Macrotrachela petulans Milne, 1916

Song, Min Ok & Lee, Chang-Ho, 2020, Descriptions of two new species of Philodina (Rotifera, Bdelloidea), with notes on seven rare bdelloids from Korea, Zootaxa 4772 (2), pp. 253-276 : 265

Macrotrachela petulans Milne, 1916

Figure 6 c–d

Material. One specimen found in mosses from Jeju Gotjawal Provincial Park, Daejeong-eup, Seogwipo-si, Jejuteukbyeoljachido.

This species is quite rare and has been reported from Czech Republic only ( Bartoš 1951a) after the original description from South Africa by Milne (1916). The present study is the third record of it.

This species is easily diagnosed by the distal expansion of the spur pseudosegment. The inflated part looks like a flat cushion, which carries the spurs with wide interspace dorsally.

Milne (1916) noted that the most prominent characteristics of this species were the wide and oval stomach as well as intestine. However, Bartoš (1951) didn’t mention the shape of stomach and intestine of the Czech specimens, and the stomach was tubiform in Fig. 37C. The stomach of the Korean specimen was tubular as well. The corona of the Korean specimen was a bit wider than that in the original description. The ratio of the corona width to cingulum width was 1.3: 1 in the Korean specimen, while it was 1.1: 1 in the original description.

Measurements. Total length in creeping 211 μm. Total length in feeding 147 μm. Rostrum width in creeping 18 μm. Corona width 43 μm. Cingulum width 33 μm. Cingulum pad width 32 μm. Greatest neck width in creeping 31 μm. Greatest neck width in feeding 38 μm. Greatest trunk width in feeding 45 μm. Greatest trunk width in creeping 33 μm. Trophi length 12 μm. Spur length 3.7 μm.

Figures

FIGURE 6. Macrotrachela insulana Donner, 1962. (a) feeding head and neck, dorsolateral view; (b) foot, spurs and toes, ventral view. Macrotrachela petulans Milne, 1916. (c) foot, spurs and toes, ventral view; (d) feeding head and neck, dorsal view (scale bars: a, d = 25 μm; b, c = 10 μm).