Habrotrocha ligula aligula Burger, 1948

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 : 267

Habrotrocha ligula aligula Burger, 1948

Figure 8b

Material. One specimen found in mosses from a mountain in Jangyeol-ri, Bukpyeong-myeon, Jeongseon-gun, Gangwon-do.

Habrotrocha ligula ligula Bryce has a small process on the sulcus base. The process is cylindrical for the most part and tapers suddenly to a pointy end. Habrotrocha ligula aligula doesn't have any process on the sulcus base. The general morphology of the Korean specimen agrees well with that in the original description except the followings: (1) while the upper lip of the type specimen was trapezoidal with pointy corners, that of the Korean specimen is trapezoidal with round corners, and (2) Burger (1948) mentioned that a fleshy round swelling covered with beating cilia was present between the pedicels in the type specimen; however, any swelling of the ciliated part between pedicels was not observed in the Korean specimen. The buccal field of bdelloids is heavily ciliated. It is not clear whether the swelling between pedicels was temporary or permanent in the original description.

This subspecies-level taxon is quite rare. It has been rediscovered only once in New Zealand ( Haigh 1965) after it was described from USA by Burger (1948). Haigh (1965) mentioned that the New Zealand specimen had the flat arched upper lip, which is similar to that of the type specimens, but didn’t note whether the trapezoidal upper lip had the pointy corners. Schulte (1954) also observed this subspecies-level taxon, but he was not sure about the identification because the upper lip of German specimen was slightly bilobed medially.

Measurements. Total length in feeding 105 μm. Total length in creeping 173 μm. Corona width 37 μm. Cingu- lum width 30 μm. Cingulum pad width 28 μm. Greatest trunk width in feeding 50 μm. Trophi length 17 μm, Spur length 6.5 μm.

Figures

FIGURE 8. (a) Habrotrocha gracilis quadridens Schulte, 1954, feeding head and neck, dorsal view; (b) Habrotrocha ligula aligula Burger, 1948, feeding head and neck, dorsal view (scale bars: a–b = 25 μm).