Campylodiscus ralfsii W. Smith

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 : 49

77. Campylodiscus ralfsii W. Smith ( Figs 157–159 , 220 )

Synonym: Campylodiscus decorus var. ralfsii (W. Smith) Kisselev.

Type locality: Ilfracombe , Devon, England ( Hendey 1964) .

References: Peragallo & Peragallo 1897–1908, p. 245, pl. 56, fig. 4; Witkowski et al. 2000, p. 413, pl. 214, fig. 16; Stidolph et al. 2012, p. 6, fig. 133, pl. 21, fig. 15.

Morphometrics: Valves 39–43 (40–60) μm in diameter, transapical ribs 5–7 in 10 μm.

Remarks: It is known that the valve size of Coronia decora (Brébisson) Ruck & Guiry are larger than Campylodiscus ralfsii (Peragallo & Peragallo 1897–1908), the specimens collected in local areas were in the same ranges. But transapical striae in the pyriform cup between the ribs are more distinct in C. decora to be observed under the light microscopy, unlike C. ralfsii .

C. ralfsii was found in Portobello Bay of New Zealand ( Wood 1961), Palawan of Philippines ( Podzorski & Håkansson 1987), the Bahamas ( Hein et al. 2008), Yap Islands of the west Pacific Ocean ( Navarro & Lobban 2009), the Azores of the North Atlantic Ocean and Galapagos Islands of the east Pacific Ocean ( Stidolph et al. 2012), Amurskiy Bay of the East Sea in Russia ( Tsoy & Moiseenko 2014), Singapore Strait ( Tan et al. 2016), and Villa Rica of Mexico in the southern Gulf of Mexico ( Siqueiros-Beltrones & Martínez 2017). This taxon is widely distributed in the tropical and subtropical zones. but is rarely epiphytic in the Seogwipo coast, Jeju Island.

Figures

FIGURES 157–164. Diatom taxa of Seogwipo coast in Jeju Island (16). Figs 157–159. Campylodiscus ralfsii. Fig. 160. Coronia impressa. Figs 161–163. Campylodiscus brightwellii. Fig. 164. C. biangulatus. Scale bars = 10 μm.

FIGURES 219–223. Diatom taxa of Seogwipo coast in Jeju Island (23). Fig. 219. Campylodiscus fastuosus: external view of valve. Fig. 220. Campylodiscus ralfsii: internal view of valve. Fig. 221. Diploneis notabilis: internal view of valve. Figs 222, 223. Campylodiscus neofastuosus: internal (Fig. 222) and external view of valve (Fig. 223). Figs 219–223: SEM. Scale bars = 10 μm (Figs 219, 222, 223), 5 μm (Fig. 221), 2.5 μm (Fig. 220).