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(b) Chloroplasts brown to golden-brown.
Storage product leucosin. No obvious wide
mucilaginous envelope. Each cell has two
flagella of unequal length. . . .......
Synura
Cells of
Synura
have two golden-brown
chloroplasts and are more pear-shaped, 7-
17 μm wide. Up to 40 closely packed cells
per colony. Cells are covered with fine silica
scales which are not always obvious. Com-
mon in the plankton. Can impart both taste
and odour to drinking waters (Palmer, 1962).
Chrysophyta. Plate X. Figs. 1.3 and 4.37.
73
(71) (a) Coloniesof64cellsorless.........
74
30 μm
Figure 4.38
Gonium
. Single colony (one cell deep)
showing regular arrangement of cells. Internal detail:
prominent nucleus, cup-shaped chloroplast, orange eye-
spot, but no flagella are visible in this DIC image.
10 μm
(b) Colonies with many more than 64 cells,
oftenover100........................
75
74
(73) (a) Colony a flat plate of 4-16 (sometimes
32) ovoid to spherical cells. Cell flagellae are
all directed within the same plane (i.e. point
directly outwards from the side of cells rather
thanupwardsordownwards)......
Gonium
Cells (7-20 μm wide) within a
Gonium
colony are arranged in a flat gelatinous enve-
lope. Each cell has two equal-length flag-
ella. The chloroplast is green and cup-shaped
with one or more pyrenoids and an eye-
spot. Common in relatively still waters. Can
impart both taste and odour to drinking
waters (Palmer, 1962). Chlorophyta. Plate X.
Fig. 4.38.
25 μm
(b) Colony globular to elliptical composed
of 16-32 (sometimes 64) cells. Cells spher-
ical in shape and arranged near to the sur-
face of the mucilaginous matrix. Each cell
Figure 4.37
Synura
. Top: Edge of colony (lightly
fixed preparation) showing biflagellate golden cells. Bot-
tom: Live colony, phase contrast image.
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