Environmental Engineering Reference
In-Depth Information
A
5 μm
B
30 μm
Figure 4.32
Gloeocapsa.
Two colonies with thick
mucilaginous sheaths. The plates of cells can be seen in
both face (A) and side (B) view. Indian ink preparation.
20 μm
which is usually laminate, can be up to 10 μm
thick and can vary in colour. Colonies may
grow large enough to see with the naked
eye. Abundant especially on wet rocks and
tree trunks although sometimes epiphytic.
Can produce taste and odour in drinking
waters(Palmer,1962).Cyanophyta.PlateIX.
Fig. 4.32.
Figure 4.33
Chroococcus.
Top: High contrast image
of pair of cells, with granular contents and central pale
nucleoid. Bottom: Actively growing culture with cells at
various stages of division and separation.
distinct since surface layers are often con-
fluent with the surrounding mucilage. Eas-
ily confused with
Gloeocapsa.
Cyanophyta.
Plate IX. Fig. 4.33.
(b) Cells nearly spherical. After division
daughter cells occur in groups of 2-4-8-
16 in a gelatinous sheath which is often
homogenous with the surrounding mucilage
but may be lamellate in some species
...........................
Chroococcus
66
(63) (a) Large mucilaginous colonies. Cells
approximately spherical to globular in
shape . ...............................
67
(b) Large mucilaginous colonies.
Cells cylindrical to elongate in shape
...........................
Aphanothece
Chroococcus
usually forms small groups of
cells which can either be free-floating or
attached. Cells (2-58 μm diameter) have dis-
tinct sheaths which may be reformed after
each cell division resulting in a multilay-
ered sheath. Planktonic species tend to have
gas vacuoles and cell sheaths that are less
Aphanothece
cells are spherical to ovate or
cylindrical and loosely embedded in copious
mucilage.Free-loatingorsedentarycolonies
which may be tens of millimetres in size.
Cells (1-4 μm wide, 2-8 μm long) have a
Search WWH ::
Custom Search