, 1909) by original designation.
Genus diagnosis: eyes one pair, esophageal organ, crop caeca seven pairs, mouth pore terminal (Oosthuizen 1979).
Genus distribution: Placobdelloides species can be found in Africa (P. fimbriata (Johansson, 1909); P. jaegerskioeldi (Johansson, 1909); P. multistriata (Johansson, 1909)), Australia and United States, eastward to India (P. fulva (Harding, 1924); P. emydae (Harding, 1920); P. undulata (Harding, 1924); P. horai (Baugh, 1960); P. indica (Baugh, 1960)), Southeast Asia (P. siamensis in China and Thailand; P. okadai (Oka, 1925) in China; P. okai (Soós, 1969); P. stellapapillosa Govedich et al., 2002 in Malaysia and Singapore), and throughout Australia and New Zealand (P. octostriata (Grube, 1866); P. maorica (Benham, 1907); P. bancrofti (Best, 1931); P. bdellae (Ingram, 1957)).
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| Figure 2. Dorsal surface (upper) and ventral surface (lower) of the live holotype of Placobdelloides sirikanchanae sp. nov. |
Placobdelloides sirikanchanae sp. nov.
Material examined: Holotype (ZMKU-ANN-0006), puddle on rubber plantation, Sadao District, Songkhla Province, Thailand , 21 October 2018. Paratypes (nine individuals, ZMKU-ANN-0007 to 0015), same locality data as the holotype. All collected specimens were kept in 70% alcohol and deposited at the Zoological Museum of Kasetsart University (ZMKU), Department of Zoology, Faculty of Science, Kasetsart University on 23 November 2018.
Diagnosis: This species can be recognized from its elongated, narrow body, crimson median dorsal line, rich dark green pigmentation, 13–17 well-developed knob papillae on each annulus, symmetrical dorsal papillae between the left and right body sides, male gonopore on XIa1/a2, female gonopore on XIa3/XIIa1, amorphous salivary glands, smooth surface with random pits inside the anterior sucker, and rugged surface with randomly distributed pits inside the posterior sucker.
Etymology: The species is named in honor of Associate Professor Prapaisiri Sirikanchana, the pioneer aquatic parasitologist of Thailand. The following common names, Sirikanchana’s leech (English), Pling Arjan Prapaisiri (Thai: ปลิงอาจารย์ประไพสิริ), and Sirikanchanas Plattegel (German) are suggested.
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| Figure 1. Live Placobdelloides sirikanchanae sp. nov. (arrows) on the Asian leaf turtle (Cyclemys dentata (Gray, 1831)) (left) and the dark-bellied leaf turtle (C. enigmatica Fritz et al., 2008) (right): carapace (lower), plastron (upper). |
Type host: Dark-bellied leaf turtles (Cyclemys enigmatica).
Additional host: Asian leaf turtles (C. dentata).
Habitat: Placobdelloides sirikanchanae sp. nov. can be found attached on the shell surface, both the carapace and plastron, of C. dentata and C. enigmatica, which inhabit the bottom of enclosed shallow muddy puddles on rubber plantations. In the rainy season, several puddles will be connected due to an increase in the water level. Numerous small vertebrates are present in these puddles, such as small fishes or tadpoles. In the dry season, the puddles will be disconnected as the shallower waters disappear from evaporation. These aquatic ecosystems usually have low oxygen due to decomposition of leaf litter and nonflowing water.
Poramad Trivalairat, Krittiya Chiangkul and Watchariya Purivirojkul. 2019. Placobdelloides sirikanchanae sp. nov., A New Species of Glossiphoniid Leech and A Parasite of Turtles from lower southern Thailand (Hirudinea, Rhynchobdellida). ZooKeys. 882: 1-24. DOI: 10.3897/zookeys.882.35229
