Plumatella casmiana Oka, 1907

Chae, Hyun Sook, Kil, Hyun Jong & Seo, Ho Jin Yang and Ji Eun, 2024, Freshwater bryozoans of Korea-observations on living colonies and three new records, Journal of Species Research 13 (1), pp. 50-60 : 54-55

5. Plumatella casmiana Oka, 1907 ( Fig. 5 )

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Material examined. Dongrim Reservoir, 10 July 2015; Chopyeong Reservoir, 2 August 2016; Baekgok Reservoir, 30 September 2016.

Substratum. Wood and plastic.

Remarks. We collected the colony and two different statoblasts, leptoblasts, and sessoblasts, for the first time since Toriumi (1941) reported from the Korea. Colony is light brown to sandish in color, short branched and entirely attached to substratum ( Fig. 5A ). Leptoblast unique to Pl. casmiana ( Wood and Okamura, 2005) is elliptical, 288-320 μm long and 124-155 μm wide, with length/ width ratio of about 2.2 ( Fig. 5B ), lacks the internal capsule, and has shallow tubercles on the surface and narrow annulus. Sessoblast is tuberculated weakly on the surface, but nearly smooth. It is 341-345 μm long and 234-241 μm wide, with length/width ratio of about 1.4 and narrow and smooth annulus ( Fig. 5C, D ).

Distribution. Korea and Cosmopolitan.

Figures

Fig. 5. Plumatella casmiana Oka, 1907. A, Colony (white arrow); B, Leptoblast; C, Dorsal view, Sessoblast; D, Lateral view, sessoblast. Scale bars: A=2 mm, B-D=100 μm.