Plumatella pirassununga Wood & Okamura, 2017

Wood, Timothy S. & Okamura, Beth, 2022, Further species and range extensions of Amazonian bryozoans: chipping away at the iceberg, Zootaxa 5169 (4), pp. 381-391 : 388

Plumatella pirassununga Wood & Okamura, 2017

Material examined. NHMUK 2021.11 .23.22 from the Río Negro , municipality of Iranduba, 4 km SW of Manaus, Amazonas State, Brazil, 3° 9.956’ S, 60° 3.264’ W (Site 4), collected 5 May 2018 by T. Wood and B. Okamura. Colonies were attached to a disposable plastic plate .

Remarks. This species was previously known only from a lake on the campus of São Paulo University at Pirassununga, São Paulo State, Brazil ( Wood & Okamura 2017).

In the original description the colony ectocyst was described as “well encrusted, giving it a velvety appearance” ( Wood & Okamura 2017). In the Amazon material the ectocyst was colorless and nearly transparent, but with distinct raphe and furrow. One feature of the floatoblast, shown but not emphasized in the original description, is the prominent polar groove at each end of the dorsal fenestra that is much wider than in most other plumatellids ( Fig. 6a ). The slightly curved lateral profile of the floatoblast is shown in Fig. 6b ; the crenulated suture is easily seen in Fig. 6c where it has a more serrated appearance. Floatoblast dimensions in Table 1 are consistent with those of the type material ( Wood & Okamura 2017).

Figures

FIGURE 6. Floatoblasts of Plumatella pirassununga. (a) Floatoblast valves, dorsal (left) and ventral (right), the former showing unusually wide, crescent-shaped polar grooves (arrows). scale bar. (b) Lateral view of a floatoblast showing a slight curve. (c) Enlarged view of a dorsal valve showing the serrated margin. Scale bars: a = 100 µm; c = 50 µm.