Pleuretra hystrix Bartoš, 1950

Lee, Sue Yeon, Yoo, Jung Sun & Kim, Seung Tae, 2017, New records of 13 rotifers including Bryceella perpusilla Wilts et al., 2010 and Philodina lepta Wulfert, 1951 from Korea, Journal of Species Research 6, pp. 26-37 : 34-36

13. Pleuretra hystrix Bartoš, 1950 ( Fig. 6)

Pleuretra hystrix Bartoš, 1950, p. 290 , figs. 1A-C; Donner, 1965, pp. 192-193, figs. 139a-c; Fontaneto and Melone, 2003, pp. 154-155, figs. 1-13.

Philodina brycei (Weber) var.: Murray, 1908, p. 192, fig. 13.

Material examined. Two specimens found in wet mosses at a stream around Daegwallyeong, Pyeongchang-gun, Gangwon-do, 37°41 ʹ 19.7 ʺ N 128°45 ʹ 39.0 ʺ E, 5 June 2016.

Diagnosis. Corona much wider than cingulum. Sulcus slightly narrower than pedicel width. Pedicel long. Upper lip arched and as high as sulcus base. Trunk integument rather stiff, highly granulated and with 10 prominent longitudinal ridges; each ridge ending in an acute spine in the middle of trunk. Anterodorsal margin of the first trunk pseudosegment with a pair of bifurcated projections, which flanking a dorsal antenna.

Measurements. Total length in feeding 130 μm. Total length in creeping 260 μm. Greatest trunk width in creeping 60 μm. Corona width 44 μm. Cingulum width 36 μm. Sulcus width 12 μm. Spur length 6 μm.

Remarks. This species is easily recognized by a pair of bifurcated projections on anterodorsal margin of the first trunk pseudosegment. The characteristics of the Korean specimens agree well with those in the original description.

Fontaneto and Melone (2003) rediscovered this species in the western Italian Alps about 50 years after the original description by Bartoš (1950), and redescribed this species in detail using scanning electron micrographs, confirming the validity of it. In their faunistic survey on the global distribution of bdelloids, Fontaneto et al. (2007) suggested P. hystrix as Alpine endemic because it had been found only in the Alpine regions of Switzerland and Italy until then. Recently, its distribution has been expanded to Canada and the Arctic region by Kaya et al. (2010). This species was rediscovered from Korea in 2016 (current study), which was the first observation of this species in Asia.

World distribution. The Arctic, Canada, Italy, Switzerland and Korea.

Deposition. Deposited in the collection of the National Institute of Biological Resources, Incheon, Korea (ZIIY IV0000001552, ZIIYGR0000000004).