A Key to the More Frequently Occurring Freshwater Algae - Freshwater Algae: Identification, Enumeration and Use as Bioindicators - page 247

5 μm

10 μm

20 μm

Figure 4.79 Monoraphidium . Top: Detailed view of
elongate cells containing dispersed (iodine stained)
starch grains. Bottom: General view of culture.

50 μm

Figure 4.78 Selenastrum. Top: DIC image of
crescent-shaped cells. Bottom: General view of culture
showing range of cell size (iodine-stained preparation).

Cells of Ankyra are fusiform or spindle-
shaped with long drawn out apices.
There is a single chloroplast with
one to several pyrenoids. Common in
the plankton of lakes. Chlorophyta.
Plate XXX.

being present. Cells (2-8 μm wide, 13-
50 μm long) with a single chloroplast
which fills the whole cell. Common
in plankton. Chlorophyta. Plate XXX.
Fig. 4.78.

(b) Cells do not have either of the spines
forked at the end and are not markedly
fusiform.......................... 222

(b) Cells spindle-shaped to fusiform,
straight, curved or sigmoid. Either solitary
or in loose aggregations ............ 221 222 (221) (a) Cells needle- or sickle-shaped and

solitary............... Monoraphidium

221 (220) (a) Cells fusiform with ends drawn into
long narrow spines, one of which has a
forkedend..................... Ankyra

Monoraphidium cells (1-5 μm wide, 7-
100 μm long) have a single chloroplast,