Freshwater Bryozoa of Okinawa, Japan, with descriptions of Rumarcanella gen. nov. (Phylactolaemata: Plumatellidae) and two new species Author Hirose, Masato Author Mawatari, Shunsuke F. text Zootaxa 2011 2732 1 19 journal article 10.5281/zenodo.276554 ec9d7b62-108f-45a6-bb9b-d1c9565c00fa 1175-5326 276554 Plumatella repens ( Linnaeus, 1758 ) ( Figure 2 E) Tubipora repens Linnaeus, 1758 : 790 ; Allman 1844b : 74 ; 1851: 330; Jullien 1885 : 100 , figs 16–68; Braem 1890 : 2 , pl. 1(4, 5, 7), pl. 2(21); Toriumi 1955a : 51 , pl. 1(1–42); Wood et al . 1998 : 642 , figs 7, 11; Mukai 1999 : 56 , figs 2B, 3E, 5B, 7 B. Wood & Okamura 2005 : 59 , 89, figs 29b, 30, 31, 52. Material examined. Floatoblasts from pond in city of Uruma; floatoblasts from Kurashiki Dam, city of Okinawa; colony with floatoblasts, Benoki Dam, village of Kunigami. Description. Observed colony tubular, branching, light or yellowish brown; almost entirely recumbent, with ends of branches usually swollen; surface encrusted. Tentacle number 32–64. Floatoblasts in our material oval, 353–378 (366±6) μm long by 235–272 (256±11) μm wide (n=10), with length/width ratio of about 1.4. Fenestra of floatoblast almost circular; surface of fenestra covered with rounded tubercles; annulus smooth ( Fig. 2 E); valves almost symmetrical in lateral view. Sessoblast fenestra also covered with tubercles; annulus weakly reticulate ( Wood & Okamura 2005 ). Distribution. Plumatella repens is common, and broadly distributed worldwide; distributed from Okinawa to Hokkaido in Japan . Remarks. The colony and statoblasts of Plumatella repens vary environmentally, and the floatoblast is the commonest gross morphological type among plumatellids. Accordingly, other species with similar gross floatoblast morphology (e.g. P . fungosa and P . rugosa may have been misidentified as P. repens before SEM was used for observations.