Cocconeis convexa Giffen

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 : 25

35. Cocconeis convexa Giffen ( Figs 39–41 , 193, 194 )

Type locality: Kidd’s Beach , Cape Province, South Africa .

References: Giffen 1967, p. 257, pl. 60(2), figs 26–28; Witkowski et al. 2000, p. 104, pl. 37, figs 5, 6, pl. 41, figs 1–4; Riaux-Gobin et al. 2011, p. 22, pl. 3, figs 1–5, pl. 32, figs 1–7.

Morphometrics: Valves 16–26(12–32) μm long, 12–18 (9–20) μm wide, transapical striae of sternum valve unresolved, (32–40) in 10 μm, 30 (24–28) in 10 μm of raphe valve.

Remarks: Cocconeis convexa is widespread along the coasts of the Indian and Pacific Oceans, South Africa, Shatt al-Arab River, Oman, New Caledonia in Melanesia ( Witkowski et al. 2000). This taxon has been reported from the eastern coast of Japan (Suzuki 2001), Patagonia coast of Argentina ( Sar et al. 2003), Yap and Guam of the western Pacific Ocean ( Navarro & Lobban 2009), and frequently in Réunion and Rodrigues Islands of the western Indian Ocean ( Riaux-Gobin et al. 2011), and the coast of Baja California Peninsula, Mexico ( Siqueiros-Beltrones & Argumedo-Hernández 2015). In South Korea, it was already reported from the coasts of Jeju Island ( Kim et al. 2017), and is frequently found as an epiphyte on seaweeds along the Seogwipo coast in Jeju Island.

Figures

FIGURES 39–45. Diatom taxa of Seogwipo coast in Jeju Island (5). Figs 39–41. Cocconeis convexa. Figs 42, 43. Climacosphenia moniligera. Figs 44, 45. Gephyria media. Scale bars = 10 μm.

FIGURES 193–202. Diatom taxa of Seogwipo coast in Jeju Island (20). Figs. 193, 194. Cocconeis convexa: sternum valve (Fig. 180) and raphe valve (Fig. 181) of external view. Figs. 195–197, 200, 201. Navicula zostereti: characteristic lineate striation and cental raphe endings in external valves. Figs 198, 199. Hydrosynedra lanceolata: external valves. Fig. 202. Amphipentas pentacrinus: internal valve. Figs 193–202: SEM. Scale bars = 20 μm (Fig. 201), 10 μm (Figs 196, 202), 5 μm (Figs 193, 194, 197), 2 μm (Figs 195, 200), 1 μm (Figs 198, 199).