Otostephanos torquatus amoenus Milne, 1916

Song, Min Ok & Lee, Chang-Ho, 2021, New records of three monogonont and seven bdelloid rotifers from Korea, Journal of Species Research 10 (4), pp. 392-404 : 399

7. Otostephanos torquatus amoenus Milne, 1916 ( Fig. 7 )

DƋIJ÷åŀqĒÊệ (ṵḋ)

Otostephanos torquatus var. amoenus Milne, 1916 , pp. 173, 174, pl. 14, figs. 20, 20a.

Otostephanos torquatus amoenus : Donner, 1965, p. 100, figs. 72j, l.

Material examined. Three specimens sorted out from mosses at Galcheon-ri, Seo-myeon, Yangyang-gun, Gangwon-do, 37°54′3.0″N, 128° 30′6.4″E, 1 August 2020.

Diagnosis. Body finely granulated and brownish. Rostrum short. Rostral lamella bilobed and with narrow median interspace between them. Corona as wide as or slightly narrower than cingulum. Sulcus very narrow. Upper lip arched and with triblobed median lobe; median lobe rimmed; much lower than trochal discs. Fine ring between corona and upper lip without disconnection. Spurs conical and with narrow interspace.

Measurements. Total length in creeping 259 μm. Corona width 25 μm. Cingulum width 24 μm. Cingulum pad width 26 μm. Greatest trunk width in feeding 53 μm. Spur length 6.4 μm.

Remarks. The most prominent difference between Otostephanos torquatus amoenus and O. t. torquatus (Bryce, 1913) appears in the morphology of the upper lip. The median lobe of the upper lip is simply arched in O. t. torquatus , while it is trilobed in O. t. amoenus. Otostephanos t. torquatus has been reported from Korea by Song (2015).

This subspecies has been reported from Austria, Czech Republic, Poland and Ukraine ( Donner, 1965; Iakovenko et al., 2013) after the description from South Africa ( Milne, 1916). The present study is the first report of this subspecies from Asian fauna.

World distribution. Austria, Czech Republic, Korea, Poland, Ukraine and South Africa.

Deposition. Deposited in the collection of the National Institute of Biological Resources, Incheon, Korea ( KDELIV 0000003105 ) .

Figures

Fig. 7. Otostephanos torquatus amoenus Milne, 1916. A. feeding, dorsal view; B. feeding, dorsal view; C. creeping, ventral view (Scales: A-C=50μm).