Psammodiscaceae Round & Mann

Al-Handal, Adil Y., Compère, Pierre & Criobe-Usr, Catherine Riaux-Gobin, 2016, Marine benthic diatoms in the coral reefs of Reunion and Rodrigues Islands, West Indian Ocean, Micronesica 2016 (3), pp. 1-78 : 11

Family Psammodiscaceae Round & Mann

Psammodiscus nitidus (W.Gregory) Round et D.G. Mann (Pl. 1, Fig. 6) References: Witkowski et al. 2000, p. 75, pl. 23, figs 12-14; Hein et al. 2008, p. 29, pl. 5, figs 5, 6; Lobban et al. 2012, p. 258, pl. 14, figs 6, 7.

Features: Diameter 27-30 µm, areolae 6-7 in 10 µm. Valves almost flat covered with coarse, sparsed irregularly arranged rounded areoale. Areolae size slightly smaller around the center of the valve while those near the valve margin are arranged in short lines.

Remarks: After a detailed investigation of Psammodiscus valve structure under SEM, Watanabe et al. (2013) concluded that this genus shares common features with some members of the family Rhaphoneidaceae such as Raphoneis and Delphineis , a finding that removed Psammodiscus from the centric diatoms and considered it as araphid. Furthermore, valve ultrastructure of Psammodiscus bear differences from Delphineis enough to erect a new family, Psammodiscaceae . Occurrence: Rare in Reunion Island. Previously reported from Mauritius (D).