Nannotax3 - ntax_Farinacci - Chrysochromulina planisquama

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.
Taxa are sorted alphabetically for simple browsing, or you can use search boxes at the top & bottom of the page

Citation: Chrysochromulina planisquama Hu et al. 2005

Type locality: From cultures of surface water sample in Jiaozhou Bay (358129N, 1208109E) collected 15 November, 2001 (30.0 psu, 15.18C)

Farinacci catalog page (& compiler): n/a

Cells spherical to subspherical, 3.0–6.0 µm in diameter. Two unequal flagella, the shorter 8–12 µm in length, the longer 22–30 µm in length, heterodynamic. Haptonema 6–10 µm long when fully extended. Two types of flat, circular scales cover the cell in multiple layers. Larger scales 0.70–0.85 µm in diameter, without a marginal rim; the proximal surface patterned with 52–60 radiating ribs and a central cruciform structure. The distal surface is patterned with concentric rings. Smaller scales similar to larger scales, 0.38–0.45 µm in diameter, patterned with 28–30 radiating ribs on the proximal surface.

Latin planisquama = flat scale, indicating the presence of two types of flat scales.

Further description: Cells are somewhat flattened at the flagellar pole and have a depression at the opposite end of the cell. The appendages insert apically, and the two flagella are unequal. The two flagella undulate heterodynamically along the side of the cell with the haptonema coiled up in a swimming cell (Figure 1). Cells may adhere to a substrate with the haptonema and, while stationary, rotate around the longitudinal axis (Figures 2, 3). The haptonema is 6–10 µm long when fully extended, but it usually coils up into 3–6 gyres when prepared for electron microscopy (Figure 4). In old cultures, the flagella and haptonema of some cells are shed and cells become spherical, settling on the bottom of the culture flask.

The scales form multiple overlapping layers (Figure 5). Both types of scales are thin, lacking both an upright and an inflexed rim (Figures 6, 7). The radiating ribs are arranged in four quadrants. There is a cruciform pattern in the middle of the scale; the four arms measure 400 nm in length. The scale investment readily detaches during fixation and in thin sections tends to pile up into many (more than 20) layers (Figure 8).

Cells have two laterally positioned chloroplasts extending along the sides of the cell (Figure 9). Each chloroplast has an immersed pyrenoid, inside which there is a single tubule (Figure 10). The nucleus is located centrally at the posterior end of the cell. There are usually two profiles of mitochondria visible. The Golgi apparatus is situated at the anterior end of the cell, and scales are commonly produced in the cisternae. Sometimes, the dilations typical of haptophyte Golgi apparatus cisternae are visible (Figure 11). A large vacuole containing decomposed material is present, suggesting that cells are phagotrophic (Figure 12).

The flagellar apparatus was not studied in detail. The two flagella form an angle of ca. 45° at their point of insertion (Figure 13). The number of microtubules in the haptonema is seven (Figure 14), increasing to nine in the basal part of the haptonema (Figure 15).

References:

Hu, X., Yin, M. & Tseng, C. (2005). Morphology of Chrysochromulina planisquama sp. nov. (Haptophyta, Prymnesiophyceae) isolated from Jiaozhou Bay, China. Botanica Marina. 48: 52-57. gs

CATALOG - Chrysochromulina planisquama

References:

Add Comment

Comments