Habrotrocha longicalcarata Bērzinš, 1950

Song, Min Ok & Lee, Chang-Ho, 2017, A new and five rare bdelloids from Korea, Zootaxa 4242 (3), pp. 529-547 : 540-543

Habrotrocha longicalcarata Bērzinš, 1950

Figure 6 a

Material. One specimen found in leaf litter, mosses and soil at Mongsanpo, Nam-myun, Taean-gun, Chungcheongnam-do.

This rare species has been rediscovered again in Korea 65 years after its original description from Sweden by Bērzinš (1950). It can be easily diagnosed by its long neck, plump trunk, a dorsal hump on the first foot pseudosegment, and thin and long spurs with a wide interspace. The general morphology of the Korean specimen coincides well with those of the Swedish populations, except the following characteristics: (1) in the Korean specimen, spur length is about 4.9 % of the total length, while it is about 6.2–6.5 % of that in the original description; and (2) the spur pseudosegment width of the Korean specimen is slightly narrower than the greatest foot width, while that in the original description is about half of it. Even though the spur of the Korean specimen is slightly shorter than recorded in the original description, the ratio of spur length to spur pseudosegment width is slightly less than one in the Korean specimen, while it is about three in the original description. That is mainly because the spur pseudosegment width in the original description is much narrower than that of the Korean specimen. The Korean specimen is much smaller than the original specimens. Its total length is somewhat smaller than half of that recorded in the original description. Of interest, Bērzinš did not have a chance to observe feeding ( Bērzinš, 1950). Feeding behavior has never been observed in the Korean specimen, either.

Measurements. Total length in creeping 231 µm. Greatest trunk width in creeping 54 µm. Greatest foot width in creeping 17 µm. Spur length 9 µm.

Figures

FIGURE 6. (a) Habrotrocha longicalcarata Bērzinš, 1950, creeping, dorsal view; (b) Habrotrocha solida Donner, 1949, creeping, dorsal view (scale bars: a – b = 50 µm).