Habrotrocha valida Milne, 1916

Song, Min Ok & Lee, Chang-Ho, 2023, Four bdelloid rotifers new to Korea, Journal of Species Research 12 (2), pp. 115-121 : 117-119

3. Habrotrocha valida Milne, 1916 ḪȒffiữṞệ (ṳḑ)

Habrotrocha valida Milne, 1916, pp. 160 - 161 , pl. 13,

figs. 16 - 16a.

Material examined. One specimen found from leaf litter and soil at Gyeongpo Wetland, Unjeong-dong, Gangneungsi, Gangwon-do, 37°47′32.0″N, 128°54′14.2″E, on 3 June 2021.

Diagnosis. Rostrum short. Rostral lamella very short and without median notch. Corona slightly narrower than cingulum. Sulcus very narrow; trochal discs and pedicels almost attached. Pedicel very short. Upper lip arched; median lobe truncated and slightly wavy; lower than trochal discs. Antenna short; about 1/4 of neck width. Teeth 6/6. Foot with 4 pseudosegments; much narrower than rump. Spurs conical and with narrow interspace; interspace much narrower than spur base width.

Measurements. Total length in creeping 264 μm. Total length in feeding 185 μm. Corona width 28 μm. Cingulum width 25 μm. Cingulum pad width 31 μm. Greatest trunk width in feeding 71 μm. Spur length 7.5 μm.

Remarks. The characteristics of the Korean specimen agree well with the original description except the length of the spurs. The spurs were as long as the spur base width in the original description, while that of the Korean specimen was slightly longer than the spur base width.

Milne (1916) mentioned that there was a band or ridge which was parallel to the anterior margin of the upper lip. The same structure was observed in the Korean specimen, and it turned out to be the disc retractor, even though Milne (1916) thought it was a part of upper lip.

This species was not found again after the original description from South Africa in 1916. The present study is the second report of this species.

World distribution. South Africa and Korea.

Deposition. Deposited in the collection of the National Institute of Biological Resources, Incheon, Korea ( VSJAIV 0000000398 ) .