Original descriptions of taxa. For coccolithophores, and many calcispheres, these are pages from the Farinacci & Howe Catalog of Calcareous Nannofossils. In other cases (e.g. non-calcifying haptophytes) the data is directly compiled on this site. The "Catalogue of Calcareous Nannofossils" was originally compiled by Prof A. Farinacci 1969-1989, since 2000 it has been updated and extended by Richard Howe - see The Farinacci and Howe Catalog - an Introduction.
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Citation: Chrysochromulina ahrengotii Jensen and Moestrup 1999Rank: SpeciesType sample (& lithostrat): A fixed and embedded sample of the unialgal culture from which thin sections were cut for this study has been deposited in the Botanical Museum, University of Copenhagen (M-99-1). The culture used for this study is available from the Scandinavian Culture Center for Algae and Protozoa as culture number K-0588.Farinacci catalog page (& compiler): n/a Current citation: Chrysochromulina ahrengotii Jensen and Moestrup 1999
Original Description Cell saddle-shaped, subspherical to rhomboid in outline, typically 5-6 µm long and 4-5 µm wide. Two yellow-green chloroplasts. Two equal flagella, 12-21 µm long. One coiling haptonema, 54-74 µm long. Two types of scales. An inner layer of plate scales, measuring 0.28-0.69 X 0.25-0.46 µm, with a pattern of sparse radiating ribs (c. 40) disappearing toward the center of the scale, and a narrow, marginal thick ening. Distal face of the scale with an inflexed rim, c. 0.05 µm wide, and a faint pattern of concentric fibrils. The outer layer consisting of spine scales with a diameter of 0.28-0.48 µm, spine length 0.20-0.43 µm. Spine supported by four struts, usually extending to a narrow marginal thickening. Proximal face of spine scale with c. 24 radiating ribs and a narrow marginal thickening. Distal, spine-bearing face with faint concentric fibrils. Size: Cell 5-6 µm; inner scale 0.3-0.7 µm; out spine scales 0.3-0.5 µm Etymology: Chrysochromulina ahrengotii is named after the Danish phycologist Tyge Ahrengot Christensen. Extra details from original publication Scaly periplast. The cells are covered with two types of scales, both visible in the shadowcast preparations illustrated as Figs 9-12 and in position on the cell in Figs 13-15. A field of detached scales is reproduced as Fig. 12, and details are shown in Figs 9-11. One type of scale is elongate, oval, with an inflexed distal rim, whereas the other bears a spine supported by four struts. The elongate scales show a pattern of c. 40 radiating ribs on the rimless side (Fig. 9) which extend from the periphery but do not reach the scale center. The rimmed side has a system of faint concentric lines (Fig. 11), but the rim itself appears patternless or with a faint concentric striation. Each spine scale has a thickened rim and the four struts extend from the spine to the rim. The spineless side shows radiating lines ex tending from the rim to the scale center (Fig. 10, scale on the left, Figs 13, 14). The spine-bearing upper side has a system of concentric ribs, but the radial fibrils on the underside are visible through the scales (Fig. 10, scale on the right). The scales are arranged in two irregular layers, the scales in each layer overlapping with each other (Figs 13-15). The spines of the outer layer insert on the base plate in a characteristic man ner, the struts appearing as two back-to-back 'L's (Figs 13, 14). In thin sections, each spine is seen to terminate distally with a tiny transverse plate overlain by more diffuse material (Fig. 15). Scale dimensions of the two types of investment scales are given in Table I. Editors' Notes
Jensen, M. Ø. & Moestrup, Ø. (1999). Ultrastructure of Chrysochromulina ahrengotii sp. nov. (Prymnesiophyceae), a new saddle-shaped species of Chrysochromulina from Danish coastal waters. Phycologia. 38: 195-207. gs
Chrysochromulina ahrengotii: Catalog entry compiled by Jeremy Young. Viewed: 5-12-2022