Nitzschia composita Giffen, 1971

Joh, Gyeongje, 2021, Distribution and frequent occurrence of diatom taxa (Bacillariophyta) inhabiting warmer oceans in Seogwipo coast of Jeju Island, southernmost Korea, Phytotaxa 517 (1), pp. 1-67 : 41

66. Nitzschia composita Giffen ( Figs 111 , 128, 129 )

Type locality: Dictyota dichotoma from tidal pool, South of Gordon’s Bay village, False Bay, Cape Province, South Africa .

References: Giffen 1971, p. 8, figs 42, 43; Witkowski et al. 2000. p. 376, pl. 211, fig. 12.

Morphometrics: Valves 51–61 (60–75) μm long, 5–6 (4–7) μm wide, fibulae 10–12 (9–11) in 10 μm, and transapical striae unresolved under light microscopy (ca. 20 in 10 μm).

Remarks: This taxon is characterized by transverse ribs from the keel to the opposite margin and the presence of either double rows of small puncta or two finely punctate transapical striae between the ribs ( Giffen 1971). Nitzschia composita was found in the coasts of South Africa and Namibia ( Giffen 1971, Witkowski et al. 2000), and is not reported elsewhere. It is probably a subtropical taxon occurring in warmer oceans. In South Korea, it was reported previously in the Yeongil Bay of Pohang ( Joh 2017), and is currently rarely epiphytic on seaweeds in the lagoon of the Seogwipo coast in Jeju Island.

Figures

FIGURES 111–120. Diatom taxa of Seogwipo coast in Jeju Island (12). Fig. 111. Nitzschia composita. Figs 112, 113. Diploneis nitescens. Figs 114, 115. Trachyneis velata var. ornata. Figs 116, 117. T. velata. Figs. 118, 119. Caloneis cf. excentrica. Fig. 120. Lyrella concilians. Scale bars = 10 μm.

FIGURES 121–134. Diatom taxa of Seogwipo coast in Jeju Island (13). Figs 121, 122. Amphora bigibba var. interrupta. Figs 123, 124. A. staurohyalina. Figs 125, 130. Nitzschia marginulata var. didyma. Figs 126, 127. Seminavis cf. pusilla. Figs 128, 129. Nitzschia composita. Figs 131, 132. Seminavis latior. Fig. 133. Tetramphora intermedia. Fig. 134. T. decussata. Scale bars = 10 μm.