Trachyneis velata var. ornata Meister, 1937

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 : 36

56. Trachyneis velata var. ornata Meister ( Figs 114, 115 )

References: Meister 1937, p. 272, pl. 10, fig. 10; Podzorski & Håkansson 1987, p. 91, pl. 34, fig. 2.

Type locality: Nagasaki .

Morphometrics: Valves 35–46 (27–44) μm long, 12–13 (11–15) μm wide, transapical striae 17–19 (19–20) in 10 μm.

Remarks: The striae on valves are composed of more or less elongated areolae. Six to seven very long areolae surround the central area, which is significantly smaller than that of the nominate variety, Trachyneis velata .

This taxon was first discovered in Nagasaki of Japan, and described by Meister (1937). It has been reported from Palawan of Philippines by Podzorski & Håkansson (1987). Until now, only two locations have been reported, but the taxon appears to grow in the warmer marine waters of Asia. However, it is possible that it may have been considered as small forms of the nominate variety, due to similar valve morphology. It was found rarely in rock pools and pseudo-lagoons along the Seogwipo coast in Jeju Island, and thus represents a new record for South Korea.

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.