Asteromphalus flabellatus (Brébisson) Greville

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 : 7-9

3. Asteromphalus flabellatus (Brébisson) Greville ( Fig. 8 )

Basionym: Spatangidium flabellatum Brébisson.

Type locality: Peru, guano .

References: Hustedt 1927 –1930, p. 498, fig. 279; Simonsen 1974, p. 25. Hasle & Syvertsen 1996, p. 135, pl. 25; Garcia & Odebrecht 2012, p. 419, figs 7, 11, 12; Lee 2015, p. 63, figs 51A–D.

Morphometrics: Valves 61–63 (40–92) μm in diameter, areolae 13 (12–15) in 10 μm, and 10 (7–11) hyaline rays.

Remarks: This taxon is closely similar to Asteromphalus elegans Greville in valve morphology, but the separating lines in the central area of the former are smooth, whereas those of the latter are genuflexed and sometimes bifurcated once or twice ( Hasle & Syvertsen 1996).

Asteromphalus flabellatus was frequent in the Arabian Sea and the Persian Gulf ( Simonsen 1974), and was abundant as a typical plankton in the continental shelves of northern Australia ( Hallegraeff & Jeffrey 1984). It occurred frequently in the Caribbean Sea ( Navarro & Hernández-Becerril 1997) and southern Brazil ( Garcia & Odebrecht 2012), and was found in Maldives ( Stanca et al. 2013). In terms of distribution, it is a tropical or subtropical taxon, preferring warmer marine waters. It was reported in the western coast of South Korea as planktons ( Shim 1994). The distribution of this species in Korea shows that it is concentrated in the southeastern coast and near Dokdo Island (37 oN 131 oW) (Lee 2015), and is consistent with the path of the Kuroshio warm current. It was rare currently in a rock pool of the Seogwipo coast in Jeju Island.

Figures

FIGURES 2–11. Diatom taxa of Seogwipo coast in Jeju Island (1). Figs 2–4. Pseudictyota dubium. Fig. 5, 6. Trigonium formosum. Fig. 7. Triceratium reticulum. Fig. 8. Asteromphalus flabellatus. Fig. 9. Aulacodiscus orientalis. Fig. 10, 11. A. affinis. Scale bars = 10 μm.