Habrotrocha scepanotrochoides

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 : 396-397

4. Habrotrocha scepanotrochoides

De Koning, 1947 ( Fig. 4 )

ḏḆḍĒÊệ (ṵḋ)

Habrotrocha scepanotrochoides De Koning, 1947, p. 195 , pl. 5, figs. 22a- h; Donner, 1951, pp. 619-621, figs. 7a, e, k; Donner, 1965, pp. 85, 86, figs. 65i, j.

Material examined. Two specimens found from mosses and leaf litter at Galcheon-ri, Seo-myeon, Yangyang-gun, Gangwon-do, 37°54′3.0″N, 128°30′6.4″E, 20 June 2020.

Diagnosis. Many long cilia under rostral lamella. Rostral lamella with shallow median notch. Corona much narrower than cingulum. Sulcus very narrow and shallow. Upper lip consisting of two parts; upper one arched, transparent, and much lower than sulcus base; lower one thicker than upper one, arched and slightly bilobed. A small projection right beneath sulcus base dorsally. Each corner of cingulum protruding laterally. Cingulum pad narrower than cingulum. Teeth 7/7.

Measurements. Total length in feeding 195 μm. Corona width 17 μm. Cingulum width 26 μm. Cingulum pad width 25 μm. Greatest trunk width in feeding 40 μm.

Remarks. This species has been reported from Austria, Belgium, Germany and New Zealand ( Donner, 1951; 1965; Schulte, 1954; Haigh, 1968) after the description from the Netherlands by De Koning (1947).

There is some variation in the feeding head morphology of this species. The morphology of the feeding head of the Korean specimens is similar to that in the original description in that corona is much narrower than cingulum, and each corner of cingulum has lateral protrusion; however, the upper lip of the Korean specimen is arched and much lower than sulcus base, while that of the original description is slightly lower than the trochal discs and with small projection medially. The morphology of the feeding head of the Korean specimens is most similar to that of the Austrian specimen ( Fig. 7K ) reported by Donner (1951).

The pharyngeal tube of the European specimens was twice as long as trophi length and with loop medially, while that of the Korean specimen is as long as trophi length and without median loop.

World distribution. Austria, Belgium, Germany, New Zealand, the Netherlands and Korea.

Deposition. Deposited in the collection of the Nakdonggang National Institute of Biological Resources, Sangju-si, Gyeongsangbuk-do, Korea (NNIBR2020525IV5979).

Figures

Fig. 4. Habrotrocha scepanotrochoides De Koning, 1947.A. feeding habitus; B-D. feeding head, dorsal view; E. creeping habitus(Scales:A, E=50μm; B-D=20 μm).

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