Abstract

Coccolithophorids in the northeastern and central South China Sea (SCS) were surveyed in March and October 1996. The cell density of coccolithophorids ranged from 25 x 103 cells L-1 to 31 x 103 cells L-1 in sea-surface water (0–25 m in depth), and from 12 x 103 cells L-1 to 62 x 103 cells L-1 in subsurface water (150 m in depth). The lowest cell number was recorded in the subsurface (150 m in depth) in the central gyral area, while the highest one was at the same depth in the northeastern realm. A total of thirty-one species were identified. The species richness in the northeastern SCS is higher than in the central area. Emiliania huxleyi (Lohmann) Hay et Mohler, Gephyrocapsa oceanica Kamptner, Umbellosphaera Paasche spp. And Syracosphaera Lohmann spp. Dominated the surface assemblages, whereas Florisphaera profunda Okada et Honjo, Gladiolithus flabellatus (Halldal et Markali) Jordan et Chamberlain predominated in the subsurface layer. In contrast, Palusphaera vandeli Lecal emend. R. E. Norris presented in both surface and subsurface assemblages.

中文摘要

本研究檢視1996 年3 月及10 月分別在南中國海東北部及中部採得之海水樣本中所 含之鈣板藻族群。鈣板藻密度在0-25 公尺的海表水為每公升25 x 103 至 31 x 103 細 胞，而在次表水150 公尺深處則為每公升12 x 103 至 62 x 103 細胞。在南海中部150 公尺水深之次表水層的鈣板藻量最低，而在東北部之次表層水則紀錄到最高量。所鑑定出鈣板藻共屬31 種，種歧異度以東北部的表水層較高。海表層的優勢種屬為Emiliania huxleyi (Lohmann) Hay et Mohler, Gephyrocapsa oceanica Kamptner, Umbellosphaera Paasche spp.和Syracosphaera Lohmann spp.，至於次表水層則以Florisphaera profunda Okada et Honjo 和Gladiolithus flabellatus (Halldal et Markali) Jordan et Chamberlain 為優勢種，而Palusphaera vandeli Lecal emend. R. E. Norris 則在表水層和次表水層皆佔有相當高的比例。

Keyword: Biogeography, Cell number, Coccolithophorids, South China Sea