Plumatella mukaii Wood, 2001

Wood, Timothy S., 2022, Phylactolaemate bryozoans at the Zoological Survey of India and a taxonomic key to Indian Phylactolaemata, Zootaxa 5200 (2), pp. 401-435 : 408-409

Plumatella mukaii Wood, 2001

( Fig. 6 )

Original description. Wood, 2001: p. 52, figs 1, 3–6.

Type material. ZSI Nos. P1179 (holotype) and P1184 (paratype) collected 26 May 1914 at Peshok, 3000ft, Darjeeling by F.H. Gravely .

Characterization. Colony composed of branching tubules but otherwise variable in appearance; incrustation light to heavy, raphe and furrow faint. Floatoblasts broadly oval, about 400 µm in length ( Table 1 ), laterally asymmetrical with dorsal valve nearly flat; floatoblast fenestra showing distinct tubercles, dorsal fenestra length less than half floatoblast length, ventral fenestra slightly smaller than capsule outline; sessoblast with crowded tubercles, annulus faintly reticulated with occasional nodules ( Fig. 6a, b ). SEM examination reveals all statoblast surfaces having a minutely wrinkled appearance, a feature that is unique to this species ( Fig. 6c ).

Status. The species is valid.

Additional references. Plumatella emarginata . Shrivastava & Rao (1985): p.125–128, figs 2–4; Mukai et al. (1990): p. 51–59, figs 1B, 2c, f, 3c, f.

Distribution. Plumatella mukaii is known from Indonesia, Japan, Thailand, China, Chile, and northwestern United States ( Wood 2001; Orellana Liebbe 2006; Marsh & Wood 2002). In India specimens at the ZSI include ZEV3757 from tank at a Residency in Gangtok, Sikkim, 18 September 1909 by R. Hodgart, and P1560 collected 4 December 1949 at Peshok, Darjeeling, by F.H. Gravely. Plumatella mukaii was reported (as P. emarginata ) from Maharastra (Rao 1985) and Assam ( Kalita & Goswami 2006).

Remarks. All four specimens examined at the ZSI are in excellent condition with numerous floatoblasts and sessoblasts. While the statoblasts are all very much alike, the colonies differ in their appearance. In P1560 the ectocyst is soft and unsclerotized, zooids becoming upright when crowded; in P1179 the incrustation is moderate to heavy; in ZEV 3757 the ectocyst is clear and sclerotized with a reddish color. In P1184 the colony forms long, ropey masses extending free of the substratum. A full description based on P1179 was provided by Wood (2001).

Figures

FIGURE 6. Plumatella mukaii. (a) Floatoblast valves from P1184, scale bar = 100 µm; (b) SEM image from P1179 showing floatoblast asymmetry, scale bar = 100 µm; (c) Floatoblast SEM image from P1179 showing wrinkled texture, scale bar = 30 µm.