Extended Observation Description on Eremosphaera viridis
Eremosphaera viridis De Bary 1858
Development of Vegetative Cells from Cystozygotes in Resting Stage
Eremosphaera viridis from a bog near Pass Thurn (Tyrol, Austria).
Cells in vegetative stage.

Fig. 1: The image shows the parietal chloroplasts, each with a central pyrenoid (arrow). The bright rings that surround them are the sectional images of their starch sheaths. In green algae (Chlorophyta and Streptophyta), the pyrenoids are the production sites for the reserve substance starch.
Scale bars indicate 25 µm.

Fig. 2: The spherical cell body is largely filled with a sap vacuole. The chloroplasts are mainly on the surface of the sphere, covered by a thin layer of cell plasma, the cell nucleus (the arrowhead shows the location) is in the center.
Scale bar indicates 25 µm.
Development of vegetative cells from cystozygotes in resting stage
Green algae can develop resistant permanent forms in the course of sexual reproduction. Reserve substances (starch, oil) are accumulated in the cells, and carotenoids cover the green of the chlorophyll. These cystozygotes survive habitat desiccation and winter cold with freezing water bodies and usually require a short or longer dormancy period before they can germinate again. Many resting stages of chlorophytes have carotenoids in plasma, so they are colored yellow/orange/red/brown. The carotenoids protect against UV radiation. This is especially important for the chromosomes.

Fig. 3: Cystozygotes of Eremosphaera viridis.
Scale bar indicates 50 µm.

Fig. 4: In the first step, the cystozygote cells divide in their protective gelatinous shell (left image). In the further division steps, the original gelatinous protective layer is dissolved (right image).
Scale bars indicate 25 µm (left) and 250 µm (right).

Fig. 5: Cell in division. The reserve substances (oil) and the protective carotenoids from the cystozygote phase are still clearly visible. In the overview picture on the right a cell in asexual division (left), producing two autospores; in the middle of the picture is an empty cell envelope of a mother cell, which remains after autospore production.
Scale bars indicate 100 µm (left) and 250 µm (right).

Fig. 6: After asexual division, in which the cell envelope of the mother cell usually bursts and releases (in the case of Eremosphaera viridis) two autospores. In this case a autospore remained in the old envelope. Remnants of the carotenoids can still be seen in the core area in the middle of the cell. Now the cells are in the vegetative state.
Scale bars indicate 100 µm
© Wolfgang Bettighofer,
images under Creative Commons License V 3.0 (CC BY-NC-SA).
For permission to use of (high resolution) images please contact postmaster@protisten.de.
New items
crassa
digitus
var. lamellosum
digitus
var. latum
oblongum
interruptum
spec.
spec.
kinahanii
spec.
polymorphum
var. polymorphum
spec.
spirostriolatum
digitus
brebissonii
rotata
swartzii
capitulum
antilopaeum
neosinuosum
brebissonii
pachydermum
thomasiana
var. notata
ansatum
forficulatum
var. verrucosum
neodepressum
armatum
oblongum
porteanum
truncata
rhomboidale
furcatum
uncinatum
dissiliens
pseudonitidulum
var. validum
truncata
var. bahusiensis
bidentatum
hirsutum
cucurbitinum
minor
pyramidatum
truncata
var. quadrata
binale
var. gutwinskii
inconspicuum
borreri
americana
quadratulum
trabecula
var. elongatum
coeseli
margaritacaeum
bicuneatum
apiculata
simplicius
crenulatum
crassum
simonyi
var. sparsiaculeatum
caelatum
crux-melitensis
sparsepunctatum
ehrenbergii
didelta
spongiosum
var. perbifidum
connatum
denticulata
subarctoum
trabecula
var. trabecula
humerosum
teliferum
dejectus
spec.
conspersum
komarekii
papillifera
arboricola
venustum
var. excavatum
viridis
pulchellum
tripus
granulatus
var. granulatus
subspicatus
humerosum
var. affine
nostochinearum
convergens
arcuata
integrum
aureus
rotata
lunaris
grevillei
lunatus
alternans
irregularis
laevis
var. laevis
ehrenbergianum
luetkemuelleri
var. carniolicum
reticulatum
tetras
limneticum
viridis
cystozygote
tetrachotoma
simplex
var. sturmii
biradiatum
microporum
var. octaedricum
braunii
reinhardtii
pusillum
lacustris
speculum
diaphanum
New items
crassa
digitus
var. lamellosum
digitus
var. latum
oblongum
interruptum
spec.
spec.
kinahanii
spec.
polymorphum
var. polymorphum
spec.
spirostriolatum
digitus
brebissonii
rotata
swartzii
capitulum
antilopaeum
neosinuosum
brebissonii
pachydermum
thomasiana
var. notata
ansatum
forficulatum
var. verrucosum
neodepressum
armatum
oblongum
porteanum
truncata
rhomboidale
furcatum
uncinatum
dissiliens
pseudonitidulum
var. validum
truncata
var. bahusiensis
bidentatum
hirsutum
cucurbitinum
minor
pyramidatum
truncata
var. quadrata
binale
var. gutwinskii
inconspicuum
borreri
americana
quadratulum
trabecula
var. elongatum
coeseli
margaritacaeum
bicuneatum
apiculata
simplicius
crenulatum
crassum
simonyi
var. sparsiaculeatum
caelatum
crux-melitensis
sparsepunctatum
ehrenbergii
didelta
spongiosum
var. perbifidum
connatum
denticulata
subarctoum
trabecula
var. trabecula
humerosum
teliferum
dejectus
spec.
conspersum
komarekii
papillifera
arboricola
venustum
var. excavatum
viridis
pulchellum
tripus
granulatus
var. granulatus
subspicatus
humerosum
var. affine
nostochinearum
convergens
arcuata
integrum
aureus
rotata
lunaris
grevillei
lunatus
alternans
irregularis
laevis
var. laevis
ehrenbergianum
luetkemuelleri
var. carniolicum
reticulatum
tetras
limneticum
viridis
cystozygote
tetrachotoma
simplex
var. sturmii
biradiatum
microporum
var. octaedricum
braunii
reinhardtii
pusillum
lacustris
speculum
diaphanum